Silicon-based alloy negative electrode for all-solid-state battery, preparation method of silicon-based alloy negative electrode and solid-state battery

Abstract

The invention relates to a silicon-based alloy negative electrode for an all-solid-state battery, a preparation method of the silicon-based alloy negative electrode and the solid-state battery. The negative electrode comprises a current collector, a silicon-based active material composite layer and a surface metal layer, the current collector is coated with the silicon-based active material composite layer to form a silicon-based pole piece, the surface metal layer is deposited on the surface of the silicon-based pole piece, the silicon-based active material composite layer comprises a silicon-based active material and a binder, and the binder is deposited on the surface of the silicon-based pole piece. The surface metal layer is a metal coating deposited on the surface of the silicon-based pole piece in a magnetron sputtering mode, and the metal layer has good conductivity and ductility. Therefore, the solid-solid contact between the silicon-based electrode and the electrolyte is improved, and the problem of interface contact failure between the silicon-based electrode and the solid electrolyte is solved; meanwhile, the electrochemical performance of the silicon-based all-solid-state battery can be improved.

Description

Technical Field

[0001] This invention relates to the field of solid-state battery technology, specifically to a silicon-based alloy anode for all-solid-state batteries, its preparation method, and the solid-state battery itself. Background Technology

[0002] Solid-state batteries have recently garnered significant attention in the battery industry due to their numerous superior performance characteristics. The anode material is a crucial component of solid-state batteries. Currently known anode materials primarily include: carbon materials, silicon materials, tin-based materials, lithium-containing transition metal nitrides, alloy materials, nanoscale anode materials, and metallic lithium.

[0003] Silicon is favored due to its extremely high theoretical specific capacity (4200 mAh / g) and suitable lithiation potential (approximately 0.4 V vs. Li / Li). + Silicon-carbon / silicon-oxygen anode materials have become one of the most promising anode materials. However, although existing silicon-carbon / silicon-oxygen anode materials have the advantages of high specific capacity and energy density, they have problems with insufficient cycle stability, large charge-discharge volume expansion, and easy structural cracking.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] One object of the present invention is to provide a silicon-based alloy negative electrode for all-solid-state batteries, characterized in that it comprises: a current collector, a silicon-based active material composite layer, and a surface metal layer, wherein the silicon-based active material composite layer is coated on the current collector to form a silicon-based electrode sheet, the surface metal layer is deposited on the surface of the silicon-based electrode sheet, the silicon-based active material composite layer comprises a silicon-based active material and a binder, and the surface metal layer is a metal plating layer deposited on the surface of the silicon-based electrode sheet by magnetron sputtering, wherein the metal layer has good conductivity and ductility.

[0006] According to embodiments of this application, the metal in the metal plating layer is selected from one or more of indium, tin, antimony, silver, and magnesium, which have good conductivity and ductility, and the plating layer thickness is 20-2000 nm. The binder is selected from at least one of polyacrylic acid, acrylic acid derivative copolymers, sodium carboxymethyl cellulose, polyacrylonitrile, polyvinylidene fluoride, and styrene-butadiene rubber. Optionally, the particle size D50 of the active material does not exceed 10 μm. The current collector is selected from copper foil and stainless steel foil.

[0007] Another objective of this invention is to provide a method for preparing a silicon-based alloy negative electrode, characterized by comprising the following steps: uniformly mixing a silicon-based active material, a binder, and a solvent to obtain an electrode slurry; wherein the active material is selected from one or more of micron-sized silicon, nano-sized silicon, porous silicon, silicon oxide, silicon carbon, and porous silicon carbon; coating the electrode slurry onto a current collector and drying it to obtain a silicon-based electrode sheet; and depositing a metal coating layer on the surface of the silicon-based electrode sheet by magnetron sputtering; wherein the metal of the metal coating layer is selected from one or more of indium, tin, antimony, silver, and magnesium, which have ductility.

[0008] The drying process involves drying the silicon-based electrode in a vacuum oven at a temperature between 60 and 80°C for 24 hours. Optionally, the protective atmosphere during the magnetron sputtering process is argon. The coating thickness is 20–2000 nm, the sputtering time is 50–4000 s, and the sputtering current is 15–30 mA. The binder is selected from at least one of polyacrylic acid, acrylic acid derivative copolymers, sodium carboxymethyl cellulose, polyacrylonitrile, polyvinylidene fluoride, and styrene-butadiene rubber.

[0009] Based on the electrode paste, the binder in the active material has a mass percentage content of 0.5-5%; optionally, the particle size D50 of the active material does not exceed 10 μm; optionally, the current collector is selected from copper foil and stainless steel foil.

[0010] Another object of the present invention is to provide a solid-state battery, characterized in that the solid-state battery comprises a silicon-based alloy anode as described above, or a silicon-based alloy anode obtained according to the aforementioned preparation method. Compared with the prior art, the beneficial effects of the present invention are: The present invention also provides the application of the alloy negative electrode described in the above technical solution in all-solid-state batteries.

[0011] According to the technical solution provided by the present invention, the obtained silicon-based alloy electrode can effectively improve the solid-solid contact with the electrolyte, suppress the capacity loss caused by contact failure during cycling, and improve the cycle performance of silicon-based batteries. Attached Figure Description

[0012] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0013] Figure 1 The images shown are SEM and EDS images of the alloy negative electrode sheets prepared in Examples 2-5 of this invention.

[0014] Figure 2 The batteries assembled in the comparative application examples and application examples 1-4 of this invention are at 0.2 mA·cm -2 Cyclic stability.

[0015] Figure 3 SEM images of silicon-based negative electrode sheets obtained after disassembly following a long cycle in the application example are shown for comparison.

[0016] Figure 4 SEM images of the alloy negative electrode sheets obtained after disassembly following long cycles in Application Examples 1-4. Detailed Implementation

[0017] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0018] All raw materials used in this invention are not particularly limited in their source; they can be purchased from the market or prepared using conventional methods known to those skilled in the art.

[0019] Through research, the inventors of this application have discovered the following reasons for the defects in existing silicon anode materials: The large volume expansion of silicon during lithiation often leads to stress concentration, causing chemical-mechanical fracture of the electrode, resulting in the pulverization and detachment of silicon particles, and failure of electrochemical contact between silicon and the current collector and electrolyte, severely affecting the cycle stability of silicon-based batteries. Simultaneously, the low electronic conductivity and lithium diffusion coefficient of silicon affect its electrode reaction rate, causing a decrease in battery capacity and poor rate performance at high current densities. Solving one of the above problems can improve the performance of silicon-based anode materials in at least one aspect.

[0020] The purpose of this invention is to provide a method for preparing an alloy negative electrode, comprising the following steps: (1) The active material, binder and solvent are uniformly mixed to obtain an electrode slurry; the active material is selected from one or more of micron silicon, nano silicon, porous silicon, silicon oxide, silicon carbon and porous silicon carbon; (2) The electrode paste is coated onto the current collector and dried to obtain a silicon-based electrode sheet; (3) A metal coating is deposited on the surface of the silicon-based electrode by magnetron sputtering; the metal coating is one or more of indium, tin, antimony, silver and magnesium.

[0021] In embodiments of the present invention, the electrode slurry comprises active materials, binders, and solvents, or only active materials, binders, and solvents. These components are uniformly mixed to obtain a uniform and stable electrode slurry. The active materials include one or more of micron-sized silicon, nano-sized silicon, porous silicon, silicon oxide, and silicon carbon. In the present invention, the binder preferably includes polyacrylic acid and its derivative binders, or lithium-ionized polyacrylic acid and its derivative binders, such as PAALi. The binder's mass percentage is preferably 0.5% to 5%. The solvent in the present invention is not particularly required and can be added appropriately as needed. Those skilled in the art can select from non-aqueous solvents as required.

[0022] As an example, the adhesive and solvent in this invention can also be commercially available brand adhesives containing binders and solvents. The active material is thoroughly mixed with the adhesive to obtain the electrode slurry. Those skilled in the art can choose the mixing method as needed, considering factors such as the particle size of the active material, and select ball milling or stirring mixing.

[0023] In this invention, the particle size D50 of the active material is preferably no more than 10 μm, and more preferably 1~5 μm. The preparation method provided by this invention is suitable for preparing wet-coated negative electrodes using small-particle-size negative electrode active materials as raw materials, resulting in electrode sheets with uniform thickness.

[0024] In this invention, the current collector is preferably a copper foil or a stainless steel foil, more preferably a copper foil. In this invention, the silicon-based electrode is preferably dried in a vacuum drying oven; the drying temperature is preferably between 60 and 80°C; and the drying time is preferably not less than 24 hours. During drying, the solvent evaporates, and trace amounts of solvent may remain in the silicon-based electrode after drying.

[0025] After obtaining the silicon-based electrode, a metal coating is deposited on the surface of the silicon-based electrode by magnetron sputtering to obtain an alloy negative electrode.

[0026] In this invention, the metal coating comprises one or more of indium, tin, antimony, silver, and magnesium. The metal must possess good ductility and excellent electrical conductivity. In this invention, the protective atmosphere during the magnetron sputtering process is preferably argon. In this invention, the metal coating thickness is preferably 20-2000 nm, more preferably 20-1000 nm; the sputtering time is preferably 50-4000 s, more preferably 50-2000 s; and the sputtering current is preferably 15-30 mA.

[0027] This invention uses one or more of the malleable indium, tin, antimony, silver, and magnesium as a metal coating. The malleability of the metals alleviates the stress concentration caused by the expansion of silicon during lithiation, preventing the pulverization and detachment of silicon particles due to the chemical mechanical fracture of the electrode, thereby improving the solid-solid contact between the silicon-based electrode and the electrolyte and solving the problem of interfacial contact failure between the silicon-based electrode and the solid electrolyte. Simultaneously, the good conductivity of these metals helps to construct excellent interfacial electron-ion transport channels, improving the electrochemical performance of silicon-based all-solid-state batteries. The results of the embodiments show that the alloy anode provided by this invention, used in sulfide-based all-solid-state lithium batteries, achieves a performance of 0.1 mA·cm⁻¹. -2 The initial discharge specific capacity at the surface current density exceeds 3000 mAh / g, and the areal specific capacity reaches 5.0 mAh·cm². -2 In conclusion, compared to existing silicon-based anodes, the electrochemical performance of the silicon-based alloy anode of this application is significantly improved.

[0028] The alloy negative electrode sheet obtained by this invention has a uniform thickness, and the ductility of the metal alleviates the stress concentration caused by the expansion of silicon during lithiation, thereby improving the solid-solid contact between the silicon-based electrode and the electrolyte and solving the problem of interface contact failure between the silicon-based electrode and the solid electrolyte. At the same time, the good conductivity helps to build an excellent interfacial electron-ion transport channel and improve the electrochemical performance of the all-solid-state battery.

[0029] To further illustrate the present invention, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Comparative Example 1 Micron-sized silicon particles and PAALi were added to a desktop ball mill at a mass ratio of 99.5:0.5 and ball milled to obtain an electrode slurry. The desktop ball mill was rotated at 3000 rpm, and each ball milling session lasted 180 seconds. The ball milling was repeated 5 times. The obtained electrode paste was coated onto copper foil and then transferred to a vacuum oven at 60°C to dry for 24 hours to obtain a silicon-based electrode sheet.

[0031] Example 1 Micron-sized silicon particles and PAALi were added to a desktop ball mill at a mass ratio of 99.5:0.5 and ball milled to obtain an electrode slurry. The desktop ball mill was rotated at 3000 rpm, and each ball milling session lasted 180 seconds. The ball milling was repeated 5 times. The obtained electrode paste was coated onto copper foil and then transferred to a vacuum oven at 60°C to dry for 24 hours to obtain a silicon-based electrode sheet.

[0032] The obtained silicon-based electrode was coated with indium by magnetron sputtering under the protection of argon atmosphere, and the thickness of the indium coating was 30 nm, thus obtaining an indium-silicon alloy negative electrode.

[0033] Example 2 Micron-sized silicon particles and PAALi were added to a desktop ball mill at a mass ratio of 99.5:0.5 and ball milled to obtain an electrode slurry. The desktop ball mill was rotated at 3000 rpm, and each ball milling session lasted 180 seconds. The ball milling was repeated 5 times. The obtained electrode paste was coated onto copper foil and then transferred to a vacuum oven at 60°C to dry for 24 hours to obtain a silicon-based electrode sheet.

[0034] The obtained silicon-based electrode was tin-plated by magnetron sputtering under the protection of argon atmosphere, and the tin plating thickness was 30nm, resulting in a tin-silicon alloy negative electrode.

[0035] Example 3 Micron-sized silicon particles and PAALi were added to a desktop ball mill at a mass ratio of 99.5:0.5 and ball milled to obtain an electrode slurry. The desktop ball mill was rotated at 3000 rpm, and each ball milling session lasted 180 seconds. The ball milling was repeated 5 times. The obtained electrode paste was coated onto copper foil and then transferred to a vacuum oven at 60°C to dry for 24 hours to obtain a silicon-based electrode sheet.

[0036] The obtained silicon-based electrode was coated with antimony by magnetron sputtering under the protection of argon atmosphere, and the thickness of the antimony coating was 30nm, thus obtaining an antimony-silicon alloy negative electrode.

[0037] Example 4 Micron-sized silicon particles and PAALi were added to a desktop ball mill at a mass ratio of 99.5:0.5 and ball milled to obtain an electrode slurry. The desktop ball mill was rotated at 3000 rpm, and each ball milling session lasted 180 seconds. The ball milling was repeated 5 times. The obtained electrode paste was coated onto copper foil and then transferred to a vacuum oven at 60°C to dry for 24 hours to obtain a silicon-based electrode sheet.

[0038] The obtained silicon-based electrode was coated with silver by magnetron sputtering under the protection of argon atmosphere, and the resulting silver coating thickness was 30nm, thus obtaining a silver-silicon alloy negative electrode.

[0039] Example 5 Micron-sized silicon particles and PAALi were added to a desktop ball mill at a mass ratio of 99.5:0.5 and ball milled to obtain an electrode slurry. The desktop ball mill was rotated at 3000 rpm, and each ball milling session lasted 180 seconds. The ball milling was repeated 5 times. The obtained electrode paste was coated onto copper foil and then transferred to a vacuum oven at 60°C to dry for 24 hours to obtain a silicon-based electrode sheet.

[0040] The obtained silicon-based electrode was coated with indium by magnetron sputtering under the protection of argon atmosphere, and the thickness of the indium coating was 500 nm, thus obtaining an indium-silicon alloy negative electrode.

[0041] Example 6 Micron-sized silicon particles and PAALi were added to a desktop ball mill at a mass ratio of 99.5:0.5 and ball milled to obtain an electrode slurry. The desktop ball mill was rotated at 3000 rpm, and each ball milling session lasted 180 seconds. The ball milling was repeated 5 times. The obtained electrode paste was coated onto copper foil and then transferred to a vacuum oven at 60°C to dry for 24 hours to obtain a silicon-based electrode sheet.

[0042] The obtained silicon-based electrode was coated with indium by magnetron sputtering under the protection of argon atmosphere, and the thickness of the indium coating was 1000 nm, thus obtaining an indium-silicon alloy negative electrode.

[0043] Example 7 Micron-sized silicon particles and PAALi were added to a desktop ball mill at a mass ratio of 99.5:0.5 and ball milled to obtain an electrode slurry. The desktop ball mill was rotated at 3000 rpm, and each ball milling session lasted 180 seconds. The ball milling was repeated 5 times. The obtained electrode paste was coated onto copper foil and then transferred to a vacuum oven at 60°C to dry for 24 hours to obtain a silicon-based electrode sheet.

[0044] The obtained silicon-based electrode was tin-plated by magnetron sputtering under the protection of argon atmosphere, and the tin plating thickness was 500nm, resulting in a tin-silicon alloy negative electrode.

[0045] Example 8 Micron-sized silicon particles and PAALi were added to a desktop ball mill at a mass ratio of 99.5:0.5 and ball milled to obtain an electrode slurry. The desktop ball mill was rotated at 3000 rpm, and each ball milling session lasted 180 seconds. The ball milling was repeated 5 times. The obtained electrode paste was coated onto copper foil and then transferred to a vacuum oven at 60°C to dry for 24 hours to obtain a silicon-based electrode sheet.

[0046] The obtained silicon-based electrode was tin-plated by magnetron sputtering under the protection of argon atmosphere, and the tin plating thickness was 1000nm, resulting in a tin-silicon alloy negative electrode.

[0047] Examples 9-12 Based on the preparation method provided in Example 8, different tin-silicon alloy negative electrode sheets were obtained by changing the active material, binder, and solvent. The active material was selected from nano-silicon, porous silicon, silicon oxide, silicon carbon, and porous silicon carbon. The binder was selected from acrylic acid derivative multi-component copolymer, sodium carboxymethyl cellulose, polyacrylonitrile, polyvinylidene fluoride, and styrene-butadiene rubber, as shown in Table 1. Table 1. Specific components of Examples 9-12

[0048] Comparative application examples Using a lithium-indium alloy as the counter electrode, the silicon-based electrode sheet prepared in Comparative Example 1 was cut into small circular pieces with a diameter of 10 mm to serve as the silicon-based anode. The loading of the silicon-based anode was 1.5 mg·cm⁻¹. -2 75 mg of Li5.5PS4.5Cl1.5 powder was weighed into an infrared mold with a diameter of 10 mm and held under a pressure of 3.5 t for 10 min to form an electrolyte disc. The disc was then assembled in a PEEK mold to obtain an all-solid-state battery. The entire assembly process was carried out in an argon-filled glove box.

[0049] Application Example 1 Using the indium-silicon alloy negative electrode sheet prepared in Example 1, an all-solid-state battery was assembled according to the method of the comparative application example.

[0050] Application Example 2 Using the tin-silicon alloy negative electrode sheet prepared in Example 2, an all-solid-state battery was assembled according to the method of the comparative application example.

[0051] Application Example 3 Using the antimony-silicon alloy negative electrode sheet prepared in Example 3, an all-solid-state battery was assembled according to the method of the comparative application example.

[0052] Application Example 4 Using the silver-silicon alloy negative electrode sheet prepared in Example 4, an all-solid-state battery was assembled according to the method of the comparative application example.

[0053] Application Example 5 Using NCM811 as the positive electrode, the active material loading of the positive electrode is 19.2 mg·cm³. -2 The indium-silicon alloy negative electrode sheet prepared in Example 5 was cut into small circular pieces with a diameter of 10 mm to serve as the negative electrode. The loading of the alloy negative electrode was 1.75 mg·cm³. -2 75 mg of Li5.5PS4.5Cl1.5 powder was weighed into an infrared mold with a diameter of 10 mm and held under a pressure of 3.5 t for 10 min to form an electrolyte disc. The disc was then assembled in a PEEK mold to obtain a full cell. The entire assembly process was carried out in an argon-filled glove box.

[0054] Application Example 6 Using the indium-silicon alloy negative electrode sheet prepared in Example 6, a full cell was assembled according to the method in Application Example 5. Application Example 7 Using the tin-silicon alloy negative electrode sheet prepared in Example 7, a full cell was assembled according to the method in Application Example 5. Application Example 8 Using the tin-silicon alloy negative electrode sheet prepared in Example 8, a full cell was assembled according to the method in Application Example 5. Test Example 1 The microstructure of the alloy negative electrode sheets provided in Examples 1, 2, 3, and 4 was observed using a scanning electron microscope, and SEM and EDS images were obtained, as shown below. Figure 1 As shown. From Figure 1 It can be seen that indium, tin, antimony, and silver in Examples 1-4 are uniformly distributed on the surface of the silicon-based electrode.

[0055] Test Example 2 The batteries assembled in Comparative Application Example and Application Examples 1-4 were placed on the LandCT2001A battery testing system for electrochemical performance testing. The test temperature was 25°C, and the voltage range was -0.59~0.9V vs. In / LiIn; with a current of 0.1mA·cm -2 After activation with a surface current density of 0.2 mA·cm⁻¹ for three cycles, -2 Long-cycle charge-discharge tests were performed using current density to obtain charge-discharge test curves, as shown below. Figure 2 As shown.

[0056] from Figure 2 As can be seen, the capacity of the batteries assembled using the comparative examples decreased rapidly. However, the batteries assembled using Examples 1-4 showed significantly improved cycle performance due to the metal coating between the silicon anode and the electrolyte. This confirms the effectiveness of the metal coating as an interface layer on the silicon anode surface. Furthermore, the metal coating did not affect the initial lithiation capacity of the batteries, which reached over 3000 mAh / g.

[0057] Test Example 3 The silicon-based anode in Test Example 2 after cycling was observed using a scanning electron microscope, such as... Figure 3 and Figure 4 As shown.

[0058] from Figure 3 It can be seen that the uncoated silicon electrode cracked into irregular blocks after long cycling, and micron-sized silicon particles were clearly visible inside the blocks. Figure 4As can be seen, the silicon electrode with the metal coating has a thin film-like substance on its surface. The electrode is cracked into pentagonal blocks, and the particles inside the blocks are tightly bonded together. This indicates that the metal coating plays a role in stabilizing the local electrode structure, improving the contact between the silicon anode and the electrolyte, reducing contact failure during cycling, and enhancing the cycle stability of the battery.

[0059] Test Example 4 The full cells assembled in Application Examples 5-8 were placed on the LandCT2001A battery testing system for electrochemical performance testing. The test temperature was 25°C, the voltage range was 2.0-4.25V, and the cells were cycled at a current density of 0.1C. The initial coulombic efficiency and the capacity of the first three cycles are shown in Table 2.

[0060] Table 2 shows the electrochemical performance of the full cells obtained from Application Examples 5-8.

[0061] As can be seen from Table 1, the full batteries assembled in Application Examples 5 to 8 all achieved an initial efficiency of over 80% and an initial charge specific capacity of over 240 mAh / g.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A silicon-based alloy anode for all-solid-state batteries, characterized in that, include: Current collector, silicon-based active material composite layer, surface metal layer, The silicon-based active material composite layer is coated on the current collector to form a silicon-based electrode. The surface metal layer is deposited on the surface of the silicon-based electrode. The silicon-based active material composite layer includes silicon-based active materials and binders. The surface metal layer is a metal plating layer deposited on the surface of the silicon-based electrode by magnetron sputtering.

2. The silicon-based alloy negative electrode according to claim 1, characterized in that, The metal in the metal coating is selected from one or more of indium, tin, antimony, silver and magnesium, and the thickness of the metal coating is 20~2000nm.

3. The silicon-based alloy negative electrode according to claim 1 or 2, characterized in that, The binder is selected from at least one of polyacrylic acid, acrylic acid derivative copolymers, sodium carboxymethyl cellulose, polyacrylonitrile, polyvinylidene fluoride and styrene-butadiene rubber. Optionally, the particle size D50 of the active material does not exceed 10 μm.

4. The silicon-based alloy negative electrode according to claim 3, characterized in that, The current collector is selected from either copper foil or stainless steel foil.

5. A method for preparing a silicon-based alloy negative electrode, characterized in that, Includes the following steps: A silicon-based active material, binder, and solvent are uniformly mixed to obtain an electrode paste; the active material is selected from one or more of micron-sized silicon, nano-sized silicon, porous silicon, silicon oxide, and silicon carbon. The electrode paste is coated onto the current collector and dried to obtain a silicon-based electrode sheet. A metal coating is deposited on the surface of the silicon-based electrode using magnetron sputtering; the metal in the metal coating is selected from one or more of indium, tin, antimony, silver and magnesium.

6. The preparation method according to claim 5, characterized in that, The drying process involves drying the silicon-based electrode in a vacuum oven at a temperature between 60 and 80°C for 24 hours. Optionally, the protective atmosphere during the magnetron sputtering process is argon.

7. The preparation method according to claim 5 or 6, characterized in that, The coating thickness is 20~2000nm, the sputtering time is 50~4000s, and the sputtering current is 15~30mA.

8. The preparation method according to claim 7, characterized in that, The adhesive is selected from at least one of polyacrylic acid, acrylic acid derivative multi-element copolymers, sodium carboxymethyl cellulose, polyacrylonitrile, polyvinylidene fluoride, and styrene-butadiene rubber.

9. The preparation method according to claim 8, characterized in that, Based on the electrode paste, the binder in the active material has a mass percentage content of 0.5-5%; optionally, the particle size D50 of the active material does not exceed 10 μm; optionally, the current collector is selected from copper foil and stainless steel foil.

10. A solid-state battery, characterized in that, The solid-state battery comprises a silicon-based alloy anode as described in any one of claims 1-4, or a silicon-based alloy anode obtained by the preparation method described in any one of claims 5-9.

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