Method for preparing lithium battery negative electrode material from biomass carbon composite metal

Abstract

The invention discloses a method for preparing a lithium battery negative electrode material from biomass carbon composite metal, and relates to the technical field of lithium ion battery materials. The biomass carbon composite gold material is synthesized through induction of a biological template, the biological template comprises one of chitosan, an eggshell membrane, cross-linked bovine serum albumin and chlorella, and the biomass carbon composite gold material comprises one of a SnS2 / C composite material, a SnS2 / CN composite material and a Sb2S3 / CN composite material. The biomass carbon composite metal negative electrode material disclosed by the invention not only shows excellent charge transfer capability in an electrochemical reaction process, but also shows good stability and relatively long service life in a recycling process, so that the performance of the lithium battery is remarkably improved. And the technological process has the characteristics of simplicity, convenience and feasibility, and shows higher feasibility in practical application.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium-ion battery materials, and specifically to a method for preparing a lithium battery anode material by compounding biomass carbon with metal. Background Art

[0002] Developing lithium batteries with high energy density, high safety and long cycle life is a current research hotspot in the energy storage field and a key technology for meeting major demands such as electric vehicles, smart grids, and distributed energy storage. To achieve the safe operation of lithium batteries, efforts must be made to develop new electrode materials. Among them, biomass carbon-based lithium battery composite materials have excellent properties and have attracted extensive attention from researchers. Developing biomass carbon-based anode materials is a low-cost, sustainable strategy of "turning waste into treasure", which meets the development needs of a resource-saving and environment-friendly society.

[0003] Common lithium battery anode materials include graphite-based carbon anode materials, biomass carbon anode materials, and metal materials. Graphite-based carbon anode materials have excellent electrode (anode / cathode) material properties, are stable, do not react with electrolytes, and have high ion mobility. However, graphite-based carbon anode materials are sensitive to their structure, morphology (the capacity difference between open and closed carbon nanotubes is about 120 mAh·g -1 ) and defects, and have a high surface area, which easily leads to agglomeration between graphite-based carbon anode materials, thereby reducing their specific capacity and the lithium electron transfer between graphite-based carbon anode materials. Biomass generally refers to various organisms formed through photosynthesis, including agricultural and forestry crops, aquatic plants, algae, animals, and their various biological wastes. Due to its wide distribution, easy availability, low cost, environmental friendliness, and renewable characteristics, it has become a carbon source with high development and utilization value. Biomass has a special microstructure and contains abundant N, S, O, etc., which is conducive to in-situ doping of heteroatoms and can improve the lithium storage performance of materials. However, the composition of biomass is complex and the microstructure and morphology vary greatly. The preparation process of biomass carbon has a significant impact on the physical and chemical properties of the materials. Metal materials are mainly anode materials such as Si, Al, Sb, Sn, etc. These alloy materials will have volume change problems during the lithiation process, which limits their application in practical engineering.

[0004] Therefore, from the perspective of the structure and composition of materials, designing and developing, and improving their performance by utilizing the performance characteristics and microstructure of materials themselves have important research and practical significance for developing anode materials with better and safer performance. Moreover, it is difficult for a single material to meet all parameter requirements, and it is necessary to develop efficient, environmentally friendly, and low-cost synthesis technologies to obtain new anode materials. Summary of the Invention

[0005] The object of the present invention is to provide a method for preparing a lithium battery anode material by using biomass carbon composite metal, so as to solve the problems existing in the prior art.

[0006] To solve the above technical problems, in a first aspect, the present invention provides a method for preparing a lithium battery anode material by using biomass carbon composite metal. The preparation method is to induce the synthesis of biomass carbon composite gold material with a biological template;

[0007] The biological template includes one of chitosan, eggshell membrane, cross-linked bovine serum albumin, and chlorella;

[0008] The biomass carbon composite gold material includes SnS 2 / C composite material, SnS 2 / CN composite material, Sb 2 S 3 / CN composite material.

[0009] Further, the preparation steps of the SnS 2 / C composite material are as follows: add a tin chloride solution to an acetic acid solution of chitosan, stir until it becomes transparent, then add a potassium hydroxide solution with a mass fraction of 10-20%, and the mass ratio of chitosan to potassium hydroxide is 1:1-1:3. Heat to 100 °C and evaporate to a paste, then put it into a tube furnace, heat up to 180 °C at a rate of 1-4 °C / min, keep warm for 3 h, then heat up to 800-900 °C at a rate of 1-4 °C / min, keep warm for 4 h. After the calcination is completed, wash it 5 times with 1M hydrochloric acid, 8M nitric acid, and deionized water respectively, and put it into a drying oven for drying to obtain the SnS 2 / C composite material;

[0010] The present invention utilizes the characteristic of oxygen-containing functional groups on the surface of chitosan to realize the complexation of Sn 4+ , improve the distribution of SnS 2 in the chitosan carbide. At the same time, this complexation forms a dynamic equilibrium, and Sn 4+ is slowly released during the reaction process, avoiding explosive nucleation caused by local supersaturation and affecting the performance of lithium batteries. At the same time, the steric hindrance effect of the complexation can expand the layer spacing of SnS 2 , enhance the interlayer lithium ion diffusion ability, and reduce defects, which is beneficial to improving the cycle stability of the battery.

[0011] Or, the SnS 2The preparation steps of the SnS / C composite material are as follows: Place the eggshell membrane in a stannous chloride solution, with the mass ratio of the eggshell membrane to stannous chloride pentahydrate being 1:1 - 5. Pour it into a polytetrafluoroethylene inner liner and place it in a stainless-steel hydrothermal autoclave. Heat it to 180 °C and keep it warm for 12 h. After the reaction is completed, cool it to room temperature, wash it 3 times each with deionized water and alcohol, and then, under an argon atmosphere, heat it to 100 °C at a rate of 1 - 4 °C / min, keep it warm for 12 h, heat it to 350 °C at a rate of 1 - 4 °C / min, keep it warm for 2 h, and heat it to 450 - 550 °C at a rate of 1 - 4 °C / min and keep it warm for 2 h to obtain SnS 2 / C composite material.

[0012] In the present invention, the eggshell membrane is used as a biological template, and sulfur amino acids in the eggshell membrane release H 2 S gas during the carbonization process, which can increase a part of the sulfur source. H 2 S reacts with Sn 4+ adsorbed on the surface of the eggshell membrane to generate SnS 2 nanoparticles. At the same time, after the carbonization of the eggshell membrane, the fiber structure in the original membrane is retained, which has a higher charge-discharge specific capacity. It not only shows excellent charge transfer ability during the electrochemical reaction process but also shows good stability and a long service life during the recycling process, thus significantly improving the performance of lithium batteries.

[0013] Furthermore, the acetic acid solution of chitosan is obtained as follows: Add 0.5 - 2 g of chitosan to 10 - 100 mL of acetic acid solution and stir for 2 - 10 h. The mass fraction of acetic acid in the acetic acid solution is 2% - 10%.

[0014] Furthermore, the stannous chloride solution is prepared by dissolving 4 mmol of stannous chloride pentahydrate and 4 - 8 mmol of thioacetamide in 30 mL of deionized water.

[0015] Furthermore, the preparation steps of the SnS 2 / CN composite material are as follows: Place cross-linked bovine serum albumin in a stannous chloride solution, with the mass ratio of the eggshell membrane to stannous chloride pentahydrate being 1:1 - 5. Pour it into a polytetrafluoroethylene inner liner and place it in a stainless-steel hydrothermal autoclave. Heat it to 180 °C and keep it warm for 12 h. After the reaction is completed, cool it to room temperature, wash it 3 times each with deionized water and alcohol, and then, under an argon atmosphere, heat it to 100 °C at a rate of 1 - 4 °C / min, keep it warm for 12 h, heat it to 350 °C at a rate of 1 - 4 °C / min, keep it warm for 2 h, and heat it to 450 - 550 °C at a rate of 1 - 4 °C / min and keep it warm for 2 h to obtain SnS 2 / CN composite material.

[0016] In the present invention, cross-linked bovine serum albumin provides a porous framework to limit SnCl 4The diffusion ensures the uniform dispersion of Sn species. Cross-linked bovine serum albumin is rich in amino groups, mercapto groups and sulfur-containing amino acids. During the carbonization process, N and S elements are released to achieve in-situ nitrogen doping and sulfur source supply, forming nitrogen-doped carbon with excellent conductivity. The nitrogen-containing functional groups on its surface can enhance the anchoring of SnS 2 and Li + adsorption. The small size and high dispersibility of SnS 2 synergistically optimize the lithium-ion storage kinetics and structural stability with the conductive / confining effect of CN.

[0017] Furthermore, the preparation steps of the Sb 2 S 3 / CN composite are as follows: Weigh the chlorella powder, add distilled water to prepare a chlorella solution with a mass fraction of 5-10%. After complete dissolution, add an antimony trichloride-ethanol solution with a concentration of 33 mM of antimony trichloride. The mass ratio of antimony trichloride to chlorella powder is 1-5:1. Stir at 40 rpm for 3 h, then add thiourea until the color of the solution changes from green to dark green. Transfer it to an autoclave, seal it and heat it to 200 °C, keep it warm for 10 h. After cooling to room temperature, collect the precipitate, wash it 6 times with ethanol and distilled water, and then under an argon atmosphere, heat it to 100 °C at a rate of 1-4 °C / min, keep it warm for 12 h, and then heat it to 450-550 °C at a rate of 1-4 °C / min and keep it warm for 2 h.

[0018] In the present invention, Sb 2 S 3 is in an embedded state on the chlorella matrix. Through physical constraints, interfacial chemical bonding and functional complementarity between components, the lithium storage performance is significantly improved. The surface of Sb 2 S 3 is bonded to the carbon matrix through Sb-O-C chemical bonds, enhancing the electron transfer efficiency. And part of the Sb 2 S 3 particles are coated with a carbon layer, inhibiting the direct contact between the active substance and the electrolyte and reducing side reactions. The sp 2 hybrid carbon skeleton of chlorella carbon forms a three-dimensional conductive network, improving the intrinsic conductivity of Sb 2 S 3 and reducing electrode polarization. The rigid porous structure of the carbon matrix limits the expansion space of Sb 2 S 3 particles, preventing electrode pulverization, and thus providing capacitance and cycle stability.

[0019] In the second aspect, the embodiment of the present invention provides a negative electrode sheet, including the negative electrode material described in the first aspect above.

[0020] Furthermore, the negative electrode sheet is used for a lithium-ion battery, a lithium-ion capacitor, a lithium-sulfur battery or an all-solid-state lithium battery.

[0021] Further, the preparation method of the negative electrode sheet is as follows: Weigh the negative electrode material, acetylene black, polyvinylidene fluoride, and N-methylpyrrolidone according to a mass ratio of 8:1:1:10-19. Place the negative electrode material, acetylene black, and polyvinylidene fluoride in an agate mortar and grind and mix them until uniform. Transfer the uniformly mixed powder to a bottle, add N-methylpyrrolidone, place it on a magnetic stirrer and stir evenly for 24 hours. Use a film applicator to evenly coat the above slurry on a copper foil, put in an electrode sheet of 10 mm preheated to 120 °C, and compact it with a tablet press at a pressure of 20 MPa. Then put it into a vacuum drying oven and dry it at 120 °C for 8 hours.

[0022] In the third aspect, an embodiment of the present invention provides a lithium battery, including the negative electrode sheet described in the second aspect above. The preparation method of the lithium battery is as follows: Use a CR2025 button battery case to assemble a half-cell in a glove box filled with argon (the water and oxygen content is less than 1 ppm). First, put the negative electrode sheet into the negative electrode case, cover the separator, drop an appropriate amount of electrolyte (1 M LiPF 6 solution, and the solvent is EC, DMC, and DEC with a volume ratio of 1:1:1), place a lithium metal sheet above the separator, and then cover it with nickel foam and a positive current collector.

[0023] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0024] The present invention relates to a lithium battery negative electrode material prepared by using biomass carbon composite metal. This biomass carbon composite metal negative electrode material has a higher charge-discharge specific capacity. It not only shows excellent charge transfer ability during the electrochemical reaction process, but also shows good stability and a long service life during the recycling process, thus significantly improving the performance of the lithium battery. Moreover, the process has the characteristics of being simple and easy to implement, and shows high feasibility in practical applications. In particular, the biomass carbon fiber negative electrode material used in lithium ion batteries has a wide and rich raw material source, and has the characteristics of environmental protection and renewable. In addition, the entire process is not only simple, but also has a low cost, which makes this material have high economic efficiency in practical applications. Description of the Drawings

[0025] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention, and do not constitute a limitation to the present invention. In the drawings:

[0026] Figure 1 is a flowchart for preparing the SnS 2 / C composite material by inducing synthesis with natural chitosan as a biological template in the present invention;

[0027] Figure 2The present invention uses eggshell membrane as a biological template to induce the synthesis of SnS 2 / C composite material preparation flow chart;

[0028] Figure 3 The present invention uses cross-linked bovine serum albumin as a biological template to induce the synthesis of SnS 2 / CN composite material preparation flow chart;

[0029] Figure 4 The present invention uses Chlorella as a biological template to induce the synthesis of Sb 2 S 3 / CN composite material preparation flow chart. Detailed implementation manners

[0030] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0031] Example 1

[0032] (1) Add 1.4 g of chitosan to 60 mL of acetic acid solution and stir for 6 h. The mass fraction of acetic acid in the acetic acid solution is 6%. Obtain the acetic acid solution of chitosan; add stannous chloride solution to the acetic acid solution of chitosan. The stannous chloride solution is prepared by dissolving 4 mmol of stannous chloride pentahydrate and 8 mmol of thioacetamide in 30 mL of deionized water. Stir until it becomes transparent, and then add a potassium hydroxide solution with a mass fraction of 15%. The mass ratio of chitosan to potassium hydroxide is 1:2. Heat to 100 °C and evaporate to a paste, then put it into a tube furnace, heat to 180 °C at a rate of 2 °C / min, keep it warm for 3 h, then heat to 850 °C at a rate of 2 °C / min, keep it warm for 4 h. After the calcination is completed, wash it 5 times with 1M hydrochloric acid, 8M nitric acid and deionized water respectively, and put it into a drying oven to dry, then obtain the SnS 2 / C negative electrode material;

[0033] (2) Weigh the negative electrode material, acetylene black, polyvinylidene fluoride, and N-methylpyrrolidone according to the mass ratio of 8:1:1:14. Place the negative electrode material, acetylene black, and polyvinylidene fluoride in an agate mortar and grind and mix them until they are uniform. Transfer the uniformly mixed powder to a bottle, add N-methylpyrrolidone, place it on a magnetic stirrer and stir evenly for 24 hours. Use a film applicator to evenly coat the above slurry on the copper foil, put in a 10 mm electrode sheet preheated to 120 °C, and compact it with a press at a pressure of 20 MPa. Put it into a vacuum drying oven and dry it at 120 °C for 8 hours to obtain the negative electrode plate;

[0034] (3) The CR2025 button cell case is adopted, and the half-cell is assembled in a glove box filled with argon (the water and oxygen content is less than 1 ppm). First, the negative electrode sheet is placed into the negative electrode case, the separator is covered, an appropriate amount of electrolyte (1 M LiPF 6 solution, and the solvent is EC, DMC, and DEC with a volume ratio of 1:1:1) is dropped, a lithium metal sheet is placed above the separator, and then nickel foam and the positive current collector are covered. When assembling the full cell, the lithium metal sheet is replaced with a commercial ternary positive electrode material. Using the Neware battery test system, constant current charge and discharge tests are carried out on the battery charge and discharge system. The charge and discharge current is 0.1 mA, and the charge and discharge voltage range is controlled between 0 and 2.6 V;

[0035] The results show that the initial discharge capacity of the SnS 2 / C negative electrode material is 934.8 mAh / g, the charge capacity is 830.1 mA / g, the initial Coulomb efficiency is 88.8%, the capacity remains at 595.5 mAh / g after 30 cycles, the capacity retention rate is 63.7%, and the charge and discharge efficiency is maintained at 97.66%.

[0036] Example 2

[0037] (1) 2 g of chitosan is added to 100 mL of acetic acid solution and stirred for 6 h. The mass fraction of acetic acid in the acetic acid solution is 10%, and a chitosan acetic acid solution is obtained. A tin chloride solution is added to the chitosan acetic acid solution. The tin chloride solution is prepared by dissolving 4 mmol of tin (II) chloride pentahydrate and 8 mmol of thioacetamide in 30 mL of deionized water, stirred until transparent, and then a potassium hydroxide solution with a mass fraction of 10 - 20% is added. The mass ratio of chitosan to potassium hydroxide is 1:3. It is heated to 100 °C and evaporated into a paste, then placed in a tube furnace, heated to 180 °C at a rate of 4 °C / min, held for 3 h, then heated to 850 °C at a rate of 4 °C / min, held for 4 h. After the calcination is completed, it is washed 5 times with 1 M hydrochloric acid, 8 M nitric acid, and deionized water respectively, and placed in a drying oven to dry, thus obtaining the SnS 2 / C composite material;

[0038] (2) Weigh the negative electrode material, acetylene black, polyvinylidene fluoride, and N-methylpyrrolidone according to the mass ratio of 8:1:1:19. Place the negative electrode material, acetylene black, and polyvinylidene fluoride in an agate mortar and grind and mix them until uniform. Transfer the uniformly mixed powder to a bottle, add N-methylpyrrolidone, place it on a magnetic stirrer and stir evenly for 24 hours. Use a film applicator to evenly coat the above slurry on the copper foil, put in a 10 mm electrode sheet preheated to 120 °C, and press it with a press at a pressure of 20 MPa, then place it in a vacuum drying oven and dry at 120 °C for 8 hours to obtain the negative electrode sheet;

[0039] (3) Use a CR2025 button battery case and assemble the half-cell in a glove box filled with argon (water and oxygen content less than 1 ppm). First, place the negative electrode sheet into the negative electrode case, cover it with a separator, and drop an appropriate amount of electrolyte (1 M LiPF 6 solution, and the solvent is EC, DMC, and DEC with a volume ratio of 1:1:1). Place a lithium metal sheet above the separator, then cover it with nickel foam and use the positive current collector. When assembling the full cell, replace the lithium metal sheet with a commercial ternary positive electrode material.

[0040] Charge and discharge test: The operation is the same as the "Charge and discharge test" in Example 1; the results show that the first discharge capacity of the SnS 2 / C negative electrode material is 928.7 mAh / g, the charge capacity is 855.4 mA / g, the first Coulombic efficiency is 92.1%, the capacity remains at 514.5 mAh / g after 30 cycles, the capacity retention rate is 55.4%, and the charge and discharge efficiency is maintained at 92.4%.

[0041] Example 3

[0042] (1) Rinse the eggshells clean to remove impurities, then soak them in 2 M HCl for 12 h. After the eggshell membrane is separated from the eggshells, wash the eggshell membrane with water until the pH is neutral. Place the eggshell membrane in a tin chloride solution, which is prepared by dissolving 4 mmol of tin(II) chloride pentahydrate and 4 mmol of thioacetamide in 30 mL of deionized water. The mass ratio of the eggshell membrane to tin(II) chloride pentahydrate is 1:1. Pour it into a polytetrafluoroethylene inner liner and place it in a stainless steel hydrothermal autoclave. Heat it to 180 °C and keep it warm for 12 h. After the reaction is completed, cool it to room temperature, wash it 3 times with deionized water and alcohol respectively, and then under an argon atmosphere, heat it to 100 °C at a rate of 2 °C / min and keep it warm for 12 h. Heat it to 350 °C at a rate of 2 °C / min and keep it warm for 2 h. Heat it to 450 °C at a rate of 2 °C / min and keep it warm for 2 h to obtain the SnS 2 / C negative electrode material;

[0043] (2) Weigh the negative electrode material, acetylene black, polyvinylidene fluoride, and N-methylpyrrolidone according to a mass ratio of 8:1:1:10. Place the negative electrode material, acetylene black, and polyvinylidene fluoride in an agate mortar and grind and mix them evenly. Transfer the evenly mixed powder to a bottle, add N-methylpyrrolidone, place it on a magnetic stirrer and stir it evenly for 24 hours. Use a film applicator to evenly coat the above slurry on the copper foil, put in a 10 mm electrode sheet preheated to 120 °C, and compact it with a press at a pressure of 20 MPa. Place it in a vacuum drying oven and dry it at 120 °C for 8 hours to obtain the negative electrode sheet;

[0044] (3) The CR2025 button cell case is adopted, and the half-cell is assembled in a glove box filled with argon (the water and oxygen content is less than 1 ppm). First, the negative electrode sheet is placed into the negative electrode case, the separator is covered, an appropriate amount of electrolyte (1 M LiPF 6 solution, and the solvent is EC, DMC and DEC with a volume ratio of 1:1:1) is dropped, a lithium metal sheet is placed above the separator, and then nickel foam and the positive current collector are covered. When assembling the full cell, the lithium metal sheet is replaced with a commercial ternary positive electrode material.

[0045] Charge and discharge test: The operation is the same as that of the "Charge and discharge test" in Example 1; the results show that the first discharge capacity of the SnS 2 / C negative electrode material is 920.5 mAh / g, the charge capacity is 840.4 mA / g, the first Coulombic efficiency is 91.3%, the capacity remains at 519.16 mAh / g after 30 cycles, the capacity retention rate is 56.4%, and the charge and discharge efficiency is maintained at 88.61%.

[0046] Example 4

[0047] (1) The eggshells are rinsed clean to remove impurities, and then soaked in 2 M HCl for 12 h. After the eggshell membrane is separated from the eggshells, the eggshell membrane is washed with water until the pH is neutral. The eggshell membrane is placed in a stannous chloride solution, which is prepared by dissolving 4 mmol of stannous chloride pentahydrate and 4 mmol of thioacetamide in 30 mL of deionized water. The mass ratio of the eggshell membrane to stannous chloride pentahydrate is 1:3. It is poured into a polytetrafluoroethylene inner liner and placed in a stainless steel hydrothermal autoclave, heated to 180 °C and kept warm for 12 h. After the reaction is completed, it is cooled to room temperature, washed 3 times with deionized water and alcohol respectively, and then heated to 100 °C at a rate of 2 °C / min under an argon atmosphere and kept warm for 12 h, heated to 350 °C at a rate of 2 °C / min and kept warm for 2 h, and heated to 520 °C at a rate of 2 °C / min and kept warm for 2 h to obtain the SnS 2 / C negative electrode material;

[0048] (2) Weigh the negative electrode material, acetylene black, polyvinylidene fluoride, and N-methylpyrrolidone according to the mass ratio of 8:1:1:14. Place the negative electrode material, acetylene black, and polyvinylidene fluoride in an agate mortar and grind and mix them evenly. Transfer the evenly mixed powder to a bottle, add N-methylpyrrolidone, place it on a magnetic stirrer and stir evenly for 24 hours. Use a film applicator to evenly coat the above slurry on the copper foil, put in a 10 mm electrode sheet preheated to 120 °C, and press it with a press at a pressure of 20 MPa. Place it in a vacuum drying oven and dry it at 120 °C for 8 hours to obtain the negative electrode sheet;

[0049] (3) The CR2025 button cell case is adopted, and the half-cell is assembled in a glove box filled with argon (the water and oxygen content is less than 1 ppm). First, the negative electrode sheet is placed into the negative electrode case, the separator is covered, an appropriate amount of electrolyte (1 M LiPF 6 solution, and the solvent is EC, DMC and DEC with a volume ratio of 1:1:1) is dropped, a lithium metal sheet is placed above the separator, and then nickel foam and the positive electrode current collector are covered. When assembling the full cell, the lithium metal sheet is replaced with a commercial ternary positive electrode material.

[0050] Charge and discharge test: The operation is the same as that of the "charge and discharge test" in Example 1; the results show that the initial discharge capacity of the SnS 2 / C negative electrode material is 931.1 mAh / g, the charge capacity is 857.5 mA / g, the initial Coulomb efficiency is 92.1%, the capacity remains at 547.5 mAh / g after 30 cycles, the capacity retention rate is 58.8%, and the charge and discharge efficiency is maintained at 91.2%.

[0051] Example 5

[0052] (1) Prepare 2 mg / mL bovine serum albumin solution, 25 mM N-hydroxysuccinimide and 75 mM 1-ethyl-(3-dimethylaminopropyl)carbodiimide solution, and then evenly mix the above three solutions. After incubating for 72 h, cross-linked bovine serum albumin is obtained. The cross-linked bovine serum albumin is washed with water several times until the pH is neutral and then dried;

[0053] (2) Place the cross-linked bovine serum albumin in a tin chloride solution, and the mass ratio of eggshell membrane to tin chloride pentahydrate is 1:1 - 5. Pour it into a polytetrafluoroethylene inner liner and place it in a stainless steel hydrothermal autoclave. Heat it to 180 °C and keep it warm for 12 h. After the reaction is completed, cool it to room temperature, wash it 3 times with deionized water and alcohol respectively, and then under an argon atmosphere, heat it to 100 °C at a rate of 2 °C / min and keep it warm for 12 h, heat it to 350 °C at a rate of 2 °C / min and keep it warm for 2 h, heat it to 500 °C at a rate of 2 °C / min and keep it warm for 2 h to obtain the SnS 2 / CN negative electrode material;

[0054] (3) Weigh the negative electrode material, acetylene black, polyvinylidene fluoride, and N-methylpyrrolidone according to the mass ratio of 8:1:1:12. Place the negative electrode material, acetylene black, and polyvinylidene fluoride in an agate mortar and grind and mix them evenly. Transfer the evenly mixed powder to a bottle, add N-methylpyrrolidone, place it on a magnetic stirrer and stir it evenly for 24 hours. Use a film coater to evenly coat the above slurry on the copper foil, put in a 10 mm electrode sheet preheated to 120 °C, and compact it with a tablet press at a pressure of 20 MPa. Place it in a vacuum drying oven and dry it at 120 °C for 8 hours to obtain the negative electrode sheet;

[0055] (4) The CR2025 button cell case is adopted, and the half-cell is assembled in a glove box filled with argon (the water and oxygen content is less than 1 ppm). First, the negative electrode sheet is placed into the negative electrode case, the separator is covered, an appropriate amount of electrolyte (1 M LiPF 6 solution, and the solvent is EC, DMC and DEC with a volume ratio of 1:1:1) is dropped, a lithium metal sheet is placed above the separator, and then nickel foam and the positive electrode current collector are covered. When assembling the full cell, the lithium metal sheet is replaced with a commercial ternary positive electrode material.

[0056] Charge and discharge test: The operation is the same as the "charge and discharge test" in Example 1; the results show that the first discharge capacity of the SnS 2 / CN negative electrode material is 931.1 mAh / g, the charge capacity is 857.5 mA / g, the first Coulombic efficiency is 92.1%, the capacity remains at 547.5 mAh / g after 30 cycles, the capacity retention rate is 58.8%, and the charge and discharge efficiency is maintained at 91.2%.

[0057] Example 8

[0058] (1) Prepare 2 mg / mL bovine serum albumin solution, 25 mM N-hydroxysuccinimide and 75 mM 1-ethyl-(3-dimethylaminopropyl)carbodiimide solution, and then evenly mix the above three solutions. After incubating for 72 h, cross-linked bovine serum albumin is obtained. The cross-linked bovine serum albumin is washed with water several times until the pH is neutral and then dried;

[0059] (2) Place the cross-linked bovine serum albumin in a tin chloride solution, and the mass ratio of eggshell membrane to tin chloride pentahydrate is 1:1 - 5. Pour it into a polytetrafluoroethylene inner liner and place it in a stainless steel hydrothermal autoclave. Heat it to 180 °C and keep it warm for 12 h. After the reaction is completed, cool it to room temperature, wash it 3 times with deionized water and alcohol respectively, and then under an argon atmosphere, heat it to 100 °C at a rate of 1 - 4 °C / min and keep it warm for 12 h. Heat it to 350 °C at a rate of 1 - 4 °C / min and keep it warm for 2 h. Heat it to 450 - 550 °C at a rate of 1 - 4 °C / min and keep it warm for 2 h to obtain the SnS 2 / CN composite material;

[0060] (3) Weigh the negative electrode material, acetylene black, polyvinylidene fluoride, and N-methylpyrrolidone according to the mass ratio of 8:1:1:10 - 19. Place the negative electrode material, acetylene black, and polyvinylidene fluoride in an agate mortar and grind and mix them evenly. Transfer the evenly mixed powder to a bottle, add N-methylpyrrolidone, place it on a magnetic stirrer and stir it evenly for 24 hours. Use a film applicator to evenly coat the above slurry on the copper foil, put in a 10 mm electrode sheet preheated to 120 °C, and press it with a tablet press at a pressure of 20 MPa. Put it into a vacuum drying oven and dry it at 120 °C for 8 hours to obtain the negative electrode sheet;

[0061] (4) Use a CR2025 button cell case to assemble a half-cell in a glove box filled with argon (water and oxygen content less than 1 ppm). First, place the negative electrode sheet into the negative electrode case, cover it with a separator, and drop an appropriate amount of electrolyte (1 M LiPF 6 solution, and the solvent is EC, DMC, and DEC with a volume ratio of 1:1:1). Place a lithium metal sheet above the separator, then cover it with nickel foam and use the positive current collector. When assembling the full cell, replace the lithium metal sheet with a commercial ternary positive electrode material.

[0062] Charge and discharge test: The operation is the same as the "Charge and discharge test" in Example 1; the results show that the initial discharge capacity of the SnS 2 / CN negative electrode material is 941.2 mAh / g, the charge capacity is 848.9 mA / g, the initial Coulomb efficiency is 90.2%, the capacity remains at 543.1 mAh / g after 30 cycles, the capacity retention rate is 57.7%, and the charge and discharge efficiency is maintained at 93.1%.

[0063] Example 9

[0064] (1) Weigh the chlorella powder, add distilled water to prepare a 5% chlorella solution by mass. After full dissolution, add an antimony trichloride-ethanol solution with a concentration of 33 mM of antimony trichloride. The mass ratio of antimony trichloride to chlorella powder is 2:1. Stir at 40 rpm for 3 h, then add thiourea until the solution color changes from green to dark green. Transfer it to an autoclave, seal it, and heat it to 200 °C, keep it warm for 10 h. After cooling to room temperature, collect the precipitate, wash it 6 times with ethanol and distilled water, and then under an argon atmosphere, heat it to 100 °C at a rate of 2 °C / min, keep it warm for 12 h, and then heat it to 450 °C at a rate of 1 - 4 °C / min and keep it warm for 2 h to obtain the Sb 2 S 3 / CN negative electrode material;

[0065] (2) Weigh the negative electrode material, acetylene black, polyvinylidene fluoride, and N-methylpyrrolidone according to a mass ratio of 8:1:1:12. Place the negative electrode material, acetylene black, and polyvinylidene fluoride in an agate mortar and grind and mix them evenly. Transfer the evenly mixed powder to a bottle, add N-methylpyrrolidone, and place it on a magnetic stirrer and stir evenly for 24 hours. Use a film applicator to evenly coat the above slurry on the copper foil, put in a 10 mm electrode sheet preheated to 120 °C, and press it with a press at a pressure of 20 MPa. Place it in a vacuum drying oven and dry it at 120 °C for 8 hours to obtain the negative electrode sheet;

[0066] (3) Use a CR2025 button cell case to assemble a half-cell in a glove box filled with argon (water and oxygen content less than 1 ppm). First, place the negative electrode sheet into the negative electrode case, cover it with a separator, and drop an appropriate amount of electrolyte (1 M LiPF6 Solution, with the solvent being EC, DMC, and DEC in a volume ratio of 1:1:1. Place a lithium metal sheet above the separator, then cover it with nickel foam and use the positive current collector. When assembling the full cell, replace the lithium metal sheet with a commercial ternary cathode material.

[0067] Charge and discharge test: The operation is the same as the "Charge and discharge test" in Example 1; the results show that 2 S 3 The initial discharge capacity of the Sb

[0068] Example 10

[0069] (1) Weigh the chlorella powder, add distilled water to prepare a 10% chlorella solution by mass. After complete dissolution, add an antimony trichloride-ethanol solution with a concentration of 33 mM of antimony trichloride. The mass ratio of antimony trichloride to chlorella powder is 2:1. Stir at 40 rpm for 3 h, then add thiourea until the solution color changes from green to dark green. Transfer it to an autoclave, seal it, and heat it to 200 °C, keep it warm for 10 h. After cooling to room temperature, collect the precipitate, wash it 6 times with ethanol and distilled water, and then under an argon atmosphere, heat it to 100 °C at a rate of 2 °C / min, keep it warm for 12 h, and then heat it to 550 °C at a rate of 2 °C / min and keep it warm for 2 h to obtain the Sb 2 S 3 / CN anode material;

[0070] (2) Weigh the anode material, acetylene black, polyvinylidene fluoride, and N-methylpyrrolidone according to a mass ratio of 8:1:1:19. Place the anode material, acetylene black, and polyvinylidene fluoride in an agate mortar and grind and mix them evenly. Transfer the evenly mixed powder to a bottle, add N-methylpyrrolidone, place it on a magnetic stirrer and stir evenly for 24 hours. Use a film applicator to evenly coat the above slurry on the copper foil, put in a 10 mm electrode sheet preheated to 120 °C, and press it with a tablet press at a pressure of 20 MPa, then put it into a vacuum drying oven and dry it at 120 °C for 8 hours to obtain the anode electrode sheet;

[0071] (3) Use a CR2025 coin cell case to assemble a half cell in a glove box filled with argon (the water and oxygen content is less than 1 ppm). First, put the anode electrode sheet into the anode shell, cover the separator, and drop an appropriate amount of electrolyte (1 M LiPF 6Solution, with the solvent being EC, DMC, and DEC in a volume ratio of 1:1:1). Place a lithium metal sheet above the separator, then cover it with nickel foam and use the positive current collector. When assembling the full cell, replace the lithium metal sheet with a commercial ternary cathode material.

[0072] Charge-discharge test: The operation is the same as the "Charge-discharge test" in Example 1; the results show that 2 S 3 The initial discharge capacity of the Sb

[0073] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be encompassed by the present invention. Any reference signs in the claims should not be construed as limiting the claimed invention.

Claims

1. A method for preparing a negative electrode material for a lithium battery from a biomass carbon composite metal, characterized in that: The preparation method is to use biological templates to induce the synthesis of biomass carbon composite gold materials; The biological template includes one of chitosan, eggshell membrane, cross-linked bovine serum albumin, and Chlorella; The biomass carbon composite gold material includes one of a SnS2 / C composite material, a SnS2 / CN composite material, and a Sb2S3 / CN composite material.

2. The method for preparing a negative electrode material for a lithium battery from a biomass carbon composite metal according to claim 1, characterized in that: The SnS2 / C composite material is prepared by adding a tin chloride solution to an acetic acid solution of chitosan, stirring until transparent, then adding a potassium hydroxide solution with a mass fraction of 10 to 20%, wherein the mass ratio of chitosan to potassium hydroxide is 1:1 to 1:3, heating to 100°C and steaming into a paste, then placing in a tubular furnace, heating to 180°C at a rate of 1 to 4°C / min, keeping the temperature for 3 hours, then heating to 800 to 900°C at a rate of 1 to 4°C / min, keeping the temperature for 4 hours, and after calcination, washing with 1M hydrochloric acid, 8M nitric acid and deionized water for 5 times respectively, and placing in a drying oven for drying to obtain the SnS2 / C composite material; Alternatively, the preparation steps of the SnS2 / C composite material are: placing eggshell membrane in a tin chloride solution, the mass ratio of eggshell membrane to tin chloride pentahydrate is 1:1-5, pouring it into a polytetrafluoroethylene liner, and placing it in a stainless steel hydrothermal autoclave, heating it to 180°C and keeping it warm for 12 hours, after the reaction is completed, cooling it to room temperature, washing it with deionized water and alcohol three times respectively, and then heating it to 100°C at 1-4°C / min in an argon atmosphere, keeping it warm for 12 hours, heating it to 350°C at 1-4°C / min, keeping it warm for 2 hours, heating it to 450-550°C at 1-4°C / min, and keeping it warm for 2 hours to obtain the SnS2 / C composite material.

3. The method for preparing a negative electrode material for a lithium battery from a biomass carbon composite metal according to claim 2, characterized in that: The chitosan acetic acid solution is obtained by the following process: 0.5-2g chitosan is added into 10-100mL acetic acid solution and stirred for 2-10h, wherein the mass fraction of acetic acid in the acetic acid solution is 2%-10%.

4. The method for preparing a negative electrode material for a lithium battery from a biomass carbon composite metal according to claim 2, characterized in that: The tin chloride solution is prepared by dissolving 4 mmol of tin chloride pentahydrate and 4-8 mmol of thioacetamide in 30 mL of deionized water.

5. The method for preparing a negative electrode material for a lithium battery from a biomass carbon composite metal according to claim 1, characterized in that: The preparation steps of the SnS2 / CN composite material are as follows: cross-linked bovine serum albumin is placed in a tin chloride solution, the mass ratio of eggshell membrane to tin chloride pentahydrate is 1:1-5, poured into a polytetrafluoroethylene liner, and placed in a stainless steel hydrothermal autoclave, heated to 180°C and kept warm for 12 hours, after the reaction is completed, cooled to room temperature, washed with deionized water and alcohol three times respectively, and then heated to 100°C at 1-4°C / min in an argon atmosphere, kept warm for 12 hours, heated to 350°C at 1-4°C / min, kept warm for 2 hours, heated to 450-550°C at 1-4°C / min, and kept warm for 2 hours to obtain the SnS2 / CN composite material.

6. The method for preparing a negative electrode material for a lithium battery from a biomass carbon composite metal according to claim 1, characterized in that: The preparation steps of the Sb2S3 / CN composite material are as follows: weighing chlorella powder, adding distilled water, preparing a chlorella solution with a mass fraction of 5-10%, adding antimony trichloride-ethanol solution with an antimony trichloride concentration of 33mM after it is fully dissolved, the mass ratio of antimony trichloride to chlorella powder is 1-5:1, stirring at 40rpm for 3h, then adding thiourea until the color of the solution changes from green to dark green, transferring it to an autoclave, sealing it and heating it to 200℃, keeping it warm for 10h, cooling it to room temperature, collecting the precipitate, washing it with ethanol and distilled water for 6 times, and then heating it to 100℃ at 1-4℃ / min under argon atmosphere, keeping it warm for 12h, heating it to 450-550℃ at 1-4℃ / min, and keeping it warm for 2h.

7. A negative electrode material for a lithium ion battery, characterized in that: The lithium-ion battery negative electrode material is prepared by the method according to any one of claims 1 to 6.

8. A battery pole piece, characterized in that: The battery pole piece comprises the negative electrode material according to claim 7.

9. The negative electrode sheet according to claim 8, characterized in that: The negative electrode plate is used for lithium ion batteries, lithium ion capacitors, lithium sulfur batteries or all-solid-state lithium batteries.

10. A lithium battery, characterized in that: The lithium battery comprises the negative electrode material described in any one of claims 1 to 6.

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