A self-supporting composite lithium negative electrode material with controllable lithium loading and a preparation method thereof

Abstract

The application discloses a self-supporting composite lithium negative electrode material with controllable lithium loading and a preparation method thereof. In view of problems of lithium dendrite growth, volume shrinkage / expansion in lithium stripping / deposition and low lithium metal utilization of a lithium metal electrode, lithiumophilic metal oxide is loaded on a flexible carbon nanofiber film, and a composite negative electrode with different lithium loadings is prepared through a low-temperature lithium melting injection mode. The three-dimensional structure of the flexible carbon fiber film plays a self-supporting role and alleviates the influence of volume shrinkage / expansion in the lithium stripping / deposition process, and the lithiumophilic metal oxide serves as an active site to guide uniform distribution of lithium, effectively inhibits lithium dendrite growth, and improves the electrochemical performance of the battery.

Description

Technical Field

[0001] This invention belongs to the field of composite lithium anode material technology, specifically relating to a self-supporting composite lithium anode material with controllable lithium loading and its preparation method. Background Technology

[0002] Lithium metal anodes have the highest theoretical specific capacity and the lowest electrochemical potential, making them ideal anode materials for simultaneously achieving high energy density and efficient fast charging.

[0003] Lithium metal anodes have attracted widespread research attention due to their ultra-high theoretical capacity, lowest redox potential, and low weight density. However, problems such as lithium dendrite growth and lithium stripping / deposition processes lead to low coulombic efficiency and poor cycle life. Secondly, during lithium stripping, the reduced lithium thickness creates gaps between the separator and the lithium metal, resulting in separator stress and posing serious safety hazards. Furthermore, in traditional lithium metal batteries, active lithium metal is continuously consumed due to lithium dendrite growth and uncontrolled reactions with the liquid electrolyte. Therefore, to ensure performance, lithium metal is often used in excess, which significantly reduces the battery's energy density and increases its cost, hindering the practical application of lithium metal batteries.

[0004] Currently, there are many designs for negative electrode current collectors. Among them, carbon materials have advantages such as light weight, tunable physicochemical properties, high electronic conductivity, and low cost, and are considered a perfect host for lithium. Carbon nanofiber membranes prepared by electrospinning have characteristics such as high porosity, large specific surface area, and controllable diameter, which can enhance the wettability of electrolytes and form a matrix similar to a three-dimensional network reservoir for storing active materials. Furthermore, tunable functional carbon fibers can be synthesized by reasonably adjusting the composition of the spinning solution. However, carbon nanofiber membranes suffer from problems such as low strength, poor toughness, and poor lithium affinity, which limits their use as negative electrode current collectors. Summary of the Invention

[0005] The purpose of this invention is to provide a self-supporting composite lithium anode material with controllable lithium loading and its preparation method, thereby solving one or more of the aforementioned technical problems. This invention uses a soluble polymer as a carbon source to prepare a flexible carbon fiber film via electrospinning, and uniformly loads metal oxide particles onto its surface. Then, a composite lithium anode is prepared by melt-implantation lithium. The carbon fiber has a three-dimensional network structure, which acts as a self-supporting framework to mitigate volume changes during lithium stripping / deposition. The interaction between the lithium-loving metal oxides on the carbon fiber surface and lithium ensures uniform lithium deposition on the carbon fiber surface, suppressing lithium dendrite formation and improving the cycle stability of the battery.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for preparing a self-supporting composite lithium anode material with controllable lithium loading includes the following steps:

[0008] A soluble polymer, metal acetate, and pore-forming agent in a mass ratio of 1:0.1~0.4:0.1~0.2:10 were weighed and dissolved in a dimethylformamide solution for mixing to obtain a precursor solution.

[0009] The precursor solution was transferred to the electrospinning experimental platform to obtain an organic polymer fiber membrane;

[0010] The organic polymer fiber membrane is pre-oxidized in a muffle furnace and then heated in a tube furnace under a nitrogen atmosphere to complete the carbonization, thus obtaining a flexible carbon fiber membrane. During this process, the metal acetate is thermally decomposed and reduced to elemental metals that coat the inside of the carbon fiber.

[0011] The obtained carbon fiber membrane was immersed in a metal salt solution with a concentration of 0.2~1 mol / L, dried, and then placed in a tube furnace and heated under a nitrogen atmosphere. The metal salt thermally decomposed into metal oxide particles that adhered to the surface of the carbon fiber, thus obtaining a flexible carbon fiber membrane loaded with metal oxide particles.

[0012] By heating the carbon fiber membrane and then melting and injecting lithium, lithium of different masses is combined with the flexible carbon fiber membrane loaded with metal oxide particles to obtain a self-supporting composite lithium anode material with controllable lithium loading.

[0013] A further improvement of this invention is that the selected soluble polymer is polyacrylonitrile, polyvinylidene fluoride, or polystyrene; the selected metal acetate is zinc acetate, copper acetate, or aluminum acetate; and the selected pore-forming agent is urea, ammonium bicarbonate, or ferrocene.

[0014] A further improvement of the present invention is that the mass ratio of the soluble polymer to the metal acetate is 3:1~3.

[0015] A further improvement of the present invention is that the selected metal oxide particles are zinc oxide, lead oxide, molybdenum oxide or titanium oxide.

[0016] A further improvement of the present invention is that the voltage for electrospinning is set to 12~17kV.

[0017] A further improvement of the present invention is that the pre-oxidation temperature is 200 ~ 300℃ and the holding time is more than 2 hours.

[0018] A further improvement of this invention is that the carbonization temperature under a nitrogen atmosphere is 600 ~ 1000℃, and the holding time is more than 2 hours.

[0019] A further improvement of this invention is that the heat treatment temperature under a nitrogen atmosphere is 400~600℃, and the holding time is more than 3 hours.

[0020] A further improvement of the present invention is that the lithium melting temperature is 200 ~ 300°C when lithium is injected into carbon fiber.

[0021] A self-supporting composite lithium anode material with controllable lithium loading is prepared using the method described above.

[0022] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0023] 1. The carbon fiber membrane prepared in this invention is produced by electrospinning and has the characteristics of high porosity, large specific surface area, and controllable diameter. It can enhance the wettability of electrolyte, and the carbon fiber has a three-dimensional network structure that provides self-support. This can effectively avoid volume changes during the lithium deposition and stripping process, and no gap will be generated between the membrane and the negative electrode, thereby eliminating membrane stress and effectively improving safety.

[0024] 2. The carbon fiber membrane prepared in this invention contains a small amount of metal acetate. During the heat treatment process, the metal acetate decomposes and is reduced to metal nanoparticles that coat the interior of the carbon fiber, giving the carbon fiber good flexibility and allowing it to remain intact even after multiple bends and rolls.

[0025] 3. A pore-forming agent of a predetermined proportion is added during the preparation of the metal salt solution in this invention. The aim is to create a more uniform and suitable pore structure during subsequent processing through the action of the pore-forming agent. These pores not only provide more adhesion sites for the metal oxide particles but also ensure that the particles can adhere uniformly and firmly to the surface of the carbon fiber membrane. This uniform adhesion greatly increases the contact area between the metal oxide and the carbon fiber membrane, thereby enhancing the interaction force between them. Furthermore, the use of the pore-forming agent also facilitates the diffusion and transport of lithium ions in the carbon fiber membrane, promoting the effective bonding of lithium with the carbon fiber membrane. This provides a superior material choice for applications such as lithium-ion batteries.

[0026] 4. In this invention, a carbon fiber membrane loaded with metal oxide is obtained by immersing the carbon fiber in a lithiophilic metal salt solution followed by high-temperature heat treatment. The metal oxide effectively improves the lithiophilicity of the carbon fiber while retaining the advantage of its low density. The preparation process involves simple equipment, avoids complex processes, and has low raw material costs.

[0027] 5. This invention employs a low-temperature molten lithium impregnation method, which can complete lithium impregnation at 200~300℃. Furthermore, by controlling the mass of the molten lithium block, composite anodes with different lithium loadings can be obtained. Attached Figure Description

[0028] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of carbon fiber membrane after multiple folds and rolls.

[0030] Figure 2 This is the XRD pattern of a flexible carbon fiber membrane loaded with zinc oxide particles after being kept at 500℃ for 4 hours.

[0031] Figure 3 These are SEM images of flexible carbon fiber membrane composite lithium anodes with different lithium loadings.

[0032] Figure 4 This is a comparison chart of the rate performance of symmetrical batteries using flexible carbon fiber film composite lithium anodes with different lithium loadings.

[0033] Figure 5 This is a comparison chart of the cycle performance of symmetrical batteries using flexible carbon fiber membrane composite lithium anodes with different lithium loadings.

[0034] Figure 6 This is a comparison chart of the cycle performance of lithium iron phosphate batteries with flexible carbon fiber membrane composite lithium anodes of different lithium loadings.

[0035] Figure 7 These are the charge-discharge curves of the lithium iron phosphate batteries assembled with the composite lithium anodes prepared in Examples 4 and 5 after 300 cycles. Detailed Implementation

[0036] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0037] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0038] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0039] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0040] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0041] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0042] A method for preparing a self-supporting composite lithium anode material with controllable lithium loading according to an embodiment of the present invention, wherein the preparation method includes the following steps:

[0043] I. Preparation of Flexible Carbon Fiber Membranes by Electrospinning

[0044] 1. Preparation of precursor solution: Metal acetate and pore-forming agent are added to dimethylformamide solution in a set ratio and dispersed and dissolved by ultrasonication to form a clear and transparent solution; then the solution is transferred to a magnetic stirrer and the speed is set to 300~400 rpm, while soluble polymer powder is slowly added; when the soluble polymer powder is completely dissolved and a clear solution is obtained, the precursor solution is obtained.

[0045] 2. Preparation of Flexible Carbon Fiber Membrane: The spinning solution was transferred to a syringe in the electrospinning experimental platform. After electrospinning was completed, the organic fiber membrane was transferred to a forced-air drying oven to remove unevaporated dimethylformamide solvent. Pre-oxidation was then carried out at 200-300°C. The pre-oxidized fiber membrane was then transferred to a tube furnace. After purging the air from the quartz tube, it was held at 600-1000°C for 2-6 hours to complete carbonization, yielding the flexible carbon fiber membrane.

[0046] II. Preparation of self-supporting composite lithium anode materials with controllable lithium loading

[0047] 1. Flexible carbon fiber composite metal oxide particles: Prepare a 0.2~1 mol / L zinc acetate solution (or lead nitrate, molybdenum acetate, or other metal salt solutions). Immerse a certain mass of carbon fiber membrane in the above solution, remove and dry it, then transfer it to a tube furnace. Use nitrogen gas as a protective atmosphere, purging at a rate of 100~200 ml / h, and heat to 450~600℃ at 10℃ / min, holding for 2~6 h. During this process, the metal salt completely decomposes into metal oxides and is uniformly distributed on the carbon fiber surface.

[0048] 2. Flexible carbon fiber melt lithium injection: The lithium melting process is carried out in a glove box under an argon atmosphere. The lithium block is placed on a carbon fiber film maintained at 200~300℃ to melt and prepare the material. By controlling the respective masses of the lithium block and the carbon fiber film, composite anodes with different lithium loadings are obtained. Following the above operation, a self-supporting composite lithium anode material with controllable lithium loading is prepared.

[0049] Furthermore, the selected soluble polymers are polyacrylonitrile, polyvinylidene fluoride, or polystyrene; the selected metal acetates are zinc acetate, copper acetate, or aluminum acetate; and the selected pore-forming agents are urea, ammonium bicarbonate, or ferrocene. The selected metal oxide particles are zinc oxide, lead oxide, molybdenum oxide, or titanium oxide.

[0050] Polyacrylonitrile is commonly used as a precursor in the preparation of carbon fibers, and also in the preparation of ultrafiltration and nanofiltration membranes. Polyvinylidene fluoride (PVDF) possesses excellent chemical resistance, thermal stability, and electrical insulation properties, and is widely used in battery separators, microfiltration membranes, and nanofiltration membranes. Polystyrene is a commonly used plastic material with good processing properties and transparency, and can be used to prepare foam materials, packaging materials, etc.

[0051] Among metal acetates, zinc acetate, copper acetate, and aluminum acetate are commonly used as metal sources and play an important role in the preparation of metal oxides, metal sulfides, and other nanomaterials. They can be converted into the corresponding metal oxides or sulfides through methods such as thermal decomposition or chemical precipitation.

[0052] Among pore-forming agents, urea, ammonium bicarbonate, and ferrocene play a crucial role in the preparation of porous materials. They can generate gases or volatilize during the material preparation process, thereby leaving pores in the material and increasing its specific surface area and porosity. This is significant for improving the material's adsorption and catalytic properties.

[0053] Among metal oxide particles, zinc oxide, lead oxide, molybdenum oxide, and titanium oxide possess unique physical and chemical properties, and are widely used in photocatalysis, electrocatalysis, sensors, and energy storage materials. For example, zinc oxide and titanium oxide are commonly used photocatalysts, which can be used to degrade organic pollutants and to prepare solar cells.

[0054] Example 1

[0055] This embodiment provides a method for preparing a self-supporting composite lithium anode material with controllable lithium loading. The specific steps are as follows:

[0056] Weigh out 1.28 g of polyacrylonitrile, (2 mmol, 4 mmol, 6 mmol) of copper acetate, and urea (copper acetate to urea molar ratio of 2:1). Add the copper acetate and urea to 10 g of dimethylformamide solution, and disperse and dissolve them by ultrasonication to form a clear and transparent solution. Then transfer the solution to a magnetic stirrer, set the speed to 400 rpm, and slowly add polyacrylonitrile powder. Once the polyacrylonitrile powder is completely dissolved, a clear blue-green solution is obtained, which is labeled as samples #1, #2, and #3.

[0057] Samples #1, #2, and #3 were transferred to syringes in the electrospinning experimental platform. The solution injection rate was set to 0.8 mL / h, the distance between the needle tip and the roller was 15 cm, the voltage was set to 16 kV, and the roller speed was set to 60 rpm. After electrospinning was completed, the polyacrylonitrile fibers were transferred to a forced-air drying oven to remove unevaporated dimethylformamide solvent. Pre-oxidation was then carried out at 260°C. The pre-oxidized fiber membrane was transferred to a tube furnace, and after purging the air from the quartz tube, it was held at 700°C for 2 hours to complete carbonization, yielding a flexible carbon fiber membrane.

[0058] Example 2

[0059] This embodiment provides a method for preparing a self-supporting composite lithium anode material with controllable lithium loading. The specific steps are as follows:

[0060] Prepare a 1 mol / L zinc acetate solution. Immerse 38 mg of carbon fiber membrane (sample #1) in the zinc acetate solution for 30 min. Evaporate the water and ethanol at 80 °C, transfer the membrane to a tube furnace, and heat to 550 °C at a rate of 10 °C / min, holding for 6 h. This yields a carbon fiber membrane loaded with zinc oxide particles.

[0061] The above product was cut into small circular pieces with a diameter of 1.4 cm and a thickness of 200 μm, placed on a heating stage, and heated to 280 °C. 5 mg of lithium block was placed on the carbon fiber film until it was completely absorbed, thus obtaining a composite lithium anode with lithium loading #1.

[0062] Example 3

[0063] This embodiment provides a method for preparing a self-supporting composite lithium anode material with controllable lithium loading. The specific steps are as follows:

[0064] Prepare a 1 mol / L zinc acetate solution. Immerse 38 mg of carbon fiber membrane (sample #1) in the zinc acetate solution for 30 min. Evaporate the water and ethanol at 80 °C, transfer the membrane to a tube furnace, and heat to 550 °C at a rate of 10 °C / min, holding for 6 h. This yields a carbon fiber membrane loaded with zinc oxide particles.

[0065] The above product was cut into small circular pieces with a diameter of 1.4 cm and a thickness of 200 μm, placed on a heating stage, and heated to 280 °C. 6.5 mg of lithium block was placed on the carbon fiber film until it was completely absorbed, thus obtaining a composite lithium anode with lithium loading #1.

[0066] The difference from Example 2 is that the mass of lithium injected into the carbon fiber is changed from 5 mg to 6.5 mg, resulting in a composite lithium anode with lithium loading #2; otherwise, it is exactly the same as Example 2.

[0067] Example 4

[0068] This embodiment provides a method for preparing a self-supporting composite lithium anode material with controllable lithium loading. The specific steps are as follows:

[0069] Prepare a 1 mol / L zinc acetate solution. Immerse 38 mg of carbon fiber membrane (sample #1) in the zinc acetate solution for 30 min. Evaporate the water and ethanol at 80 °C, transfer the membrane to a tube furnace, and heat to 550 °C at a rate of 10 °C / min, holding for 6 h. This yields a carbon fiber membrane loaded with zinc oxide particles.

[0070] The above product was cut into small circular pieces with a diameter of 1.4 cm and a thickness of 200 μm, placed on a heating stage, and heated to 280 °C. 8 mg of lithium was placed on the carbon fiber film until it was completely absorbed, thus obtaining a composite lithium anode with lithium loading #1.

[0071] The difference from Example 2 is that the mass of lithium injected into the carbon fiber was changed from 5 mg to 8 mg, resulting in a composite lithium anode with lithium loading #3; otherwise, it is exactly the same as Example 2.

[0072] Example 5

[0073] This embodiment provides a method for preparing a self-supporting composite lithium anode material with controllable lithium loading. The specific steps are as follows:

[0074] Prepare a 1 mol / L zinc acetate solution. Immerse 38 mg of carbon fiber membrane (sample #1) in the zinc acetate solution for 30 min. Evaporate the water and ethanol at 80 °C, transfer the membrane to a tube furnace, and heat to 550 °C at a rate of 10 °C / min, holding for 6 h. This yields a carbon fiber membrane loaded with zinc oxide particles.

[0075] The above product was cut into small circular pieces with a diameter of 1.4 cm and a thickness of 200 μm, placed on a heating stage, and heated to 280 °C. 10 mg of lithium block was placed on the carbon fiber film until it was completely absorbed, thus obtaining a composite lithium anode with lithium loading #1.

[0076] The difference from Example 2 is that the mass of lithium injected into the carbon fiber is changed from 5 mg to 10 mg, resulting in a composite lithium anode with lithium loading #4; otherwise, it is exactly the same as Example 2.

[0077] This invention provides a method for preparing a self-supporting composite lithium anode material with controllable lithium loading. The prepared composite lithium anode is then assembled into a symmetrical battery, and its performance is tested. (At 1 Am / cm...) 2 At the specified current density, the battery cycled stably for 400 hours, and also exhibited good rate performance. When assembled lithium iron phosphate batteries were subjected to cycle performance testing, they retained 92% of their capacity after 400 cycles.

[0078] In summary, this invention prepares a flexible carbon fiber membrane using a soluble polymer as the carbon source via electrospinning, and uniformly loads metal oxide particles onto its surface. A composite lithium anode is then prepared via melt-implantation. The carbon fiber possesses a three-dimensional network structure, which acts as a self-supporting framework to mitigate volume changes during lithium stripping / deposition. The interaction between the lithium-loving metal oxides on the carbon fiber surface and lithium ensures uniform lithium deposition on the carbon fiber surface, suppressing lithium dendrite formation and improving the battery's cycle stability.

[0079] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0080] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for preparing a self-supporting composite lithium anode material with controllable lithium loading, characterized in that, Includes the following steps: A soluble polymer, a metal acetate, and a pore-forming agent in a mass ratio of 1:0.1~0.4:0.1~0.2:10 were dissolved in a dimethylformamide solution and mixed to obtain a precursor solution; the selected metal acetate was zinc acetate, copper acetate, or aluminum acetate. The precursor solution was transferred to the electrospinning experimental platform to obtain an organic polymer fiber membrane; The organic polymer fiber membrane is pre-oxidized in a muffle furnace and then heated in a tube furnace under a nitrogen atmosphere to complete the carbonization, thus obtaining a flexible carbon fiber membrane. During this process, the metal acetate is thermally decomposed and reduced to elemental metals that coat the inside of the carbon fiber. The obtained carbon fiber membrane was immersed in a metal salt solution with a concentration of 0.2~1 mol / L, dried, and then placed in a tube furnace and heated under a nitrogen atmosphere. The metal salt thermally decomposed into metal oxide particles that adhered to the surface of the carbon fiber, thus obtaining a flexible carbon fiber membrane loaded with metal oxide particles. The selected metal oxide particles were zinc oxide, lead oxide, molybdenum oxide, or titanium oxide. By heating the carbon fiber membrane and melting it with lithium, lithium of different masses is combined with the flexible carbon fiber membrane loaded with metal oxide particles to obtain a self-supporting composite lithium anode material with controllable lithium loading. When the carbon fiber membrane is 38 mg, the lithium loading is 8 mg-10 mg.

2. The method for preparing a self-supporting composite lithium anode material with controllable lithium loading according to claim 1, characterized in that, The selected soluble polymers are polyacrylonitrile, polyvinylidene fluoride, or polystyrene; the selected pore-forming agents are urea, ammonium bicarbonate, or ferrocene.

3. The method for preparing a self-supporting composite lithium anode material with controllable lithium loading according to claim 1, characterized in that, The mass ratio of soluble polymer to metal acetate is 3:1~3.

4. The method for preparing a self-supporting composite lithium anode material with controllable lithium loading according to claim 1, characterized in that, The voltage for electrospinning is set to 12~17kV.

5. The method for preparing a self-supporting composite lithium anode material with controllable lithium loading according to claim 1, characterized in that, The pre-oxidation temperature is 200 ~ 300℃, and the holding time is more than 2 hours.

6. The method for preparing a self-supporting composite lithium anode material with controllable lithium loading according to claim 1, characterized in that, The carbonization temperature under a nitrogen atmosphere is 600 ~ 1000℃, and the holding time is more than 2 hours.

7. The method for preparing a self-supporting composite lithium anode material with controllable lithium loading according to claim 1, characterized in that, The heat treatment temperature under nitrogen atmosphere is 400 ~ 600℃, and the holding time is more than 3 hours.

8. A method for preparing a self-supporting composite lithium anode material with controllable lithium loading according to claim 1, characterized in that, When lithium is injected into carbon fiber, the melting temperature is 200 ~ 300℃.

9. A self-supporting composite lithium anode material with controllable lithium loading, characterized in that, It is prepared by any one of the preparation methods according to claims 1 to 8.

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