High-rate long-cycle porous silicon-based negative electrode material and preparation method thereof

Abstract

The invention discloses a high-rate long-cycle porous silicon-based negative electrode material and a preparation method thereof, and relates to the field of battery negative electrodes and lithium ion batteries. The preparation method of the high-magnification long-cycle porous silicon-based negative electrode material comprises the following steps: firstly, heating a binary or ternary silicon-metal alloy serving as a raw material in a vacuum atmosphere to volatilize metal components; then, dissolving the obtained porous silicon in deionized water or an organic solvent, adding a small amount of weakly alkaline substances to form a solution, and preparing a precursor solution for generating an oxide solid electrolyte at the same time; mixing the two, forming a solid electrolyte layer in situ in pores and the surface of the porous silicon, and centrifuging or filtering and drying to obtain the porous silicon of the composite solid electrolyte; the porous silicon prepared by the preparation method disclosed by the invention is relatively uniform in pore diameter and relatively stable in structure, and the cycle performance and the rate performance of the battery are improved.

Description

Technical Field

[0001] This invention relates to the fields of battery anodes and lithium-ion batteries, and particularly to a high-rate, long-cycle porous silicon-based anode material and its preparation method. Background Technology

[0002] In recent years, with the increasingly urgent need for the development of high-energy-density lithium-ion batteries, silicon-based anode materials, due to their ultra-high theoretical specific capacity (approximately 4200 mAh / g), suitable operating voltage platform, and abundant resource reserves, are considered one of the most promising anode materials for breaking through the current energy density bottleneck. Currently, silicon-based anode materials have been first applied in batches in fields such as 3C consumer electronics, power tools, and drones, and are gradually expanding into the power battery field. The market size is showing a year-on-year upward trend and is expected to usher in explosive growth.

[0003] The most mature silicon-based anode material currently in use is a silicon-carbon composite material made by depositing nano-silicon particles in the pores of porous carbon and then coating the surface with carbon. This type of material fully utilizes the structural advantages of the porous carbon matrix, effectively accommodating the volume expansion of silicon during charging and discharging. At the same time, the carbon coating layer can stabilize the electrode / electrolyte interface and improve electronic conductivity, thus giving the material a comprehensive performance of high capacity, low expansion, and excellent cycle performance. Its electrochemical performance is significantly better than that of traditional silicon-based anode materials.

[0004] Porous silicon, as an important branch of silicon-based anode materials, exhibits significant application advantages due to its unique pore structure. Firstly, its interconnected pore network provides a buffer space for the volume expansion of silicon during lithium-ion insertion / extraction, effectively alleviating mechanical stress at the electrode level and suppressing electrode pulverization and structural collapse. Secondly, the porous structure provides a large specific surface area, facilitating thorough electrolyte wetting, increasing contact sites between the electrolyte and active material, and promoting interfacial transport of lithium ions. Furthermore, the porous structure shortens the diffusion path of lithium ions in the solid phase, reducing electrochemical polarization and contributing to improved rate performance. Methods for preparing porous silicon mainly include template methods, magnesothermic reduction methods, metal-assisted chemical etching methods, and electrochemical etching methods. For example, patent CN 107742715B proposes a method for preparing nanoporous silicon by placing a nano-silicon-based alloy in a vacuum heat treatment furnace and gradually volatilizing volatile alloying elements through heating. This method is relatively simple and does not require the introduction of additional templates or etching agents.

[0005] Oxide solid electrolytes (OSEs) have been widely used in recent years for the modification and performance optimization of silicon-based anode materials due to their excellent chemical stability, high room-temperature ionic conductivity, and high lithium-ion transference number. They are not only used in the preparation of electrolyte films for solid-state batteries but are also often introduced into silicon-based anode systems as doping phases or coating layers to improve interface stability and ion transport kinetics. Patent CN119252894A describes a method for preparing a carbon-silicon composite material with high lithium-ion transport rates by mixing and reacting lithium, lanthanum, and titanium source compounds with a carbon source compound, followed by carbonization, activation, and deposition of nano-silicon particles. This method improves the problem of poor intrinsic electronic conductivity of silicon to some extent. However, the resulting product has an uneven particle size distribution, which adversely affects electrode processing performance, and large-scale mass production still faces challenges. Patent CN118016985A provides a method for preparing a solid electrolyte-coated porous silicon-carbon material. This method involves preparing a solid electrolyte solution to impregnate porous silicon-carbon powder, drying it, and then laser sintering it to obtain a composite material coated with a solid electrolyte layer. However, this technical solution is difficult to achieve uniform coating of the electrolyte layer, and the laser sintering process increases the material preparation cost, which limits its large-scale promotion.

[0006] In summary, existing technical solutions for silicon-based anodes mainly focus on the modification of porous carbon, while research on the modification and performance of porous silicon is relatively limited. The lack of reasonable structural design and control has resulted in the underutilization of the performance of porous silicon-based materials. Summary of the Invention

[0007] To overcome the shortcomings of existing porous silicon-based anode materials in achieving both rapid ion / electron transport and structural stability under high-rate charge-discharge conditions, this application provides a high-rate, long-cycle porous silicon-based anode material and its preparation method.

[0008] In a first aspect, this application provides a method for preparing a high-rate, long-cycle porous silicon-based anode material, comprising the following preparation steps:

[0009] 1) Purchased or self-made binary or ternary porous silicon alloys are heated and calcined under vacuum conditions to volatilize the volatile components in the alloy and obtain porous silicon particles.

[0010] 2) Disperse the porous silicon particles obtained in step 1) in deionized water or an organic solvent, add a weak alkaline substance to form solution A; disperse the raw materials of each component used to generate the oxide solid electrolyte in deionized water or an organic solvent to form solution B;

[0011] 3) Mix solutions A and B to obtain mixed solution C, and dry the mixed solution to obtain precursor powder material;

[0012] 4) Using vapor phase deposition, an amorphous carbon coating layer is formed on the surface of the precursor powder material obtained in step 3), resulting in a porous silicon-based anode material.

[0013] Preferably, the molar concentration of lithium in solution B is in the range of 0.001-0.05 mol / ml; and the mass concentration of porous silicon particles in solution A is in the range of 0.1-0.5 g / ml.

[0014] Furthermore, in step 1), the self-made silicon alloy is prepared by ball milling or melting gas atomization of different metal components, and the metal components in the porous silicon alloy are one or two of lithium, magnesium, aluminum, sodium, potassium, barium, rubidium, cesium, calcium and gallium.

[0015] Optionally, the mass of metallic elements in porous silicon alloys can be 20% to 60%.

[0016] The conventional method for preparing porous silicon in the industry involves the thermal reduction reaction of SiO2 with metals Al or Mg: 3SiO2 + 4Al → 2Al2O3 + 3Si or SiO2 + 2Mg → 2MgO + Si. The Al2O3 / MgO components are then removed by acid washing to obtain porous silicon. However, the aluminum / magnesium thermal reduction reaction is exothermic and may lead to severe local overheating and agglomeration, resulting in uneven pore size and poor product performance. Therefore, this invention uses alloy evaporation to prepare porous silicon, which allows for adjustable pore structure and eliminates the need for subsequent steps such as acid washing, simplifying the process. Furthermore, the in-situ liquid-phase generation of solid electrolytes within the porous silicon pores is a first-time proposal in this invention. Compared to other physical mixing methods such as ball milling, the solid electrolytes offer controllable size and more uniform distribution within the porous silicon pores, contributing to the material's electrical properties.

[0017] Furthermore, in step 1), the heating and calcination process is carried out at a temperature of 500~1500℃ and a vacuum degree of -0.1~0MPa.

[0018] Furthermore, in step 1), the specific surface area is 52~200 m². 2 / g, and the volume ratio of macropores above 50nm is 40~60%.

[0019] Preferably, the obtained porous silicon particles have a particle size of 5-50 μm and a pore volume of 0.3-0.8 cm³. 3 / g, the pore size is mainly mesopores and macropores, with pore sizes ranging from 5 to 200 nm.

[0020] Further, in step 2), the organic solvent is any one or a combination of ethanol, methanol, benzene, toluene, acetone, and diethyl ether, and the weak alkaline substance is any one or a combination of ammonia, urea, and ammonium bicarbonate. The molar ratio of the weak alkaline substance added to the porous silicon is 0.05~0.5:1.

[0021] Further, in step 2), the oxide solid electrolyte is one of lithium lanthanum zirconium oxide (LLZO), lithium lanthanum zirconium tantalum oxide (LLZTO), lithium lanthanum titanium oxide (LLTO), lithium titanium aluminum phosphate (LATP), and lithium germanium aluminum phosphate (LAGP).

[0022] The raw materials used to generate oxide solid electrolytes include at least two of the following: lithium source, lanthanum source, zirconium source, titanium source, aluminum source, phosphorus source, and germanium source.

[0023] The lithium source includes one or more of lithium hydroxide, lithium carbonate, lithium acetate, lithium sulfate, lithium chloride, lithium nitrate, lithium dihydrogen phosphate, and lithium hydrogen phosphate.

[0024] The lanthanum source includes one or more of lanthanum nitrate, lanthanum oxide, lanthanum hydroxide, lanthanum chloride, lanthanum sulfate, and lanthanum acetate;

[0025] The zirconium source includes one or more of zirconium nitrate, zirconium chloride, zirconium sulfate, and zirconium acetate;

[0026] The titanium source includes one or more of titanium oxide, tetraethyl titanate, tetrabutyl titanate, titanium tetrachloride, and isopropyl titanate.

[0027] The aluminum source is one of aluminum oxide, aluminum hydroxide, and aluminum sulfate;

[0028] The phosphorus source is one of phosphoric acid, ammonium dihydrogen phosphate, and diammonium hydrogen phosphate;

[0029] The germanium source is germanium dioxide; the tantalum source is tantalum pentoxide.

[0030] Furthermore, the raw materials used to generate the oxide solid electrolyte include lithium source, aluminum source, titanium source and phosphorus source;

[0031] The molar ratio of lithium, aluminum, titanium, phosphorus and porous silicon contained in the lithium source, aluminum source, titanium source and phosphorus source, respectively, is 1-3:0.1-1:0.5-3:1-5:10-100.

[0032] Furthermore, in step 3), the drying method of the mixed solution is one of blower drying, spray drying, or freeze drying.

[0033] Furthermore, in step 4) vapor deposition, the carbon source gas used is one of acetylene, methane, propylene, acetone, or natural gas, and the carrier gas is one of nitrogen, argon, or helium. The ratio of carrier gas to carbon source gas is 1-5:1, the surface carbon coating temperature is 800-1000℃, and the coating time is 2-8h.

[0034] Secondly, this application provides a high-rate, long-cycle porous silicon-based anode material, prepared by the method described in any one of claims 1-9; it comprises porous silicon, oxide solid electrolyte particles attached to the pores and surface of the porous silicon, and an amorphous carbon coating layer covering the outermost layer of the porous silicon.

[0035] Optionally, porous silicon can be an irregular blocky, spherical, or near-spherical structure.

[0036] Beneficial effects: 1. This application provides a high-rate, long-cycle porous silicon-based anode material and its preparation method. First, a binary or ternary silicon-metal alloy is used as raw material and heated under a vacuum atmosphere to volatilize the volatile components in the silicon alloy, leaving a porous silicon framework. Then, the obtained porous silicon is dissolved in deionized water or an organic solvent, and a small amount of weakly alkaline substance is added to form a solution. At the same time, a precursor solution for generating an oxide solid electrolyte is prepared. The two are mixed to form a solid electrolyte layer in situ in the pores and surface of the porous silicon. After centrifugation or filtration and drying, a porous silicon composite solid electrolyte is obtained. Finally, it is placed in a CVD deposition environment. The furnace is used to coat the surface with a carbon layer to obtain a finished porous silicon-based anode material. The porous silicon-based anode material prepared by this invention can achieve a more uniform pore size and a more stable structure by adjusting the type and content of metal components in the silicon alloy. This improves the lithium-ion mobility of the solid electrolyte, reduces polarization, and enhances rate performance. The surface carbon coating layer isolates the electrolyte from direct contact, further reducing expansion. The porous silicon prepared by this invention has a more uniform pore size and a more stable structure, achieving improved rate performance without sacrificing cycle life. This fully utilizes the material advantages of porous silicon, thereby improving the battery's cycle life and rate performance.

[0037] 2. Existing porous silicon typically has an open pore structure and high pore volume, which often leads to a decrease in mechanical strength and thus sacrifices cycle life. This application introduces an oxide solid electrolyte to construct a rigid-flexible composite electrolyte, and combines it with uniform and stable surface coating and multi-level pore structure control. This enhances the structural strength and interface stability of the material while retaining efficient transport channels, thereby achieving a synergistic improvement in high-rate performance and long cycle life.

[0038] 3. By preparing porous silicon with suitable pore size and specific surface area for LATP ion entry and a stable structure, the recombination effect of LATP ions and porous silicon is improved, thereby enhancing the rate performance and cycle performance of the anode material:

[0039] Silicon-magnesium alloys are calcined in a vacuum high-temperature environment. In a vacuum furnace, magnesium volatilizes, and the sites originally occupied by magnesium atoms become vacancies. As magnesium continues to escape, these vacancies aggregate and connect, eventually forming interconnected nanopores. The remaining silicon atoms remain and self-assemble to form a porous framework. This vacuum evaporation method does not introduce other difficult-to-remove byproducts, leaving high-purity, uniform porous silicon. It eliminates the need for acid washing, making it both environmentally friendly and simplifying the process. The high-temperature calcination process heat-treats the silicon framework, helping to eliminate lattice defects generated during dealloying, increasing the crystallinity of silicon, which is beneficial for improving its conductivity and structural stability, and reducing side reactions. Attached Figure Description

[0040] Figure 1 This is a flowchart of the preparation method of the highly porous silicon-based anode material of this application;

[0041] Figure 2 This is a schematic diagram of the structure of the negative electrode material prepared according to the embodiments of this application;

[0042] Figure 3 This is a chart showing the cell capacity recovery rate of batteries prepared using silicon-based anode materials obtained in the examples and comparative examples.

[0043] Figure 4 The chart shows the high-temperature cycle performance of batteries made from silicon-based anode materials obtained using the examples and comparative examples.

[0044] Figure label:

[0045] 1. Porous silicon; 2. LATP particles; 3. Carbon coating layer. Detailed Implementation

[0046] To make the technical solution of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0047] Example 1: A method for preparing a high-rate, long-cycle porous silicon-based anode material, the preparation process is as follows: Figure 1 This includes the following steps:

[0048] 1) Place the silicon-magnesium alloy in a vacuum furnace, maintain a vacuum of -0.05MPa, and calcine at 1000℃ for 2 hours to allow the magnesium metal component to volatilize, thereby obtaining porous silicon with a specific surface area of ​​85m² / g and a macropore volume ratio of 50nm and above.

[0049] 2) Disperse the porous silicon particles obtained in step 1) in deionized water, and add ammonia, a weakly alkaline substance with a molar ratio of 0.05:1 to the porous silicon, to form a solution A with a porous silicon particle mass concentration of 0.2 g / ml; disperse lithium carbonate, aluminum oxide, titanium dioxide, and ammonium dihydrogen phosphate in deionized water to form a lithium mass concentration of 0.005 mol / ml solution B, wherein the molar ratio of lithium, aluminum, titanium, and phosphorus is 2.5:0.4:1.8:3.

[0050] 3) Mix solutions A and B and stir for 2 hours to obtain solution C, wherein the molar ratio of lithium, aluminum, titanium, phosphorus and porous silicon is 2.5:0.4:1.8:3:30; Centrifuge and dry solution C to obtain precursor powder material, wherein lithium, aluminum, titanium and phosphorus form LATP particles in the pores of porous silicon.

[0051] 4) Place the precursor powder material obtained in step 3) in a CVD deposition furnace, introduce N2, heat to 850℃, and then introduce acetylene, wherein the flow ratio of acetylene to N2 is 1:3. After deposition for 4 hours, the finished porous silicon-based anode material is obtained, and its structural schematic diagram is shown below. Figure 2 The carbon coating content is 5% by weight based on the total mass of the porous silicon-based anode material (in other embodiments, the carbon coating content can be 3% to 8%).

[0052] Example 2: A method for preparing a high-rate, long-cycle porous silicon-based anode material, comprising the following steps:

[0053] 1) Industrial silicon powder, magnesium powder and aluminum powder were ball-milled in a molar ratio of 1:1:1 and then heated and alloyed (placed in a high-temperature melting furnace, under a nitrogen atmosphere, and heat-treated at 780℃ for 3h) to prepare a silicon-magnesium-aluminum alloy. The alloy was placed in a vacuum furnace, and the vacuum degree was maintained at -0.03MPa. It was held at 1200℃ for 2.5h to allow the magnesium and aluminum components to volatilize, resulting in porous silicon with a specific surface area of ​​80m² / g and a macropore volume ratio of 55% larger than 50nm.

[0054] 2) Disperse the porous silicon particles obtained in step 1) in deionized water, add urea, a weakly alkaline substance with a molar ratio of 0.1:1 to the porous silicon, to form solution A with a porous silicon particle concentration of 1.5 g / ml; disperse lithium hydroxide, lanthanum nitrate, and zirconium nitrate in deionized water to form solution B with a lithium mass concentration of 0.005 mol / ml, wherein the molar ratio of lithium, lanthanum, and zirconium is 6:3:2.

[0055] 3) Mix and stir solutions A and B for 2 hours to obtain solution C, wherein the molar ratio of lithium, lanthanum, zirconium and porous silicon is 6:3:2:50; filter and dry solution C to obtain precursor powder material.

[0056] 4) Place the precursor powder material obtained in step 3) in a CVD deposition furnace, introduce N2, heat to 900°C, introduce methane, wherein the flow rate of methane and nitrogen is 1:1, and after deposition for 3 hours, the finished porous silicon-based anode material is obtained; the mass percentage of carbon coating layer is 5% based on the total mass of porous silicon-based anode material (in other embodiments, the mass percentage of carbon coating layer can be 3%~8%).

[0057] Comparative Example 1, a method for preparing a high-rate, long-cycle porous silicon-based anode material, differs from Example 1 in that, in step 1), the porous silicon is not synthesized by vacuum volatilization dealloying, but by mixing silicon dioxide with magnesium powder, followed by magnesothermic reduction and acid washing; the specific process is as follows:

[0058] Macroporous silica with an average particle size of 10 μm was used as a precursor. It was then gently mixed with magnesium powder at a mass ratio of 0.8:1 and heated to 650℃ under vacuum for 6 hours for magnesothermic reduction to generate a silicon-magnesium oxide composite. Finally, the magnesium oxide template was removed by soaking in 0.8 mol / L dilute hydrochloric acid at room temperature for 6 hours. After washing, drying and screening, a porous silicon material with a specific surface area of ​​85 m² / g and a macropore volume ratio of 35% above 50 nm was obtained.

[0059] Comparative Example 2, a method for preparing a high-rate, long-cycle porous silicon-based anode material, differs from Example 1 in that the composite of porous silicon particles and LATP solid electrolyte in step 2) is not generated in situ in the liquid phase, but rather obtained by mechanically mixing porous silicon particles and LATP particles; the specific operation is as follows:

[0060] Lithium hydroxide, lanthanum nitrate, zirconium nitrate, and porous silicon were mixed and then ground (using anhydrous ethanol as the dispersion medium, zirconium oxide as the grinding ball material, and the ball-to-material ratio controlled at 10:1, and ball milling at 300 r / min for 6 hours) to obtain a precursor powder material, wherein the molar ratio of lithium, aluminum, titanium, phosphorus, and porous silicon was 2.5:0.4:1.8:3:30.

[0061] Comparative Example 3: A method for preparing a high-rate, long-cycle porous silicon-based anode material, the same as in Example 1, except that in step 1), the ratio of silicon to magnesium in the silicon-magnesium alloy is adjusted to obtain a specific gravity of 50 g / m. 2 The porous silicon particles contain lithium, aluminum, titanium, phosphorus and porous silicon in a molar ratio of 2.5:0.4:1.8:3:30.

[0062] Performance testing:

[0063] The silicon-based anode materials prepared in the examples and comparative examples were mixed with commercial artificial graphite to achieve a capacity of 700 mAh / g. The active material, binder, and conductive agent were dispersed and slurried in a ratio of 94.35%:4.65%:1%. After cell preparation processes such as coating, rolling, and slitting, small soft-pack batteries were fabricated using Ni90 cathodes. The performance of the materials in full-cell batteries was tested. Specific tests included: 1) Rate discharge test: A 0.3C constant-capacity test was performed with a voltage range of 2.8~4.25V, followed by a 1C constant-current charge. Discharge rates of 1C, 2C, and 3C were applied to calibrate the cell capacity retention rate at different rates. Finally, a 0.3C constant-capacity test was performed to measure the cell capacity recovery rate (in %). The test results are shown in Table 1. Figure 3 2) High-temperature (45℃) cyclic test, voltage range 2.8-4.25V, charge and discharge rate both 1C, test results are as follows. Figure 4 .

[0064] Table 1. List of cell capacity recovery rates of batteries prepared using silicon-based anode materials obtained in the examples and comparative examples.

[0065]

[0066] The test results show that, compared with Example 1 of the present invention, the battery prepared by magnesium thermal reduction of porous silicon in Comparative Example 1 has poorer performance. This indicates that although a comparative surface area was obtained after acid washing, the porous silicon structure is relatively fragile due to poor pore uniformity and lack of high-temperature treatment. The composite process of lithium, lanthanum, zirconium and porous silicon in solution may be affected by non-uniform pores and structural instability, which may lead to poor composite effect and thus affect rate performance and cycle performance.

[0067] Comparative Example 2 uses mechanically composite porous silicon and LATP solid electrolyte. Because solid electrolyte particles cannot grow in the pores and the mechanical mixing uniformity is poor, the battery prepared by the comparative example material shows certain disadvantages in rate performance and cycle performance compared with the example, which proves the unique advantages of the technical solution of the present invention.

[0068] The experimental results of Example 1, Comparative Examples 1 and 3 show that the preferred specific surface area of ​​the porous silicon and the amount of LATP specified in this application result in a more uniform composite, thereby improving the rate and cycle performance of the porous silicon-based anode material and the battery. The prerequisite for uniform composite of porous silicon and LATP is that the porous silicon has a suitable pore size and specific surface area for LATP ion entry, and a relatively stable porous silicon-based structure.

[0069] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A method for preparing a high-rate, long-cycle porous silicon-based anode material, characterized in that, The preparation steps include the following: 1) Purchased or self-made binary or ternary porous silicon alloys are heated and calcined under vacuum conditions to volatilize the volatile components in the alloy and obtain porous silicon particles. 2) Disperse the porous silicon particles obtained in step 1) in deionized water or an organic solvent, add a weak alkaline substance to form solution A; disperse the raw materials of each component used to generate the oxide solid electrolyte in deionized water or an organic solvent to form solution B; 3) Mix solutions A and B to obtain mixed solution C, and dry the mixed solution to obtain precursor powder material; 4) Using vapor phase deposition, an amorphous carbon coating layer is formed on the surface of the precursor powder material obtained in step 3), resulting in a porous silicon-based anode material.

2. The method for preparing a high-rate, long-cycle porous silicon-based anode material according to claim 1, characterized in that, In step 1), the self-made silicon alloy is prepared by ball milling or melting gas atomization of different metal components. The metal components in the porous silicon alloy are one or two of lithium, magnesium, aluminum, sodium, potassium, barium, rubidium, cesium, calcium and gallium.

3. The method for preparing a high-rate, long-cycle porous silicon-based anode material according to claim 1 or 2, characterized in that, In step 1), the heating and calcination process is carried out at a temperature of 500~1500℃ and a vacuum degree of -0.1~0MPa.

4. The method for preparing a high-rate, long-cycle porous silicon-based anode material according to claim 3, characterized in that, In step 1), the specific surface area is 52~200 m². 2 / g, and the volume ratio of macropores above 50nm is 40~60%.

5. A method for preparing a high-rate, long-cycle porous silicon-based anode material according to any one of claims 1-2, 4, characterized in that, In step 2), the organic solvent is any one or a combination of ethanol, methanol, benzene, toluene, acetone, and diethyl ether, and the weak alkaline substance is any one or a combination of ammonia, urea, and ammonium bicarbonate. The molar ratio of the weak alkaline substance to the porous silicon is 0.05~0.5:

1.

6. The method for preparing a high-rate, long-cycle porous silicon-based anode material according to claim 5, characterized in that, In step 2), the oxide solid electrolyte is one of lithium lanthanum zirconium oxide (LLZO), lithium lanthanum zirconium tantalum oxide (LLZTO), lithium lanthanum titanium oxide (LLTO), lithium titanium aluminum phosphate (LATP), and lithium germanium aluminum phosphate (LAGP). The raw materials used to generate oxide solid electrolytes include at least two of the following: lithium source, lanthanum source, zirconium source, titanium source, aluminum source, phosphorus source, and germanium source. The lithium source includes one or more of lithium hydroxide, lithium carbonate, lithium acetate, lithium sulfate, lithium chloride, lithium nitrate, lithium dihydrogen phosphate, and lithium hydrogen phosphate. The lanthanum source includes one or more of lanthanum nitrate, lanthanum oxide, lanthanum hydroxide, lanthanum chloride, lanthanum sulfate, and lanthanum acetate; The zirconium source includes one or more of zirconium nitrate, zirconium chloride, zirconium sulfate, and zirconium acetate; The titanium source includes one or more of titanium oxide, tetraethyl titanate, tetrabutyl titanate, titanium tetrachloride, and isopropyl titanate. The aluminum source is one of aluminum oxide, aluminum hydroxide, and aluminum sulfate; The phosphorus source is one of phosphoric acid, ammonium dihydrogen phosphate, and diammonium hydrogen phosphate; The germanium source is germanium dioxide; the tantalum source is tantalum pentoxide.

7. The method for preparing a high-rate, long-cycle porous silicon-based anode material according to claim 6, characterized in that, The raw materials used to generate oxide solid electrolytes include lithium, aluminum, titanium and phosphorus sources. The molar ratio of lithium, aluminum, titanium, phosphorus and porous silicon contained in the lithium source, aluminum source, titanium source and phosphorus source, respectively, is 1-3:0.1-1:0.5-3:1-5:10-100.

8. A method for preparing a high-rate, long-cycle porous silicon-based anode material according to any one of claims 1-2, 4, 6, and 7, characterized in that, In step 3), the drying method of the mixed solution is one of the following: forced air drying, spray drying, or freeze drying.

9. The method for preparing high-rate, long-cycle porous silicon-based anode material according to claim 8, characterized in that, Step 4) In vapor deposition, the carbon source gas used is one of acetylene, methane, propylene, acetone, or natural gas, and the carrier gas is one of nitrogen, argon, or helium. The ratio of carrier gas to carbon source gas is 1-5:1, the surface carbon coating temperature is 800-1000℃, and the coating time is 2-8h.

10. A high-rate, long-cycle porous silicon-based anode material, characterized in that, It is prepared by the method according to any one of claims 1-9; it includes porous silicon, oxide solid electrolyte particles attached to the pores and surface of the porous silicon, and an amorphous carbon coating layer covering the porous silicon on the outermost layer.

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