Patent Application
20240105984
The present disclosure relates generally to energy storage devices, and more particularly to metal-ion battery technology and the like.
For today's lithium-ion (Li-ion) battery technologies, Cu and Al foils are commonly used current collectors for the anode and cathode, respectively. It would be preferable to adopt current collectors that are as light as possible (e.g., as thin as possible, as porous as possible). There has been tremendous progress in advanced Li-ion battery technologies in which silicon-based materials are used in the anode. Because of the large volumetric changes in silicon-based anodes during cycling, there are stringent requirements on the properties of the copper current foils. On the one hand, the copper foils should be as thin as possible, but on the other hand, the copper foils must be able to withstand the repetitive swelling of the silicon-based anode materials during multiple charging and discharging cycles.
Embodiments disclosed herein address the above stated needs by providing improved manufacturing processes, related equipment and materials, and electrode materials and batteries made using such improved manufacturing processes, equipment, and materials.
The following presents a simplified summary relating to one or more aspects disclosed herein. Thus, the following summary should not be considered an extensive overview relating to all contemplated aspects, nor should the following summary be considered to identify key or critical elements relating to all contemplated aspects or to delineate the scope associated with any particular aspect. Accordingly, the following summary has the sole purpose to present certain concepts relating to one or more aspects relating to the mechanisms disclosed herein in a simplified form to precede the detailed description presented below.
In an aspect, a lithium-ion battery configured to undergo multiple charging and discharging cycles includes an anode component, comprising an anode current collector and a respective anode coating on each side of the anode current collector; a cathode component, comprising a cathode current collector and a respective cathode coating on each side of the cathode current collector; a separator interposed between the anode component and the cathode component; and an electrolyte infiltrated in the separator between the anode component and the cathode component, wherein: the anode coatings comprise composite particles comprising carbon and silicon, a mass fraction of the silicon in the composite particles of the anode coatings being in a range of about 5 wt. % to about 70 wt. % of the anode coatings; the anode component undergoes a maximum areal expansion (Amax) during the multiple charging and discharging cycles, expressed as a percentage of an area of the anode component before the multiple charging and discharging cycles; the anode current collector comprises a copper foil, the copper foil being characterized, before the respective anode coatings are formed thereon, by an ultimate tensile stress (UTS) and a strain at the UTS (εUTS), expressed in %; and the maximum areal expansion and the strain at the UTS are related as follows:
A
max≤εUTS (Formula 1).
In some aspects, the maximum areal expansion and the strain at the UTS are related as follows:
A
max
≤aε
UTS
−b (Formula 2);
In some aspects, the a is in a range of about 0.6 to about 0.7; and the b is in a range of about 0.6 to about 0.7.
In some aspects, the strain at the UTS is in a range of about 2% to about 18%.
In some aspects, the maximum areal expansion is in a range of about 0.1% to about 6.0%.
In some aspects, the UTS is about 250 MPa or greater.
In some aspects, the mass fraction of the silicon in the composite particles of the anode coatings is in a range of about 15 wt. % to about 40 wt. % of the anode coatings.
In some aspects, the mass fraction of the silicon in the composite particles of the anode coatings is in a range of about 10 wt. % to about 65 wt. % of the anode coatings.
In some aspects, a capacity of the silicon in the composite particles of the anode coatings is in a range of about 500 mAh/g to about 1500 mAh/g.
In some aspects, the copper foil is an electrodeposited copper foil.
In some aspects, the copper foil exhibits a yield strength of about 170 MPa or greater.
In some aspects, a thickness of the copper foil is in a range of about 7 μm to about 12 μm.
In some aspects, the thickness of the copper foil is in a range of about 8 μm to about 10 μm.
In some aspects, an average thickness of the anode coatings is in a range of about 25 μm to about 75 μm.
In some aspects, the anode coatings comprise graphite.
In some aspects, the anode component is a first anode component; the lithium-ion battery comprises a plurality of the first anode components; the cathode component is a first cathode component; the lithium-ion battery comprises a plurality of the first cathode components; and the plurality of the first anode components and the plurality of the first cathode components are stacked along a stacking direction perpendicular to a plane of the plurality of the first anode components and the plurality of the first cathode components, the plurality of the first anode components and the plurality of the first cathode components alternating along the stacking direction.
In some aspects, the lithium-ion battery is configured as a pouch cell, a prismatic cell, or a coin cell.
In some aspects, the anode component, the cathode component, and the separator are wound around a common core.
In some aspects, the lithium-ion battery is configured as a cylindrical cell, a coin cell, or a jelly roll cell.
In an aspect, a method of making a lithium-ion battery configured to undergo multiple charging and discharging cycles includes (A1) providing an anode component comprising an anode current collector and a respective anode coating on each side of the anode current collector; (A2) providing a cathode component comprising a cathode current collector and a respective cathode coating on each side the cathode current collector; and (A3) assembling the lithium-ion battery with a separator interposed between the anode component and the cathode component and an electrolyte infiltrated in the separator between the anode component and the cathode component, wherein: the anode coatings comprise composite particles comprising carbon and silicon, a mass fraction of the silicon in the composite particles of the anode coatings being in a range of about 5 wt. % to about 70 wt. % of the anode coatings; the anode component undergoes a maximum areal expansion (Amax) during the multiple charging and discharging cycles, expressed as a percentage of an area of the anode component before the multiple charging and discharging cycles; the anode current collector comprises a copper foil, the copper foil being characterized, before the respective anode coatings are formed thereon, by an ultimate tensile stress (UTS) and a strain at the UTS (εUTS), expressed in %; and the maximum areal expansion and the strain at the UTS are related as follows:
A
max≤εUTS (Formula 1).
In some aspects, the maximum areal expansion and the strain at the UTS are related as follows:
A
max
≤aε
UTS
−b (Formula 2);
In some aspects, the a is in a range of about 0.6 to about 0.7; and the b is in a range of about 0.6 to about 0.7.
In some aspects, the strain at the UTS is in a range of about 2% to about 18%.
In some aspects, the maximum areal expansion is in a range of about 0.1% to about 6.0%.
In some aspects, the mass fraction of the silicon in the composite particles of the anode coatings is in a range of about 15 wt. % to about 40 wt. % of the anode coatings.
In some aspects, the mass fraction of the silicon in the composite particles of the anode coatings is in a range of about 10 wt. % to about 65 wt. % of the anode coatings.
In some aspects, a capacity of the silicon in the composite particles of the anode coatings is in a range of about 500 mAh/g to about 1500 mAh/g.
In some aspects, the copper foil is an electrodeposited copper foil.
In some aspects, a thickness of the copper foil is in a range of about 7 μm to about 12 μm.
In some aspects, the thickness of the copper foil is in a range of about 8 μm to about 10 μm.
In some aspects, an average thickness of the anode coating is in a range of about 25 μm to about 75 μm.
In some aspects, the anode coatings comprise graphite.
In one aspect, a lithium-ion battery configured to undergo multiple charging and discharging cycles includes at least one anode component, at least one cathode component, and a separator and an electrolyte interposed between adjacent ones of the anode components and the cathode components. Each of the anode components includes an anode current collector and a respective anode coating on each side of the anode current collector. Each of the cathode components includes a cathode current collector and a respective cathode coating on each side of the cathode current collector. In some embodiments, the anode components and the cathode components are stacked along a stacking direction perpendicular to a plane of the anode components and the cathode components (e.g., with a separator in between those), the anode components and the cathode components alternating along the stacking direction. Such a lithium-ion battery may be referred to as a stacked cell. In some implementations, a lithium-ion battery (e.g., a stacked cell) may be configured as a pouch cell or a prismatic cell. In other embodiments, the anode components and the cathode components (e.g., with a separator in between) are wound to form a lithium-ion battery cell (e.g., into a wound pouch cell or a wound prismatic cell or a wound cylindrical cell).
In another aspect, at least one of the anode components (e.g., in a stacked cell or in a wound cell) undergoes a maximum areal expansion in a range of about 0% to about 3.5% during one or multiple charging and discharging cycles. In some implementations, the maximum areal expansion in an anode (or at least one of the anode components) is in a range of about 0% to about 2%.
In yet another aspect, at least one of the anode coatings of the at least one of the anode components (e.g., of a stacked cell) may include silicon-carbon composite (or silicon-carbon nanocomposite) (e.g., active material) particles (or, more broadly, silicon oxide-silicon-carbon composite particles or silicon oxide-carbon composite particles or silicon oxide-silicon-silicon carbide-carbon composite particles or silicon-silicon carbide-carbon composite particles or silicon oxide-silicon nitride-carbon composite particles or silicon oxide-silicon-silicon nitride-carbon composite particles or silicon oxide-silicon-silicon carbide-silicon nitride-carbon composite particles or other silicon element-comprising and carbon element-comprising composite particles, including but not limited to nanocomposite silicon particles), which may comprise silicon nanoparticles and other (silicon element-comprising or not comprising silicon element) component(s). In some implementations, a weight fraction of silicon in the silicon-carbon composite (or nanocomposite) active material particles (or, more broadly, silicon element-comprising and carbon element-comprising composite particles, including but not limited to nanocomposite silicon particles) may be in a range of about 30 wt. % to about 90 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 40 wt. % to about 80 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 45 wt. % to about 75 wt. %. In some implementations, the specific reversible capacity of the silicon-carbon composite (or nanocomposite) active material particles (or, more broadly, silicon element-comprising and carbon element-comprising composite particles, including but not limited to nanocomposite silicon particles) may range from about 1200 mAh/g to about 2600 mAh/g (in some implementations, from about 1200 mAh/g to about 1500 mAh/g; in some implementations, from about 1500 mAh/g to about 1700 mAh/g; in some implementations, from about 1700 mAh/g to about 1900 mAh/g; in some implementations, from about 1900 mAh/g to about 2100 mAh/g; in some implementations, from about 2100 mAh/g to about 2300 mAh/g; in some implementations, from about 2300 mAh/g to about 2600 mAh/g). In some implementations, the weight-average size of the silicon-carbon composite (or silicon-carbon nanocomposite) (or, more broadly, silicon element-comprising and carbon element-comprising composite particles, including but not limited to nanocomposite silicon particles) may be in a range of about 1 micron (μm) to about 25 micron. In some implementations, the weight-average size may be in a range of about 3 micron to about 15 micron. In some implementations, the weight-average size may be in a range of about 5 micron to about 12 micron. In some implementations, a weight fraction of (elemental) silicon in the at least one anode coating (e.g., elemental Si in Si—C(nano)composite anode particles) may be in a range of about 5 wt. % to about 70 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 5 wt. % to about 25 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 15 wt. % to about 40 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 10 wt. % to about 65 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 25 wt. % to about 40 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 40 wt. % to about 55 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 55 wt. % to about 70 wt. %.
In yet another aspect, the anode current collector of the at least one of the anode components (e.g., of a stacked cell) includes a copper foil. The copper foil (or, more broadly, copper-dominant alloy foil with copper element content in excess of about 80 wt. %; in some designs—in excess of about 90 wt. %; in yet some designs—in excess of about 95 wt. %) is characterized, before the respective anode coatings are formed thereon, by a yield strength of at least 220 MPa. In some implementations, the yield strength is in a range of about 220 MPa to about 700 MPa (in some designs, from about 220 MPa to about 350 MPa; in other designs, from about 350 MPa to about 500 MPa; in yet other designs, from about 500 to about 700 MPa). In some implementations, the copper foil is an electrodeposited copper foil. In some implementations, the thickness of the copper foil is in a range of about 6 μm to about 12 μm. In some implementations, the thickness of the copper foil is in a range of about 6 μm to about 8 μm. In some implementations, the thickness of the copper foil is in a range of about 8 μm to about 10 μm. In some implementations, the thickness of the copper foil is in a range of about 10 μm to about 12 μm.
In yet another aspect, areal capacity loading of the at least one of the anode coatings (e.g., of a stacked cell) is in a range of about 2 mAh/cm2 to about 20 mAh/cm2 (in some designs, from about 2 mAh/cm2 to about 4 mAh/cm2; in other designs, from about 4 mAh/cm2 to about 6 mAh/cm2; in other designs, from about 6 mAh/cm2 to about 8 mAh/cm2; in other designs, from about 8 mAh/cm2 to about 10 mAh/cm2; in other designs, from about 10 mAh/cm2 to about 14 mAh/cm2; in other designs, from about 14 mAh/cm2 to about 20 mAh/cm2).
In some implementations, the at least one of the anode coatings includes graphite (e.g., natural or synthetic graphite) or hard carbon or soft carbon. In some implementations, the at least one of the anode coatings includes a binder, which may, in some designs, advantageously comprise a styrene-butadiene rubber or another type of a styrene-comprising rubber. In some implementations, the at least one of the anode coatings may include a buffer layer. In some implementations, a thickness of the at least one of the anode coatings is in a range of 25 μm to 200 μm (in some designs, in a range of about 25 μm to about 40 μm; in other designs, in a range of about 40 μm to about 70 μm; in other designs, in a range of about 70 μm to about 100 μm; in other designs, in a range of about 100 μm to about 150 μm; in other designs, in a range of about 150 μm to about 200 μm).
In yet another aspect, a lithium-ion battery (e.g., stacked cell) includes (1) a wrapper wrapped around the anode components and the cathode components and (2) a container. In some implementations, the anode components, the cathode components, the separator, the electrolyte, and the wrapper are sealed in the container. In some implementations, the wrapper includes an adhesive tape adhered to at least some portion of the anode components and/or the cathode components.
In yet another aspect, the at least one anode component (e.g., of a stacked cell or a wound cell) includes a plurality of anode components. In some implementations, the respective anode current collectors are electronically coupled to each other. In some implementations, the separator is discontiguous (e.g., separator layers are not joined together).
In yet another aspect, the at least one cathode component (e.g., of a stacked cell or a wound cell) includes a plurality of cathode components. In some implementations, the respective cathode current collectors are electronically coupled to each other. In some implementations, the separator is discontiguous.
In yet another aspect, a lithium-ion battery configured to undergo multiple charging and discharging cycles includes an anode component, a cathode component, and at least one separator and an electrolyte interposed between the anode component and the cathode component. The anode component includes an anode current collector and a respective anode coating on each side of the anode current collector. The cathode component includes a cathode current collector and a respective cathode coating on each side of the cathode current collector. In some embodiments, the anode component, the cathode component, and the at least one separator are wound a common core. Such a lithium-ion battery may be referred to as a wound cell. In some implementations, a lithium-ion battery (e.g., a wound cell) may be configured as a cylindrical cell, a coin cell, a prismatic cell, a pouch cell or a jelly roll cell.
In yet another aspect, the anode current collector (e.g., of a wound cell) includes a copper foil. In some implementations, the copper foil is characterized, before the respective anode coatings are formed thereon, by (1) a yield strength in a range of about 100 MPa to about 400 MPa, and/or (2) an elongation at break parameter in a range of about 4% to about 20%. In some implementations, the yield strength is in a range of 100 MPa to 200 MPa. In other implementations, the yield strength is in a range of about 200 MPa to about 300 MPa. In other implementations, the yield strength is in a range of about 300 MPa to about 400 MPa. In some implementations, the elongation at break parameter is in a range of about 4% to about 7.5%. In some implementations, the elongation at break parameter is in a range of about 7.5% to about 13%. In some implementations, the copper foil is an electrodeposited copper foil. In some implementations, the elongation at break parameter is in a range of about 13% to about 20%. In some implementations, a thickness of the copper foil is in a range of about 6 μm to about 12 μm. In some implementations, the thickness of the copper foil is in a range of about 6 μm to about 8 μm. In some implementations, the thickness of the copper foil is in a range of 8 μm to 10 μm. In some implementations, the thickness of the copper foil is in a range of about 10 μm to about 12 μm.
In yet another aspect, at least one of the anode coatings of the at least one of the anode components (e.g., of a wound cell) may include silicon-carbon composite (or silicon-carbon nanocomposite) (e.g., active material) particles (or, more broadly, silicon oxide-silicon-carbon composite particles or silicon oxide-carbon composite particles or silicon oxide-silicon-silicon carbide-carbon composite particles or silicon-silicon carbide-carbon composite particles or silicon oxide-silicon nitride-carbon composite particles or silicon oxide-silicon-silicon nitride-carbon composite particles or silicon oxide-silicon-silicon carbide-silicon nitride-carbon composite particles or other silicon element-comprising and carbon element-comprising composite particles, including but not limited to nanocomposite silicon particles), which may comprise silicon nanoparticles and other (silicon element-comprising or not comprising silicon element) component(s). In some implementations, a weight fraction of silicon in the silicon-carbon composite (or nanocomposite) active material particles (or, more broadly, silicon element-comprising and carbon element-comprising composite particles, including but not limited to nanocomposite silicon particles) may be in a range of about 30 wt. % to about 90 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 40 wt. % to about 80 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 45 wt. % to about 75 wt. %. In some implementations, the weight-average size of the silicon-carbon composite (or silicon-carbon nanocomposite) (or, more broadly, silicon element-comprising and carbon element-comprising composite particles, including but not limited to nanocomposite silicon particles) may be in a range of about 1 micron (μm) to about 25 micron. In some implementations, the weight-average size may be in a range of about 3 micron to about 15 micron. In some implementations, the weight-average size may be in a range of about 5 micron to about 12 micron. In some implementations, a weight fraction of (elemental) silicon in the at least one anode coating (e.g., elemental Si in Si—C(nano)composite anode particles) may be in a range of about 5 wt. % to about 70 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 5 wt. % to about 25 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 15 wt. % to about 40 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 10 wt. % to about 65 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 25 wt. % to about 40 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 40 wt. % to about 55 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 55 wt. % to about 70 wt. %.
In yet another aspect, a capacity loading of the at least one of the anode coatings (e.g., of a wound cell) is in a range of about 2 mAh/cm2 to about 20 mAh/cm2 (in some designs, from about 2 mAh/cm2 to about 4 mAh/cm2; in other designs, from about 4 mAh/cm2 to about 6 mAh/cm2; in other designs, from about 6 mAh/cm2 to about 8 mAh/cm2; in other designs, from about 8 mAh/cm2 to about 10 mAh/cm2; in other designs, from about 10 mAh/cm2 to about 14 mAh/cm2; in other designs, from about 14 mAh/cm2 to about 20 mAh/cm2).
In some implementations, the at least one of the anode coatings includes graphite (e.g., natural or synthetic graphite) or hard carbon or soft carbon. In some implementations, the at least one of the anode coatings may include a binder comprising a styrene-butadiene rubber. In some implementations, the at least one of the anode coatings may include a buffer layer. In some implementations, a thickness of the at least one of the anode coatings is in a range of about 25 μm to about 200 μm (in some designs, in a range of about 25 μm to about 40 μm; in other designs, in a range of about 40 μm to about 70 μm; in other designs, in a range of about 70 μm to about 100 μm; in other designs, in a range of about 100 μm to about 150 μm; in other designs, in a range of about 150 μm to about 200 μm).
In yet another aspect, a lithium-ion battery (e.g., wound cell) may include a container. In some implementations, the anode component, the cathode component, the at least one separator, and the electrolyte are sealed in the container.
In yet another aspect, a method of making a lithium-ion battery configured to undergo multiple charging and discharging cycles is disclosed. The method includes (A1), (A2), (A3), and (A4). (A1) includes providing at least one anode component. Each of the anode components includes an anode current collector and a respective anode coating on each side of the anode current collector. (A2) includes providing at least one cathode component. Each of the cathode components includes a cathode current collector and a respective cathode coating on each side the cathode current collector. (A3) includes stacking the anode components and the cathode components along a stacking direction perpendicular to a plane of the anode components and the cathode components. The anode components and the cathode components alternate along the stacking direction. A separator is interposed between adjacent ones of the anode components and the cathode components. (A4) includes infiltrating an electrolyte between adjacent ones of the anode components and the cathode components. Such a method may be referred to as a method of making a stacked cell. In some implementations, a lithium-ion battery (e.g., according to a method of making a stacked cell) may be configured as a pouch cell or a prismatic cell or a coin cell. In some implementations, (A1) includes providing a roll of the anode current collector, forming the respective anode coatings on the roll of the anode current collector, and forming the anode component from the roll of the anode current collector and the anode coatings.
In yet another aspect, at least one of the anode components (e.g., according to a method of making a stacked cell) undergoes a maximum areal expansion in a range of about 0% to about 3.5% during one or the multiple charging and discharging cycles. In some implementations, the maximum areal expansion is in a range of about 0% to about 2%.
In yet another aspect, at least one of the anode coatings of the at least one of the anode components (e.g., according to a method of making a stacked cell) includes silicon-carbon composite particles (or, more broadly, silicon oxide-silicon-carbon composite particles or silicon oxide-carbon composite particles or silicon oxide-silicon-silicon carbide-carbon composite particles or other silicon element-comprising and carbon element-comprising composite particles), which may comprise silicon nanoparticles. In some implementations, a weight fraction of silicon (element) in the at least one anode coating may be in a range of about 5 wt. % to about 70 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 5 wt. % to about 25 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 15 wt. % to about 40 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 10 wt. % to about 65 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 25 wt. % to about 55 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 55 wt. % to about 70 wt. %.
In yet another aspect, the anode current collector of the at least one of the anode components (e.g., according to a method of making a stacked cell) includes a copper foil (or, more broadly, copper-dominant alloy foil with copper element content in excess of about 80 wt. %; in some designs—in excess of about 90 wt. %; in yet some designs—in excess of about 95 wt. %). The copper foil is characterized, before the respective anode coatings are formed thereon, by a yield strength of at least about 220 MPa. In some implementations, the yield strength is in a range of about 220 MPa to about 700 MPa (in some designs, from about 220 MPa to about 400 MPa; in other designs, from about 400 MPa to about 600 MPa; in other designs, from about 600 MPa to about 700 MPa). In some implementations, the copper foil is an electrodeposited copper foil. In some implementations, a thickness of the copper foil is in a range of about 6 μm to about 12 μm. In some implementations, the thickness of the copper foil is in a range of about 6 μm to about 8 μm. In some implementations, the thickness of the copper foil is in a range of 8 μm to 10 μm. In some implementations, the thickness of the copper foil is in a range of about 10 μm to about 12 μm.
In yet another aspect, a capacity loading of the at least one of the anode coatings (e.g., according to a method of making a stacked cell) is in a range of about 2 mAh/cm2 to about 20 mAh/cm2 (in some designs, from about 2 mAh/cm2 to about 4 mAh/cm2; in other designs, from about 4 mAh/cm2 to about 6 mAh/cm2; in other designs, from about 6 mAh/cm2 to about 8 mAh/cm2; in other designs, from about 8 mAh/cm2 to about 10 mAh/cm2; in other designs, from about 10 mAh/cm2 to about 14 mAh/cm2; in other designs, from about 14 mAh/cm2 to about 20 mAh/cm2). In some implementations, the at least one of the anode coatings includes graphite (or soft or hard carbon or their various mixtures). In some implementations, the at least one of the anode coatings includes a binder, which may comprise a styrene-butadiene rubber. In some implementations, the at least one of the anode coatings includes a buffer layer. In some implementations, a thickness of the at least one of the anode coatings is in a range of about 25 μm to about 200 μm (in some designs, in a range of about 25 μm to about 40 μm; in other designs, in a range of about 40 μm to about 70 μm; in other designs, in a range of about 70 μm to about 100 μm; in other designs, in a range of about 100 μm to about 150 μm; in other designs, in a range of about 150 μm to about 200 μm).
In yet another aspect, at least one of the cathode coatings of the at least one of the cathode components (e.g., according to a method of making a stacked cell) comprises one or more of the following classes of active materials: lithium cobalt oxide (LCO), lithium nickel cobalt manganese oxide (NCM), lithium nickel cobalt aluminum oxide (NCA), lithium nickel cobalt manganese oxide (NCMA), other types of layered nickel-comprising lithium metal oxides (in some designs, with Ni content in the range from about 50 at. % to about 95 at. % relative to all transition metals in such oxides), lithium manganese oxide (LMO), lithium manganese nickel oxide (LMNO), disordered rocksalt lithium metal oxides (DRX), lithium iron phosphate (LFP), lithium iron manganese phosphate (LFMP).
In yet another aspect, a method of making a lithium-ion battery (e.g., a method of making a stacked cell) additionally includes (B1) and (B2). (B1) includes wrapping a wrapper around the anode components and the cathode components. (B2) includes sealing the anode components, the cathode components, the separator, the electrolyte, and the wrapper in a container. In some implementations, the anode components, the cathode components, the separator, the electrolyte, and the wrapper are sealed in the container. In some implementations, the wrapper includes an adhesive tape adhered to at least some portion of the anode components and/or the cathode components. In some embodiments, the cathode active material in the cathode component comprises one or more of the following classes of active materials: lithium cobalt oxide (LCO), lithium nickel cobalt manganese oxide (NCM), lithium nickel cobalt aluminum oxide (NCA), lithium nickel cobalt manganese oxide (NCMA), other types of layered nickel-comprising lithium metal oxides (in some designs, with Ni content in the range from about 50 at. % to about 95 at. % relative to all transition metals in such oxides), lithium manganese oxide (LMO), lithium manganese nickel oxide (LMNO), disordered rocksalt lithium metal oxides (DRX), lithium iron phosphate (LFP), lithium iron manganese phosphate (LFMP).
In yet another aspect, the at least one anode component (e.g., according to a method of making a stacked cell) includes a plurality of anode components. In some implementations, the method of making a lithium-ion battery (e.g., a method of making a stacked cell) additionally includes electronically coupling the respective anode current collectors to each other. In some implementations, the separator is discontiguous.
In yet another aspect, the at least one cathode component (e.g., according to a method of making a stacked cell) includes a plurality of cathode components. In some implementations, the method of making a lithium-ion battery (e.g., a method of making a stacked cell) additionally includes electronically coupling the respective cathode current collectors to each other. In some implementations, the separator is discontiguous.
In yet another aspect, a method of making a lithium-ion battery configured to undergo multiple charging and discharging cycles is disclosed. The method includes (C1), (C2), (C3), and (C4). (C1) includes providing an anode component including an anode current collector and a respective anode coating on each side of the anode current collector. (C2) includes providing a cathode component including a cathode current collector and a respective cathode coating on each side of the cathode current collector. (C3) includes winding the anode component, the cathode component, and at least one separator interposed between the anode component and the cathode component around a common core. (C4) includes infiltrating an electrolyte between the anode component and the cathode component. Such a method may be referred to as a method of making a wound cell. In some implementations, a lithium-ion battery (e.g., according to a method of making a wound cell) may be configured as a cylindrical cell, a coin cell, or a jelly roll cell. In some implementations, (C1) includes providing a roll of the anode current collector, forming the respective anode coatings on the roll of the anode current collector, and forming the anode component from the roll of the anode current collector and the anode coatings.
In yet another aspect, the anode current collector (e.g., according to a method of making a wound cell) includes a copper foil. In some implementations, the copper foil (or, more broadly, copper-dominant alloy foil with copper element content in excess of about 80 wt. %; in some designs—in excess of about 90 wt. %; in yet some designs—in excess of about 95 wt. %) is characterized, before the respective anode coatings are formed thereon, by (1) a yield strength in a range of about 100 MPa to about 400 MPa, and/or (2) an elongation at break parameter in a range of about 4% to about 20%. In some implementations, the yield strength is in a range of about 100 MPa to about 250 MPa. In some implementations, the elongation at break parameter is in a range of about 7.5% to about 13%. In some implementations, the copper foil is an electrodeposited copper foil. In some implementations, a thickness of the copper foil is in a range of about 6 μm to about 12 μm. In some implementations, a thickness of the copper foil is in a range of about 7 μm to about 12 μm. In some implementations, the thickness of the copper foil is in a range of about 6 μm to about 8 μm. In some implementations, the thickness of the copper foil is in a range of about 8 μm to about 10 μm. In some implementations, the thickness of the copper foil is in a range of about 10 μm to about 12 μm.
In yet another aspect, at least one of the anode coatings of the anode component (e.g., according to a method of making a wound cell) may include silicon-carbon composite (or silicon-carbon nanocomposite) (e.g., active material) particles (or, more broadly, silicon oxide-silicon-carbon composite particles or silicon oxide-carbon composite particles or silicon oxide-silicon-silicon carbide-carbon composite particles or silicon-silicon carbide-carbon composite particles or silicon oxide-silicon nitride-carbon composite particles or silicon oxide-silicon-silicon nitride-carbon composite particles or silicon oxide-silicon-silicon carbide-silicon nitride-carbon composite particles or other silicon element-comprising and carbon element-comprising composite particles, including but not limited to nanocomposite silicon particles), which may comprise silicon nanoparticles (or porous silicon) and other (silicon element-comprising or not comprising silicon element) component(s). In some implementations, a weight fraction of silicon in the silicon-carbon composite (or nanocomposite) active material particles (or, more broadly, silicon element-comprising and carbon element-comprising composite particles, including but not limited to nanocomposite silicon particles) may be in a range of about 30 wt. % to about 90 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 40 wt. % to about 80 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 45 wt. % to about 75 wt. %. In some implementations, the weight-average size of the silicon-carbon composite (or silicon-carbon nanocomposite) (or, more broadly, silicon element-comprising and carbon element-comprising composite particles, including but not limited to nanocomposite silicon particles) may be in a range of about 1 micron (μm) to about 25 micron. In some implementations, the weight-average size may be in a range of about 3 micron to about 15 micron. In some implementations, the weight-average size may be in a range of about 5 micron to about 12 micron. In some implementations, a weight fraction of (elemental) silicon in the at least one anode coating (e.g., elemental Si in Si—C(nano)composite anode particles) may be in a range of about 5 wt. % to about 70 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 5 wt. % to about 25 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 15 wt. % to about 40 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 10 wt. % to about 65 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 25 wt. % to about 40 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 40 wt. % to about 55 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 55 wt. % to about 70 wt. %.
In yet another aspect, areal capacity loading of the at least one of the anode coatings (e.g., according to a method of making a wound cell) is in a range of about 2 mAh/cm2 to about 20 mAh/cm2 (in some designs, from about 2 mAh/cm2 to about 4 mAh/cm2; in other designs, from about 4 mAh/cm2 to about 6 mAh/cm2; in other designs, from about 6 mAh/cm2 to about 8 mAh/cm2; in other designs, from about 8 mAh/cm2 to about 10 mAh/cm2; in other designs, from about 10 mAh/cm2 to about 14 mAh/cm2; in other designs, from about 14 mAh/cm2 to about 20 mAh/cm2). In some implementations, the at least one of the anode coatings includes graphite (e.g., natural or synthetic graphite) or hard carbon or soft carbon. In some implementations, the at least one of the anode coatings includes a binder, which may, in some designs, advantageously comprise a styrene-butadiene rubber. In some implementations, the at least one of the anode coatings includes a buffer layer. In some implementations, a thickness of the at least one of the anode coatings is in a range of 25 μm to 200 μm (in some designs, in a range of about 25 μm to about 40 μm; in other designs, in a range of about 40 μm to about 70 μm; in other designs, in a range of about 70 μm to about 100 μm; in other designs, in a range of about 100 μm to about 150 μm; in other designs, in a range of about 150 μm to about 200 μm).
In yet another aspect, at least one of the cathode coatings of the at least one of the cathode components (e.g., according to a method of making a wound cell) comprises one or more of the following classes of active materials: lithium cobalt oxide (LCO), lithium nickel cobalt manganese oxide (NCM), lithium nickel cobalt aluminum oxide (NCA), lithium nickel cobalt manganese oxide (NCMA), other types of layered nickel-comprising lithium metal oxides (in some designs, with Ni content in the range from about 50 at. % to about 95 at. % relative to all transition metals in such oxides), lithium manganese oxide (LMO), lithium manganese nickel oxide (LMNO), disordered rocksalt lithium metal oxides (DRX), lithium iron phosphate (LFP), lithium iron manganese phosphate (LFMP).
Other objects and advantages associated with the aspects disclosed herein will be apparent to those skilled in the art based on the accompanying drawings and detailed description.
The accompanying drawings are presented to aid in the description of embodiments of the invention and are provided solely for illustration of the embodiments and not limitation thereof.
Aspects of the present invention are disclosed in the following description and related drawings directed to specific embodiments of the invention. The term “embodiments of the invention” does not require that all embodiments of the invention include the discussed feature, advantage, process, or mode of operation, and alternative embodiments may be devised without departing from the scope of the invention. Additionally, well-known elements of the invention may not be described in detail or may be omitted so as not to obscure other, more relevant details.
While the description below may describe certain examples in the context of particular electrode or electrode particle chemistry, composition, architecture and morphology, certain examples in the context of particular or electrode particle synthesis steps, certain examples in the context of particular electrolyte composition, certain examples in the context of particular electrolyte incorporation into an electrode or a battery cell, certain examples in the context of particular separator chemistry, composition, architecture, morphology, certain examples in the context of particular or electrode separator fabrication or integration steps, it will be appreciated that various aspects may be applicable to battery cells that advantageously incorporate various combinations of some of the described electrode chemistries, composition, architecture, electrolyte composition and integration, separator composition and integration, electrode or cell manufacturing techniques.
Any numerical range described herein with respect to any embodiment of the present invention is intended not only to define the upper and lower bounds of the associated numerical range, but also as an implicit disclosure of each discrete value within that range in units or increments that are consistent with the level of precision by which the upper and lower bounds are characterized. For example, a numerical distance range from 7 nm to 20 nm (i.e., a level of precision in units or increments of ones) encompasses (in nm) a set of [7, 8, 9, 10, . . . , 19, 20], as if the intervening numbers 8 through 19 in units or increments of ones were expressly disclosed. In another example, a temperature range from about −120° C. to about −60° C. encompasses (in ° C.) a set of temperature ranges from about −120° C. to about −119° C., from about −119° C. to about −118° C., . . . from about −61° C. to about −60° C., as if the intervening numbers (in ° C.) between −120° C. and −60° C. in incremental ranges were expressly disclosed. In yet another example, a numerical percentage range from 30.92% to 47.44% (i.e., a level of precision in units or increments of hundredths) encompasses (in %) a set of [30.92, 30.93, 30.94, . . . , 47.43, 47.44], as if the intervening numbers between 30.92 and 47.44 in units or increments of hundredths were expressly disclosed. Hence, any of the intervening numbers encompassed by any disclosed numerical range are intended to be interpreted as if those intervening numbers had been disclosed expressly, and any such intervening number may thereby constitute its own upper and/or lower bound of a sub-range that falls inside of the broader range. Each sub-range (e.g., each range that includes at least one intervening number from the broader range as an upper and/or lower bound) is thereby intended to be interpreted as being implicitly disclosed by virtue of the express disclosure of the broader range. In yet another example, a numerical range with upper and lower bounds defined at different levels of precision shall be interpreted in increments corresponding to the bound with the higher level of precision. For example, a numerical percentage range from 30.92% to 47.4% (i.e., levels of precision in units or increments of hundredths and tenths, respectively) encompasses (in %) a set of [30.92, 30.93, 30.94, . . . , 47.39, 47.40], as if 47.4% (tenths) was recited as 47.40% (hundredths) and as if the intervening numbers between 30.92 and 47.40 in units or increments of hundredths were expressly disclosed.
It will be appreciated that the level of precision of any particular measurement, threshold or other inexact parameter may vary based on various factors such as measurement instrumentation, environmental conditions, and so on. Below, reference to such measurements or thresholds may thereby be interpreted as a respective value assuming a pseudo-exact level of precision (e.g., a threshold of 80% comprises 80.0000 . . . %). Alternatively, reference to such measurements or thresholds may be described via a qualifier that captures pseudo-exact value(s) plus a range that extends above and/or below the pseudo-exact value(s). For example, the above-noted threshold of 80% may be interpreted as “about”, “approximately”, “around” or “˜” 80%, which encompasses “exactly” 80% (e.g., 80.0000 . . . %) plus some range around 80%. In some designs, the range encompassed around a measurement or threshold via the “about”, “approximately”, “around” or “˜” qualifier may encompass the level of precision for which the respective measurement or threshold is capable of being measured by the most accurate commercially available instrumentation as of the priority date of the subject application.
In the following description, various material properties are described so as to characterize materials (e.g., molecules, particles, powders, slurries, electrodes, separators, electrolytes, battery cells, etc.) in various states. Note that one of ordinary skill in the art is generally capable of selecting (and is herein assumed to select) the most appropriate measurement technique for any particular measurement. Moreover, in some cases, the most appropriate measurement technique may include a combination of techniques. While the following Table characterizes various measurement type options for particular material types and particular material properties, certain embodiments of the disclosure may be more specifically characterized in context with a specific measurement technique and/or specific commercially available instrumentation, if warranted. Note that while the Table below characterizes measurements with respect to active material particles, similar measurements may also be made with respect to other particle types such as precursor particles (e.g., carbon particles, etc.). Hence, unless otherwise indicated, the following Table provides examples of how such material properties may be readily measured by one of ordinary skill in the art using commercially available instrumentation:
In some embodiments described below, certain parameters (e.g., temperature, state-of-charge (SOC), etc.) may be defined in terms of relative terminology such as low, reduced, high, increased, elevated, and so on. With regard to temperature, unless otherwise stated, this relative terminology may be characterized relative to battery cell storage temperature or battery cell operating temperature, depending on the context of the relevant example. With regard to SOC, unless otherwise stated, a high SOC may be defined as higher than about 70% SOC (e.g., in some designs, about 70-80% SOC; in some designs, about 80-90% SOC; in some designs, about 90-100% SOC).
Further, while the description below may also describe certain examples of polymer particles or polymer-derived particles or porous particles or composite particles having spherical or spheroidal three dimensional (3D) shape, it will be appreciated that various aspects may be applicable to particles having other shapes, including, for example, irregular shapes, elongated two-dimensional (2D), such as (nano)composite platelets or porous carbon sheets, etc.) shapes or one dimensional (1D, such as, for example, (nano)composite nanofibers and fibers or porous carbon nanofibers and fibers, etc.) shapes.
While the description below may describe certain embodiments in the context of improved battery electrodes or improved battery cells, it will be appreciated that improved battery modules or packs may be enabled with different aspects of the disclosed technologies. Such modules or packs, for example, may be smaller, lighter, safer, simpler, less expensive, provide more energy, provide higher power, provide longer cycle life, provide longer calendar life, provide better operation at low temperatures, provide better operation at high temperatures and other important features. It will similarly be appreciated that improved electronic devices, improved electric scooters, electric bicycles, electric cars, electric trucks, electric buses, electric ships, electric planes and, more broadly, improved electric and hybrid electric ground, sea, and aerial (flying) vehicles (including heavy vehicles, autonomous vehicles, unmanned vehicles, planes, space vehicles, satellites, submarines, etc.), improved robots, improved stationary home or stationary utility energy storage units and improved other end products may be enabled with different aspects of the disclosed technologies. Such devices may be smaller, lighter, offer longer range, faster charging, faster acceleration, better operation at different temperatures, lower cost, longer calendar life, slower degradation with repeated charging and discharging, better safety, etc.
While the description below may also describe certain examples of the material formulations in a Li-free state (for example, as in silicon-comprising nanocomposite anodes or metal fluoride cathodes or sulfur cathodes, etc.), it will be appreciated that various aspects may be applicable to Li-comprising electrodes and active materials (for example, partially or fully lithiated Si-comprising anodes or partially or fully lithiated Si-comprising anode particles, partially or fully lithiated metal fluoride comprising cathodes (such as a mixture of LiF and metals such as Cu, Fe, Ni, Bi, Zr, Ti, Mg, Nb, and various other metals and metal alloys and mixtures of such and other metals, etc.) or partially or fully lithiated metal halide comprising cathode particles, partially or fully lithiated chalcogenides (such as Li2S, Li2S/metal mixtures, Li2Se, Li2Se/metal mixtures, Li2S—Li2Se mixtures, various other compositions comprising lithiated chalcogenides etc.), partially or fully lithiated metal oxides (such as Li2O, Li2O/metal mixtures, etc.), partially or fully lithiated intercalation-type cathode materials, partially or fully lithiated carbons, among others). In some designs, various material properties (e.g., at particle level, at inter-particle level, at electrode level, etc.) may change based on whether active material particle(s) are in a Li-free state, a partially lithiated state, or a fully lithiated state. Such Li-dependent material properties may include particle pore volume, electrode pore volume, and so on. Below, unless stated or implied otherwise, reference to such Li-dependent anode material properties (e.g., at particle level, at inter-particle level, at electrode level, etc.) may be assumed to be provided as if the active material particles are in the Li-free state. Further, some examples below are characterized at the electrode level (e.g., as opposed to particle level or interparticle level or cell level, etc.). Below, unless stated or implied otherwise, reference to such electrode level properties (e.g., electrode porosity or areal capacity loading or gravimetric/volumetric capacity, etc.) may be assumed to refer to the electrode components (e.g., active material particles, binder, conductive additives, etc.), excluding the current collector.
Stacked cell 230 includes a respective separator (206B, 206C, 206D) interposed between adjacent ones of the anode components and the cathode components. In the example shown, there is also a “top outer” separator 206A, adjacent to (in contact with) anode component 212-1 and a “bottom outer” separator 206E, adjacent to (in contact with) cathode component 202-2.
For brevity of illustration, containers (e.g., battery cases, sealing members) have been omitted from the views of stacked cells of
Subsequently, the anode component 300 undergoes initial charging, which includes lithiation of the active material particles 302.
Subsequently, the anode component 300 undergoes initial discharging, which includes delithiation of the active material particles 302.
Multiple copper foils were characterized and incorporated into lithium-ion battery test cells for evaluation. Table 1 (
Tensile testing was conducted on bare copper foils before formation of anode coatings thereon. A stress-strain curve was obtained for each copper foil. Measurements of the stress-strain curve were carried out using the INSTRON Universal Tensile Machine 5900 series. Cu foils were cut in dogbone shape with 1.2 cm width and 5 cm gauge length. The specimens were gripped securely to ensure axial alignment and minimize bending and then pulled in tension until failure in accordance with the IPC-TM-650 tensile test method. For each copper foil, the yield strength was defined as the stress at 0.2% plastic strain offset on the respective stress-strain curve.
For the areal expansion, test cells of the stacked cell configuration (containing one anode component and one cathode component, with a separator between them, infiltrated with liquid electrolyte) were formed and were observed in the experimental setup described with reference to
Test cells of the stacked cell configuration were fabricated for areal expansion and cracking observations. The anode component included a respective anode coating on both sides of the anode current collector (copper foil). The anode coating included Si-based nanocomposite active material (with specific reversible capacity of 1550 mAh/g (for the experimental results reported in
To avoid cracking of the copper foils in stacked cells in some designs, it may be preferable to choose copper foils that are characterized by a yield strength of at least about 220 MPa, or in a range of about 220 MPa to about 600 MPa. In some designs, yield strength may be interpreted as one indicator of the resistance of a material to deformation. However, there are copper foils with yield strengths of at least about 220 MPa or in range of about 220 MPa to about 600 MPa that exhibit cracking (e.g., foil #1-2, which has a yield strength of about 229.1 MPa, foil #1-10 which has a yield strength of about 295.1 MPa, and foil #1-15, which has a yield strength of about 304.9 MPa, were observed to crack in test cells). Therefore, in the examples considered, yield strength has not been a sole indicator of the “resistance” of a copper foil to cracking. Accordingly, other material properties such as the strain at the ultimate tensile strength (UTS) and strain at fracture (also known as strain at break or elongation at break or fracture strain) are also considered. The anode components that incorporated these copper foils exhibited maximum areal expansion of greater than about 3.5% (e.g., foil #1-2 exhibited a maximum areal expansion of about 8.76%, foil #1-10 exhibited a maximum areal expansion of about 3.76%, and foil #1-15 exhibited a maximum areal expansion of about 5.19%). Accordingly, in some designs, it may be preferable to choose a copper foil such that its yield strength is at least about 220 MPa, or in a range of about 220 MPa to about 600 MPa (e.g., typically higher for anodes having a higher density or higher fraction of silicon, etc.), and to fabricate an anode component incorporating the copper foil that undergoes a maximum areal expansion in a range of about 0% to about 3.5% during the multiple charging and discharging cycles, or a maximum areal expansion in a range of about 0% to about 2% during the multiple charging and discharging cycles, or both.
As shown in Table 1 (
Si-based nanocomposite active particles (including, but not limited to silicon-comprising and carbon-comprising composite particles) may have a relatively high weight fraction (concentration) of silicon, and exhibit moderately high volume changes (e.g., about 8-180 vol. %) during the first charge-discharge cycle and moderate volume changes (e.g., about 5-50 vol. %) during the subsequent charge-discharge cycles.
The calendared anode coating density and areal capacity (also referred to as capacity loading) relate to the areal density of Si-based nanocomposite active particles (e.g., silicon-carbon nanocomposite particles) that undergo significant volume expansion (also referred to as swelling) during lithiation. In some designs, the calendared anode coating density may range from about 0.9 g/cc to about 1.75 g/cc (depending on the wt. % of Si element in the anodes and the wt. % of graphite in the anodes). In some implementations (e.g., when 70-100% of anode capacity is provided by the Si-based nanocomposite active particles), the calendared anode coating density may range from about 0.9 g/cc to about 1.1 g/cc or from about 1.1 g/cc to about 1.3 g/cc or from about 1.3 g/cc to about 1.5 g/cc or from about 1.5 g/cc to about 1.6 g/cc. In other implementations (e.g., when 5-70% of anode capacity is provided by the Si-based nanocomposite active particles), the calendared anode coating density may be higher and may range from about 1.4 g/cc to about 1.8 g/cc or from about 1.4 g/cc to about 1.5 g/cc or from about 1.5 g/cc to about 1.6 g/cc or from about 1.6 g/cc to about 1.7 g/cc or from about 1.7 g/cc to about 1.75 g/cc or from about 1.75 g/cc to about 1.8 g/cc, depending on the cell design requirements. Because of the relatively large volume changes of silicon during lithiation and delithiation in some designs, these silicon-carbon composite particles may exhibit moderately high volume changes (e.g., about 8-180 vol. %) during the first charge-discharge cycle and moderate volume changes (e.g., about 5-50 vol. %) during the subsequent charge-discharge cycles.
In some implementations, a weight fraction of silicon in the anode coating may be in a range of about 35 wt. % to about 55 wt. %. To increase the charge capacity of the silicon-carbon composite particles, it may be preferable for the weight fraction of silicon in the anode coating to be in a range of about 55 wt. % to about 60 wt. %, or in a range of about 60 wt. % to about 65 wt. %, or in a range of about 65 wt. % to about 70 wt. %. On the other hand, in some designs, it may be preferable to reduce the areal expansion of the anode component, and one technique for reducing the areal expansion is to reduce the weight fraction of silicon in the anode coating. Accordingly, in some designs, it may be preferable for the weight fraction of silicon to be in a range of about 25 wt. % to about 35 wt. %, or in a range of about 15 wt. % to about 25 wt. %, or in a range of about 5 wt. % to about 15 wt. %. In some implementations, a weight fraction of silicon in the anode coating of a lithium-ion battery (e.g., stacked cell configuration) may be in a range of about 5 wt. % to about 70 wt. %. In some implementations, a weight fraction of silicon in the anode coating of a lithium-ion battery (e.g., stacked cell configuration) may be in a range of about 10 wt. % to about 65 wt. %. In some implementations, a weight fraction of silicon in the anode coating of a lithium-ion battery (e.g., stacked cell configuration) may be in a range of about 15 wt. % to about 65 wt. %. In some implementations, a weight fraction of silicon in the anode coating of a lithium-ion battery (e.g., stacked cell configuration) may be in a range of about 25 wt. % to about 60 wt. %. In some implementations, a weight fraction of silicon in the anode coating of a lithium-ion battery (e.g., stacked cell configuration) may be in a range of about 35 wt. % to about 55 wt. %. In some implementations, a specific (gravimetric) reversible capacity of (e.g., the silicon-graphite blended) anode coating of a LIB (e.g., wound cell configuration) may be in a range of about 500 mAh/g to about 1900 mAh/g (normalized by the total weight of the active materials, binder, conductive and other additives and, if present, a buffer layer, but not counting the weight of the electrolyte or current collector foils; as measured in half cell configuration according to the standard procedure described above—e.g., by anode lithiation at an approximately 0.1 C current density rate to 0.01 V vs. Li/Li+ cutoff potential and then at an approximately 0.01 C current density rate to the same 0.01 V vs. Li/Li+ cutoff potential and discharging at 0.1 C rate to 1.5V vs. Li/Li+ cutoff potential); in some configurations, from about 500 mAh/g to about 800 mAh/g; in some configurations, from about 800 mAh/g to about 1200 mAh/g; in some configurations from about 1200 mAh/g to about 1500 mAh/g; in some configurations from about 1500 mAh/g to about 1900 mAh/g. In some implementations, a thickness of an anode coating of a lithium-ion battery (e.g., stacked cell configuration) may be in a range of about 25 μm to about 75 μm. In some implementations, a capacity loading of an anode coating of a lithium-ion battery (e.g., stacked cell configuration) may be in a range of about 2 mAh/cm2 to about 10 mAh/cm2 (e.g., from about 2 mAh/cm2 to about 4 mAh/cm2 or 4 mAh/cm2 to about 6 mAh/cm2 or 6 mAh/cm2 to about 8 mAh/cm2 or 8 mAh/cm2 to about 10 mAh/cm2).
The areal expansion can be reduced by increasing the current collector (e.g., copper or copper alloy foil) thickness. However, a thicker foil lowers a battery's overall capacity and increases its cost. In many battery implementations, it is preferable to adopt copper foils (or broadly, current collector) with thicknesses of about 20 μm or less, or about 12 μm or less, because of these cost and capacity constraints. On the other hand, extremely thin current collectors (e.g., copper or copper alloy foils) (e.g., thinner than about 6 μm) may be unable to withstand the repeated areal expansion and contraction. Accordingly, in some implementations, a thickness of a current collector (e.g., copper or copper alloy foil) in a lithium-ion battery (e.g., stacked cell configuration) may be in a range of about 6 μm to about 12 μm. In some implementations, a thickness of a current collector (e.g., copper or copper alloy foil) in a lithium-ion battery (e.g., stacked cell configuration) may be in a range of about 8 μm to about 10 μm. Note that in some designs, a polymer sheet coated with a copper layer (e.g., on both sides) may be used instead of copper (or copper alloy) foils to reduce current collector weight or enable thermal shutdown behavior or enhance specific (e.g., weight-normalized) mechanical properties.
In the case of LIBs, silicon is an example of an alloying-type electrode material. Other examples of alloying-type electrode materials are germanium, antimony, aluminum, magnesium, zinc, gallium, arsenic, phosphorus, silver, cadmium, indium, tin, lead, bismuth, and their alloys. These materials typically offer higher gravimetric and volumetric capacity than so-called intercalation-type electrode materials (e.g., graphite) commonly used in commercial Li-ion batteries. Silicon-comprising electrode materials are particularly advantageous for use in certain high-capacity anodes for Li-ion batteries. Silicon-carbon (Si—C) composite particle-based anodes (where Si and C comprise over 90 at. % of all elements in the particles) may be particularly attractive for such applications.
One technique for reducing areal expansion of an anode component is to use low-swell anode materials. Such a low-swell anode material may include a mixture of alloying-type silicon-comprising active material (e.g., a Si-comprising nanocomposite material, where Si may be in a pure or doped form and/or in the form of silicon oxide or silicon nitride or silicon phosphide or silicon carbide, for example) and graphite (or graphite-like lithium intercalation materials, such as soft carbon or hard carbon), which may be referred to broadly as a silicon-graphite blend. In such blended anode the Si-based nanocomposite (which may comprise silicon nanoparticles in some designs) is from about 20% to about 95% by capacity, while the rest of the capacity (e.g., 5-80%) is from graphite. Such materials offer much higher volumetric and gravimetric energy density than the intercalation-type graphite electrodes commonly used in commercial Li-ion batteries. In addition, in such blended anode, the graphite can be composed of natural, artificial or a mixture of natural and artificial graphites. In some designs, it is more advantageous to use natural graphite or a mixture of natural and artificial graphites since they exhibit different mechanical properties (e.g., different hardness or different elastic modulus or different porosity), different size and different swell at the graphite particle level. This may be advantageous to reducing the overall anode swell in blends since such graphite particles may be able to accommodate stresses caused by the high-swelling Si particles. Such properties of Si-based (e.g., Si—C) nanocomposite-graphite blends may offer overall moderate volume changes during the first cycle and low volume changes during the subsequent charging cycles. In some implementations, an anode coating in a lithium-ion battery (e.g., stacked cell configuration) may include graphite.
Another technique for reducing areal expansion of an anode component may be to use a buffer layer (e.g., composed of one or more polymer(s) or co-polymers, one or more conductive additive particles and pores, among other optional components) at an interface between the anode coating and the anode current collector (e.g., copper foil). The buffer layer (e.g., having an average typical thickness from about 0.05 micron to about 2 micron; in some designs—from about 0.1 micron to about 1 micron) may be configured to absorb some of the stress from the swelling anode coating and reduce stress concentration in those areas that may initiate crack formation and propagation, for example, upon repeated stresses. In some implementations, an anode coating of a lithium-ion battery (e.g., stacked cell configuration) may include a buffer layer. Yet another technique for reducing areal expansion of an anode component may be to use a binder comprising a rubber such as styrene-butadiene rubber (SBR) or another type of styrene-containing rubber in an anode coating. In some implementations, an anode coating of a lithium-ion battery (e.g., stacked cell configuration) may include a binder comprising a styrene-butadiene rubber or another styrene-comprising rubber (e.g., with about 25-90 wt. % styrene; in some designs with about 35-55 wt. % styrene) or another rubber.
Commercially available copper foils were characterized and incorporated into lithium-ion battery test cells (wound cell configuration) for evaluation. Table 2 (
Test cells of the wound cell configuration were fabricated for cracking observations. These cells used anode materials, cathode materials, and electrolytes similar to those reported herein for the stacked cell testing.
As shown in Table 2 (
The findings about areal expansion of the anode components in stacked cells may also be applicable to wound cells. It may be preferable to reduce the areal expansion of the anode components in wound cells. In some implementations, a weight fraction of silicon (element) in the anode coating of a LIB (e.g., wound cell configuration) may be in a range of about 5 wt. % to about 70 wt. %. In some implementations, a weight fraction of silicon in the anode coating of a LIB (e.g., wound cell configuration) may be in a range of about 10 wt. % to about 65 wt. %. In some implementations, a weight fraction of silicon in the anode coating of a lithium-ion battery (e.g., wound cell configuration) may be in a range of about 15 wt. % to about 60 wt. %. In some implementations, a weight fraction of silicon in the anode coating of a lithium-ion battery (e.g., wound cell configuration) may be in a range of about 20 wt. % to about 55 wt. %. In some implementations, a weight fraction of silicon in the anode coating of a lithium-ion battery (e.g., wound cell configuration) may be in a range of about 25 wt. % to about 50 wt. %. In some implementations, a weight fraction of silicon-carbon nanocomposite (particles) in the blended anode coating of a LIB (e.g., wound cell configuration) may be in a range of about 10 wt. % to about 95 wt. % (as a wt. % of all active anode material in the anode coating, including graphite or soft carbon or hard carbon). In some implementations, a weight fraction of silicon-carbon nanocomposite (particles) in the blended anode coating of a LIB (e.g., wound cell configuration) may be in a range of about 15 wt. % to about 90 wt. % (as a wt. % of all active anode material in the anode coating). In some implementations, a weight fraction of silicon-carbon nanocomposite (particles) in the blended anode coating of a LIB (e.g., wound cell configuration) may be in a range of about 20 wt. % to about 80 wt. % (as a wt. % of all active anode material in the anode coating). In some implementations, a weight fraction of silicon-carbon nanocomposite (particles) in the blended anode coating of a LIB (e.g., wound cell configuration) may be in a range of about 25 wt. % to about 70 wt. % (as a wt. % of all active anode material in the anode coating). In some implementations, a weight fraction of silicon-carbon nanocomposite (particles) in the blended anode coating of a LIB (e.g., wound cell configuration) may be in a range of about 30 wt. % to about 60 wt. % (as a wt. % of all active anode material in the anode coating). In some implementations, a weight fraction of silicon-carbon nanocomposite (particles) in the blended anode coating of a LIB (e.g., wound cell configuration) may be in a range of about 35 wt. % to about 55 wt. % (as a wt. % of all active anode material in the anode coating). In some implementations, a specific (gravimetric) reversible capacity of (e.g., the silicon-graphite blended) anode coating of a LIB (e.g., wound cell configuration) may be in a range of about 500 mAh/g to about 1900 mAh/g (normalized by the total weight of the active materials, binder, conductive and other additives and, if present, a buffer layer, but not counting the weight of the electrolyte or current collector foils; as measured in half cell configuration according to the standard procedure described above—e.g., by anode lithiation at an approximately 0.1 C current density rate to 0.01 V vs. Li/Li+ cutoff potential and then at an approximately 0.01 C current density rate to the same 0.01 V vs. Li/Li+ cutoff potential and discharging at 0.1 C rate to 1.5V vs. Li/Li+ cutoff potential); in some configurations, from about 500 mAh/g to about 800 mAh/g; in some configurations, from about 800 mAh/g to about 1200 mAh/g; in some configurations from about 1200 mAh/g to about 1500 mAh/g; in some configurations from about 1500 mAh/g to about 1900 mAh/g. In some implementations, a thickness of an anode coating (counting the thickness of the buffer layer, if present) of a LIB (e.g., wound cell configuration) may be in a range of about 25 μm to about 75 μm. In some implementations, a capacity loading of an anode coating of a lithium-ion battery (e.g., wound cell configuration) may be in a range of about 2 mAh/cm2 to about 10 mAh/cm2. In some implementations, a thickness of a copper foil in a lithium-ion battery (e.g., wound cell configuration) may be in a range of about 7 μm to about 12 μm. In some implementations, a thickness of a copper foil in a lithium-ion battery (e.g., wound cell configuration) may be in a range of about 8 μm to about 10 μm. In some implementations, an anode coating in a lithium-ion battery (e.g., wound cell configuration) may include graphite. In some implementations, an anode coating of a lithium-ion battery (e.g., wound cell configuration) may include a buffer layer. In some implementations, an anode coating of a lithium-ion battery (e.g., wound cell configuration) may include a binder including a styrene-butadiene rubber or another styrene-comprising rubber.
At step 402, at least one anode component is provided. In some designs, each of the anode components includes an anode current collector and a respective anode coating on each side of the anode current collector. In some implementations, step 402 may include (1) providing a roll of the anode current collector, (2) forming the respective anode coatings on the roll of the anode current collector, and (3) forming the anode component from the roll of the anode current collector and the anode coatings. In the foregoing, (3) may include cutting the anode component from the roll. In some designs, the anode current collector of the at least one of the anode components includes a copper foil. In some implementations, the copper foil is characterized, before the respective anode coatings are formed thereon, by a yield strength of at least about 220 MPa. In some implementations, the yield strength is in a range of about 220 MPa to about 600 MPa. In some implementations, the copper foil is an electrodeposited copper foil. In some implementations, a thickness of the copper foil is in a range of about 7 μm to about 12 μm. In some implementations, the thickness of the copper foil is in a range of about 8 μm to about 10 μm.
In some designs, at least one of the anode components undergoes a maximum areal expansion in a range of about 0% to about 3.5% during the multiple charging and discharging cycles. In some implementations, the maximum areal expansion is in a range of about 0% to about 2%. In some designs, at least one of the anode coatings of the at least one of the anode components includes silicon-carbon composite particles, which may comprise silicon nanoparticles. In some implementations, a weight fraction of silicon (element) in the at least one anode coating may be in a range of about 5 wt. % to about 70 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 15 wt. % to about 65 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 20 wt. % to about 60 wt. % (e.g., in some designs, in a range of about 25 wt. % to about 60 wt. %). In some implementations, the weight fraction of silicon may be in a range of about 25 wt. % to about 55 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 30 wt. % to about 50 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 35 wt. % to about 45 wt. %. In some implementations, a weight fraction of silicon-carbon nanocomposite (particles) in the blended anode coating of a LIB (e.g., wound cell configuration) may be in a range of about 10 wt. % to about 95 wt. % (as a wt. % of all active anode material in the anode coating, including graphite or soft carbon or hard carbon). In some implementations, a weight fraction of silicon-carbon nanocomposite (particles) in the blended anode coating of a LIB (e.g., wound cell configuration) may be in a range of about 15 wt. % to about 90 wt. % (as a wt. % of all active anode material in the anode coating). In some implementations, a weight fraction of silicon-carbon nanocomposite (particles) in the blended anode coating of a LIB (e.g., wound cell configuration) may be in a range of about 20 wt. % to about 80 wt. % (as a wt. % of all active anode material in the anode coating). In some implementations, a weight fraction of silicon-carbon nanocomposite (particles) in the blended anode coating of a LIB (e.g., wound cell configuration) may be in a range of about 25 wt. % to about 70 wt. % (as a wt. % of all active anode material in the anode coating). In some implementations, a weight fraction of silicon-carbon nanocomposite (particles) in the blended anode coating of a LIB (e.g., wound cell configuration) may be in a range of about 30 wt. % to about 60 wt. % (as a wt. % of all active anode material in the anode coating). In some implementations, a weight fraction of silicon-carbon nanocomposite (particles) in the blended anode coating of a LIB (e.g., wound cell configuration) may be in a range of about 35 wt. % to about 55 wt. % (as a wt. % of all active anode material in the anode coating). In some implementations, a specific (gravimetric) reversible capacity of the silicon-graphite blended anode coating of a LIB (e.g., wound cell configuration) may be in a range of about 500 mAh/g to about 1900 mAh/g (normalized by the total weight of the active materials, binder, conductive and other additives and, if present, a buffer layer, but not counting the weight of the electrolyte or current collector foils); in some configurations, from about 500 mAh/g to about 800 mAh/g; in some configurations, from about 800 mAh/g to about 1200 mAh/g; in some configurations from about 1200 mAh/g to about 1500 mAh/g; in some configurations from about 1500 mAh/g to about 1900 mAh/g.
At step 404, at least one cathode component is provided. Each of the cathode components includes a cathode current collector and a respective cathode coating on each side the cathode current collector. At step 406, other components are provided. Examples of other components are a separator, an electrolyte, a wrapper, and a container (including a sealing member).
At step 408, the anode components and the cathode components are stacked along a stacking direction perpendicular to a plane of the anode components and the cathode components. The anode components and the cathode components alternate along the stacking direction. A separator is interposed between adjacent ones of the anode components and the cathode components.
In implementations in which there are multiple anode components in the stack, method 400 also includes electronically coupling the respective anode current collectors to each other (e.g., welding the tabs that extend from the anode components). This optional step may be carried out at a suitable time after step 408. In implementations in which there are multiple cathode components in the stack, method 400 also includes electronically coupling the respective cathode current collectors to each other (e.g., welding the tabs that extend from the cathode components). This optional step may be carried out after step 408.
At step 410, the wrapper is wrapped around a stack of the anode components and the cathode components. In some implementations, the wrapper includes an adhesive tape adhered to at least some portion of the anode components and/or the cathode components. Step 410 may be an optional step. At step 412, the stack of anode components and the cathode components and the wrapper, if any, are inserted into the container.
At step 414, the electrolyte is infiltrated between adjacent ones of the anode components and the cathode components. At step 416, the anode components, the cathode components, the separator, the electrolyte, and the wrapper may be sealed in the container. Step 416 may also include making electrical connections to the anode and cathode tabs from outside of the container. At step 418, a formation cycle is carried out, leading to the formation of the SEI layer. At this point, the lithium-ion battery is ready to undergo multiple charging and discharging cycles.
At step 422, an anode component is provided. In some designs, the anode component includes an anode current collector and a respective anode coating on each side of the anode current collector. In some implementations, step 422 may include (1) providing a roll of the anode current collector, (2) forming the respective anode coatings on the roll of the anode current collector, and (3) forming the anode component from the roll of the anode current collector and the anode coatings. In the foregoing, (3) may include cutting the anode component from the roll. The anode current collector includes a copper foil. In some implementations, the copper foil is characterized, before the respective anode coatings are formed thereon, by a yield strength in a range of about 100 MPa to about 400 MPa. In some implementations, the yield strength is in a range of about 100 MPa to about 250 MPa. In some implementations, the copper foil is characterized, before the respective anode coatings are formed thereon, by an elongation at break parameter in a range of about 4% to about 20%. In some implementations, the elongation at break parameter is in a range of about 7.5% to about 13%. In some implementations, the copper foil is an electrodeposited copper foil. In some implementations, a thickness of the copper foil is in a range of about 7 μm to about 12 μm. In some implementations, the thickness of the copper foil is in a range of about 8 μm to about 10 μm.
In some designs, at least one of the anode coatings of the anode component includes silicon-carbon composite particles, which may be comprise silicon nanoparticles. In some implementations, a weight fraction of silicon (element) in the at least one anode coating may be in a range of about 5 wt. % to about 70 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 15 wt. % to about 65 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 20 wt. % to about 60 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 25 wt. % to about 55 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 30 wt. % to about 55 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 35 wt. % to about 50 wt. %.
At step 424, a cathode component is provided. In some designs, the cathode component includes a cathode current collector and a respective cathode coating on each side of the cathode current collector. At step 426, other components are provided. Examples of other components are at least one separator, an electrolyte, and a container (including a sealing member).
At step 428, the anode component, the cathode component, and at least one separator interposed between the anode component and the cathode component are wound around a common core. At step 432, the assembly of the anode components, the cathode components, and the at least one separator are inserted into the container.
At step 434, the electrolyte is infiltrated between the anode component and the cathode component. At step 436, the anode component, the cathode component, the at least one separator, and the electrolyte may be sealed in the container. In some designs, step 436 may also include making electrical connections to the anode and cathode tabs from outside of the container. At step 438, a formation cycle is carried out, leading to the formation of the SEI layer. At this point, the lithium-ion battery is ready to undergo multiple charging and discharging cycles.
For illustration,
Tensile testing was conducted on bare copper foils before formation of anode coatings thereon. A stress-strain curve was obtained for each copper foil. For each copper foil, the yield strength was defined as the stress at 0.2% plastic strain offset on the respective stress-strain curve. From the actual measurement, the force at yield (expressed in N) is initially obtained, and the yield strength (expressed in MPa) is obtained by dividing the force at yield by a cross-sectional area of the copper foil. Measurements of certain mechanical properties of copper foils using the INSTRON Universal Tensile Machine 5900 series were conducted after the respective copper foils had been annealed at an anneal temperature of about 100° C. for a period of about 24 hours. Cu foils were cut in strip shape with about 1.2 cm width and about 5 cm gauge length. The specimens were gripped securely to ensure axial alignment and minimize bending and then pulled in tension until failure in accordance with the IPC-TM-650 tensile test method. The measured mechanical properties included the following: Young's modulus (express in GPa), the force at yield (N), the yield strength (expressed in MPa), the ultimate tensile strength (also sometimes referred to as ultimate tensile stress and abbreviated as UTS, and expressed in MPa), strain at the UTS (expressed in %), and strain at break (expressed in %). The measured data are tabulated in
Test cells of the stacked pouch cell configuration were fabricated for areal expansion and cracking observations. The test cells were evaluated for the presence of cracks upon conclusion of cycle 10; a determination of pass or fail was made for each test cell ID comprising approximately three test cells. The following categories of cracks were seen under microscope observation at high magnification and reported in Table 3 under the Failure Mode column: (a) micro edge cracks are characterized as cracks with crack widths smaller than about 200 μm around the edge of the foil, (b) fatigue stress cracks or stress corrosion cracks are described as a collection of transverse or longitudinal hairline cracks on the body of the foil (shown as fatigue cracks in Table 3), (c) macro edge cracks are characterized as cracks with crack widths larger than about 200 μm. A test cell ID was determined to have passed the cracking test if no cracks were observed, or only micro edge cracks were observed. Otherwise, a test cell ID was determined to have failed the cracking test if cracks other than micro cracks were observed.
Some trends may be discerned from the graphical plot 600. Dotted line (thinner dotted line) 610 represents a linear relationship between the maximum areal expansion and the strain at the UTS according to the following Formula 1A: Amax=εUTS (Formula 1A). Data points for 21 out of the 22 passing test cell IDs are located to the right and below dotted line 610. Accordingly, copper foils that satisfy a condition that the maximum areal expansion and the strain at the UTS are related by the following Formula 1 may have a higher likelihood of passing the cracking test: Amax≤εUTS (Formula 1). Herein, the term “higher likelihood” is used to refer to a higher likelihood than copper foils that do not meet the limitations of Formula 1. A data point for one out of the 22 passing test cell IDs is located to the left and above dotted line 610 (this data point is shown as 612). Data point 612 corresponds to test cell ID 37, for which the copper foils (Foil #3-18-10) exhibited micro edge cracks. Accordingly, although test cell ID 37 was determined to have passed the cracking test, test cell ID 37 may not be as preferable as other test cells that did not exhibit any cracks. For example, although micro edge cracks were observed after test cell ID 37 had undergone cycling to cycle 10, there is a possibility that larger cracks (e.g., cracks larger than micro edge cracks) may appear in the respective copper foil (Foil #3-18-10) during subsequent cycling after cycle 10. For example, although micro edge cracks were observed in Foil #3-18-10 in test cell ID 37, which had been configured as a stacked pouch cell, there is a possibility that larger cracks (e.g., cracks larger than micro cracks) may appear in the respective copper foil (Foil #3-18-10) when employed in other battery cells (e.g., battery cells of other configurations such as wound cells or cylindrical cells).
The region of the right and below dotted line 610 includes data points corresponding to passing test cell IDs (an example shown as 606) and data points corresponding to failing test cell IDs (an example shown as 614). In some implementations, it may be preferable to adopt a modified condition that can include most or all of the data points corresponding to passing test cell IDs and exclude at least some of the data points corresponding to failing test cell IDs. Such a modified condition may be envisioned by adjusting the vertical position along the Y-axis 604 (for example, downwards) and the slope (for example, decreasing the slope) of the dotted line 610. For example, dotted line (thicker dotted line) 620 represents a linear relationship between the maximum areal expansion and the strain at the UTS according to the following Formula 2A: Amax=aεUTS−b (Formula 2A) with a and b being respective constants. In the example of dotted line 620 shown in
The region between dotted lines 610 and 620 includes about 11 data points corresponding to failing test cell IDs (an example shown as 614) and 2 data points corresponding to passing test cell IDs (shown as 616 and 618). These data points correspond to test cell IDs that meet the limitations of Formula 1 but do not meet the limitations of Formula 2 (with a=0.65 and b=0.65). Data point 616 corresponds test cell ID 1, for which the copper foils (Foil #3-1-8) exhibited micro cracks. Accordingly, although test cell ID 1 was determined to have passed the cracking test, test cell ID 37 may not be as preferable as other test cells that did not exhibit any cracks. Data point 618 corresponds test cell ID 20, for which the copper foils (Foil #3-10-10) exhibited micro cracks. Accordingly, although test cell ID 20 was determined to have passed the cracking test, test cell ID 20 may not be as preferable as other test cells that did not exhibit any cracks.
For the test cell IDs that were determined to have passed, Young's modulus was in a range of about 56 GPa to about 88 GPa. For the test cell IDs that were determined to have failed, Young's modulus was in a range of about 56 GPa to about 80 GPa. Accordingly, there is an overlap between Young's moduli of the passing and failing test cell IDs. These Young's modulus data are shown in Table 3 (
For the test cell IDs that were determined to have passed, the UTS was in a range of about 255 MPa to about 580 MPa. For the test cell IDs that were determined to have failed, the UTS was in a range of about 286 MPa to about 641 MPa. Accordingly, there is an overlap between the UTS values of the passing and failing test cell IDs. These UTS data are shown in Table 3 (
For the test cell IDs that were determined to have passed, the strain at break was in a range of about 3% to about 20%. For the test cell IDs that were determined to have failed, the strain at break was in a range of about 2.27% to about 14.8%. Accordingly, there is an overlap between the strain at break values of the passing and failing test cell IDs. These strain at break data are shown in Table 3 (
For the test cell IDs that were determined to have passed, the force at yield was in a range of about 17.3 N to about 52 N and the yield strength was in a range of about 170 MPa to about 408 MPa. For the test cell IDs that were determined to have failed, the force at yield was in a range of about 19 N to about 52 N and the yield strength was in a range of about 203 MPa to about 449 MPa. Accordingly, there is an overlap between force at yield data of the passing and failing test cell IDs, and there is an overlap between yield strength data of the passing and failing test cell IDs. These force at yield and yield strength data are shown in Table 3 (
Each of the following pairs of test cell IDs is associated with a respective copper foil series (product) and includes a first test cell ID associated with a thinner copper foil and a second test cell ID associated with a thicker copper foil: (1) test cell IDs 2, 3 (foils 3-2-8, 3-2-10), (2) test cell IDs 8, 9 (foils 3-5-8, 3-5-10), (3) test cell IDs 18, 19 (foils 3-10-8, 3-10-10), (4) test cell IDs 25, 26 (foils 3-12-6, 3-12-8), (5) test cell IDs 29, 28 (foils 3-14-8, 3-14-10), (6) test cell IDs 34, 35 (foils 3-17-8, 3-17-10), and (7) test cell IDs 36, 38 (foils 3-18-8, 3-18-10). For each of these test cell IDs, the Si—C nanocomposite weight fraction (relative to all active anode materials) is about 50 wt. %. For each of these test cell ID pairs, except the pair with test cell IDs 25, 26 (foils 3-12-6, 3-12-8), the thinner copper foil is about 8 μm and the thicker copper foil is about 10 μm. For the pair with test cell IDs 25, 26, the thinner copper foil is about 6 μm and the thicker copper foil is about 8 μm. For some of these test cell ID pairs, the thinner copper foil exhibits a greater yield strength than the thicker copper foil (e.g., foil 3-2-8 is 428 MPa and foil 3-2-10 is 408 MPa, foil 3-5-8 is 394 MPa and foil 3-5-10 is 348 MPa, foil 3-10-8 is 339 MPa and foil 3-10-10 is 330 MPa, foil 3-14-8 is 246 MPa and foil 3-14-10 is 243 MPa, foil 3-17-8 is 243 MPa and foil 3-17-10 is 230 MPa). However, for each of the seven test cell ID pairs, the thinner copper foil has a smaller force at yield than the thicker copper foil (e.g., the force at yield of foil 3-2-8 is 44 N and the force at yield of foil 3-2-10 is 52 N). Accordingly, in some cases, it may be more likely for the thinner foil of a copper foil series (product) than the thicker foil of the same product to fail the cracking test. In four of these test cell ID pairs, the thinner foils failed the cracking test and the thicker foils passed the cracking test, namely (1) test cell IDs 2, 3 (foils 3-2-8, 3-2-10), (2) test cell IDs 8, 9 (foils 3-5-8, 3-5-10), (4) test cell IDs 25, 26 (foils 3-12-6, 3-12-8), and (7) test cell IDs 36, 38 (foils 3-18-8, 3-18-10).
There may be various aspects that explain why the forces at yield are smaller for thinner copper foils compared to thicker copper foils. For example, a ratio to/G (to is the thickness of the foil, G is a grain size) may be taken to represent an average number of grains that are in the foil along the foil's thickness direction. Presuming that two foils of different thicknesses have the same material composition including the same grain sizes, the thinner foil would have a smaller number of grains along the thickness direction and consequently would be able to withstand a smaller force at yield point. The force at yield could be an indicator for foil cracking test performance. Additionally, the grain sizes in these polycrystalline copper foils may be sufficiently small that grain boundaries may play a significant role in the plastic deformation. Hence, the inverse Hall-Petch effect may contribute to softening of the copper foil at smaller foil thicknesses.
Copper foil thicknesses of 6 μm, 8 μm, and 10 μm are represented in the test cell IDs shown in Table 3 (
For eight of the copper foils listed in Table 3 (
A variety of tensile properties is represented among the commercially available copper foils shown in Table 3 (e.g., the UTS in a range of about 255 MPa to about 580 MPa, the strain at the UTS in a range of about 2.2% to about 18%, the strain at break in a range of about 3% to about 20%, the yield strength in a range of about 170 to about 408 MPa, Young's modulus in a range of about 56 to about 88 GPa). The copper foils represented in Table 3 are electrodeposited (ED) copper foils. The copper foils shown in Table 3 represent a sampling of commercially available copper foils and other copper foils may also be used in anode electrode coatings thereon.
ED foils are formed by the deposition of copper ions onto a cathode drum via electrolysis. Alternatively, rolled copper foils may be formed by rolling from a copper block followed by annealing (e.g., in a range of 200 to 400° C., or higher than 400° C. in some circumstances). For example, the annealing temperature and other process conditions may be selected so that the grains are enlarged, while minimizing the oxidation of the copper. The grains in a rolled copper foil tend to be oriented along the longitudinal direction, whereas the grains in an ED foil tend to be oriented along the transverse direction. Therefore, the choice of the manufacturing method affects the microstructure of the thin copper foil which in turn affects the tensile properties of the copper foil. The tensile properties may also be affected by the surface finish of a copper foil. For example, a rolled annealed copper foil may have a lower surface roughness than an ED copper foil. In some cases, the surface roughness may affect the tensile properties. The surface roughness of an ED copper foil may be modified by the addition of certain additive compounds to the copper electrolyte (used during electrolysis). The surface roughness and/or the grain structure of an ED copper foil may also be modified by thermal annealing. A copper foil may include alloying elements (so called impurities) at mass fractions of up to about 1 wt. %, such as beryllium, chromium, zirconium, tin, silver, sulfur, and iron. Such elements affect the tensile properties of the copper foil by changing the grain size and fracture mode.
The maximum areal expansion of the anode is strongly dependent on the areal density (e.g., grams of silicon per cm2 of anode area) of silicon (elemental silicon) in the anode. As the areal density of silicon in the anode increases, the maximum areal expansion increases. The areal density of silicon may be tuned by tuning one or more of the following: (1) average thickness of the anode coating, (2) mass fraction of silicon in the silicon-carbon composite particles, (3) mass fraction of silicon-carbon composite particles in the anode coating, and (4) mass fraction of silicon in the anode coating. Additionally, the maximum areal expansion is dependent on the porosity of the anode coating. The porosity of the anode coating may be tuned by the coating's calendering conditions. For example, a heavily calendered coating would be less porous than a lightly calendered or un-calendered coating and may exhibit a greater maximum areal expansion. Another variable that can affect the expansion of an electrode is the % ductility (strain at break) of the respective copper foil. In some cases, a greater ductility of a copper foil may contribute to a larger maximum areal expansion of an anode coating formed on the respective copper foil.
Anode configurations of Table 3 (e.g., copper foil characteristics, Si—C nanocomposite particles weight fraction relative to all active anode materials) that were determined to have passed the cracking test and did not have any micro edge cracks were further evaluated for integration into stacked pouch cells, wound pouch cells, and/or cylindrical cells. Results of the evaluation are shown in the column named “Form Factor Examples” in Table 3. Some of the anode configurations may be suitable for more than one cell configuration. In some implementations, copper foils for integration into cylindrical cells may exhibit a strain at the UTS of greater than about 9.0% or greater than about 9.5%. In some implementations, copper foils for integration into cylindrical cells may exhibit a strain at the UTS in a range of about 9 to about 20%, or about 9.5 to about 20%, or about 9 to about 18%, or about 9.5 to about 18%. In some implementations, copper foils for integration into wound pouch cells may exhibit a strain at the UTS in a range of about 2 to about 14%, or about 2 to about 13.5%, or about 2.2 to about 14%, or about 2.2 to about 13.5%. In some implementations, copper foils for integration into stacked pouch cells may exhibit a strain at the UTS in a range of about 2 to about 11%, or about 2 to about 10.8%, or about 2.2 to about 11%, or about 2.2 to about 10.8%.
In some implementations, the anode coating includes a lower-capacity material (e.g., material with a capacity of less than about 400 mAh/g, or less than or equal to 400 mAh/g) in addition to the composite particles comprising carbon and silicon. Some examples of lower-capacity material are graphite (e.g., natural or synthetic graphite), hard carbon, soft carbon. In the examples shown in Table 3 (
In one aspect, a LIB configured to undergo multiple charging and discharging cycles includes at least one anode component, at least one cathode component, and a separator and an electrolyte interposed between adjacent ones of the anode components and the cathode components. Each of the anode components includes an anode current collector and a respective anode coating on each side of the anode current collector. Each of the cathode components includes a cathode current collector and a respective cathode coating on each side of the cathode current collector. In some embodiments, the anode components and the cathode components are stacked along a stacking direction perpendicular to a plane of the anode components and the cathode components, the anode components and the cathode components alternating along the stacking direction. Such a lithium-ion battery may be referred to as a stacked cell. In some implementations, a lithium-ion battery (e.g., a stacked cell) may be configured as a pouch cell or a prismatic cell.
In another aspect, at least one of the anode components (e.g., in a stacked cell) undergoes a maximum areal expansion in a range of about 0% to about 5.0% (e.g., in some designs, in a range of about 0% to about 3.5%) during one or multiple charging and discharging cycles. In some implementations, the strain of the anode current collector foil (e.g., Cu foil) at UTS is from about 4% to about 400% (in some implementations, from about 6% to about 40%). In some implementations, the maximum areal expansion in an anode (or at least one of the anode components) is in a range of about 0.1% to about 3.5%. In some implementations (e.g., for 0.1-3.5% areal expansion, among others), the strain of the anode current collector foil (e.g., Cu foil) at UTS may preferably be from about 6% to about 40% (in some implementations, from about 8% to about 30%). In some implementations, the maximum areal expansion in an anode (or at least one of the anode components) is in a range of about 0.1% to about 2%. In other designs, the maximum areal expansion in an anode (or at least one of the anode components) is in a range of about 0.1% to about 2%). In some implementations, the maximum areal expansion in an anode (or at least one of the anode components) is in a range of about 1% to about 2%. In some implementations (e.g., for 1-2% areal expansion, among others), the strain of the anode current collector foil (e.g., Cu foil) at UTS may preferably be from about 4% to about 100% (in some implementations, from about 8% to about 30%). In some implementations, the maximum areal expansion in an anode (or at least one of the anode components) is in a range of about 2% to about 3.5%. In some implementations (e.g., for 2-3.5% areal expansion), the strain of the anode current collector foil (e.g., Cu foil) at UTS may preferably be from about 8% to about 200% (in some implementations, from about 10% to about 40%; in yet some implementations, from about 12% to about 25%).
In yet another aspect, at least one of the anode coatings of the at least one of the anode components (e.g., of a stacked cell) may include silicon-carbon composite particles (or, more broadly, silicon oxide-silicon-carbon composite particles or silicon oxide-carbon composite particles or other silicon element-comprising and carbon element-comprising composite particles), which may comprise silicon nanoparticles. In some implementations, a weight fraction of silicon (element) in the at least one anode coating may be in a range of about 5 wt. % to about 70 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 5 wt. % to about 25 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 25 wt. % to about 40 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 40 wt. % to about 55 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 55 wt. % to about 70 wt. %.
In yet another aspect, the anode current collector of the at least one of the anode components (e.g., of a stacked cell) includes a copper foil. The copper foil (or, more broadly, copper-dominant alloy foil with copper element content in excess of about 80 wt. %; in some designs—in excess of about 90 wt. %; in yet some designs—in excess of about 95 wt. %) is characterized, before the respective anode coatings are formed thereon, by a yield strength of at least about 220 MPa. In some implementations, the yield strength is in a range of about 220 MPa to about 700 MPa (in some designs, from about 220 MPa to about 350 MPa; in other designs, from about 350 MPa to about 500 MPa; in yet other designs, from about 500 to about 700 MPa). In some implementations, the copper foil is an electrodeposited copper foil. In some implementations, a thickness of the copper foil is in a range of about 6 μm to about 12 μm. In some implementations, the thickness of the copper foil is in a range of about 6 μm to about 8 μm. In some implementations, the thickness of the copper foil is in a range of about 8 μm to about 10 μm. In some implementations, the thickness of the copper foil is in a range of about 10 μm to about 12 μm.
In yet another aspect, areal capacity loading of the at least one of the anode coatings (e.g., of a stacked cell) is in a range of about 2 mAh/cm2 to about 20 mAh/cm2 (in some designs, from about 2 mAh/cm2 to about 4 mAh/cm2; in other designs, from about 4 mAh/cm2 to about 6 mAh/cm2; in other designs, from about 6 mAh/cm2 to about 8 mAh/cm2; in other designs, from about 8 mAh/cm2 to about 10 mAh/cm2; in other designs, from about 10 mAh/cm2 to about 14 mAh/cm2; in other designs, from about 14 mAh/cm2 to about 20 mAh/cm2).
In some implementations, the at least one of the anode coatings includes graphite (e.g., natural or synthetic graphite) or hard carbon or soft carbon. In some implementations, the at least one of the anode coatings includes a binder, which may, in some designs, advantageously comprise a styrene-butadiene rubber or another styrene-comprising rubber. In some implementations, the at least one of the anode coatings may include a buffer layer. In some implementations, a thickness of the at least one of the anode coatings is in a range of about 25 μm to about 200 μm (in some designs, in a range of about 25 μm to about 40 μm; in other designs, in a range of about 40 μm to about 70 μm; in other designs, in a range of about 70 μm to about 100 μm; in other designs, in a range of about 100 μm to about 150 μm; in other designs, in a range of about 150 μm to about 200 μm).
In yet another aspect, a lithium-ion battery (e.g., stacked cell) includes (1) a wrapper wrapped around the anode components and the cathode components and (2) a container. In some implementations, the anode components, the cathode components, the separator, the electrolyte, and the wrapper are sealed in the container. In some implementations, the wrapper includes an adhesive tape adhered to at least some portion of the anode components and/or the cathode components.
In yet another aspect, the at least one anode component (e.g., of a stacked cell) includes a plurality of anode components. In some implementations, the respective anode current collectors are electronically coupled to each other. In some implementations, the separator is discontiguous (e.g., separator layers are not joined together).
In yet another aspect, the at least one cathode component (e.g., of a stacked cell) includes a plurality of cathode components. In some implementations, the respective cathode current collectors are electronically coupled to each other. In some implementations, the separator is discontiguous.
In yet another aspect, a lithium-ion battery configured to undergo multiple charging and discharging cycles includes an anode component, a cathode component, and at least one separator and an electrolyte interposed between the anode component and the cathode component. The anode component includes an anode current collector and a respective anode coating on each side of the anode current collector. The cathode component includes a cathode current collector and a respective cathode coating on each side of the cathode current collector. In some embodiments, the anode component, the cathode component, and the at least one separator are wound a common core. Such a lithium-ion battery may be referred to as a wound cell. In some implementations, a lithium-ion battery (e.g., a wound cell) may be configured as a cylindrical cell, a coin cell, a prismatic cell, a pouch cell or a jelly roll cell.
In yet another aspect, the anode current collector (e.g., of a wound cell; in some designs, of a cylindrical cell) includes a copper foil. In some implementations, the copper foil is characterized, before the respective anode coatings are formed thereon, by (1) a yield strength in a range of about 100 MPa to about 400 MPa, and/or (2) an elongation at break parameter in a range of about 4% to about 20%. In some implementations, the yield strength is in a range of 100 MPa to 200 MPa. In other implementations, the yield strength is in a range of about 200 MPa to about 300 MPa. In other implementations, the yield strength is in a range of about 300 MPa to about 400 MPa. In some implementations, the elongation at break parameter is in a range of about 4% to about 7.5%. In some implementations, the elongation at break parameter is in a range of about 7.5% to about 13%. In some implementations, the copper foil is an electrodeposited copper foil. In some implementations, the elongation at break parameter is in a range of about 13% to about 20%. In some implementations, a thickness of the copper foil is in a range of about 6 μm to about 12 μm. In some implementations, the thickness of the copper foil is in a range of about 6 μm to about 8 μm. In some implementations, the thickness of the copper foil is in a range of 8 μm to 10 μm. In some implementations, the thickness of the copper foil is in a range of about 10 μm to about 12 μm.
In yet another aspect, at least one of the anode coatings of the at least one of the anode components (e.g., of a wound cell; in some designs, of a cylindrical cell) includes silicon-carbon composite particles (or, more broadly, silicon oxide-silicon-carbon composite particles or silicon oxide-carbon composite particles or other silicon element-comprising and carbon element-comprising composite particles), which may include silicon nanoparticles. In some implementations, a weight fraction of (elemental) silicon in the at least one anode coating (e.g., elemental Si in Si—C(nano)composite anode particles) may be in a range of about 5 wt. % to about 70 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 5 wt. % to about 15 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 15 wt. % to about 25 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 25 wt. % to about 40 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 40 wt. % to about 55 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 55 wt. % to about 70 wt. %.
In yet another aspect, a capacity loading of the at least one of the anode coatings (e.g., of a wound cell; in some designs, of a cylindrical cell) is in a range of about 2 mAh/cm2 to about 20 mAh/cm2 (in some designs, from about 2 mAh/cm2 to about 4 mAh/cm2; in other designs, from about 4 mAh/cm2 to about 6 mAh/cm2; in other designs, from about 6 mAh/cm2 to about 8 mAh/cm2; in other designs, from about 8 mAh/cm2 to about 10 mAh/cm2; in other designs, from about 10 mAh/cm2 to about 14 mAh/cm2; in other designs, from about 14 mAh/cm2 to about 20 mAh/cm2).
In some implementations, the at least one of the anode coatings includes graphite (e.g., natural or synthetic graphite) or hard carbon or soft carbon. In some implementations, the at least one of the anode coatings may include a binder comprising a styrene-butadiene rubber. In some implementations, the at least one of the anode coatings may include a buffer layer. In some implementations, a thickness of the at least one of the anode coatings is in a range of about 25 μm to about 200 μm (in some designs, in a range of about 25 μm to about 40 μm; in other designs, in a range of about 40 μm to about 70 μm; in other designs, in a range of about 70 μm to about 100 μm; in other designs, in a range of about 100 μm to about 150 μm; in other designs, in a range of about 150 μm to about 200 μm).
In yet another aspect, a lithium-ion battery (e.g., wound cell) may include a container. In some implementations, the anode component, the cathode component, the at least one separator, and the electrolyte are sealed in the container.
In yet another aspect, a method of making a lithium-ion battery configured to undergo multiple charging and discharging cycles is disclosed. The method includes (A1), (A2), (A3), and (A4). (A1) includes providing at least one anode component. Each of the anode components includes an anode current collector and a respective anode coating on each side of the anode current collector. (A2) includes providing at least one cathode component. Each of the cathode components includes a cathode current collector and a respective cathode coating on each side of the cathode current collector. (A3) includes stacking the anode components and the cathode components along a stacking direction perpendicular to a plane of the anode components and the cathode components. The anode components and the cathode components alternate along the stacking direction. A separator is interposed between adjacent ones of the anode components and the cathode components. (A4) includes infiltrating an electrolyte between adjacent ones of the anode components and the cathode components. Such a method may be referred to as a method of making a stacked cell. In some implementations, a lithium-ion battery (e.g., according to a method of making a stacked cell) may be configured as a pouch cell or a prismatic cell or a coin cell. In some implementations, (A1) includes providing a roll of the suitable anode current collector, forming the respective anode coatings on the roll of the anode current collector, and forming the anode component from the roll of the anode current collector and the anode coatings.
In yet another aspect, at least one of the anode components (e.g., according to a method of making a stacked cell) undergoes a maximum areal expansion in a range of about 0% to about 5.5% during one or the multiple charging and discharging cycles. In some implementations, the maximum areal expansion is in a range of about 0% to about 3.5%. In some implementations, the maximum areal expansion is in a range of about 0% to about 2%. In some implementations, the maximum areal expansion is in a range of about 1% to about 2%. In some implementations, the maximum areal expansion is in a range of about 2% to about 3.5%.
In yet another aspect, at least one of the anode coatings of the at least one of the anode components (e.g., according to a method of making a stacked cell) includes silicon-carbon composite particles (or, more broadly, silicon oxide-silicon-carbon composite particles or silicon oxide-carbon composite particles or other silicon element-comprising and carbon element-comprising composite particles), which may include silicon nanoparticles. In some implementations, a weight fraction of (elemental) silicon in the at least one anode coating (e.g., elemental Si in Si—C(nano)composite anode particles) may be in a range of about 5 wt. % to about 70 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 5 wt. % to about 25 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 25 wt. % to about 55 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 55 wt. % to about 70 wt. %.
In yet another aspect, the anode current collector of the at least one of the anode components (e.g., according to a method of making a stacked cell) includes a copper foil (or, more broadly, copper-dominant alloy foil with copper element content in excess of about 80 wt. %; in some designs—in excess of about 90 wt. %; in yet some designs—in excess of about 95 wt. %). The copper foil is characterized, before the respective anode coatings are formed thereon, by a yield strength of at least about 220 MPa. In some implementations, the yield strength is in a range of about 220 MPa to about 700 MPa (in some designs, from about 220 MPa to about 400 MPa; in other designs, from about 400 MPa to about 600 MPa; in other designs, from about 600 MPa to about 700 MPa). In some implementations, the copper foil is an electrodeposited copper foil. In some implementations, a thickness of the copper foil is in a range of about 6 μm to about 12 μm. In some implementations, the thickness of the copper foil is in a range of about 6 μm to about 8 μm. In some implementations, the thickness of the copper foil is in a range of 8 μm to 10 μm. In some implementations, the thickness of the copper foil is in a range of about 10 μm to about 12 μm.
In yet another aspect, a capacity loading of the at least one of the anode coatings (e.g., according to a method of making a stacked cell) is in a range of about 2 mAh/cm2 to about 20 mAh/cm2 (in some designs, from about 2 mAh/cm2 to about 4 mAh/cm2; in other designs, from about 4 mAh/cm2 to about 6 mAh/cm2; in other designs, from about 6 mAh/cm2 to about 8 mAh/cm2; in other designs, from about 8 mAh/cm2 to about 10 mAh/cm2; in other designs, from about 10 mAh/cm2 to about 14 mAh/cm2; in other designs, from about 14 mAh/cm2 to about 20 mAh/cm2). In some implementations, the at least one of the anode coatings includes graphite (or soft or hard carbon or their various mixtures). In some implementations, the at least one of the anode coatings includes a binder, which may comprise a styrene-butadiene rubber. In some implementations, the at least one of the anode coatings includes a buffer layer. In some implementations, a thickness of the at least one of the anode coatings is in a range of about 25 μm to about 200 μm (in some designs, in a range of about 25 μm to about 40 μm; in other designs, in a range of about 40 μm to about 70 μm; in other designs, in a range of about 70 μm to about 100 μm; in other designs, in a range of about 100 μm to about 150 μm; in other designs, in a range of about 150 μm to about 200 μm).
In yet another aspect, a method of making a lithium-ion battery (e.g., a method of making a stacked cell) additionally includes (B1) and (B2). (B1) includes wrapping a wrapper around the anode components and the cathode components. (B2) includes sealing the anode components, the cathode components, the separator, the electrolyte, and the wrapper in a container. In some implementations, the anode components, the cathode components, the separator, the electrolyte, and the wrapper are sealed in the container. In some implementations, the wrapper includes an adhesive tape adhered to at least some portion of the anode components and/or the cathode components.
In yet another aspect, the at least one anode component (e.g., according to a method of making a stacked cell) includes a plurality of anode components. In some implementations, the method of making a lithium-ion battery (e.g., a method of making a stacked cell) additionally includes electronically coupling the respective anode current collectors to each other. In some implementations, the separator is discontiguous.
In yet another aspect, the at least one cathode component (e.g., according to a method of making a stacked cell) includes a plurality of cathode components. In some implementations, the method of making a lithium-ion battery (e.g., a method of making a stacked cell) additionally includes electronically coupling the respective cathode current collectors to each other. In some implementations, the separator is discontiguous.
In yet another aspect, a method of making a lithium-ion battery configured to undergo multiple charging and discharging cycles is disclosed. The method includes (C1), (C2), (C3), and (C4). (C1) includes providing an anode component including an anode current collector and a respective anode coating on each side of the anode current collector. (C2) includes providing a cathode component including a cathode current collector and a respective cathode coating on each side of the cathode current collector. (C3) includes winding the anode component, the cathode component, and at least one separator interposed between the anode component and the cathode component around a common core. (C4) includes infiltrating an electrolyte between the anode component and the cathode component. Such a method may be referred to as a method of making a wound cell. In some implementations, a lithium-ion battery (e.g., according to a method of making a wound cell) may be configured as a cylindrical cell, a coin cell, or a jelly roll cell. In some implementations, (C1) includes providing a roll of the anode current collector, forming the respective anode coatings on the roll of the anode current collector, and forming the anode component from the roll of the anode current collector and the anode coatings.
In yet another aspect, the anode current collector (e.g., according to a method of making a wound cell) includes a copper foil. In some implementations, the copper foil (or, more broadly, copper-dominant alloy foil with copper element content in excess of about 80 wt. %; in some designs—in excess of about 90 wt. %; in yet some designs—in excess of about 95 wt. %) is characterized, before the respective anode coatings are formed thereon, by (1) a yield strength in a range of about 100 MPa to about 400 MPa, and/or (2) an elongation at break parameter in a range of about 4% to about 20%. In some implementations, the yield strength is in a range of about 100 MPa to about 250 MPa. In some implementations, the elongation at break parameter is in a range of about 7.5% to about 13%. In some implementations, the copper foil is an electrodeposited copper foil. In some implementations, a thickness of the copper foil is in a range of about 6 μm to about 12 μm. In some implementations, a thickness of the copper foil is in a range of about 7 μm to about 12 μm. In some implementations, the thickness of the copper foil is in a range of about 6 μm to about 8 μm. In some implementations, the thickness of the copper foil is in a range of about 8 μm to about 10 μm. In some implementations, the thickness of the copper foil is in a range of about 10 μm to about 12 μm.
In yet another aspect, at least one of the anode coatings of the anode component (e.g., according to a method of making a wound cell) includes silicon-carbon composite particles (or, more broadly, silicon oxide-silicon-carbon composite particles or silicon oxide-carbon composite particles or other silicon element-comprising and carbon element-comprising composite particles), which may comprise silicon nanoparticles. In some implementations, a weight fraction of (elemental) silicon in the at least one anode coating (e.g., elemental Si in Si—C(nano)composite anode particles) may be in a range of about 5 wt. % to about 70 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 5 wt. % to about 25 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 25 wt. % to about 40 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 40 wt. % to about 55 wt. %. In some implementations, the weight fraction of silicon may be in a range of about 55 wt. % to about 70 wt. %.
In yet another aspect, areal capacity loading of the at least one of the anode coatings (e.g., according to a method of making a wound cell) is in a range of about 2 mAh/cm2 to about 20 mAh/cm2 (in some designs, from about 2 mAh/cm2 to about 4 mAh/cm2; in other designs, from about 4 mAh/cm2 to about 6 mAh/cm2; in other designs, from about 6 mAh/cm2 to about 8 mAh/cm2; in other designs, from about 8 mAh/cm2 to about 10 mAh/cm2; in other designs, from about 10 mAh/cm2 to about 14 mAh/cm2; in other designs, from about 14 mAh/cm2 to about 20 mAh/cm2). In some implementations, the at least one of the anode coatings includes graphite (e.g., natural or synthetic graphite) or hard carbon or soft carbon. In some implementations, the at least one of the anode coatings includes a binder, which may, in some designs, advantageously comprise a styrene-butadiene rubber. In some implementations, the at least one of the anode coatings includes a buffer layer. In some implementations, a thickness of the at least one of the anode coatings is in a range of 25 μm to 200 μm (in some designs, in a range of about 25 μm to about 40 μm; in other designs, in a range of about 40 μm to about 70 μm; in other designs, in a range of about 70 μm to about 100 μm; in other designs, in a range of about 100 μm to about 150 μm; in other designs, in a range of about 150 μm to about 200 μm).
In another aspect, at least one of the anode components (e.g., in a wound cell; in some designs, in a cylindrical cell) undergoes a maximum areal expansion in a range of about 0% to about 5.0% during one or multiple charging and discharging cycles. In some implementations, the strain of the anode current collector foil (e.g., Cu foil) at UTS is from about 4% to about 400% (in some implementations, from about 6% to about 40%). In some implementations, the maximum areal expansion in an anode (or at least one of the anode components) is in a range of about 0.1% to about 3.5%. In some implementations (e.g., for 0.1-3.5% areal expansion), the strain of the anode current collector foil (e.g., Cu foil) at UTS may preferably be from about 6% to about 40% (in some implementations, from about 8% to about 30%). In some implementations, the maximum areal expansion in an anode (or at least one of the anode components) is in a range of about 0.1% to about 2%. In some implementations, the maximum areal expansion in an anode (or at least one of the anode components) is in a range of about 1% to about 2%. In some implementations (e.g., for 1-2% areal expansion), the strain of the anode current collector foil (e.g., Cu foil) at UTS may preferably be from about 4% to about 100% (in some implementations, from about 8% to about 30%). In some implementations, the maximum areal expansion in an anode (or at least one of the anode components) is in a range of about 2% to about 3.5%. In some implementations (e.g., for 2-3.5% areal expansion), the strain of the anode current collector foil (e.g., Cu foil) at UTS may preferably be from about 8% to about 200% (in some implementations, from about 10% to about 40%; in yet some implementations, from about 12% to about 25%).
In the detailed description above it can be seen that different features are grouped together in examples. This manner of disclosure should not be understood as an intention that the example clauses have more features than are explicitly mentioned in each clause. Rather, the various aspects of the disclosure may include fewer than all features of an individual example clause disclosed. Therefore, the following clauses should hereby be deemed to be incorporated in the description, wherein each clause by itself can stand as a separate example. Although each dependent clause can refer in the clauses to a specific combination with one of the other clauses, the aspect(s) of that dependent clause are not limited to the specific combination. It will be appreciated that other example clauses can also include a combination of the dependent clause aspect(s) with the subject matter of any other dependent clause or independent clause or a combination of any feature with other dependent and independent clauses. The various aspects disclosed herein expressly include these combinations, unless it is explicitly expressed or can be readily inferred that a specific combination is not intended (e.g., contradictory aspects, such as defining an element as both an electrical insulator and an electrical conductor). Furthermore, it is also intended that aspects of a clause can be included in any other independent clause, even if the clause is not directly dependent on the independent clause.
Implementation examples are described in the following numbered clauses:
Clause 1. A lithium-ion battery configured to undergo multiple charging and discharging cycles, comprising: at least one anode component, each of the anode components comprising an anode current collector and a respective anode coating on each side of the anode current collector; at least one cathode component, each of the cathode components comprising a cathode current collector and a respective cathode coating on each side of the cathode current collector; and a separator and an electrolyte interposed between adjacent ones of the anode components and the cathode components, wherein: the anode components and the cathode components are stacked along a stacking direction perpendicular to a plane of the anode components and the cathode components, the anode components and the cathode components alternating along the stacking direction; at least one of the anode components undergoes a maximum areal expansion in a range of about 0% to about 3.5% during the multiple charging and discharging cycles; at least one of the anode coatings of the at least one of the anode components comprises silicon-carbon composite particles including silicon nanoparticles, a weight fraction of (elemental) silicon in the at least one anode coating (e.g., elemental Si in Si—C(nano)composite anode particles) being in a range of about 5 wt. % to about 70 wt. %; and the anode current collector of the at least one of the anode components comprises a copper foil, the copper foil being characterized, before the respective anode coatings are formed thereon, by a yield strength of at least about 220 MPa.
Clause 2. The lithium-ion battery of clause 1, wherein: the weight fraction of silicon is in a range of about 15 wt. % to about 65 wt. %.
Clause 3. The lithium-ion battery of clause 2, wherein: the weight fraction of silicon is in a range of about 25 wt. % to about 60 wt. %.
Clause 4. The lithium-ion battery of clause 3, wherein: the weight fraction of silicon is in a range of about 35 wt. % to about 55 wt. %.
Clause 5. The lithium-ion battery of any of clauses 1 to 4, wherein: the copper foil is an electrodeposited copper foil.
Clause 6. The lithium-ion battery of any of clauses 1 to 5, wherein: the maximum areal expansion is in a range of about 0% to about 2%.
Clause 7. The lithium-ion battery of any of clauses 1 to 6, wherein: the yield strength is in a range of about 220 MPa to about 600 MPa.
Clause 8. The lithium-ion battery of any of clauses 1 to 7, wherein: the lithium-ion battery comprises (1) a wrapper wrapped around the anode components and the cathode components and (2) a container; and the anode components, the cathode components, the separator, the electrolyte, and the wrapper are sealed in the container.
Clause 9. The lithium-ion battery of clause 8, wherein: the wrapper comprises an adhesive tape adhered to at least some portion of the anode components and/or the cathode components.
Clause 10. The lithium-ion battery of any of clauses 1 to 9, wherein: the at least one anode component comprises a plurality of anode components; and the respective anode current collectors are electronically coupled to each other.
Clause 11. The lithium-ion battery of any of clauses 1 to 10, wherein: the at least one cathode component comprises a plurality of cathode components; and the respective cathode current collectors are electronically coupled to each other.
Clause 12. The lithium-ion battery of any of clauses 1 to 11, wherein: the at least one anode component comprises a plurality of anode components; the at least one cathode component comprises a plurality of cathode components; and the separator is discontiguous.
Clause 13. The lithium-ion battery of any of clauses 1 to 12, wherein: a thickness of the copper foil is in a range of about 7 μm to about 12 μm.
Clause 14. The lithium-ion battery of clause 13, wherein: the thickness of the copper foil is in a range of about 8 μm to about 10 μm.
Clause 15. The lithium-ion battery of any of clauses 1 to 14, wherein: a thickness of the at least one of the anode coatings is in a range of about 25 μm to about 75 μm.
Clause 16. The lithium-ion battery of any of clauses 1 to 15, wherein: a capacity loading of the at least one of the anode coatings is in a range of about 2 mAh/cm2 to about 10 mAh/cm2.
Clause 17. The lithium-ion battery of any of clauses 1 to 16, wherein: the at least one of the anode coatings comprises graphite.
Clause 18. The lithium-ion battery of any of clauses 1 to 17, wherein: the lithium-ion battery is configured as a pouch cell, a prismatic cell, or a coin cell.
Clause 19. The lithium-ion battery of any of clauses 1 to 18, wherein: the at least one of the anode coatings comprises a binder comprising a styrene-butadiene rubber.
Clause 20. The lithium-ion battery of any of clauses 1 to 19, wherein: the at least one of the anode coatings comprises a buffer layer.
Clause 21. A lithium-ion battery configured to undergo multiple charging and discharging cycles, comprising: an anode component comprising an anode current collector and a respective anode coating on each side of the anode current collector; a cathode component comprising a cathode current collector and a respective cathode coating on each side of the cathode current collector; and at least one separator and an electrolyte interposed between the anode component and the cathode component; wherein: the anode component, the cathode component, and the at least one separator are wound around a common core; at least one of the anode coatings comprises silicon-carbon composite particles including silicon nanoparticles, a weight fraction of (elemental) silicon in the at least one anode coating (e.g., elemental Si in Si—C(nano)composite anode particles) being in a range of about 5 wt. % to about 70 wt. %; and the anode current collector comprises a copper foil, the copper foil being characterized, before the respective anode coatings are formed thereon, by (1) a yield strength in a range of about 100 MPa to about 400 MPa, and (2) an elongation at break parameter in a range of about 4% to about 20%.
Clause 22. The lithium-ion battery of clause 21, wherein: the weight fraction of silicon is in a range of about 15 wt. % to about 65 wt. %.
Clause 23. The lithium-ion battery of clause 22, wherein: the weight fraction of silicon is in a range of about 25 wt. % to about 60 wt. %.
Clause 24. The lithium-ion battery of clause 23, wherein: the weight fraction of silicon is in a range of about 35 wt. % to about 55 wt. %.
Clause 25. The lithium-ion battery of any of clauses 21 to 24, wherein: the copper foil is an electrodeposited copper foil.
Clause 26. The lithium-ion battery of any of clauses 21 to 25, wherein: the yield strength is in a range of about 100 MPa to about 250 MPa.
Clause 27. The lithium-ion battery of any of clauses 21 to 26, wherein: the elongation at break parameter is in a range of about 7.5% to about 13%.
Clause 28. The lithium-ion battery of any of clauses 21 to 27, wherein: the lithium-ion battery comprises a container; and the anode component, the cathode component, the at least one separator, and the electrolyte are sealed in the container.
Clause 29. The lithium-ion battery of any of clauses 21 to 28, wherein: a thickness of the copper foil is in a range of about 7 μm to about 12 μm.
Clause 30. The lithium-ion battery of clause 29, wherein: the thickness of the copper foil is in a range of about 8 μm to about 10 μm.
Clause 31. The lithium-ion battery of any of clauses 21 to 30, wherein: a thickness of the at least one of the anode coatings is in a range of about 25 μm to about 75 μm.
Clause 32. The lithium-ion battery of any of clauses 21 to 31, wherein: a capacity loading of the at least one of the anode coatings is in a range of about 2 mAh/cm2 to about 10 mAh/cm2.
Clause 33. The lithium-ion battery of any of clauses 21 to 32, wherein: the at least one of the anode coatings comprises graphite.
Clause 34. The lithium-ion battery of any of clauses 21 to 33, wherein: the lithium-ion battery is configured as a cylindrical cell, a coin cell, or a jelly roll cell.
Clause 35. The lithium-ion battery of any of clauses 21 to 34, wherein: the at least one of the anode coatings comprises a binder comprising a styrene-butadiene rubber.
Clause 36. The lithium-ion battery of any of clauses 21 to 35, wherein: the at least one of the anode coatings comprises a buffer layer.
Clause 37. A method of making a lithium-ion battery configured to undergo multiple charging and discharging cycles, the method comprising: (A1) providing at least one anode component, each of the anode components comprising an anode current collector and a respective anode coating on each side of the anode current collector; (A2) providing at least one cathode component, each of the cathode components comprising a cathode current collector and a respective cathode coating on each side the cathode current collector; (A3) stacking the anode components and the cathode components along a stacking direction perpendicular to a plane of the anode components and the cathode components, the anode components and the cathode components alternating along the stacking direction, a separator being interposed between adjacent ones of the anode components and the cathode components; (A4) infiltrating an electrolyte between adjacent ones of the anode components and the cathode components, wherein: at least one of the anode components undergoes a maximum areal expansion in a range of about 0% to about 3.5% during the multiple charging and discharging cycles; at least one of the anode coatings of the at least one of the anode components comprises silicon-carbon composite particles including silicon nanoparticles, a weight fraction of silicon in the at least one of the anode coatings being in a range of about 5 wt. % to about 70 wt. %; and the anode current collector of the at least one of the anode components comprises a copper foil, the copper foil being characterized, before the respective anode coatings are formed thereon, by a yield strength of at least about 220 MPa.
Clause 38. The method of clause 37, wherein: (A1) comprises providing a roll of the anode current collector, forming the respective anode coatings on the roll of the anode current collector, and forming the at least one anode component from the roll of the anode current collector and the anode coatings.
Clause 39. The method of any of clauses 37 to 38, wherein: the weight fraction of silicon is in a range of about 15 wt. % to about 65 wt. %.
Clause 40. The method of clause 39, wherein: the weight fraction of silicon is in a range of about 25 wt. % to about 60 wt. %.
Clause 41. The method of clause 40, wherein: the weight fraction of silicon is in a range of about 35 wt. % to about 55 wt. %.
Clause 42. The method of any of clauses 37 to 41, wherein: the copper foil is an electrodeposited copper foil.
Clause 43. The method of any of clauses 37 to 42, wherein: the maximum areal expansion is in a range of about 0% to about %.
Clause 44. The method of any of clauses 37 to 43, wherein: the yield strength is in a range of about 220 MPa to about 600 MPa.
Clause 45. The method of any of clauses 37 to 44, additionally comprising: (B1) wrapping a wrapper around the anode components and the cathode components; (B2) sealing the anode components, the cathode components, the separator, the electrolyte, and the wrapper in a container.
Clause 46. The method of clause 45, wherein: the wrapper comprises an adhesive tape adhered to at least some portion of the anode components and/or the cathode components.
Clause 47. The method of any of clauses 37 to 46, wherein: the at least one anode component comprises a plurality of anode components; and the method additionally comprises electronically coupling the respective anode current collectors to each other.
Clause 48. The method of any of clauses 37 to 47, wherein: the at least one cathode component comprises a plurality of cathode components; and the method additionally comprises electronically coupling the respective cathode current collectors to each other.
Clause 49. The method battery of any of clauses 37 to 48, wherein: the at least one anode component comprises a plurality of anode components; the at least one cathode component comprises a plurality of cathode components; and the separator is discontiguous.
Clause 50. The method of any of clauses 37 to 49, wherein: a thickness of the copper foil is in a range of about 7 μm to about 12 μm.
Clause 51. The method of clause 50, wherein: the thickness of the copper foil is in a range of about 8 μm to about 10 μm.
Clause 52. The method of any of clauses 37 to 51, wherein: a thickness of the at least one of the anode coatings is in a range of about 25 μm to about 75 μm.
Clause 53. The method of any of clauses 37 to 52, wherein: a capacity loading of the at least one of the anode coatings is in a range of about 2 mAh/cm2 to about 10 mAh/cm2.
Clause 54. The method of any of clauses 37 to 53, wherein: the at least one of the anode coatings comprises graphite.
Clause 55. The method of any of clauses 37 to 54, wherein: the lithium-ion battery is configured as a pouch cell or a prismatic cell.
Clause 56. The method of any of clauses 37 to 55, wherein: the at least one of the anode coatings comprises a binder comprising a styrene-butadiene rubber.
Clause 57. The method of any of clauses 37 to 56, wherein: the at least one of the anode coatings comprises a buffer layer.
Clause 58. A method of making a lithium-ion battery configured to undergo multiple charging and discharging cycles, the method comprising: (C1) providing an anode component comprising an anode current collector and a respective anode coating on each side of the anode current collector; (C2) providing a cathode component comprising a cathode current collector and a respective cathode coating on each side of the cathode current collector; (C3) winding the anode component, the cathode component, and at least one separator interposed between the anode component and the cathode component around a common core; and (C4) infiltrating an electrolyte between the anode component and the cathode component, wherein: at least one of the anode coatings comprises silicon-carbon composite particles including silicon nanoparticles, a weight fraction of silicon in the at least one of the anode coatings being in a range of about 5 wt. % to about 70 wt. %; and the anode current collector comprises a copper foil, the copper foil being characterized, before the respective anode coatings are formed thereon, by (1) a yield strength in a range of about 100 MPa to about 400 MPa, and (2) an elongation at break parameter in a range of about 4% to about 20%.
Clause 59. The method of clause 58, wherein: (C1) comprises providing a roll of the anode current collector, forming the respective anode coatings on the roll of the anode current collector, and forming the anode component from the roll of the anode current collector and the anode coatings.
Clause 60. The method of any of clauses 58 to 59, wherein: the weight fraction of silicon is in a range of about 15 wt. % to about 65 wt. %.
Clause 61. The method of clause 60, wherein: the weight fraction of silicon is in a range of about 25 wt. % to about 60 wt. %.
Clause 62. The method of clause 61, wherein: the weight fraction of silicon is in a range of about 35 wt. % to about 55 wt. %.
Clause 63. The method of any of clauses 58 to 62, wherein: the copper foil is an electrodeposited copper foil.
Clause 64. The method of any of clauses 58 to 63, wherein: the yield strength is in a range of about 100 MPa to about 250 MPa.
Clause 65. The method of any of clauses 58 to 64, wherein: the elongation at break parameter is in a range of about 7.5% to about 13%.
Clause 66. The method of any of clauses 58 to 65, additionally comprising: sealing the anode component, the cathode component, the at least one separator, and the electrolyte in a container.
Clause 67. The method of any of clauses 58 to 66, wherein: a thickness of the copper foil is in a range of about 7 μm to about 12 μm.
Clause 68. The method of clause 67, wherein: the thickness of the copper foil is in a range of about 8 μm to about 10 μm.
Clause 69. The method of any of clauses 58 to 68, wherein: a thickness of the at least one of the anode coatings is in a range of about 25 μm to about 75 μm.
Clause 70. The method of any of clauses 58 to 69, wherein: a capacity loading of the at least one of the anode coatings is in a range of about 2 mAh/cm2 to about 10 mAh/cm2.
Clause 71. The method of any of clauses 58 to 70, wherein: the at least one of the anode coatings comprises graphite.
Clause 72. The method of any of clauses 58 to 71, wherein: the lithium-ion battery is configured as a cylindrical cell, a coin cell, or a jelly roll cell.
Clause 73. The method of any of clauses 58 to 72, wherein: the at least one of the anode coatings comprises a binder comprising a styrene-butadiene rubber.
Clause 74. The method of any of clauses 54 to 73, wherein: the at least one of the anode coatings comprises a buffer layer.
Further implementation examples are described in the following numbered Further Clauses:
Further Clause 1. A lithium-ion battery configured to undergo multiple charging and discharging cycles, comprising: an anode component, comprising an anode current collector and a respective anode coating on each side of the anode current collector; a cathode component, comprising a cathode current collector and a respective cathode coating on each side of the cathode current collector; a separator interposed between the anode component and the cathode component; and an electrolyte infiltrated in the separator between the anode component and the cathode component, wherein: the anode coatings comprise composite particles comprising carbon and silicon, a mass fraction of the silicon in the composite particles of the anode coatings being in a range of about 5 wt. % to about 70 wt. % of the anode coatings; the anode component undergoes a maximum areal expansion (Amax) during the multiple charging and discharging cycles, expressed as a percentage of an area of the anode component before the multiple charging and discharging cycles; the anode current collector comprises a copper foil, the copper foil being characterized, before the respective anode coatings are formed thereon, by an ultimate tensile stress (UTS) and a strain at the UTS (εUTS), expressed in %; and the maximum areal expansion and the strain at the UTS are related as follows:
A
max≤εUTS (Formula 1).
Further Clause 2. The lithium-ion battery of clause 1, wherein: the maximum areal expansion and the strain at the UTS are related as follows:
A
max
≤aε
UTS
−b (Formula 2);
Further Clause 3. The lithium-ion battery of clause 2, wherein: the a is in a range of about 0.6 to about 0.7; and the b is in a range of about 0.6 to about 0.7.
Further Clause 4. The lithium-ion battery of any of clauses 1 to 3, wherein: the strain at the UTS is in a range of about 2% to about 18%.
Further Clause 5. The lithium-ion battery of any of clauses 1 to 4, wherein: the maximum areal expansion is in a range of about 0.1% to about 6.0%.
Further Clause 6. The lithium-ion battery of any of clauses 1 to 5, wherein: the UTS is about 250 MPa or greater.
Further Clause 7. The lithium-ion battery of any of clauses 1 to 6, wherein: the mass fraction of the silicon in the composite particles of the anode coatings is in a range of about 15 wt. % to about 40 wt. % of the anode coatings.
Further Clause 8. The lithium-ion battery of any of clauses 1 to 7, wherein: the mass fraction of the silicon in the composite particles of the anode coatings is in a range of about 10 wt. % to about 65 wt. % of the anode coatings.
Further Clause 9. The lithium-ion battery of any of clauses 1 to 8, wherein: a capacity of the silicon in the composite particles of the anode coatings is in a range of about 500 mAh/g to about 1500 mAh/g.
Further Clause 10. The lithium-ion battery of any of clauses 1 to 9, wherein: the copper foil is an electrodeposited copper foil.
Further Clause 11. The lithium-ion battery of any of clauses 1 to 10, wherein: the copper foil exhibits a yield strength of about 170 MPa or greater.
Further Clause 12. The lithium-ion battery of any of clauses 1 to 11, wherein: a thickness of the copper foil is in a range of about 7 μm to about 12 μm.
Further Clause 13. The lithium-ion battery of clause 12, wherein: the thickness of the copper foil is in a range of about 8 μm to about 10 μm.
Further Clause 14. The lithium-ion battery of any of clauses 1 to 13, wherein: an average thickness of the anode coatings is in a range of about 25 μm to about 75 μm.
Further Clause 15. The lithium-ion battery of any of clauses 1 to 14, wherein: the anode coatings comprise graphite.
Further Clause 16. The lithium-ion battery of any of clauses 1 to 15, wherein: the anode component is a first anode component; the lithium-ion battery comprises a plurality of the first anode components; the cathode component is a first cathode component; the lithium-ion battery comprises a plurality of the first cathode components; and the plurality of the first anode components and the plurality of the first cathode components are stacked along a stacking direction perpendicular to a plane of the plurality of the first anode components and the plurality of the first cathode components, the plurality of the first anode components and the plurality of the first cathode components alternating along the stacking direction.
Further Clause 17. The lithium-ion battery of clause 16, wherein: the lithium-ion battery is configured as a pouch cell, a prismatic cell, or a coin cell.
Further Clause 18. The lithium-ion battery of any of clauses 1 to 17, wherein: the anode component, the cathode component, and the separator are wound around a common core.
Further Clause 19. The lithium-ion battery of clause 18, wherein: the lithium-ion battery is configured as a cylindrical cell, a coin cell, or a jelly roll cell.
Further Clause 20. A method of making a lithium-ion battery configured to undergo multiple charging and discharging cycles, the method comprising: (A1) providing an anode component comprising an anode current collector and a respective anode coating on each side of the anode current collector; (A2) providing a cathode component comprising a cathode current collector and a respective cathode coating on each side the cathode current collector; and (A3) assembling the lithium-ion battery with a separator interposed between the anode component and the cathode component and an electrolyte infiltrated in the separator between the anode component and the cathode component, wherein: the anode coatings comprise composite particles comprising carbon and silicon, a mass fraction of the silicon in the composite particles of the anode coatings being in a range of about 5 wt. % to about 70 wt. % of the anode coatings; the anode component undergoes a maximum areal expansion (Amax) during the multiple charging and discharging cycles, expressed as a percentage of an area of the anode component before the multiple charging and discharging cycles; the anode current collector comprises a copper foil, the copper foil being characterized, before the respective anode coatings are formed thereon, by an ultimate tensile stress (UTS) and a strain at the UTS (εUTS), expressed in %; and the maximum areal expansion and the strain at the UTS are related as follows:
A
max≤εUTS (Formula 1).
Further Clause 21. The method of clause 20, wherein: the maximum areal expansion and the strain at the UTS are related as follows:
A
max
≤aε
UTS
−b (Formula 2);
Further Clause 22. The method of clause 21, wherein: the a is in a range of about 0.6 to about 0.7; and the b is in a range of about 0.6 to about 0.7.
Further Clause 23. The method of any of clauses 20 to 22, wherein: the strain at the UTS is in a range of about 2% to about 18%.
Further Clause 24. The method of any of clauses 20 to 23, wherein: the maximum areal expansion is in a range of about 0.1% to about 6.0%.
Further Clause 25. The method of any of clauses 20 to 24, wherein: the mass fraction of the silicon in the composite particles of the anode coatings is in a range of about 15 wt. % to about 40 wt. % of the anode coatings.
Further Clause 26. The method of any of clauses 20 to 25, wherein: the mass fraction of the silicon in the composite particles of the anode coatings is in a range of about 10 wt. % to about 65 wt. % of the anode coatings.
Further Clause 27. The method of any of clauses 20 to 26, wherein: a capacity of the silicon in the composite particles of the anode coatings is in a range of about 500 mAh/g to about 1500 mAh/g.
Further Clause 28. The method of any of clauses 20 to 27, wherein: the copper foil is an electrodeposited copper foil.
Further Clause 29. The method of any of clauses 20 to 28, wherein: a thickness of the copper foil is in a range of about 7 μm to about 12 μm.
Further Clause 30. The method of clause 29, wherein: the thickness of the copper foil is in a range of about 8 μm to about 10 μm.
Further Clause 31. The method of any of clauses 20 to 30, wherein: an average thickness of the anode coating is in a range of about 25 μm to about 75 μm.
Further Clause 32. The method of any of clauses 20 to 31, wherein: the anode coatings comprise graphite.
The forgoing description is provided to enable any person skilled in the art to make or use embodiments of the present invention. It will be appreciated, however, that the present invention is not limited to the particular formulations, process steps, and materials disclosed herein, as various modifications to these embodiments will be readily apparent to those skilled in the art. That is, the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention.
The present Application for Patent claims the benefit of U.S. Provisional Application No. 63/369,746, entitled “LI-ION BATTERY CELL USING IMPROVED ANODE CURRENT COLLECTOR,” filed Jul. 28, 2022, assigned to the assignee hereof, and expressly incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63369746 | Jul 2022 | US |
