Solid-state battery negative electrode material and preparation method and application thereof

Abstract

The invention belongs to the technical field of batteries, and particularly relates to a solid-state battery negative electrode material and a preparation method and application thereof. The solid-state battery negative electrode material is a silver-based MOFs derived carbon material, and a preparation method of the solid-state battery negative electrode material comprises the following steps: (1) dissolving a silver salt and an organic ligand in a solvent for solvothermal reaction, continuously stirring in the reaction process, and purifying after the reaction is finished to obtain a silver-based MOFs material; (2) carrying out drying treatment on the silver-based MOFs material to remove a solvent in pore channels; and (3) putting the silver-based MOFs material treated in the step (2) into a high-temperature furnace, slowly heating to 600-800 DEG C in an inert gas atmosphere for pyrolysis, and cooling to obtain the silver-based MOFs derived carbon material. In the negative electrode material, the silver particles are uniformly dispersed in the carbon material to inhibit lithium dendrites, solid electrolyte does not need to be added, and the energy density is improved; mOFs are used as a negative electrode framework, macroscopic volume expansion and shrinkage are greatly reduced during lithium deposition and separation, and the problem of service life is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of batteries, and in particular relates to a solid-state battery negative electrode material and a preparation method thereof, as well as a battery using the material. Background Art

[0002] Negative electrode materials are key materials for lithium-ion batteries. When charging, lithium ions migrate through the electrolyte and are embedded in the negative electrode materials for storage; when discharging, lithium ions escape from the negative electrode and return to the positive electrode, and power the device through the flow of electrons in the external circuit. Negative electrode materials are the key determinant of battery performance and need to strike a balance between capacity, stability, and conductivity. Especially in all-solid-state batteries, negative electrode materials are closely related to electrical properties and play a decisive role in key performance factors such as energy density, cycle stability, and safety. In the emerging field of all-solid-state batteries, the performance of negative electrode materials has become a key bottleneck restricting their commercial application. It is necessary to achieve a precise balance between ion transmission efficiency, volume deformation control, and interface stability to meet the stringent requirements of high-energy-density application scenarios.

[0003] In the existing technology, the development of negative electrode materials faces the following technical bottlenecks and challenges: As the mainstream commercial negative electrode, graphite material has the advantages of low cost and low volume expansion rate after lithium insertion (about 10%), but its theoretical specific capacity is only 372mAh / g, which seriously limits the improvement of battery energy density. In all-solid-state batteries, the graphite negative electrode needs to be supplemented with solid electrolytes to ensure ion conduction, which further reduces the volume energy density and makes it difficult to meet the needs of high energy density application scenarios.

[0004] Lithium metal materials have a high specific capacity, with a theoretical specific capacity of 3860mAh / g. They can be used directly as a lithium source, but repeated deposition / dissolution of lithium causes the electrode to expand and contract, destroying the structure and reducing the cycle life. After lithium metal completely leaves the negative electrode, the volume of the negative electrode side changes greatly, and it cannot be deposited evenly after returning, thus forming dendrites, which may pierce the diaphragm and cause a short circuit, posing a safety hazard. Lithium metal is soft and easy to deform. In an all-solid-state battery, it may deform once it is subjected to pressure, resulting in uneven lithium insertion. Especially under high pressure (isostatic pressing or cycling), the lithium metal electrode is deformed by rolling, affecting the NP ratio, resulting in deviation from the design and causing failure.

[0005] To alleviate the volume expansion problem, CN118763172A in situ composites the active material nano-silicon with MOFs-derived carbon, and uses carbon nanotubes to form a three-dimensional conductive network. However, nano-silicon and carbon nanotubes are easy to agglomerate in solvents, and the ultrasonic dispersion uniformity is poor. In addition, the pre-added nanomaterials will interfere with the uniform formation of the MOFs skeleton and introduce structural defects. This type of silicon-carbon composite material still requires the addition of electrolytes, and is only applicable to traditional lithium-ion batteries and cannot be directly applied to solid-state battery systems.

[0006] In order to solve the problem of lithium dendrites, CN118763172A mixes the pretreated three-dimensional porous skeleton with the metal organic framework material; then transfers it to a muffle furnace for carbonization; then melts the liquid metal lithium and pours it onto the entire skeleton to obtain a new three-dimensional metal lithium negative electrode. This process relies on growing metal oxides on a foam metal substrate, which has complex steps and high costs. In addition, the large-aperture skeleton is prone to collapse and deformation when subjected to stress, which limits its practicality in all-solid-state batteries.

[0007] Existing all-solid-state battery negative electrode materials generally have inherent defects: once the current density is uneven or the interface changes, lithium ions are very likely to deposit on the electrode surface, causing the growth of lithium dendrites, ultimately leading to life deterioration or short circuit.

[0008] To solve this inherent defect, Ag / C composite materials use a composite structure in which nanosilver particles are dispersed in a porous carbon matrix, using silver to induce uniform lithium deposition and reduce the risk of dendrite puncture. At the same time, lithium ions can be deposited into the structure of porous carbon, and the specific capacity can reach 500-900mAh / g. However, this solution also has disadvantages. When nanosilver particles are dispersed in porous carbon by mechanical stirring or high-energy ball milling, the nanosilver particles are easy to agglomerate and the dispersion effect is not good. Therefore, it is very easy to cause the local lack of the effect of inducing uniform deposition of lithium ions, resulting in lithium precipitation. In addition, the dispersion of silver particles is very random and cannot be designed in a directional manner, which further limits its performance optimization and application potential.

[0009] In summary, the development of all-solid-state battery negative electrode materials urgently needs to solve the problem of uniform dispersion of silver particles in carbon materials, while meeting stringent requirements such as rapid ion transmission, controllable volume deformation and interface stability. Promoting the development of negative electrode materials towards higher energy density, longer life and faster charging through material innovation and structural design is not only the key to improving the performance of lithium-ion batteries, but also an important driving force for technological innovation in electric vehicles, energy storage systems and other fields. Therefore, exploring new negative electrode materials or improving the dispersion technology of existing materials to maximize energy density has become a hot topic and frontier of current research. Summary of the invention

[0010] The present invention aims to provide a negative electrode material with a novel structural design, which can solve the problem of poor dispersion uniformity of silver particles in carbon materials.

[0011] To achieve the above object, the present invention provides the following technical solutions: A method for preparing a negative electrode material for a solid-state battery, wherein the negative electrode material for the solid-state battery is a silver-based MOFs-derived carbon material, and the preparation method comprises the following steps: (1) dissolving silver salt and organic ligand in a solvent for solvothermal reaction, stirring continuously during the reaction, and purifying after the reaction to obtain silver-based MOFs material; (2) drying the silver-based MOFs material to remove the solvent in the pores; (3) placing the silver-based MOFs material treated in step (2) in a high-temperature furnace, slowly heating the temperature to 600-800° C. in an inert gas atmosphere for pyrolysis, and cooling to obtain a silver-based MOFs-derived carbon material; The molar ratio of the silver salt to the organic ligand in step (1) is (1:1)-(3:1), and the stirring conditions are: stirring at 200-400 rpm for 6-18 hours, then stirring at 50-150 rpm for 4-10 hours, and then stirring at 5-40 rpm for 4-16 hours.

[0012] When the pyrolysis temperature exceeds 800°C, the MOFs-derived carbon framework is prone to irreversible collapse due to a significant decrease in structural stability, resulting in a serious degradation of the electrode cycle performance. When it exceeds 900°C, Ag volatilizes, causing the derived carbon to lose the ability to induce uniform deposition of lithium ions. When the temperature is lower than 600°C, it is not enough to drive the effective carbonization process of the MOFs material, indicating that the pyrolysis temperature needs to be precisely controlled in a moderate range to simultaneously achieve structural integrity and carbonization effect.

[0013] Optionally, the silver salt is selected from at least one of silver nitrate, silver acetate, silver chloride or silver carbonate.

[0014] Optionally, the solvent is selected from one or a mixture of two or more of N,N-dimethylformamide (DMF), water or ethanol.

[0015] Optionally, the organic ligand is an organic compound containing multiple coordination sites. Preferably, the organic ligand is selected from polycarboxylic acid compounds, hydroxyl-substituted polycarboxylic acid compounds, imidazole compounds or tetrazole compounds.

[0016] By controlling the ratio of silver salt and organic ligand, the loading amount of Ag in silver-based MOFs-derived carbon materials can be effectively controlled.

[0017] In the specific implementation, the silver salt, organic ligand and solvent can be selected according to the specific silver-based MOFs material to be prepared. For example, the organic ligand is selected as trimesic acid, and the prepared silver-based MOFs material is Ag-BTC material. 3 With H 3When the molar ratio of BTC is adjusted from 1:1 to 2:1, the loading amount of Ag increases significantly, and more Ag nanoclusters appear in the MOFs framework. When the silver-based MOFs material to be prepared is Ag-MOF-74 material, the organic ligand can be selected from 2,5-dihydroxyterephthalic acid. When the silver-based MOFs material to be prepared is Ag-ZIF material, the organic ligand is usually selected from imidazole compounds, such as 2-methylimidazole and benzimidazole. When the silver-based MOFs material to be prepared is Ag-TAZ material, the organic ligand is usually selected from tetrazole compounds, such as 5-aminotetrazole and 5-methyltetrazole.

[0018] Preferably, the temperature of the solvent thermal reaction is 80-120° C., and the reaction time is 14-44 hours.

[0019] Preferably, in step (2), the drying treatment is vacuum drying, the vacuum drying temperature is 50-120° C., and the drying time is 6-24 hours.

[0020] Optionally, the inert gas is selected from at least one of argon, nitrogen or helium.

[0021] Preferably, the rate of the slow heating is 2-10°C / min.

[0022] Specifically, a method for preparing a solid-state battery negative electrode material comprises the following steps: (1) AgNO 3 With organic ligand H 3 BTC (trimethylbenzene trimesic acid) is dissolved in water and heated to 80–120°C in a closed reactor for 14–44 hours with continuous stirring during the reaction. After the reaction, the Ag-BTC (silver trimesic acid) material is obtained by cooling, filtering, washing and drying. The AgNO 3 The molar ratio of the organic ligand to the organic ligand is (1:1)-(3:1), and the stirring conditions are: stirring at 200-400 rpm for 6-18 hours, then stirring at 50-150 rpm for 4-10 hours, and then stirring at 5-40 rpm for 4-16 hours; (2) vacuum drying the Ag-BTC material (drying temperature 50-120°C, drying time 6-24 hours) to remove the solvent in the pores; (3) Place the Ag-BTC material treated in step (2) in a tube furnace and introduce Ar or N into the tube furnace. 2 (flow rate 50–100 mL / min), excluding oxygen; The temperature is slowly increased to 600-800°C at a heating rate of 2-10°C / min in an inert gas atmosphere for pyrolysis, and the silver-based MOFs-derived carbon material is obtained after natural cooling.

[0023] The present invention also provides a battery, comprising a solid-state battery negative electrode material prepared by the method described above.

[0024] The silver-based MOFs-derived carbon material prepared by the method of the present invention utilizes the manufacturing characteristics of silver-based MOFs so that silver can be evenly distributed in the material at the atomic level; after the MOFs material is carbonized, the skeleton can provide abundant lithium storage sites as a negative electrode lithium storage material, and silver plays a role in inducing lithium deposition.

[0025] Compared with the prior art, the negative electrode material of the present invention has the following advantages: The present invention combines the porous characteristics of MOFs materials with the structural design of Ag / C composite materials, and simultaneously solves the problems of volume expansion and nanosilver dispersion, becoming an important breakthrough in the innovation of all-solid-state battery negative electrode materials. Silver particles are evenly dispersed in carbon materials, and the position arrangement of Ag particles can be designed to ensure overall uniformity and good conductivity; when making the negative electrode of the battery, it has the effect of inducing uniform lithium deposition, solving the problem of lithium dendrites easily generated in the negative electrode materials of the prior art, and at the same time, there is no need to add solid electrolytes, which improves the energy density; using this structure as the negative electrode skeleton, the macroscopic volume expansion and contraction is greatly reduced during lithium deposition and extraction, solving the life problem. DETAILED DESCRIPTION

[0026] In order to enable those skilled in the art to better understand the technical solutions in the present application, the present invention will be further described below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work should belong to the scope of protection of the present application. The relevant descriptions involving the number of parts and proportions in this specification, unless otherwise specified, refer to weight.

[0027] Example 1 A method for preparing a silver-based MOFs-derived carbon material comprises the following steps: (1) AgNO with a molar ratio of 3:1 3 With organic ligand H 3 BTC (trimethylbenzene trimesic acid) was dissolved in water and heated to 100°C in a closed reactor for 24 hours. The mixture was stirred continuously during the reaction: first stirred at 250 rpm for 12 hours, then stirred at 100 rpm for 6 hours, and then stirred at 25 rpm for 6 hours. After the reaction, the mixture was cooled, filtered, washed, and dried to obtain Ag-BTC (silver trimesic acid) material. (2) The Ag-BTC material was vacuum dried (drying temperature 60°C, drying time 12 hours) to remove the solvent in the pores; (3) Place the Ag-BTC material treated in step (2) in a tube furnace and introduce N 2 (flow rate 60 mL / min), excluding oxygen; in N 2 The temperature was slowly increased to 600°C at a heating rate of 5°C / min under a gas atmosphere for pyrolysis, and the silver-based MOFs-derived carbon material was obtained after natural cooling.

[0028] Example 2 All-solid-state lithium-ion battery preparation process (dry method): 1. Preparation of positive electrode sheet: Based on 100 parts of positive electrode formula, 80 parts of lithium nickel cobalt manganese oxide (NCM811), 3 parts of conductive carbon black (Super-P), 2 parts of polytetrafluoroethylene (PTFE) and Li 6 PS 5 After 15 parts of Cl solid electrolyte are evenly mixed, the film is formed by a dry electrode process and then coated on the surface of the aluminum foil current collector, and then punched into a positive electrode sheet.

[0029] 2. Preparation of negative electrode sheet: Silver-based MOFs-derived carbon material pyrolyzed at 600°C (i.e., the silver-based MOFs-derived carbon material prepared in Example 1) was used as the negative electrode active material. Based on 100 parts of the negative electrode formula, 97 parts of silver-based MOFs-derived carbon material, 1 part of conductive carbon black (Super-P) and 2 parts of PTFE were evenly mixed, formed into a film through a dry electrode process, and then hot-pressed on the surface of a copper foil current collector, and punched into a negative electrode sheet.

[0030] 3. Preparation of solid electrolyte membrane: Li 6 PS 5 After 98 parts of Cl and 2 parts of PTFE are evenly mixed, the mixture is formed into a film by dry rolling, and then a solid electrolyte membrane is obtained by punching.

[0031] 4. Battery assembly: The sandwich structure of positive electrode sheet / solid electrolyte membrane sheet / negative electrode sheet is stacked in sequence to construct a stack consisting of 39 layers of positive electrode sheets and 40 layers of negative electrode sheets, ensuring close contact between the layers. The stack is placed in the battery casing, and after vacuum packaging, it is further compacted by isostatic pressing to finally obtain an all-solid-state lithium-ion battery.

[0032] Example 3 The preparation process of the all-solid-state lithium-ion battery is the same as that of Example 2, except that the silver-based MOFs-derived carbon material pyrolyzed at 800°C is used as the negative electrode active material in this embodiment. Among them, the preparation process of the silver-based MOFs-derived carbon material pyrolyzed at 800°C is the same as that of Example 1, except that the pyrolysis temperature is 800°C.

[0033] Example 4 A method for preparing a silver-based MOFs-derived carbon material comprises the following steps: (1) AgNO with a molar ratio of 1:1 3 With organic ligand H 3 BTC (trimethylbenzene trimesic acid) was dissolved in water, heated to 120°C in a closed reactor and reacted for 14 hours. Stirring was continued during the reaction: first stirring at 400 rpm for 6 hours, then stirring at 150 rpm for 4 hours, and then stirring at 40 rpm for 4 hours. After the reaction, the mixture was cooled, filtered, washed, and dried to obtain Ag-BTC (silver trimesic acid) material. (2) The Ag-BTC material was vacuum dried (drying temperature 60°C, drying time 12 hours) to remove the solvent in the pores; (3) Place the Ag-BTC material treated in step (2) in a tube furnace and introduce N 2 (flow rate 60 mL / min), excluding oxygen; in N 2 The temperature was slowly increased to 600°C at a heating rate of 5°C / min under a gas atmosphere for pyrolysis, and the silver-based MOFs-derived carbon material was obtained after natural cooling.

[0034] The silver-based MOFs-derived carbon material prepared above is used as the negative electrode active material, and the preparation process of the all-solid-state lithium-ion battery is the same as that in Example 2. Example 5 A method for preparing a silver-based MOFs-derived carbon material comprises the following steps: (1) AgNO with a molar ratio of 1:1 3 With organic ligand H 3 BTC (trimethylbenzene trimesic acid) was dissolved in water and heated to 80°C in a closed reactor for 44 hours. The reaction was stirred continuously during the reaction: first stirred at 200 rpm for 18 hours, then stirred at 50 rpm for 10 hours, and then stirred at 5 rpm for 16 hours. After the reaction, the mixture was cooled, filtered, washed, and dried to obtain Ag-BTC (silver benzene trimesic acid) material. (2) The Ag-BTC material was vacuum dried (drying temperature 60°C, drying time 12 hours) to remove the solvent in the pores; (3) Place the Ag-BTC material treated in step (2) in a tube furnace and introduce N 2 (flow rate 60 mL / min), excluding oxygen; in N 2 The temperature was slowly increased to 600°C at a heating rate of 5°C / min under a gas atmosphere for pyrolysis, and the silver-based MOFs-derived carbon material was obtained after natural cooling.

[0035] The silver-based MOFs-derived carbon material prepared above is used as the negative electrode active material, and the preparation process of the all-solid-state lithium-ion battery is the same as that in Example 2. Comparative Example 1 The preparation process of the all-solid-state lithium-ion battery is the same as that of Example 2, except that the negative electrode formula of this comparative example contains only graphite, and graphite is used as the negative electrode active material.

[0036] Comparative Example 2 The preparation process of the all-solid-state lithium-ion battery is the same as that of Example 2, except that graphite is used as the negative electrode active material in this comparative example. Based on 100 parts of the negative electrode formula, graphite is 87 parts, and Li 6 PS 5 Cl solid electrolyte 10 parts, conductive agent Super-P 1 part, PTFE 2 parts.

[0037] Comparative Example 3 The preparation process of the all-solid-state lithium-ion battery is the same as that of Example 2, except that the negative electrode formula of this comparative example contains only lithium metal, and lithium metal is used as the negative electrode active material.

[0038] Comparative Example 4 The preparation process is the same as that of Example 2, except that this comparative example uses Ag / C as the negative electrode active material. Based on 100 parts of the negative electrode formula, there are 97 parts of Ag / C, 1 part of the conductive agent Super-P, and 2 parts of PTFE.

[0039] Comparative Example 5 The preparation process of the all-solid-state lithium-ion battery is the same as that of Example 2, except that the silver-based MOFs-derived carbon material treated at 1000°C is used as the negative electrode active material in this embodiment. Among them, the preparation process of the silver-based MOFs-derived carbon material pyrolyzed at 1000°C is the same as that of Example 1, except that the pyrolysis temperature is 1000°C.

[0040] Comparative Example 6 A method for preparing a silver-based MOFs-derived carbon material comprises the following steps: (1) AgNO with a molar ratio of 3:1 3 With organic ligand H 3 BTC (trimethylbenzene trimesic acid) was dissolved in water, heated to 100°C in a closed reactor for 24 hours, and stirred at 25 rpm during the reaction; after the reaction, the mixture was cooled, filtered, washed, and dried to obtain Ag-BTC (silver benzene trimesic acid) material; (2) The Ag-BTC material was vacuum dried (drying temperature 60°C, drying time 12 hours) to remove the solvent in the pores; (3) Place the Ag-BTC material treated in step (2) in a tube furnace and introduce N 2 (flow rate 60 mL / min), excluding oxygen; in N 2 The temperature was slowly increased to 600°C at a heating rate of 5°C / min under a gas atmosphere for pyrolysis, and the silver-based MOFs-derived carbon material was obtained after natural cooling.

[0041] The silver-based MOFs-derived carbon material prepared above is used as the negative electrode active material, and the preparation process of the all-solid-state lithium-ion battery is the same as that in Example 2. Comparative Example 7 A method for preparing a silver-based MOFs-derived carbon material comprises the following steps: (1) AgNO with a molar ratio of 3:1 3 With organic ligand H 3 BTC (trimethylbenzene trimesic acid) was dissolved in water, heated to 100°C in a closed reactor for 24 hours, and stirred at 500 rpm during the reaction; after the reaction, the mixture was cooled, filtered, washed, and dried to obtain Ag-BTC (silver benzene trimesic acid) material; (2) The Ag-BTC material was vacuum dried (drying temperature 60°C, drying time 12 hours) to remove the solvent in the pores; (3) Place the Ag-BTC material treated in step (2) in a tube furnace and introduce N 2 (flow rate 60 mL / min), excluding oxygen; in N 2 The temperature was slowly increased to 600°C at a heating rate of 5°C / min under a gas atmosphere for pyrolysis, and the silver-based MOFs-derived carbon material was obtained after natural cooling.

[0042] The silver-based MOFs-derived carbon material prepared above is used as the negative electrode active material, and the preparation process of the all-solid-state lithium-ion battery is the same as that in Example 2. The performance of the all-solid-state lithium-ion batteries prepared in the examples and comparative examples is shown in Table 1.

[0043] Table 1 When the battery is cycled at a rate of 1C and the capacity retention rate decays from the initial 100% SOH to 80% SOH, the number of cycles experienced is the cycle life. It can be seen from the results in Table 1 that the energy density and life of the battery are significantly optimized by using the silver-based MOFs-derived carbon material prepared by the present invention as the negative electrode active material. The higher the pyrolysis temperature of the silver-based MOFs-derived carbon material, the higher the porosity, the stronger the lithium storage capacity, and thus the higher the energy density. However, when the pyrolysis temperature exceeds 800°C, the MOFs-derived carbon framework is prone to irreversible collapse due to a significant decrease in structural stability, resulting in a serious decline in the electrode cycle performance. When the pyrolysis temperature exceeds 900°C (for example, 1000°C in Comparative Example 5), Ag volatilizes, causing the derived carbon to lose the ability to induce uniform deposition of lithium ions, and there is no solid electrolyte in the negative electrode, and lithium ions cannot be transmitted, so the capacity is lost. In Comparative Example 6, the Ag dispersion is uneven and Ag is missing or insufficient locally due to the continuous low stirring speed, and the energy density and cycle life are significantly reduced. Although Comparative Example 7 improves the Ag dispersion by increasing the stirring speed, it inhibits the crystal nucleus growth process and cannot construct an effective continuous skeleton structure, but instead greatly reduces the energy density.

Claims

1. A method for preparing a negative electrode material for a solid-state battery, characterized in that: The solid-state battery negative electrode material is a silver-based MOFs-derived carbon material, and the preparation method comprises the following steps: (1) dissolving silver salt and organic ligand in a solvent for solvothermal reaction, stirring continuously during the reaction, and purifying after the reaction to obtain silver-based MOFs material; (2) drying the silver-based MOFs material to remove the solvent in the pores; (3) placing the silver-based MOFs material treated in step (2) in a high-temperature furnace, slowly heating the temperature to 600-800° C. in an inert gas atmosphere for pyrolysis, and cooling to obtain a silver-based MOFs-derived carbon material; The molar ratio of the silver salt to the organic ligand in step (1) is (1:1)-(3:1), and the stirring conditions are: stirring at 200-400 rpm for 6-18 hours, then stirring at 50-150 rpm for 4-10 hours, and then stirring at 5-40 rpm for 4-16 hours.

2. The preparation method according to claim 1, characterized in that: The silver salt is selected from at least one of silver nitrate, silver acetate, silver chloride or silver carbonate.

3. The preparation method according to claim 1, characterized in that: The solvent is selected from N,N-dimethylformamide, water or ethanol, or a mixture of two or more thereof.

4. The preparation method according to claim 1, characterized in that: The organic ligand is an organic compound containing multiple coordination sites.

5. The preparation method according to claim 4, characterized in that: The organic ligand is selected from polycarboxylic acid compounds, hydroxyl-substituted polycarboxylic acids, imidazole compounds or tetrazole compounds.

6. The preparation method according to claim 4, characterized in that: The organic ligand is trimesic acid, 2,5-dihydroxyterephthalic acid, 2-methylimidazole, benzimidazole, 5-aminotetrazolyl or 5-methyltetrazolyl.

7. The preparation method according to claim 1, characterized in that: The temperature of the solvent thermal reaction is 80-120° C., and the reaction time is 14-44 hours.

8. The preparation method according to claim 1, characterized in that: The rate of the slow heating is 2-10°C / min.

9. A solid-state battery negative electrode material, characterized in that: The method is prepared by any one of claims 1 to 8.

10. A battery, characterized in that: Comprising the solid-state battery negative electrode material as described in claim 9.

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