Lithium metal negative electrode, negative electrode precursor therefor, and method for producing the same

Abstract

The present invention relates to lithium metal anodes, anode precursors therefor, and methods for their manufacture. According to another embodiment of the present invention, there is provided a lithium metal anode comprising a current collector, a metal layer formed on the current collector, and a protective coating layer formed on the metal layer, wherein the metal layer comprises a lithium alloy at an interface in contact with the protective coating layer, and the protective coating layer is a mixture of a carbonaceous material and a binder, and the binder may be a polymer obtained by polymerizing a highly ion-conductive monomer to which a high-strength monomer is grafted.

Description

[Technical Field]

[0001] The present invention relates to lithium metal anodes, anode precursors therefor, and methods for their manufacture. [Background technology]

[0002] Lithium secondary batteries have been used mainly in small devices such as mobile phones and laptops. Recently, as demand for medium to large batteries such as those for electric vehicles has increased, there has been a growing need to increase the energy density of lithium secondary batteries.

[0003] Therefore, lithium metal, which has a high specific capacity, has been attracting attention as an anode. However, when using lithium metal as an anode, it is difficult to overcome the problem of reduced lifespan due to dendrite growth, and this problem has not yet been completely solved. Summary of the Invention [Problem to be solved by the invention]

[0004] According to one embodiment of the present invention, a lithium metal anode is provided that has high energy density and extended life.

[0005] According to another embodiment of the present invention, there is provided a precursor for producing the above-described lithium metal negative electrode.

[0006] According to another embodiment of the present invention, there is provided a method for producing the above-described lithium metal anode or the above-described precursor.

[0007] The object of the present invention is not limited to the above-mentioned content, and anyone having ordinary skill in the art to which the present invention pertains will have no difficulty in understanding further object of the present invention from the overall content described in this specification. [Means for solving the problem]

[0008] A precursor of a lithium metal negative electrode according to one embodiment of the present invention includes a current collector, a metal layer formed on the current collector, and a protective coating layer formed on the metal layer. The protective coating layer is a mixture of a carbon-based material and a binder. The binder may be a polymer obtained by polymerizing a highly ion-conductive monomer or polymer to which a high-strength monomer is grafted.

[0009] According to another embodiment of the present invention, there is provided a lithium metal anode comprising a current collector, a metal layer formed on the current collector, and a protective coating layer formed on the metal layer, wherein the metal layer comprises a lithium alloy and lithium at an interface in contact with the protective coating layer, and the protective coating layer is a mixture of a carbon-based material and a binder, and the binder may be a polymer obtained by polymerizing a highly ion-conductive monomer or polymer to which a high-strength monomer is grafted.

[0010] According to yet another embodiment of the present invention, a method for manufacturing a lithium metal anode precursor includes: preparing a current collector; forming a metal layer on a surface of the current collector; and coating the surface of the metal layer with a slurry containing a carbon-based material, a binder, and a solvent to form a protective coating layer. The binder may be a polymer obtained by polymerizing a highly ion-conductive monomer or polymer to which a high-strength monomer is grafted.

[0011] According to yet another embodiment of the present invention, a method for manufacturing a lithium metal anode includes: preparing a current collector; forming a metal layer on a surface of the current collector; coating the surface of the metal layer with a slurry containing a carbon-based material, a binder, and a solvent to form a protective coating layer; and electrodepositing lithium metal onto the anode precursor, wherein the binder may be a polymer obtained by polymerizing a highly ion-conductive monomer or a polymer to which a high-strength monomer is grafted. [Effects of the Invention]

[0012] As described above, the present invention provides a negative electrode for a lithium secondary battery having high energy density and long life by forming a protective coating layer containing a binder obtained by polymerizing a grafted monomer on a thin lithium alloy layer. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a scanning electron microscope photograph showing a cross section of a negative electrode precursor produced in Example 1. [Figure 2] 1 is a photograph showing the morphology of a lithium metal negative electrode prepared in Example 4. [Figure 3] 1 is a photograph of a cross section of a lithium metal negative electrode prepared in Example 4 and Comparative Example 4, observed with a scanning electron microscope. [Figure 4] 1 is a photograph showing the results of observing the comparison of binding properties between Example 4 of the present invention and Comparative Example 4. [Figure 5] 1 is an asymmetric cell life graph of all-solid-state batteries manufactured using the negative electrodes of Example 4 and Comparative Example 4. DETAILED DESCRIPTION OF THE INVENTION

[0014] The present invention is not limited to the embodiments disclosed below. For example, a person skilled in the art who understands the concept of the present invention can easily propose other embodiments that fall within the scope of the concept of the present invention by adding, changing, or deleting components, and these embodiments can also be said to fall within the scope of the concept of the present invention.

[0015] Furthermore, throughout the specification, unless specifically stated to the contrary, "comprising" an element does not exclude other elements, but means that other elements may also be included.

[0016] It should be noted that unless otherwise specified in the present invention, the blending ratios and compositions are based on weight.

[0017] Furthermore, each of the embodiments described below is merely an example of realizing the technical idea of ​​the present invention, and the scope of the present invention is not limited to each embodiment.

[0018] The present invention will be described in detail below.

[0019] To maximize the energy density of batteries, an ultra-thin lithium metal electrode strategy is essential, reducing the thickness of the lithium to less than 20 μm. However, there are still many challenges in manufacturing thin lithium metal electrodes through commercial processes. Lithium metal anodes suffer from non-uniform current density and dendrite growth due to electrochemical reactions during the charge and discharge process of secondary batteries. This can lead to persistent side reactions with the electrolyte and ultimately to internal short circuits where the anode and cathode come into contact. This dendrite growth can also cause serious problems, such as poor lifespan and stability. Therefore, it is difficult to practically utilize ultra-thin lithium metal anodes.

[0020] Although various methods have been proposed to suppress the formation of lithium dendrites and increase the lifespan, it is still difficult to simultaneously achieve high energy density and sufficient lifespan characteristics by ultra-thinning the lithium.

[0021] The inventors of the present invention have confirmed that, in one embodiment of the present invention, a thin lithium affinity metal layer is formed on the surface of a current collector, and this metal layer is alloyed with lithium to suppress dendrite growth of lithium, thereby effectively improving the lifespan. However, the above-described process is one advantageous step of the present invention, and the present invention is not limited thereto. It is also possible to form a thin metal layer in the form of an alloy from the beginning.

[0022] In one embodiment of the present invention, a protective coating layer may be formed on the surface of the metal layer. The protective coating layer has excellent ion transfer properties and structural stability, allowing lithium ions to be stably electrodeposited onto the thin metal layer and alloyed therewith, thereby preventing direct contact between the electrolyte and lithium metal, thereby contributing to improved charge / discharge life.

[0023] Thus, an anode precursor according to one embodiment of the present invention may be a pre-processed article that is subsequently processed into a lithium metal anode via electrodeposition of lithium metal, and may include a current collector, a metal layer formed on the current collector, and a protective coating layer formed on the metal layer.

[0024] The current collector may be any current collector used in lithium secondary batteries, and therefore the material and thickness are not particularly limited, and any material and thickness usable in the technical field to which the present invention pertains may be used. However, as some examples that do not limit the present invention, copper (Cu), nickel (Ni), stainless steel, and Invar alloy may be used, and foil-shaped materials may be used.

[0025] Furthermore, the metal layer of the present invention does not contain lithium, and can be made of a material that has a high affinity with lithium and can be alloyed with it. By using such a metal, the lithium metal negative electrode obtained later can contain a lithium alloy layer. Examples of metals that can be alloyed with lithium include Al, In, Ag, Au, Zn, Mg, and Si. These metals can be used alone or as an alloy of two or more of them.

[0026] By limiting the thickness of the metal layer to a small value, the thickness of the alloy layer formed later by alloying can be reduced. Reducing the thickness of the alloy layer in this manner increases the energy density, which refers to the amount of energy per unit weight. Taking this into consideration, in one embodiment of the present invention, the thickness of the metal layer can be limited to 5 μm or less. While a thinner thickness is more advantageous for increasing the energy density and suppressing the problem of volume expansion, if the thickness is too thin, the uniformity of the metal layer may decrease, potentially limiting the efficient formation of a lithium alloy. Therefore, in one embodiment of the present invention, the thickness of the metal layer can be limited to 10 nm or more. A more preferred thickness of the metal layer may be 100 nm to 500 nm.

[0027] In addition, according to one embodiment of the present invention, the protective coating layer may be a mixture of a carbon-based material and a binder. The carbon-based material may be amorphous carbon, such as, but not limited to, furnace black, acetylene black, ketjen black, graphene, etc. The binder may be a polymer obtained by grafting a high-strength monomer onto a highly ion-conductive monomer or polymer. When a high-strength monomer is grafted onto a highly ion-conductive polymer, the high-strength monomer may be partially polymerized during the polymerization process after grafting. When a polymer is formed after grafting monomers having two properties, the physical and chemical properties of each monomer can be effectively utilized. As a result, the protective coating layer can be stably attached to the electrode, achieving excellent electrochemical properties. In addition, after forming the protective coating layer according to one embodiment of the present invention, lithium can be electrodeposited through an electroplating process. However, in this case, lithium may easily be transferred to the metal layer below the protective coating layer, potentially causing alloying. Such easy ion transfer properties may be advantageous for charging and replenishing lithium ions as a lithium metal anode.

[0028] Furthermore, if lithium ions are not easily transported into the protective coating layer, lithium may accumulate on the surface of the protective coating layer during the lithium electrodeposition process or the battery charging process, forming dendrites. However, in the case of the anode provided in one embodiment of the present invention, the lithium metal alloy layer and the highly ion-conductive binder contained in the protective coating layer allow lithium ions to be easily transported to the bottom of the protective coating layer, which is effective in suppressing the growth of dendrites.

[0029] The highly ion-conductive monomer of the binder contained in the protective coating layer is not particularly limited as long as it easily conducts ions, but in one embodiment of the present invention, it may be one or more selected from the group consisting of vinyl acetate, ethylene glycol, aniline ethylene imine, acrylonitrile, pyromellitic dianhydride, 4,4-oxydianiline, 3,4-dihydroxyphenylethylamine, hexamethylolmelamine, methyl cyanoacrylate, isophorone diisocyanate, and methylenediphenyl diisocyanate. The highly ion-conductive polymer that may be contained in the protective coating layer may be a polymer of the above monomers.

[0030] The high-strength monomer may be one or more selected from the group consisting of acrylic acid, ethylene, propylene, styrene, methyl methacrylate, carboxylic acid, vinyl chloride, carbonyl chloride, oxalic acid, and succinic acid.

[0031] In this case, the high ion conductive monomer may be included in a ratio of 0.25 to 2 moles per mole of the high strength monomer. If the high strength monomer is grafted onto a high ion conductive polymer as a starting material, the ratio of the number of moles of the monomer included in the polymer to the number of moles of the high strength monomer may be within the above range. When added in the above ratio, the highest binding stability can be obtained.

[0032] The protective coating layer may have a thickness of 1 to 20 μm. A thickness of 1 μm or more can maintain the structure during the lithium metal electrodeposition process, while a thickness of 20 μm or less can prevent an excessive increase in interlayer resistance, facilitate lithium metal transfer beneath the protective coating layer, and advantageously ensure battery density. A more preferred thickness of the protective coating layer may be 5 to 10 μm. When lithium metal is electrodeposited onto the precursor to obtain a negative electrode, the thickness of the entire negative electrode layer, including the protective layer (i.e., the sum of the thicknesses of the metal layer and the protective layer), can be approximately 2 to 30 μm, preferably 10 to 25 μm.

[0033] The protective coating layer may have a porosity of 40% or more. If the porosity is too small, impregnation with a plating solution may be difficult when plating lithium to prepare a lithium metal anode, as described below, which may result in lithium metal being deposited on the top surface of the protective coating layer. Therefore, although a larger porosity is advantageous, considering structural stability, the porosity may be limited to 80% or less. The porosity can be measured, for example, by photographing a cross-section of a mirror-finished protective coating layer using an ion beam device, as shown in FIG. 1, and then calculating the area of ​​the pore region relative to the total area using an image analysis program.

[0034] In another implementation of the present invention, a lithium metal anode can be provided.

[0035] A lithium metal negative electrode according to one embodiment of the present invention includes a current collector, a metal layer formed on the current collector, and a protective coating layer formed on the metal layer, and the metal layer may contain a lithium alloy and lithium at an interface in contact with the protective coating layer.

[0036] According to one embodiment of the present invention, the lithium alloy may be an alloy of metallic lithium and one or more elements selected from Al, In, Ag, Au, Zn, Mg, Si, etc.

[0037] The lithium metal negative electrode can be prepared from the above-described negative electrode precursor, but it can also be prepared by other methods, such as forming a separate alloy on a current collector and then forming a protective layer thereon, or by any other possible method.

[0038] The following describes a method for producing the anode precursor and lithium metal anode of the present invention. However, the method described below is merely a preferred example for producing the anode precursor and lithium metal anode of the present invention, and does not necessarily mean that the anode precursor or lithium metal anode of the present invention must be produced by the following method.

[0039] First, a metal layer may be formed on the surface of a current collector. The method for forming the metal layer is not particularly limited, and various methods such as plating, vapor deposition, and transfer may be used.

[0040] Thereafter, a slurry containing a carbon-based material, a binder, and a solvent is coated on the surface of the metal layer, and dried to form a protective coating layer, thereby obtaining a negative electrode precursor.

[0041] According to one embodiment of the present invention, the blending ratio of the carbon-based material and the binder can be adjusted so that the binder accounts for 3 to 15% of the total weight of the carbon-based material and the binder. The amount of solvent is not particularly limited, and can be blended to an extent that the slurry has a viscosity suitable for coating. However, in one embodiment of the present invention, the solvent can be added in a weight ratio of about 8 to 10 times the total solid content of the carbon-based material, the solid content in the binder, etc. The binder may be a polymer obtained by polymerizing a highly ion-conductive monomer or polymer to which a high-strength monomer has been grafted.

[0042] A lithium metal negative electrode according to one embodiment of the present invention can be prepared by preparing a negative electrode precursor including a current collector, a metal layer formed on the current collector, and a protective coating layer formed on the metal layer, and then electrodepositing lithium metal onto the negative electrode precursor. The lithium metal electrodeposition can be performed by electroplating. [Example]

[0043] (Example) The present invention will be described in detail below with reference to examples. However, it should be noted that the following examples are intended to illustrate and embody the present invention, and are not intended to limit the scope of the present invention. The scope of the present invention is determined by the matters described in the claims and matters that can be reasonably inferred therefrom.

[0044] Preliminary experiment - adhesive strength test of protective coating layer The following experiments were conducted to examine the adhesive strength of the protective coating layer depending on the type and content of binder. Specifically, a polymer (PVA-g-PAA) was prepared by grafting a high-strength monomer, acrylic acid monomer, onto a highly ion-conductive polymer, polyvinyl acetate, to obtain the binder (Preliminary Experiments 1–4). The moles of vinyl acetate monomer added per mole of acrylic acid monomer in polyvinyl acetate were varied from 0.25 to 2 for each experiment. However, in Comparative Experiment 1, a 1:2 mixture of styrene butadiene rubber (SBR) and carboxymethyl cellulose (CMC) was used as the binder, rather than a polymer of a highly ion-conductive monomer grafted with a high-strength monomer. Each binder was coated onto one side of a current collector to form a polymer film, which was then dried at 130°C or higher to thoroughly remove the solvent. A peel-off test was then conducted to measure the adhesive strength between the current collector and the polymer film, and the results are shown in Table 1. The peel test was carried out by attaching peeling tape to the polymer film and measuring the adhesive strength while peeling the tape from the polymer film layer at a set speed using a Universal Testing Machine (UTM, Petrol Lab. DA-01). In Table 1, adhesive strength A is the result when the peeling speed was 5 mm / min, and adhesive strength B is the result when the peeling speed was 200 mm / min.

[0045] [Table 1]

[0046] As described above, according to one embodiment of the present invention, high binding strength was obtained when a high-strength monomer grafted onto a high-ion-conductive polymer was polymerized. In particular, it was confirmed that the binding strength was excellent when the ratio of the number of moles of high-ion-conductive monomer per mole of high-strength monomer was between 0.25 and 2, and was best when the ratio was 1. Comparative Experiments 2 and 3 were cases where the monomer ratio was outside the range specified by the present invention, and showed binding strength inferior to that of the invention examples.

[0047] Preparation of negative electrode precursor A copper current collector was prepared, and silver was formed on the current collector using an electroless plating process to a thickness of approximately 300 nm. In all examples except Comparative Example 3, PVA-g-PAA (the binder used in Preliminary Experiment 3) was prepared as the binder, with a 1:1 molar ratio of vinyl acetate monomer to acrylic acid monomer. In Comparative Example 3, the binder used in Comparative Experiment 1 was used. A slurry was prepared by mixing the binder with carbon black and water. The water content in the slurry was adjusted to ensure the slurry had a viscosity suitable for coating, and the carbon black to binder ratio was adjusted for each example as shown in Table 2. The slurry was coated onto the current collector using a blade and dried at 100°C for 10 minutes. This was followed by vacuum drying for an additional 3 hours to form a protective coating layer. The protective coating layer was confirmed to be approximately 5 μm thick in all examples. Using the above process, a negative electrode precursor for a lithium metal negative electrode was prepared. In the table, the porosity of the protective coating layer was measured by taking a photograph of the cross section of the mirror-finished protective coating layer using an ion beam device and calculating the area of ​​the pore region relative to the total area using an image analysis program.

[0048] [Table 2]

[0049] In Table 2, the protective coating layer for Comparative Example 1 was not sufficiently adhered, making it difficult to measure the binding strength, and therefore the binding strength and porosity values ​​were not separately listed. As can be seen from the results in Table 2, if the binder content is too low, the protective coating layer does not adhere to the metal layer on the current collector with sufficient binding strength. Therefore, to achieve a sufficient binding strength, the binder ratio in the binder and carbon black must be 3% or more, and more preferably 6% or more. However, it was confirmed that when the binder content exceeds 15% and reaches 20%, the binding strength is excellent, but the porosity of the electrode is excessively reduced. Therefore, in one embodiment of the present invention, the preferred binder content of the protective coating layer is set to 15% or less. Figure 1 shows a cross-section of the negative electrode precursor prepared according to Example 1. As shown in the figure, the protective coating layer is approximately 5 μm thick, and sufficient pores are formed in the protective coating layer.

[0050] Lithium metal anode manufacturing Example 4 The negative electrode precursor prepared according to Example 2 above was subjected to lithium electroplating. A 500 μm-thick lithium metal foil was used as the counter electrode during plating, and the electrodeposition solution used contained lithium bis(fluorosulfonyl)imide and 1,2-dimethoxyethanol at 30 wt % and 68 wt %, respectively, with 1 wt % lithium nitrate and fluoroethylene carbonate added. The counter electrode was attached to a copper current collector while insulated from the negative electrode precursor, and immersed in the electrodeposition solution. Lithium was then electroplated onto the metal layer of the negative electrode precursor by applying a constant current. The applied current density was 4 mA / cm. 2 The lithium alloy and lithium metal layers were formed to a thickness of about 10 μm. The morphology of the lithium metal anode obtained by the above process is shown in FIG.

[0051] Comparative Example 4 A lithium metal negative electrode was prepared in the same manner as in Example 4, except that the negative electrode precursor prepared in Comparative Example 3 was used.

[0052] Cross-sectional photographs of the lithium metal negative electrodes prepared in Example 4 and Comparative Example 4 are shown in FIG.

[0053] Figure 4 shows the results of comparing the binding properties of Example 4 and Comparative Example 4. To evaluate the binding properties, tape (3M Magic 810D) was applied to the surface protective coating layer of the negative electrode on which lithium had been electrodeposited in a glove box, and then peeled off to evaluate the state of the remaining protective coating layer. As can be seen from the figure, in the case of the lithium metal negative electrode prepared in Example 4, the protective coating layer remained on the electrode even after the test, whereas in the case of the lithium metal negative electrode prepared in Comparative Example 4, most of the protective coating layer had disappeared.

[0054] Battery life evaluation All-solid-state batteries were manufactured using the lithium metal negative electrodes provided in Example 4 and Comparative Example 4, and their life characteristics were evaluated.

[0055] In the battery, a lithium-indium alloy (500 μm thick) was used as the counter electrode, and a sulfide-based argyrodite (700 μm thick) was used as the solid electrolyte. During battery assembly, the solid electrolyte was pressurized to 370 MPa to form a dense electrolyte, and then the working electrode and counter electrode were attached to both sides of the solid electrolyte at a pressure of 50 MPa to complete the battery assembly. The life evaluation was performed at 1 mA / cm in a pressurized environment of 16 MPa. 2 and a current density of 1 mAh / cm 2 The test was carried out under the conditions of a charge / discharge capacity of 1000 kJ / cm2. Table 3 below compares the lifespan of the electrodes including the negative electrodes prepared according to each example. The lifespan of the electrodes was expressed as the number of cycles until a short circuit occurred.

[0056] [Table 3]

[0057] As can be seen from Table 3 above, a battery including a lithium metal anode prepared according to the conditions provided in one embodiment of the present invention exhibited an approximately 80% increase in lifespan compared to a battery including a lithium metal anode prepared according to a comparative example that deviates from the conditions of the present invention. Figure 5 shows an asymmetric cell lifespan graph of all-solid-state batteries prepared using the anodes of Inventive Example 4 and Comparative Example 4. As can be seen from the diagram, the lifespan of Comparative Example 4 was confirmed to end at just over 900 hours, while Inventive Example 4 had a lifespan approaching 1600 hours.

[0058] Therefore, the advantageous effects of the present invention were confirmed.

Claims

1. A current collector; a metal layer formed on the current collector; a protective coating layer formed on the metal layer, the protective coating layer is a mixture of a carbon-based material and a binder; The binder is a polymer obtained by polymerizing a highly ion-conductive monomer or polymer to which a high-strength monomer is grafted.

2. 2. The negative electrode precursor of claim 1, wherein the metal layer has a thickness of 10 nm to 5 μm.

3. 2. The negative electrode precursor according to claim 1, wherein the metal layer contains one or two selected from the group consisting of Al, In, Ag, Au, Zn, Mg, and Si.

4. The negative electrode precursor of claim 1, wherein the protective coating layer has a thickness of 1 to 20 μm.

5. The negative electrode precursor of claim 1 , wherein the protective coating layer has a porosity of 40% or more.

6. 2. The negative electrode precursor of claim 1, wherein the high ion conductive monomer is included in a ratio of 0.25 to 2 moles per mole of the high strength monomer.

7. A current collector; a metal layer formed on the current collector; a protective coating layer formed on the metal layer, the metal layer includes an alloy of lithium at an interface with the protective coating layer; the protective coating layer is a mixture of a carbon-based material and a binder; The binder is a polymer obtained by polymerizing a highly ion-conductive monomer or polymer to which a high-strength monomer is grafted.

8. The highly ion-conductive monomers include vinyl acetate, ethylene glycol, aniline ethylene imine, acrylonitrile, pyromellitic dianhydride, 4,4-oxydianiline, 3,4-dihydroxyphenylethylamine, hexamethylolmelamine, methyl cyanoacrylate, and isophorone diisocyanate.

8. The lithium metal negative electrode according to claim 7, wherein the highly ion-conductive polymer is one or more selected from the group consisting of methylenediphenyl diisocyanate and methylenediphenyl diisocyanate, and the highly ion-conductive polymer is a polymer obtained by polymerizing the highly ion-conductive monomer.

9. 8. The lithium metal negative electrode according to claim 7, wherein the high-strength monomer is one or more selected from the group consisting of acrylic acid, ethylene, propylene, styrene, methyl methacrylate, carboxylic acid, vinyl chloride, carbonyl chloride, oxalic acid, and succinic acid.

10. 8. The lithium metal anode of claim 7, wherein the high ion conductivity monomer is present in a ratio of 0.25 to 2 moles per mole of the high strength monomer.

11. 8. The lithium metal negative electrode according to claim 7, wherein the lithium alloy is an alloy with one or more elements selected from the group consisting of Al, In, Ag, Au, Zn, Mg, and Si.

12. 8. The lithium metal anode of claim 7, wherein the metal layer further comprises lithium metal.

13. 8. The lithium metal anode of claim 7, wherein the combined thickness of the metal layer and the protective coating layer is 2 to 30 μm.

14. providing a current collector; forming a metal layer on the surface of the current collector; and coating a slurry containing a carbon-based material, a binder, and a solvent on the surface of the metal layer to form a protective coating layer; The method for producing a negative electrode precursor, wherein the binder is a polymer obtained by polymerizing a highly ion-conductive monomer to which a high-strength monomer is grafted.

15. 8. The method for producing a negative electrode precursor according to claim 7, wherein the high ion conductive monomer is contained in a ratio of 0.25 to 2 moles per mole of the high strength monomer.

16. providing a current collector; forming a metal layer on the surface of the current collector; forming a protective coating layer by coating a slurry containing a carbon-based material, a binder, and a solvent on the surface of the metal layer; and electrodepositing lithium metal onto the negative electrode precursor; The method for producing a lithium metal negative electrode, wherein the binder is a polymer obtained by polymerizing a highly ion-conductive monomer to which a high-strength monomer is grafted.

17. The highly ion-conductive monomers include vinyl acetate, ethylene glycol, aniline ethylene imine, acrylonitrile, pyromellitic dianhydride, 4,4-oxydianiline, 3,4-dihydroxyphenylethylamine, hexamethylolmelamine, methyl cyanoacrylate, and isophorone diisocyanate.

17. The method for producing a lithium metal negative electrode according to claim 16, wherein the highly ion-conductive polymer is one or more selected from the group consisting of methylenediphenyl diisocyanate and methylenediphenyl diisocyanate, and the highly ion-conductive polymer is a polymer obtained by polymerizing the highly ion-conductive monomer.

18. 17. The method of claim 16, wherein the high-strength monomer is one or more selected from the group consisting of acrylic acid, ethylene, propylene, styrene, methyl methacrylate, carboxylic acid, vinyl chloride, carbonyl chloride, oxalic acid, and succinic acid.

19. 17. The method for producing a lithium metal negative electrode according to claim 16, wherein the weight ratio of the binder to the total weight of the carbonaceous material and the binder is 3 to 15%.

20. 17. The lithium metal anode of claim 16, wherein the high ion conductivity monomer is present in a ratio of 0.25 to 2 moles per mole of the high strength monomer.

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