Method for modulating lithium wettability of anode current collectors using plasma surface modification

Abstract

The invention relates to a method for modulating lithium wettability of an anode current collector using plasma surface modification. A method for manufacturing an anode electrode includes supplying an anode current collector; coating a first portion of the anode current collector with a precursor coating; coating a second portion of the anode current collector without the precursor coating; treating the anode current collector with a plasma to at least one of reduce lithium wettability of the first portion and increase lithium wettability of the second portion; and coating the anode current collector with lithium metal to form an anode active material layer.

Description

Technical Field

[0001] The present disclosure relates to battery cells and, more particularly, to methods for making anode electrodes. Background Art

[0002] The information provided in this section is for the purpose of generally introducing the background of the present disclosure. No admission is made, either explicitly or implicitly, that the work of the presently named inventors described in this section is prior art to the present disclosure, nor is it admitted that the work is prior art to the present disclosure, as described in this section, which may not otherwise be identified as prior art at the time of filing.

[0003] Electric vehicles (EVs), such as battery electric vehicles (BEVs), hybrid electric vehicles and / or fuel cell vehicles, include one or more motors and a battery system including one or more battery cells, modules and / or packs. A power control module is used to control the charging and / or discharging of the battery system during charging and / or driving.

[0004] The battery cell includes one or more cathode electrodes, an anode electrode and a separator. The cathode electrode includes a cathode active material layer (including cathode active material) disposed on a cathode current collector. The anode electrode includes an anode active material layer (including anode active material) disposed on an anode current collector. Summary of the invention

[0005] A method for manufacturing an anode electrode includes supplying an anode current collector; coating a first portion of the anode current collector with a lithium-philic coating; not coating a second portion of the anode current collector with the lithium-philic coating; treating the anode current collector with plasma to reduce at least one of the lithium wettability of the first portion and increasing the lithium wettability of the second portion; and coating the anode current collector with lithium metal to form an anode active material layer.

[0006] In other features, the first portion corresponds to an edge of the anode current collector. Coating the anode current collector with lithium metal includes passing the anode current collector through a bath including molten lithium metal. In other features, a gas is directed to the anode current collector after the anode current collector passes through the bath to remove at least one of excess molten lithium metal and improve thickness uniformity of the molten lithium metal.

[0007] In other features, the gas is selected from molecular nitrogen and argon.

[0008] The method includes injecting a secondary gas into the plasma. Coating the anode current collector with the lithium metal includes supplying molten lithium metal onto the anode current collector using a coating device. Coating the anode current collector with the lithium metal includes supplying lithium metal powder onto the anode current collector at intervals using an engraved roller including a plurality of cavities; and heating the lithium metal powder to melt the lithium metal powder.

[0009] In other features, the method includes heating the engraving roller to melt the lithium metal powder. Heating the lithium metal powder includes heating using at least one of plasma, infrared heating, a furnace, an oven, and induction heating. The method includes supplying a plasma gas for the plasma, the plasma gas including one or more elements selected from nitrogen (N), phosphorus (P), oxygen (O), halogens, and / or combinations thereof.

[0010] In other features, the method includes supplying a plasma gas for the plasma, the plasma gas selected from molecular nitrogen (N2), ammonia (NH3), an amine compound, a silazane, and / or a combination thereof. The method includes treating the anode current collector with an oxygen plasma before coating a first portion of the anode current collector with the lithium-philic coating.

[0011] In other features, the anode current collector is made of stainless steel, and further includes heating a second portion of the anode current collector to a temperature of 250° C. to 400° C. before treating the anode current collector with plasma. The method includes cooling a first portion of the anode current collector to a temperature of 10° C. to 25° C. before treating the anode current collector with plasma.

[0012] A method for manufacturing an anode electrode includes supplying an anode current collector; coating a first portion of the anode current collector with a lithium-philic coating, wherein the first portion corresponds to an edge of the anode current collector; not coating a second portion of the anode current collector with the lithium-philic coating, wherein the second portion corresponds to a position where an anode active material layer of the anode current collector is arranged; and treating the anode current collector with a plasma to reduce the lithium wettability of the first portion and increase the lithium wettability of the second portion. The plasma gas used for the plasma includes one or more elements selected from molecular nitrogen (N2), ammonia (NH3), an amine compound, a silazane and / or a combination thereof. The method includes coating the anode current collector with lithium metal to form the anode active material layer by passing the anode current collector through a bath including molten lithium metal.

[0013] In other features, the method includes directing a gas to the anode current collector after the anode current collector passes through the bath to remove excess molten lithium metal and improve thickness uniformity of the molten lithium metal, wherein the gas is selected from molecular nitrogen and argon. The method includes injecting a secondary gas into the plasma. The method includes treating the anode current collector with an oxygen plasma prior to coating a first portion of the anode current collector with the lithiophilic coating.

[0014] The present invention discloses the following scheme:

[0015] Scheme 1. A method for manufacturing an anode electrode, comprising:

[0016] supplying an anode current collector;

[0017] coating a first portion of the anode current collector with a precursor coating;

[0018] not coating a second portion of the anode current collector with the precursor coating;

[0019] treating the anode current collector with a plasma to at least one of reduce lithium wettability of the first portion and increase lithium wettability of the second portion; and

[0020] The anode current collector is coated with lithium metal to form an anode active material layer.

[0021] Option 2. The method according to Option 1, wherein the first portion corresponds to an edge of the anode current collector.

[0022] Option 3. A method according to Option 1, wherein coating the anode current collector with lithium metal comprises passing the anode current collector through a bath comprising molten lithium metal.

[0023] Option 4. The method according to Option 3 further includes introducing a gas to the anode current collector after the anode current collector passes through the bath to remove excess molten lithium metal and improve at least one of the thickness uniformity of the molten lithium metal.

[0024] Option 5. A method according to Option 4, wherein the gas is selected from molecular nitrogen and argon.

[0025] Option 6. The method according to Option 1 further includes injecting a secondary gas into the plasma, wherein the secondary gas includes at least one element that forms a bond on the surface of the anode current collector to increase wettability to lithium.

[0026] Option 7. The method according to Option 1, wherein coating the anode current collector with the lithium metal comprises supplying molten lithium metal onto the anode current collector using a coating device.

[0027] Option 8. The method according to Option 1, wherein coating the anode current collector with the lithium metal comprises:

[0028] supplying lithium metal powder onto the anode current collector at intervals using an engraved roller including a plurality of cavities; and

[0029] The lithium metal powder is heated to melt the lithium alloy powder.

[0030] Option 9. The method according to Option 8 further includes heating the engraving roller to melt the lithium metal powder.

[0031] Option 10. A method according to Option 8, wherein heating the lithium metal powder includes heating using at least one of plasma, infrared heating, a furnace, an oven, and induction heating.

[0032] Option 11. The method according to Option 1 further includes supplying a plasma gas for the plasma, wherein the plasma gas includes one or more elements selected from nitrogen (N), phosphorus (P), oxygen (O), halogens and / or combinations thereof.

[0033] Option 12. The method according to Option 1 further includes supplying a plasma gas for the plasma, wherein the plasma gas is selected from molecular nitrogen (N2), ammonia (NH3), an amine compound, silazane and / or a combination thereof.

[0034] Option 13. The method according to Option 1, further comprising treating the anode current collector with a plasma comprising molecular oxygen before coating the first portion of the anode current collector with the precursor coating.

[0035] Option 14. The method according to Option 1, wherein the anode current collector is made of stainless steel, and further comprises heating a second portion of the anode current collector to a temperature of 250° C. to 400° C. before treating the anode current collector with plasma.

[0036] Embodiment 15. The method according to Embodiment 14, further comprising cooling a first portion of the anode current collector to a temperature of 10° C. to 25° C. before treating the anode current collector with plasma.

[0037] Option 16. The method according to Option 3 further comprises exposing a surface of the molten lithium in the bath to plasma to reduce the surface tension of the molten lithium in the bath.

[0038] Embodiment 17. A method for manufacturing an anode electrode, comprising:

[0039] supplying an anode current collector;

[0040] coating a first portion of the anode current collector with a precursor coating, wherein the first portion corresponds to an edge of the anode current collector;

[0041] not coating a second portion of the anode current collector with the precursor coating, wherein the second portion corresponds to a location where an anode active material layer of the anode current collector is disposed;

[0042] treating the anode current collector with plasma to at least one of reduce lithium wettability of the first portion and increase lithium wettability of the second portion,

[0043] wherein the plasma gas used for the plasma comprises one or more elements selected from molecular nitrogen (N2), ammonia (NH3), amine compounds, silazane and / or combinations thereof; and

[0044] The anode current collector is coated with lithium metal to form the anode active material layer by passing the anode current collector through a bath including molten lithium metal.

[0045] Option 18. A method according to Option 17, further comprising introducing a gas to the anode current collector after the anode current collector passes through the bath to remove excess molten lithium metal and improve at least one of the thickness uniformity of the molten lithium metal, wherein the gas is selected from molecular nitrogen and argon.

[0046] Option 19. The method according to Option 17 further comprises injecting a secondary gas into the plasma.

[0047] Option 20. The method according to Option 17, further comprising treating the anode current collector with oxygen plasma before coating the first portion of the anode current collector with the precursor coating.

[0048] Further areas of applicability of the present disclosure will become apparent from the detailed description, claims and drawings.The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The present disclosure will be more fully understood from the detailed description and accompanying drawings, in which:

[0050] Figure 1 is a side cross-sectional view of a battery cell including one or more anode electrodes according to the present disclosure;

[0051] Figure 2A , 2B , 2C and 2D are plan views showing a method of treating an anode current collector with a lithium-philic coating and plasma and coating the anode current collector with molten lithium according to the present disclosure;

[0052] Figure 3 is a functional block diagram of an example of a method of adjusting the lithium wettability of an anode current collector and coating an anode electrode with molten lithium from a bath using a lithiophilic coating and plasma according to the present disclosure;

[0053] Figure 4 is a functional block diagram of an example of a method of adjusting lithium wettability of an anode current collector using a lithiophilic coating and plasma and coating an anode electrode with molten lithium using a coating apparatus according to the present disclosure;

[0054] Figure 5A , 5B and 5C is a functional block diagram of an example of a method of adjusting lithium wettability of an anode current collector using a lithiophilic coating and plasma and coating an anode electrode with molten lithium using an engraved roller according to the present disclosure; and

[0055] Figure 6 and 7 is a functional block diagram of an example of a method for adjusting lithium wettability by coating an anode current collector, cooling a first portion and preheating a second portion, plasma modifying, and then coating with molten lithium according to the present disclosure.

[0056] In the drawings, reference numerals may be repeated to designate similar and / or identical elements. DETAILED DESCRIPTION

[0057] Although battery cells according to the present disclosure are shown in the context of electric vehicles and / or testing of battery cells for electric vehicles, the battery cells may be used in stationary applications and / or other applications.

[0058] Battery cells with lithium metal anode electrodes can be used for high-power batteries for electric vehicles. Several fabrication methods for lithium metal anode electrodes using molten lithium as the active material are under development. However, the poor wettability of molten lithium on the anode current collector prevents uniform coating.

[0059] The present disclosure relates to a plasma surface modification for modifying the surface of an anode current collector to adjust the wettability of the anode current collector to molten lithium. The manufacturing method described herein is simple, cost-effective, and can be integrated into a roll-to-roll (R2R) process. The wettability of molten lithium can be adjusted by using different lithium-philic coatings and / or plasma gas modification.

[0060] In some examples, a first portion of the anode current collector (e.g., the edge where the outer pole ear is arranged) is coated with a lithium-philic coating to reduce the wettability of the first portion to molten lithium (e.g., to achieve a sharp edge and maintain a clean surface for subsequent processing). The second portion of the anode current collector corresponds to a position where the anode active material layer is not coated. Plasma is directed to the surface of the anode current collector to cure the lithium-phobic coating on the first portion to reduce wettability and / or modify the surface of the second portion to increase wettability. After coating with the lithium-philic coating and plasma modification, the second portion is coated with molten lithium, which forms an improved bond due to increased wettability. In contrast, the first portion remains free of molten lithium to provide a clean surface for notching and welding of the outer pole ear.

[0061] Reference now Figure 1 The battery cell 10 includes C cathode electrodes 20, A anode electrodes 40, and S separators 32 arranged in a predetermined order in the battery cell stack 12, where C, S, and A are integers greater than zero. The C cathode electrodes 20-1, 20-2, ..., and 20-C include a cathode active material layer 24 disposed on one or both sides of a cathode current collector 26.

[0062] During charge / discharge, the A anode electrodes 40 and the C cathode electrodes 20 exchange lithium ions. The A anode electrodes 40-1, 40-2, ..., and 40-A include an anode active material layer 42 containing lithium metal (from molten lithium and / or other manufacturing methods) (disposed on one or both sides of the anode current collector 46). In some examples, the cathode active material layer 24 includes a coating including one or more active materials, one or more conductive additives, and / or one or more binder materials applied to the current collector (e.g., using a wet or dry roll-to-roll process).

[0063] In some examples, the cathode current collector 26 and / or the anode current collector 46 comprises a metal foil, a metal mesh, a perforated metal, a three-dimensional (3D) metal foam and / or a porous metal sheet (expanded metal). In some examples, the current collector is made of one or more materials selected from copper, stainless steel, brass, bronze, zinc, aluminum and / or their alloys. In some examples, the anode current collector is made of copper or stainless steel. The outer pole ears 28 and 48 extend from the current collector and can be arranged on the same side or different sides of the battery cell stack 12. The outer pole ears 28 and 48 are connected to the terminals of the battery cells.

[0064] Reference now Figures 2A to 2D , anode current collector 46 ( Figure 2A ) is coated with a first portion 72 (eg, edge) of the Figure 2B). A second portion 75 of the anode current collector 46 (corresponding to the future location of the anode active material layer 42) remains uncoated. For example, the first portion 72 may correspond to the location of the outer tab 48.

[0065] Then, the anode current collector 46 and the lithium-philic coating 74 are exposed to plasma modification to promote the chemical reaction of the lithium-philic coating 74 and / or the second portion 75 to adjust the wettability. The chemical reaction causes the first portion 72 to become more lithium-philic and / or the second portion 75 to become more lithium-philic. In other words, the plasma modification reduces the wettability of the precursor coating 73 to molten lithium and / or increases the wettability of the second portion 75 to molten lithium ( Figure 2C ).exist Figure 2D In the embodiment of the present invention, the molten lithium is preferentially coated on the second portion 75 relative to the first portion 72. In some examples, the first portion 72 (e.g., edge) is arranged along the opposite side of the second portion 75 of the anode current collector 46, and the anode current collector 46 is cut in half to produce two anode electrodes at a time.

[0066] Reference now Figure 3 , roller 110 supplies anode current collector 112 onto guide rollers 120, 122 and 124, through bath 130 and onto roller 148. Coating source 113 supplies precursor material to coating device 114, which coats a first portion of anode current collector 112 with a precursor coating.

[0067] The first gas source 115 supplies a plasma gas or a plasma gas mixture to a plasma generator 116, which maintains a plasma adjacent to the anode current collector 112. The plasma causes a chemical reaction of the precursor coating on the first portion and / or the second portion of the anode current collector 112. In some examples, the second gas source 117 supplies a secondary gas or a gas mixture to a gas injector 119, which injects the gas directly into the plasma. After plasma modification, the anode current collector 112 is guided by guide rollers 120, 122, and 124 into a bath 130 including molten lithium 132. The heater 134 can be used to heat the bath 130 to a predetermined temperature higher than the melting temperature of lithium metal.

[0068] After coating the anode current collector with molten lithium, a gas blade 140 connected to a gas source 141 supplies gas to one or both outer surfaces of the anode current collector 112 to remove excess molten lithium and / or to improve the thickness uniformity of the molten lithium metal. In some examples, the gas source 141 supplies an inert gas such as molecular nitrogen (N2), argon (Ar) or other suitable gas. After coating with molten lithium, the anode electrode 145 is collected on a roller 148. In some examples, the anode electrode 145 is cooled using a cooling gas flow, a cooling roller, a cooler or other cooling source (not shown) before being collected on the roller 148.

[0069] In some examples, one or more additional plasma sources 133 expose the surface of the molten lithium to plasma to reduce the surface tension of the lithium and improve the wettability of the molten lithium to the current collector. The plasma gas or secondary gas includes a compound containing an element that forms a new Li-X bond, which is more wettable to the anode current collector.

[0070] In some examples, the surface modification includes coating a first portion of the anode current collector with a precursor coating and converting the precursor coating using plasma modification to form a lithium-phobic surface. In some examples, plasma modification of a second portion of the anode current collector produces a lithium-philic surface. Plasma modification of the second portion improves the bonding strength with molten lithium.

[0071] In some examples, the plasma gas mixture includes a compound containing an element or chemical group that is incorporated into the surface of the anode current collector (in an area not coated with a precursor coating) to improve the wettability of the surface to molten lithium. In some examples, the plasma gas mixture includes a gas selected from molecular nitrogen (N2), ammonia (NH3), an amine compound, a silazane, and / or a combination thereof. In other examples, the plasma gas or plasma gas mixture includes a compound containing one or more elements that form a bond with molten lithium and is incorporated into the surface of the anode current collector. In some examples, the plasma gas mixture includes a compound containing one or more of nitrogen (N), phosphorus (P), oxygen (O), halogens, and / or a combination thereof. In some examples, plasma modification reduces the surface tension of lithium and improves the wettability of molten lithium (e.g., when plasma is directed to the surface of the molten lithium pool to form new Li-X bonds, it is more wettable on the current collector).

[0072] In some examples, a secondary gas mixture is injected directly into the plasma after the plasma is struck, and the secondary gas mixture includes one or more compounds containing elements or chemical groups that are incorporated onto the surface of the anode current collector to improve wettability by molten lithium.

[0073] In some examples, the plasma surface modification is performed immediately before the substrate is immersed in molten lithium. The plasma surface modification can generate new bonds wettable to lithium on the surface of the current collector. In some examples, the precursor coating and the plasma surface modification of the precursor coating generate lithium-repellent surface portions along the edge (one or more) of the anode electrode to enable the clean edge area for subsequent notching and / or welding methods of the outer tab.

[0074] Reference now Figure 4 , an example of a single-sided coating is shown. After coating the edge of the anode current collector with a precursor coating using a coating device 114 and plasma modification using a plasma generator 116, a coating device 220 supplies molten lithium to the anode current collector 112. In some examples, the coating device 220 includes a slot die and / or a scraper that provides a uniform layer of molten lithium to the anode current collector 112. In some examples, the coating device 220 includes a heater 224, which is configured to heat lithium to a melting temperature higher than lithium. In some examples, the process is repeated to coat the opposite side of the anode current collector.

[0075] Reference now Figure 5A and 5B The engraved roller 180 includes a plurality of cavities 182 configured to receive lithium metal powder 183 from a lithium powder source 186. The engraved roller 180 forms a pattern 190 of lithium metal powder 183 at certain intervals (e.g., corresponding to the intervals of the cavities 182) on the anode current collector 112. Figure 5A In the embodiment, the anode current collector 112 having a lithium powder pattern 190 at certain intervals passes through an oven 192 to melt the lithium powder into molten lithium. The molten lithium flows to form a uniform lithium metal layer. In some examples, an additional roller is arranged between the oven 192 and the winding roller 148 to further improve the uniformity of the lithium metal layer (not shown). In some examples, such as Figure 5B As shown, the engraved roller 180 is heated by a heater 196 (instead of or in addition to the oven 192).

[0076] exist Figure 5B In the embodiment of the present invention, the anode current collector 112 and the lithium powder pattern 190 pass through an engraving roller 180 including a heater 196 to heat the lithium powder to melt the lithium powder into molten lithium. The molten lithium flows to form a lithium layer on the lithium-philic surface. It is understood that the thickness of the lithium layer can be controlled by the speed of the engraving roller, the temperature of the heater 196 and / or the amount of lithium powder in each cavity 182.

[0077] exist Figure 5CIn the embodiment of the present invention, additional plasma modification can be performed before coating with the precursor coating. Gas source 221 supplies a plasma gas mixture to plasma electrode 222. In some examples, the plasma gas mixture includes molecular oxygen. Before coating the first portion with the precursor coating, the plasma modification forms an oxide layer on the anode current collector (or limited to the first portion or the second portion).

[0078] Reference now Figure 6 and 7 , when certain types of materials (e.g., stainless steel) are used as the anode current collector, cooling of the first portion of the anode current collector and preheating of the second portion may be performed prior to plasma modification. After coating the first portion with the precursor coating, the roller 310 applies heat (and / or pressure) to the anode current collector 112. In some instances, the roller 310 (on the opposite side of the anode current collector 112) heats the second portion 330 to a temperature of 250°C to 400°C. In some instances, the edge cooling roller 320 is arranged at one or both edges 322, 324 of the anode current collector 112. In some instances, the temperature of the edge cooling roller 320 is between 10°C and 25°C. If both edges 332 and 334 are coated with the precursor coating, the anode electrode can be divided into two anode electrodes.

[0079] Surface modification can be used to make alternative current collector materials for lithium anode electrodes, such as stainless steel (cheaper and lighter than copper). Stainless steel includes standard foil, mesh and / or expanded metal. In some examples, plasma modification (e.g., using plasma gas such as molecular nitrogen) applied to the preheated anode current collector removes the passivation surface layer (which is lithium-phobic) on the stainless steel. For example, a thin chromium nitride layer is formed on a stainless steel substrate by nitrogen plasma modification, which will effectively wet the molten lithium on the stainless steel anode current collector. The temperature range of roller 310 is based on the desired thickness of the nitride layer. In some examples, the thickness of the nitride layer is 2nm to 2μm. In some examples, the stainless steel grade for the anode current collector is selected from 304 or 316L stainless steel. In addition, in some examples, plasma treatment of the molten lithium surface immediately before contacting the stainless steel leads to the generation of Li-X bonds that are more wettable to the stainless steel.

[0080] In some examples, the width of the roller 310 is equal to the width of the second portion 330 including the active material layer of the anode current collector (the second portion 330 is plasma treated to increase wettability to molten lithium). The edge regions 332 and 334 of the anode current collector pass through the edge cooling roller 320 to be maintained at room temperature or near room temperature to avoid plasma activation / wetting. As a result, the edge region 332 of the anode current collector remains lithium-phobic to avoid coating lithium in the region with the outer tabs 28 and 48. Although a heated roller is shown, plasma heating, infrared (IR) heating, furnace heating, and / or induction heating can be used to preheat the anode current collector.

[0081] The foregoing description is exemplary only and is absolutely not intended to limit the present disclosure, its application or use. The broad teachings of the present disclosure can be implemented in various forms. Therefore, although the present disclosure includes specific examples, the true scope of the present disclosure should not be limited thereto, because after studying the drawings, the specification and the following claims, other modifications will become apparent. It should be understood that one or more steps in the method may be implemented in different orders (or simultaneously) without changing the principles of the present disclosure. In addition, although each embodiment is described above as having certain features, any one or more features described with respect to any embodiment of the present disclosure may be implemented in any other embodiment and / or combined with the features of any other embodiment, even if the combination is not explicitly described. In other words, the embodiments are not mutually exclusive, and the mutual replacement of one or more embodiments is still within the scope of the present disclosure.

[0082] Various terms are used to describe the spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.), including "connected," "engaged," "coupled," "adjacent," "next to," "on top of," "on," "under," and "disposed." Unless explicitly described as "directly," when describing the relationship between a first element and a second element in the above disclosure, the relationship can be a direct relationship in which there are no other intervening elements between the first element and the second element, or an indirect relationship in which there are one or more intervening elements (spatially or functionally) between the first element and the second element. The phrase "at least one of A, B, and C" as used herein should be interpreted to mean a logical (A or B or C) using a non-exclusive logical OR, and should not be interpreted to mean "at least one of A, at least one of B, and at least one of C."

[0083] In the drawings, the direction of the arrows, as shown by the arrows, generally shows the flow of information (such as data or instructions) that the illustration is concerned with. For example, when component A and component B exchange various information but the information sent from component A to component B is relevant to the illustration, the arrow may point from component A to component B. Such a one-way arrow does not mean that no other information is sent from component B to component A. In addition, for information transmitted from component A to component B, component B may send a request for the information or a receipt to component A.

Claims

1. A method for manufacturing an anode electrode, comprising: supplying an anode current collector; coating a first portion of the anode current collector with a precursor coating; not coating a second portion of the anode current collector with the precursor coating; treating the anode current collector with a plasma to at least one of reduce lithium wettability of the first portion and increase lithium wettability of the second portion; and The anode current collector is coated with lithium metal to form an anode active material layer. The method according to claim 1 , wherein the first portion corresponds to an edge of the anode current collector. 3 . The method of claim 1 , wherein coating the anode current collector with lithium metal comprises passing the anode current collector through a bath comprising molten lithium metal.

4. The method of claim 3, further comprising directing a gas to the anode current collector after the anode current collector passes through the bath to at least one of remove excess molten lithium metal and improve thickness uniformity of the molten lithium metal.

5. The method of claim 4, wherein the gas is selected from molecular nitrogen and argon.

6. The method of claim 1, further comprising injecting a secondary gas into the plasma, wherein the secondary gas comprises at least one element that forms a bond on a surface of the anode current collector to increase wettability to lithium. 7 . The method of claim 1 , wherein coating the anode current collector with the lithium metal comprises supplying molten lithium metal onto the anode current collector using a coating device.

8. The method of claim 1, wherein coating the anode current collector with the lithium metal comprises: supplying lithium metal powder onto the anode current collector at intervals using an engraved roller including a plurality of cavities; and The lithium metal powder is heated to melt the lithium alloy powder.

9. The method of claim 8, further comprising heating the engraved roller to melt the lithium metal powder.

10. The method of claim 8, wherein heating the lithium metal powder comprises heating using at least one of plasma, infrared heating, a furnace, an oven, and induction heating.

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