Patent Application
20250210641
This invention generally relates to energy storage devices, such as rechargeable batteries. More specifically, the present disclosure provides a molten salt process for the preparation of pre-lithiated lithium manganese-based oxides for use as a cathode active material in an energy storage device.
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Conventional lithium ion cells used in electric vehicles generally incorporate an anode (e.g., graphite, etc.) a cathode (e.g., lithium metal oxide/phosphate, etc.) and an organic electrolyte containing LiPF6. One issue with these conventional cells is that they may cause a fire during a thermal runaway situation, mainly resulting from the interaction between the organic electrolyte and the graphite anode. In addition, since the active graphite material used in the anode exhibits a limited amount of specific capacity (i.e., theoretical=372 mAh/g), the energy density of the cell becomes restricted. In order to improve overall safety and increase energy density, the battery industry has been interested in the development of lithium metal cells that use non-flammable electrolytes, including solid-state electrolytes. However, there are many challenges associated with the commercialization of this type of cell.
One of these challenges is the increased cost of using thin lithium foil as the anode in order to compensate for the lithium lost on the anode-side of the cell during cycling. These thin lithium foils, which are generally ≤20 micrometers (μm), are difficult and expensive to produce because of their softness and the high reactivity of lithium metal.
In order to reduce production costs, it is necessary to avoid using thin lithium metal foil and instead use an “anode-free” design. However, cells with an “anode-free” design generally lack good cycling capacity because there is not any or at least insufficient lithium to continually replenish the lithium lost on the anode-side of the cell. Therefore, a continual need exists for the development of a low-cost, “anode-free” battery that can provide lithium to the anode current collector similar to the use of thin lithium foils in order to compensate for the lithium loss that occurs during cycling.
Pre-lithiated LiMn2O4 (i.e., Li1+xMn2O4 with 0<x≤1.0) may be used as a cathode active material to pair with an anode active material having low Coulombic Efficiency at the 1st cycle. With the recent emergence of new anode active materials, such as Si and SiO, there is an urgent need to use such pre-lithiated cathode active materials.
Three processes are available for the preparation of pre-lithiated LiMn2O4. First, pre-lithiated LiMn2O4 may be prepared through chemical lithiation in an organic solvent using highly reactive butyllithium dissolved in an ether solvent. The use of highly reactive butyllithium with a highly flammable, ether solvent makes this process extremely challenging for commercial utilization. Second, a solid-state process using Lil as a reducing agent at a temperature of about 460° C. may be used to prepare pre-lithiated LiMn2O4. However, the by-product(s) of this reaction, i.e., I2 or LiI3, have low boiling points and can easily be deposited onto the internal surface of the reactor. Thus, this reaction requires the use of frequent washing and extensive cleaning protocols, typically using excessive amounts of acetonitrile to wash/remove the by-product(s) from contaminating the product and for cleaning the reactor. Third, a microwave process may be used to reduce LiMn2O4 with tetraethylene glycol. However, this process needs substantial capital investment in large microwave equipment suitable for large-scale production, which is challenging with respect to technology, cost, and integration considerations. Therefore, there is a need to find an alternative process for the preparation of pre-lithiated lithium manganese-based oxides that is less challenging with respect to commercial viability.
This disclosure generally provides a process for the preparation of a pre-lithiated lithium manganese-based oxide product. This process comprises the steps of:
According to one aspect of the present disclosure, the pre-lithiated lithium manganese-based oxide product may be defined according to the formula F-1
Li1+xMn2−yAyO4, (F-1)
wherein x is within the range of 0<x≤1.0; y is within the range of 0≤y≤0.5; and A is a metal or a combination of metals, selected from the group consisting of Co, Cr, Fe, Ir, Mo, Ni, Pd, Pr, Rh, Ti, V, Ce, Tb, Ru, and Ta. The pre-lithiated lithium manganese-based oxide product may also comprise a spinel crystal structure.
According to another aspect of the present disclosure, when y>0 the metal or combination of metals, A, includes Ni, Co, or Cr. In addition, the lithium manganese-based oxide having a spinel crystal structure in step a) may be either LiMn2O4 or LiMn1.5Ni0.5O4 and the lithium salt may be LiOH and/or a hydrate thereof. The lithium salt and the lithium manganese-based oxide used to form the mixture in step a) may be present in a molar ratio of lithium manganese-based oxide:Li salt that is in range of about 1.0 to about 10.0.
According to another aspect of the present disclosure, the molar ratio of the lithium salt:KOH is in range of about 10.0 to about 0.1. The amount of the lithium salt and the KOH present may be in a ratio that results in all of the lithium salt being in a liquid state at the predetermined temperature.
In the process, the temperature is at least 300° C. Alternatively, the temperature may range from about 350° C. to about 400° C. The mixture is exposed to the temperature for a period of time that ranges from about 10 minutes to about 24 hours.
According to yet another aspect of the present disclosure, the reducing agent may comprise 100% ammonia by volume. Alternatively, the reducing agent may comprises ammonia mixed with an inert gas in a volume ratio of NH3 to inert gas that ranges from 5% to 95%
The collecting of the pre-lithiated lithium manganese-based oxide product may comprise filtering, washing, and drying the pre-lithiated lithium manganese-based oxide product. In addition, the removal of residual KOH may comprise exposing the pre-lithiated lithium manganese-based oxide product to an aqueous solution.
The pre-lithiated lithium manganese-based oxide product may be dried at a temperature that ranges from about 110° C. to about 250° C. In addition, the pre-lithiated lithium manganese-based oxide product may be dried in air, an inert atmosphere, or under vacuum.
According to yet another aspect of the present disclosure, the lithium manganese-based oxide may have a spinel structure doped with at least one additional element in an amount that ranges from 0.1 wt. % to 1.0 wt. % relative to the overall weight of the lithium manganese-based oxide. This at least one additional element may be selected from the group consisting of aluminum (Al), magnesium (Mg), calcium (Ca), boron (B), nitrogen (N), and fluorine (F).
An energy storage device having a positive electrode that comprises a cathode active material that is at least partially formed of the pre-lithiated lithium manganese-based oxide product prepared as previously described and further defined herein. The cathode active material in the energy storage device may be comprised entirely of the pre-lithiated lithium manganese-based oxide product. When desirable, the cathode active material may further comprise one or more conventional cathode active materials selected from the group consisting of pristine LiMn2O4, LiFePO4, LiFexMnyPO4 (i.e., x+y=1.0, 0.1≥x≤0.5, and 0.5≥y≤0.9), lithium nickel manganese cobalt oxides (NCM or Li-NCM), LiCoO2, LiNi0.5Mn1.5O4, and sulfur. The cathode active material may comprise a mass ratio of the pre-lithiated lithium manganese-based oxide to the conventional cathode active material that ranges from about 99:1 to about 10:90.
According to yet another aspect of the present disclosure, a positive electrode for use in an electrochemical cell is provided. This positive electrode may comprise a cathode active material that is at least partially formed of the pre-lithiated lithium manganese-based oxide product prepared as previously described above and as further defined herein.
Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
In order that this disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings. The components in each of the drawings may not necessarily be drawn to scale, but rather emphasis is placed upon illustrating the principles of the invention.
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. It should be understood that throughout the description and drawings, corresponding reference numerals indicate like or corresponding parts and features.
The following description is merely exemplary in nature and is in no way intended to limit the present disclosure or its application or uses. The present disclosure generally provides a method of synthesizing pre-lithiated lithium manganese-based oxides, which may also be referred to as Li1+xMn2−yAyO4 (0<x≤1.0; 0≤y≤0.5; A=metal), without using any organic solvent. More specifically, the pre-lithiated lithium manganese-based oxide is synthesized in a solid-state process from a molten salt system, followed by washing with water.
The method of making and using the pre-lithiated lithium manganese-based oxides according to the teachings contained herein is described throughout the present disclosure using LiMn2O4 as the lithium manganese-based oxide having a spinel crystal structure in order to more clearly illustrate the process. One skilled in the art will understand that the process may utilize other lithium manganese-based oxide materials, such as without limitation LiMn1.5Ni0.5O4, which also exhibit a spinel crystal structure without exceeding the scope of the present disclosure. The pre-lithiated lithium manganese-based oxides formed herein may be used as a pre-lithiated active cathode material in an energy storage device.
The pre-lithiated lithium manganese-based oxides prepared according to the process of the present disclosure comprise the chemical formula shown in F-1,
Li1+xMn2−yAyO4, (F-1)
wherein x is within the range of 0<x≤1.0; y is within the range of 0≤y≤0.5; and A is a metal or a combination of metals, provided the pre-lithiated lithium manganese-based oxide comprises a spinel crystal structure. Alternatively, x is within the range of 0.1≤x≤1.0. Alternatively, y is within the range of 0.1≤y≤0.5. The metal, A, may be selected from the group comprising, consisting of, or consisting essentially of cobalt (Co), chromium (Cr), iron (Fe), iridium (Ir), molybdenum (Mo), nickel (Ni), palladium (Pd), praseodymium (Pr), rhodium (Rh), titanium (Ti), vanadium (V), cerium (Ce), terbium (Tb), ruthenium (Ru), tantalum (Ta), or a combination thereof; alternatively, nickel, cobalt, or chromium; alternatively, nickel. Thus, several examples of a pre-lithiated lithium manganese-based oxide according to formula F-1 that comprise a spinel crystal structure include, but are not limited to, Li1+xMn2O4 (0<x≤1.0) wherein y=0 and Li1+xMn1.5Ni0.5O4 (0<x≤1.0) wherein A=Ni and y=0.5.
The incorporation of greater than 0% up to 100% of an excess amount of lithium in the pre-lithiated active cathode material, alternatively, about 10% to 100%, changes the crystal structure of the lithium manganese-based oxide from spinel to tetragonal, which can be converted back to spinel during cycling. If the lithium content in the pre-lithiated active cathode material is too high (i.e., x>1.0 in formula F-1), a non-tetragonal crystal phase will be formed that cannot be easily converted back to a spinel crystal phase during charging and the reversible capacity of the energy storage device or cell will be reduced.
For the purpose of this disclosure, the terms “about” and “substantially” as used herein with respect to measurable values and ranges refer to the expected variations known to those skilled in the art (e.g., limitations and variability in measurements).
For the purpose of this disclosure, the terms “at least one” and “one or more of” an element are used interchangeably and may have the same meaning. These terms, which refer to the inclusion of a single element or a plurality of the elements, may also be represented by the suffix “(s)” at the end of the element. For example, “at least one metal”, “one or more metals”, and “metal(s)” may be used interchangeably and are intended to have the same meaning.
Referring now to
The mixture is then sintered 10 at a predetermined temperature ranging from at least 226° C. to about 450° C. in the presence of a reducing agent (e.g., NH3) for about 5 minutes to about 36 hours to form the pre-lithiated LiMn2O4 or Li1+xMn2O4 (0<x≤1.0). Water is then added 15 to the pre-lithiated LiMn2O4 in order to dissolve any potassium hydroxide that may still be present, e.g., remove the KOH from the product. The pre-lithiated LiMn2O4 is then collected 20. This collection may comprise one or more of filtering, further washing, and drying. The collection 20 of the pre-lithiated LiMn2O4 may be performed in air or under an inert atmosphere, such as nitrogen (N2) for example. By slightly varying the LiMn2O4/lithium salt ratio used in this process, a Li1+xMn2O4 (0<x≤1.0) product with various x values may be obtained. Since there is no highly flammable, organic solvent used in this process, this process may be considered to be safe.
Still referring to
According to another aspect of the present disclosure, the ammonia may be present as a pure gas or when desirable may be mixed with other gases, including but not limited to nitrogen (N2) and/or argon (Ar), in order to reduce cost and to adjust the length of time associated with heating at the predetermined moderate temperature. When a gas mixture, such as for example, NH3/N2, is used, the NH3 mass ratio may range from less than 100% to 1%; alternatively, from about 99% to about 5%; alternatively, from about 95% to about 10%.
A lithium salt is used to provide the lithium ions in the pre-lithiation process 1. In other words, any lithium salt may be utilized that is capable of lithiating the lithium manganese-based oxide (LiMn2O4, etc.), e.g., forming a brownish powder, in the process of the present disclosure under the conditions defined above and as further described herein. For example, the lithium precursor may include, but not be limited to, LiOH and/or the hydrate thereof, i.e., LiOH*H2O. One skilled in the art will understand that other lithium salts may be used without exceeding the scope of the present disclosure, as long as the lithium salt can form a molten salt solution with KOH within the temperature range as further defined herein. Several salts, such as lithium acetate, lithium nitrate, and lithium carbonate, are excluded from the definition of the lithium precursor because in the process and under the conditions described in the present disclosure, the lithium manganese-based oxide (LiMn2O4, etc.) powder is not lithiated, e.g., the powder appears to remain black in color.
In order to facilitate the lithiation reaction of the lithium manganese-based oxide (LiMn2O4, etc.) in the presence of NH3, the formation of a molten salt solution is desirable in order to dissolve the lithium salt (e.g., LiOH) in the temperature range of at least 226° C. to about 450° C. In the absence of a molten salt solution, the reaction between the lithium salt particles and the lithium manganese-based oxide (LiMn2O4, etc.) particles is limited and the resulting lithiation content added to the lithium manganese-based oxide (LiMn2O4, etc.) will be very low. In order to increase the reaction rate, it is desirable that at least a portion of the lithium salt becomes a liquid, thereby, significantly increasing the contact area between the lithium salt and the lithium manganese-based oxide (LiMn2O4, etc.), thereby, enabling the production of the desired pre-lithiated lithium manganese-based oxide product, e.g., the Li1+xMn2O4 (0<x≤1.0) product.
When LiOH is used as the lithium salt, it is possible to facilitate the transition of solid LiOH into a liquid state by raising the reaction temperature above its melting temperature (i.e., ≥477° C.). However, at this high temperature, at least a portion of the LiMn2O4 is reduced in an ammonia environment to MnO and/or Mn3O4 having manganese in an oxidation state of <+3. This occurrence is demonstrated in
In comparison, at 490° C., the LiOH peak disappeared in the measured XRD pattern as shown in
On the one hand, the reaction temperature should be kept substantially less than 477° C. in order to avoid the formation of MnO and/or Mn3O4 in entirety or as a by-product. A temperature of about 450° C. is low enough that the formation of MnO and/or Mn3O4 is minimized. On the other hand, LiOH or LiOH*H2O should be in a liquid or molten state (melting point ≥477° C.) in order to facilitate or accelerate the lithiation reaction. This technical dilemma is solved by the use of a molten salt system that comprises LiOH or LiOH*H2O along with potassium hydroxide (KOH) as a co-salt. Potassium hydroxide has a melting temperature of 403.9° C.
Referring now to
Referring now to
Although not wanting to be strictly held to theory, it is believed that the reduction reaction that occurred in the second sample (i.e., with the KOH) gives rise to a greater degree of lithiation than the reduction reaction that took place in the first sample because of the formation of a molten salt system. The formation of a liquid from the LiOH in the molten salt system of the second sample increases the interface area between the LiOH and LiMn2O4 particles as compared to the mixture of solid LiOH particles and LiMn2O4 particles present in the first sample. Thus, a greater amount of lithiation occurs in the second sample as compared to the reaction that occurs in the first sample. The KOH is subsequently removed from the formed product by exposure to an aqueous medium.
In summary, according to one aspect of the present disclosure, the molten salt process for the synthesis of pre-lithiated lithium manganese-based oxides uses a lithium salt and KOH as the co-salt. In this process, the amount of the lithium salt, e.g., LiOH or LiOH*H2O, can be adjusted to make the Li1+xMn2−yAyO4 (0<x≤1.0; 0≤y≤0.5; A=metal) with various Li contents. When using various amount of the lithium salt, e.g., LiOH or LiOH*H2O, the amount of KOH is also adjusted accordingly to ensure that at least a portion of the lithium salt melts to form a molten salt solution at the predetermined reaction temperature. This predetermined reaction temperature is less than the melting point of LiOH (i.e., <477° C.) and higher than 226° C. The gas environment to which the molten salt solution is exposed is reducing by nature, e.g., with NH3 used as the reducing reagent. The time-period over which the reaction occurs is determined based on the predetermined temperature that is selected for use.
Referring once again to
The molten salt process used for the preparation of pre-lithiated lithium manganese-based oxides utilizes a predetermined process temperature that ranges from at least 226° C. to less than 477° C., e.g., to about 450° C., alternatively, at least 300° C.; alternatively, from about 300° C. to about 425° C., alternatively, from about 350° C. to about 400° C., provided that the ratio of the lithium salt (e.g., LiOH) and the KOH are selected, such that at least a portion of the lithium salt is a liquid at the predetermined temperature. Alternatively, at least 25% of the lithium salt by weight is a liquid; alternatively, at least 50 wt. % of the lithium salt is a liquid; alternatively, at least 75 wt. % of the lithium salt is a liquid; alternatively, all of the lithium salt is a liquid at the predetermined temperature.
The period of time that the mixture of the lithium manganese-based oxide (LiMn2O4, etc.), lithium salt, and KOH is exposed to the process temperature may range from a few minutes to tens of hours, alternatively, from 5 minutes to about 36 hours, alternatively from about 10 minutes to about 24 hours, alternatively, from about 14 hour to about 24 hours. Generally, the time-period will be shorter with the use of a higher temperature.
In general, the molar ratio between the lithium manganese-based oxide (LiMn2O4, etc.) and the lithium salt (e.g., LiMn2O4:LiOH) used in the process of the present disclosure is in the range of 1.0 to 10.0. The molar ratio of the lithium precursor to the lithium manganese-based oxide (e.g., LiOH:LiMn2O4) may alternatively, range from about 2.0 to about 9.0, alternatively, from about 3.0 to about 8.0, alternatively, from about 4.0 to about 7.0.
The lithium manganese-based oxide (LiMn2O4, etc.) that is utilized as a starting material in the reaction process according to the present disclosure may be prepared according to one or more separate processes. Thus, the lithium manganese-based oxide (LiMn2O4, etc.) may exhibit various morphologies, properties, and variations in overall composition. For example, the lithium manganese-based oxide (LiMn2O4, etc.), without limitation, may exhibit a spherical shape with an average particle size (D50) that is in the range of about 0.1 micrometer (μm) to about 100 micrometers (μm), alternatively, about 1 μm to about 30 μm. Alternatively, the lithium manganese-based oxide (LiMn2O4, etc.) may exhibit an irregular shape with an average particle size (D50) that is in a similar range as described above without exceeding the scope of the present disclosure.
When desirable, the lithium manganese-based oxide (LiMn2O4, etc.) may also be doped with one or more additional metal and/or nonmetal elements or coated with various compositions containing such additional metal and/or nonmetal elements. More specifically, the lithium manganese-based oxide (LiMn2O4, etc.) may be doped or coated with at least one element selected from a group of aluminum (Al), magnesium (Mg), calcium (Ca), boron (B), nitrogen (N), and fluorine (F). The additional metal or nonmetal elements may be present in an amount ranging from 0.1 wt. % to about 10 wt. %, alternatively, from about 1 wt. % to about 5 wt. % relative to the overall weight of the LiMn2O4.
Once the reaction is completed, the pre-lithiated lithium manganese-based oxide product, i.e., the Li1+xMn2O4 (with 0<x≤1.0) product may be collected via various or different routes. According to one route, the product may be collected by filtering and washing the as-collected wet material with an organic solvent or water. The washed material is then dried in air to remove any liquid. According to another route, the product may be collected by heating the as-collected wet material in an oven. According to yet another route, the product may be collected by heating the as-collected wet material in air at a temperature ≥110° C., alternatively, about 200° C. In yet another route, the product may be collected by heating the as-collected wet material in an inert gas environment at a temperature that is in the range of 100° C. to 250° C., alternatively, about 200° C. The as-prepared pre-lithiated lithium manganese-based oxide product is relatively stable in the presence of water or moisture. Thus, water or organic solvents having a relatively high moisture level may be used for the washing of the pre-lithiated product. All of the collection processes may be performed in air without the need to restrict or control humidity.
The pre-lithiated lithium manganese-based oxide product may be used alone as the active cathode material or it may be used in combination with another active cathode material. Several examples of such conventional active cathode materials include, without limitation, pristine LiMn2O4, LiFePO4, LiFexMnyPO4 (i.e., x+y=1.0, 0.1≥x≤0.5, and 0.5≥y≤0.9), lithium nickel manganese cobalt oxides (NCM or Li-NCM), LiCoO2, LiNi0.5Mn1.5O4, and sulfur. When the pre-lithiated cathode material is used in combination with another active cathode material, the mass ratio of the pre-lithiated material to the other, e.g., conventional, material may range from about 99:1 to about 10:90 depending on the application requirements. Alternatively, the mass ratio for pre-lithiated material to the conventional or other active material is greater than 100:0 and less than or equal to 10:90; alternatively, between about 90:10 and 20:80; alternatively, in the range of about 80:20 to about 30:70; alternatively, 70:30 to 40:60; alternatively, about 60:40 to about 50:50; alternatively between greater than 100:0 and less than or equal to 51:49.
The specific examples provided in this disclosure are given to illustrate various embodiments of the invention and should not be construed to limit the scope of the disclosure. The embodiments have been described in a way which enables a clear and concise specification to be written, but it is intended and will be appreciated that embodiments may be variously combined or separated without parting from the invention. For example, it will be appreciated that all preferred features described herein are applicable to all aspects of the invention described herein.
Synthesis of Pre-Lithiated Lithium Manganese-Based Oxide Product—The pre-lithiated lithium manganese-based oxide product as described in
The mixture was then heated in flowing NH3 at 350° C. overnight (˜10 hours) to form the pre-lithiated LiMn2O4. After cooling the pre-lithiated LiMn2O4 down to room temperature, the brownish or greenish powder was soaked in water for several minutes and then collected by filtering, rinsing with additional water, and finally drying in an oven. The dried powder was characterized by measuring the x-ray diffraction (XRD) pattern (see
Preparation and Testing of an Electrode with Pre-Lithiated Lithium Manganese-Based Oxide Product—To make a pre-lithiated electrode, a composition comprising 97 wt. % of the pre-lithiated active cathode powders (Li1+xMn2O4) prepared above, 1.5 wt. % carbon nanotubes (CNT), and 1.5 wt. % polyvinylidene fluoride (PVDF) was formed by mixing the components together to form a mixed composition. This mixed composition was then coated onto an aluminum foil and calendared to form an electrode. Thus, the coated electrode comprised a mass ratio of active material/CNT/PVDF of 97/1.5/1.5.
The coated electrode was then tested in an “anode-free” single-layer pouch cell against a Cu foil wherein the voltage ranged from 3.0 V to 4.25 V at about C/10. The cell was clamped together with two clips. The charge/discharge curves at the 1st cycle for the cell containing the pre-lithiated electrode was measured and the 1st Coulombic Efficiency (CE), as well as the 1st discharge capacity determined. Referring now to
During operation, it is desirable that the Coulombic or current efficiency and the discharge capacity exhibited by the battery remains relatively constant. The Coulombic efficiency describes the charge efficiency by which electrons are transferred within the battery. The discharge capacity represents the amount of charge that may be extracted from a battery. As used herein, Coulombic Efficiency (CE) is defined as the ratio of the discharge capacity (mAh/g) to the charge capacity (mAh/g). For each electrode, the CE is generally less than 100%, in particular, for the 1st charge/discharge cycle because of irreversible capacity loss that occurs due to the occurrence of side reactions. The 1st cycle CE of an “anode-free” cell using these pre-lithiated cathode active materials may be <100%, alternatively, <90%; alternatively, <80%; alternatively, <70%; alternatively, <60%; and alternatively, about 50% as controlled by the amount of the lithium incorporated into the active cathode materials via the use of the pre-lithiation reaction. In this present disclosure, a lower 1st cycle CE, corresponds to an increase in the amount of lithium added or deposited within the structure of the active cathode material.
According to another aspect of the present disclosure, an energy storage device, such as a rechargeable battery cell, is provided that utilizes the pre-lithiated lithium manganese-based oxide product prepared according to the process described above as a cathode active material. One example of an energy storage device is a rechargeable lithium cell that includes an “anode-free” design as shown in
Still referring to
The current collector 57 in the positive 55 electrode may be made of any metal known in the art for use in an electrode of a lithium battery, such as for example, without limitation, aluminum, titanium, stainless steel, nickel, copper, carbon, zinc, gallium, silver, and combinations or alloys formed therefrom. The current collector 67 used in the negative electrode 65 may be a metallic foil that does not react with lithium ions. Several examples of such metallic foils may include, but not be limited to, Cu, Fe, Ti, Ni, Mo, W, Zr, Mn, carbon, and lithium metal alloys. Alternatively, the metallic foil for the current collector 67 of the negative electrode 65 comprises Cu, Fe, Ni, or a mixture or alloy thereof.
As used herein a “battery cell” or “cell” refers to the basic electrochemical unit of a battery. In comparison, a “battery” or “battery pack” refers to a collection of cell(s), e.g., one or more cells, and includes a housing, electrical connections, and possibly electronics for control and protection.
According to yet another aspect of the present disclosure, one or more of the anode-free cells comprising the prelithiated active cathode material prepared according to the process of the present disclosure may be combined to form a larger capacity battery or battery pack, such as a lithium-ion secondary battery used in an electric vehicle (EV). The one or more cells may be incorporated in series, in parallel, or in a combination thereof in order to form the battery or battery pack. One skilled in the art will also appreciate that in addition to using the “anode-free” cells in a lithium-ion secondary battery, the same principles may be used to encompass or encase one or more cells into a housing for use in another application.
The housing may be constructed of any material known for such use in the art and be of any desired geometry required or desired for a specific application. For example, lithium-ion batteries generally are housed in three different main form factors or geometries, namely, cylindrical, prismatic, or soft pouch. The housing for a cylindrical battery may be made of aluminum, steel, or the like. Prismatic batteries generally comprise a housing that is rectangular shaped rather than cylindrical. Soft pouch housings may be made in a variety of shapes and sizes. These soft housings may be comprised of an aluminum foil pouch coated with a plastic on the inside, outside, or both. The soft housing may also be a polymeric-type encasing. The polymer composition used for the housing may be any known polymeric materials that are conventionally used in lithium-ion secondary batteries. One specific example, among many, include the use of a laminate pouch that comprises a polyolefin layer on the inside and a polyamide layer on the outside. A soft housing needs to be designed such that the housing provides mechanical protection for the “anode-free” cells present in the battery.
Within this specification, embodiments have been described in a way which enables a clear and concise specification to be written, but it is intended and will be appreciated that embodiments may be variously combined or separated without parting from the invention. For example, it will be appreciated that all preferred features described herein are applicable to all aspects of the invention described herein.
Those skilled-in-the-art, in light of the present disclosure, will appreciate that many changes can be made in the specific embodiments which are disclosed herein and still obtain alike or similar result without departing from or exceeding the spirit or scope of the disclosure. One skilled in the art will further understand that any properties reported herein represent properties that are routinely measured and can be obtained by multiple different methods. The methods described herein represent one such method and other methods may be utilized without exceeding the scope of the present disclosure.
The foregoing description of various forms of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Numerous modifications or variations are possible in light of the above teachings. The forms discussed were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various forms and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2023/018895 | 4/18/2023 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63337665 | May 2022 | US |
