Patent Application
20250149546
This application claims the benefit of Chinese Patent Application No. 202311458786.7 filed on Nov. 3, 2023. The entire disclosure of the application referenced above is incorporated herein by reference.
The information provided in this section is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
The present disclosure relates to battery cells, and more particularly to anode electrodes including a co-sputtered silicon-metal composite layer for battery cells.
Electric vehicles (EVs) such as battery electric vehicles (BEVs), hybrid vehicles, and/or fuel cell vehicles include one or more electric machines and a battery system including one or more battery cells, modules, and/or packs. A power control system is used to control charging and/or discharging of the battery system during charging and/or driving.
A battery cell includes C cathode electrodes including a cathode active material layer arranged on a cathode current collector, A anode electrodes including an anode active material layer arranged on an anode current collector, and S separators, where A, C and S are integers greater than one. The anode active material layer comprises silicon and a metal that are co-sputtered. The metal is different than the silicon.
In other features, the metal is selected from a group consisting of titanium (Ti), zirconium (Zr), a Group 4 (IVb) metal, vanadium (V), niobium (Nb), and a Group 5 (Vb) metal.
In other features, the metal comprises titanium. The silicon comprises 30 at % to 99.5 at % of the anode active material layer, and the titanium comprises 0.5 at % to 70 at % of the anode active material layer. The anode current collector has a surface roughness in a range from 2 μm to 12 μm. The anode active material layer includes a plurality of columns. The plurality of columns have a height in a range from 1.0 μm to 80 μm and width in a range from 1.0 μm to 80 μm.
In other features, the anode active material layer is planar and has a thickness in a range from 2 μm to 80 μm. The anode active material layer is planar and includes a plurality of convex portions. A thickness of the anode active material layer is in a range from 2 μm to 80 μm. A height of the plurality of convex portions is in a range from 0.1 μm to 20 μm.
In other features, the anode active material layer is planar and includes a plurality of concave portions. A thickness of the anode active material layer is in a range from 2 μm to 80 μm. A depth of the plurality of concave portions is in a range from 0.1 μm to 20 μm.
In other features, the cathode active material layer includes cathode active material selected from a group consisting of a rock salt layered oxide, a spinel, a polyanion cathode, an olivine cathode, a lithium transition-metal oxide, a surface-coated cathode material, a doped cathode material, and combinations thereof. The cathode active material layer includes a solid electrolyte selected from a group consisting of sulfide-based solid electrolyte, a halide-based solid electrolyte, and a hydride-based solid electrolyte. A porosity of the anode active material layer is in a range from 5% to 70%.
A battery cell includes C cathode electrodes including a cathode active material layer arranged on a cathode current collector, A anode electrodes including an anode active material layer arranged on an anode current collector, and S separators, where A, C and S are integers greater than one. The anode active material layer comprises silicon and titanium that are co-sputtered, the silicon comprises 30 at % to 99.5 at % of the anode active material layer, and the titanium comprises 0.5 at % to 70 at % of the anode active material layer.
In other features, the anode active material layer includes a plurality of columns having a height in a range from 1.0 μm to 80 μm and a width in a range from 1.0 μm to 80 μm. The anode active material layer is planar and has a thickness in a range from 2 μm to 80 μm.
In other features, the anode active material layer is planar and includes a plurality of convex portions. A thickness of the anode active material layer is in a range from 2 μm to 80 μm. A height of the plurality of convex portions is in a range from 0.1 μm to 20 μm.
In other features, the anode active material layer is planar and includes a plurality of concave portions. A thickness of the anode active material layer is in a range from 2 μm to 80 μm. A depth of the plurality of concave portions is in a range from 0.1 μm to 20 μm.
In other features, the cathode active material layer includes cathode active material selected from a group consisting of a rock salt layered oxide, a spinel, a polyanion cathode, an olivine cathode, a lithium transition-metal oxide, a surface-coated cathode material, a doped cathode material, and combinations thereof. The cathode active material layer includes a solid electrolyte selected from a group consisting of sulfide-based solid electrolyte, a halide-based solid electrolyte, and a hydride-based solid electrolyte.
In other features, a porosity of the anode active material layer is in a range from 5% to 70%.
Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims, and the drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.
The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:
In the drawings, reference numbers may be reused to identify similar and/or identical elements.
While battery cells according to the present disclosure are shown in the context of electric vehicles, the battery cells can be used in stationary applications and/or other applications.
Silicon has emerged as a promising alternative to graphite-based anode electrodes for all-solid-state battery (ASSB) cells due to its environmental benignity, reasonable electrochemical potential (˜0.3 V vs Li/Li+), and high theoretical capacity (e.g., 4200 mAh/g for Li4·4Si). However, Si anode electrodes have large volumetric expansion (>300%) with high mechanical stress during charging, which causes cracking and/or pulverization of the Si anode electrodes and then rapid capacity fading during cycling. In addition, the rate performance of solid-state Si anode also needs to be enhanced.
An advanced silicon anode electrode for ASSB cells includes a co-sputtered silicon-metal layer (e.g., a silicon-titanium (Si—Ti) layer). The metal comprises titanium (Ti). Zirconium (Zr), other Group 4 (IVb) metals, vanadium (V), niobium (Nb), and other Group 5 (Vb) metals. The metal atoms in the Si-metal layer function as an atomic binding agent to grasp Si atoms together during lithiation and stabilize the Si structure. The metal atoms reduce Si volumetric expansion and improve the cycle life of the ASSB cells. The metal atoms also increase electrical conductivity of the Si anode electrode and enhance power capability.
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The A anode electrodes 40-1, 40-2, . . . , and 40-A include anode active material layers 42 arranged on one or both sides of the anode current collectors 46. The anode active material of the A anode electrodes 40-1, 40-2, . . . , and 40-A include the co-sputtered Si-metal layer as will be described further below.
In some examples, the cathode active material layers 24 are electrodes that are arranged adjacent to (or attached to) the cathode current collectors 26, respectively. In some examples, the cathode active material layers 24 comprise coatings including one or more active materials, one or more conductive fillers/additives, and/or one or more binder materials that are applied to the current collectors.
In some examples, the cathode current collectors 26 and/or the anode current collectors 46 comprise metal foil, metal mesh, and/or expanded metal. In some examples, the cathode current collectors 26 are made of one or more materials selected from a group consisting of aluminum, stainless steel, brass, bronze, zinc, and/or alloys thereof. In some examples, the anode current collectors 46 are made of one or more materials selected from a group consisting of copper or stainless steel. External tabs 28 and 48 are connected to the current collectors of the cathode electrodes and anode electrodes, respectively, and can be arranged on the same or opposite sides of the battery cell stack 12. The external tabs 28 and 48 are connected to terminals of the battery cells.
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In some examples, a surface of the anode current collector 46 is roughened to strengthen adhesion with Si (or a low roughness surface). In some examples, the anode current collector 46 has a thickness in a range from 4 μm to 30 μm. In some examples, the anode current collector 46 is approximately flat (Rz less than 2 μm). In other examples, the surface roughness Rz is in a range from 2 to 12 μm. In some examples, the anode current collector 46 comprises copper, stainless steel, nickel, iron, titanium. In some examples, the anode current collector 46 includes copper having a thickness of 16 μm and a surface roughness Rz of 8 μm.
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During deposition, a process gas mixture such as argon (Ar) from a gas source 322 is introduced into the processing chamber 310 while AC and/or DC power are supplied. In some examples, a mass flow controller 324 and a valve 326 are used to meter the process gas from the gas source 322. A throttle valve 334 and/or pump 338 may be used to control pressure within the processing chamber 310 and/or to evacuate reactants from the processing chamber 310. DC sources 344-1, 344-2, . . . (also referred to as DC sources 344) supply DC voltage to the magnetron cathodes 316. An AC source 346 supplies AC voltage to the magnetron cathodes 316. In some examples, the anode current collector 46 and the substrate support 314 are rotated during co-sputtering (as shown in
During deposition, target material (Si and the metal) is ejected from the targets 318 and deposited on the anode current collector 46. Material is also sputtered from an exposed surface of the anode current collector 46. In some examples, the Si-metal layer is deposited using pulsed DC magnetron sputtering in an argon (Ar) atmosphere.
In some examples, the DC source 344 supplies DC voltage in a range from 200V to 800V (e.g., 450V). In some examples, cathode power from the AC source 346 is supplied to the Si targets is in a range from 2 to 30 KW (e.g., 6 kW) at a frequency in a range from 20 kHz to 200 kHz. In some examples, cathode power from the AC source 346 is supplied to the metal targets is in a range from 0.1 to 30 KW (e.g., 0.7KW) at a frequency in a range from 20 kHz to 200 kHz.
Depositing the Si-metal layer is solvent-free as compared to wet processes compared to wet-coating sulfide-based electrodes (there is no need for H2O/O2 control). In addition, the anode electrodes have improved mechanical flexibility.
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In some examples, the cathode active material layer of the cathode electrodes comprises cathode active material and optionally includes one or more of a solid electrolyte, a conductive additive, and/or a binder. In some examples, the cathode active material comprises 30 wt % to 98 wt %. If used, the solid electrolyte comprises 5 wt % to 50 wt %. If used, the conductive additive comprises 0.1 wt % to 30 wt %. If used, the binder comprises 0.1 wt % to 20 wt %. In some examples, the cathode electrode has a thickness in a range from 10 μm to 500 μm (e.g., 40 μm).
In some examples, the cathode active material is selected from a group consisting of rock salt layered oxides, spinel, polyanion cathode, olivine cathode, other lithium transition-metal oxides, surface-coated and/or doped cathode materials, and low voltage cathode materials.
Examples of the rock salt layered oxides include LiCoO2, LiNixMnyCo1−x−yO2, LiNixMnyAl1−x−yO2, LiNixMn1−xO2, Li1+xMO2. Examples of spinel include LiMn2O4, LiNi0.5Mn1.5O4. Examples of polyanion cathode include LiV2(PO4)3. Examples of olivine include LiFePO4 and LiMnxFe1−xPO4. Examples of surface-coated and/or doped cathode materials include LiNbO3-coated LiMn2O4, Li2ZrO3 or Li3PO4-coated LiNixMnyCo1−x−yO2, and Al-doped LiMn2O4. Examples of low voltage cathode material include lithiated metal oxide/sulfide (e.g., LiTiS2), lithium sulfide, and sulfur.
In some examples, the solid electrolyte is selected from a group consisting of a sulfide-based solid electrolyte, a halide-based solid electrolyte, and a hydride-based solid electrolyte. In some examples, the sulfide-based solid electrolyte is selected from a group consisting of pseudobinary sulfide, pseudoternary sulfide, and pseudoquaternary sulfide. Examples of pseudobinary sulfide include Li2S—P2S5 system (Li3PS4, Li7P3S11 and Li9.6P3S12), Li2S—SnS2 system (Li4SnS4), Li2S—SiS2 system, Li2S—GeS2 system, Li2S—B2S3 system, Li2S—Ga2S3 system, Li2S—P2S3 system, and Li2S—Al2S3 system.
Examples of pseudoternary sulfide include Li2O—Li2S—P2S5 system, Li2S—P2S5—P2O5 system, Li2S—P2S5—GeS2 system (Li3.25Ge0.25P0.75S4 and Li10GeP2S12), Li2S—P2S5—LiX(X═F, Cl, Br, I) system (Li6PS5Br, Li6PS5Cl, L7P2S8I and Li4PS4I), Li2S—As2S5—SnS2 system (Li3.833Sn0.833AS0.166S4), Li2S—P2S5—Al2S3 system, Li2S—LiX—SiS2 (X═F, Cl, Br, I) system, 0.4LiI·0.6Li4SnS4 and Li11Si2PS12. Examples of pseudoquaternary sulfide include Li2O—Li2S—P2S5—P2O5 system, Li9.54Si1.74P1.44S11.7Cl0.3, Li7P2.9Mn0.1S10.7I0.3 and Li10.35[Sn0.27Si1.08]P1.65S12.
Examples of halide-based solid electrolyte include Li3YCl6, Li3InCl6, Li3YBr6, LiI, Li2CdCl4, Li2MgCl4, Li2Cdl4, Li2Znl4, Li3OCl. Examples of hydride-based solid electrolyte include LiBH4, LiBH4—LiX(X═Cl, Br or I), LiNH2, Li2NH, LiBH4—LINH2, Li3AlH6. In other examples, the solid electrolyte comprises an electrolyte having low grain-boundary resistance.
In some examples, the conductive additive is selected from a group consisting of carbon black, graphite, graphene, graphene oxide, Super P, acetylene black, carbon nanofibers, carbon nanotubes, and other electronically conductive additives.
In some examples, the binder comprises polytetrafluoroethylene (PTFE), sodium carboxymethyl cellulose (CMG), styrene butadiene rubber (SBR), poly(vinylidene fluoride) (PVDF), nitrile butadiene rubber (NBR), styrene ethylene butylene styrene copolymer (SEBS), styrene butadiene styrene copolymer (SBS), or other suitable binder.
The foregoing description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims. It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure. Further, although each of the embodiments is described above as having certain features, any one or more of those features described with respect to any embodiment of the disclosure can be implemented in and/or combined with features of any of the other embodiments, even if that combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and permutations of one or more embodiments with one another remain within the scope of this disclosure.
Spatial and functional relationships between elements (for example, between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including “connected,” “engaged,” “coupled,” “adjacent,” “next to,” “on top of,” “above,” “below,” and “disposed.” Unless explicitly described as being “direct,” when a relationship between first and second elements is described in the above disclosure, that relationship can be a direct relationship where no other intervening elements are present between the first and second elements, but can also be an indirect relationship where one or more intervening elements are present (either spatially or functionally) between the first and second elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.”
In the figures, the direction of an arrow, as indicated by the arrowhead, generally demonstrates the flow of information (such as data or instructions) that is of interest to the illustration. For example, when element A and element B exchange a variety of information but information transmitted from element A to element B is relevant to the illustration, the arrow may point from element A to element B. This unidirectional arrow does not imply that no other information is transmitted from element B to element A. Further, for information sent from element A to element B, element B may send requests for, or receipt acknowledgements of, the information to element A.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2023114587867 | Nov 2023 | CN | national |
