Preparation method and application of hydroxyl tin cobalt derivative sulfide carbon composite based on electrostatic spinning

Abstract

The application relates to the field of sodium ion battery negative electrode materials and discloses a preparation method and application of a hydroxyl cobalt stannate derivative sulfide carbon composite material based on electrostatic spinning. The method comprises the following steps: mixing a tin source solution and a cobalt source solution to obtain a mixed solution A; adding sodium hydroxide aqueous solution dropwise into the mixed solution A to obtain a suspension B; performing alkali etching treatment on the suspension B to obtain a hydroxyl cobalt stannate hollow nanobox material; dissolving the hydroxyl cobalt stannate hollow nanobox material and a high-molecular polymer in N,N dimethylformamide to form a spinning solution; preparing a fiber film through electrostatic spinning; and sequentially performing pre-oxidation, carbonization and sulfuration treatment to obtain the hydroxyl cobalt stannate derivative sulfide carbon composite material. The improved coprecipitation method is combined with the electrostatic spinning technology to prepare the hydroxyl cobalt stannate derivative sulfide carbon composite material, and the electronic conductivity, sodium ion diffusion kinetics and electrochemical sodium storage performance of the tin-based sulfide negative electrode material are effectively improved.

Description

Technical Field

[0001] This invention belongs to the technical field of sodium-ion battery anode materials, and more specifically relates to a method for preparing and applying a cobalt hydroxytin derivative sulfide carbon composite material based on electrospinning. Background Technology

[0002] The increasing demand for consumer electronics, electric vehicles, and large-scale energy storage has driven the further development of rechargeable secondary batteries. Currently, commercial lithium-ion batteries, with their advantages of long cycle life and high energy density, have become the dominant power source in the field of electronic energy storage and are widely used in various sectors of society. However, the huge demand has led to an increasingly prominent problem of lithium resource shortage, which has attracted widespread attention. Sodium-ion batteries, like lithium-ion batteries, belong to the "rocking chair" secondary battery system. Their working principle is based on the insertion / extraction mechanism of Na⁺ between the positive and negative electrodes. Compared with lithium-ion batteries, sodium-ion batteries have three core advantages: (1) Resource autonomy: Sodium resources are widely distributed; (2) Cost advantage: Iron-based / copper-based compounds are used to replace lithium cobalt oxide in the positive electrode material, hard carbon is used to replace graphite in the negative electrode, and aluminum foil current collectors are used to replace copper foil, which significantly reduces material costs; (3) Environmental friendliness: The production energy consumption of sodium-ion batteries is lower than that of lithium-ion batteries, and the carbon emissions throughout the entire life cycle are less, which meets the requirements of the "dual carbon" target. Therefore, it is crucial to develop sodium-ion batteries with low cost, high energy density, and high power density, and the research and development of high-performance anode materials is of great significance to achieving this goal.

[0003] Among them, tin-based sulfides have the advantages of high capacity and low cost. Compared with tin-based oxides, tin-based sulfides exhibit higher conductivity, mechanical stability, and better reaction reversibility due to their weaker MS bonds, thus showing greater kinetic advantages. Hexagonal SnS2 and orthorhombic SnS have unique layered structures with interlayer spacings of 0.589 nm (space group P3m1) and 0.433 nm (space group Pnma), respectively. They are converted through the reaction (SnS2 + 2Na) + + 2e - Sn + Na₂S, SnS + 2Na + +2e - Sn + Na₂S) and the subsequent alloying reaction (Sn + 3.75Na) + +3.75e - Na 3.75 The theoretical specific capacities of Sn and Na are 1137 and 1022 mAh·g, respectively. -1 However, achieving long-term stability and high capacity remains a major challenge due to the significant volume changes during cycling.

[0004] To address these issues, researchers have proposed various solutions, such as nanostructure design, carbon material composites, and heterostructure construction. For example, patent CN114050268A uses cobalt chloride, stannous chloride, CTAB, and graphene as raw materials. After uniform mixing under acidic conditions, thiourea is added, followed by a high-pressure hydrothermal reaction under alkaline conditions to prepare a bimetallic sulfide composite anode material with graphene as the matrix and in-situ supported SnS nanosheets coating hollow CoS. Although the rate performance and cycle performance of this material are improved, its large-scale promotion is still limited due to high energy consumption and high cost. Summary of the Invention

[0005] The main objective of this invention is to address the aforementioned problems by providing a method for preparing and applying a cobalt hydroxytinide-derived sulfide carbon composite material based on electrospinning. This method employs an improved co-precipitation method combined with electrospinning technology, followed by heat treatment to prepare the cobalt hydroxytinide-derived sulfide carbon composite material. This improves the electronic conductivity, sodium ion diffusion kinetics, and electrochemical sodium storage performance of tin-based sulfide anode materials, thereby solving the problems of poor cycle stability and low intrinsic conductivity of existing tin-based sulfides.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0007] One of the technical solutions of the present invention is a method for preparing a cobalt hydroxytinide-derived sulfide carbon composite material based on electrospinning, comprising the following steps:

[0008] Step 1: Add the tin source to anhydrous ethanol and stir until completely dissolved to obtain a tin source solution; add the cobalt source and dispersant to water and stir until completely dissolved to obtain a cobalt source solution; at room temperature, pour the tin source solution into the cobalt source solution and mix thoroughly to obtain mixed solution A;

[0009] Step 2: Add sodium hydroxide aqueous solution dropwise to mixed solution A, stir, and let stand for a period of time to obtain suspension B;

[0010] Step 3: Alkali etching is performed on suspension B, followed by centrifugation, washing, and drying to obtain cobalt hydroxytin bromide material;

[0011] Step 4: Dissolve cobalt hydroxytinide material and polymer in N,N-dimethylformamide to form a spinning solution; perform electrospinning to obtain a fiber film;

[0012] Step 5: The fiber film is subjected to pre-oxidation and carbonization in sequence to obtain a carbonized film;

[0013] Step 6: The carbonized film is subjected to sulfurization treatment to obtain a carbon composite material of cobalt hydroxytin derivative sulfide.

[0014] The sodium storage process of cobalt-tin sulfides typically follows a staged reaction pathway of "conversion-alloying," in which cobalt disulfide and tin disulfide play distinct and complementary roles. Cobalt disulfide is responsible for constructing a stable and conductive framework (buffer matrix), while tin disulfide provides high capacity. Furthermore, their tight bonding forms a heterojunction structure, creating an internal electric field at the interface that accelerates charge transfer rates, thereby speeding up reaction kinetics. Simultaneously, the alkaline etching of the tin hydroxyl precursor to obtain a hollow structure, and the carbon coating of the cobalt-tin sulfide by electrospinning, work synergistically to mitigate the volume expansion during alloying. Therefore, the preparation of cobalt-tin sulfides using a co-precipitation method combined with electrospinning technology, and its composite with carbon materials, holds promise for obtaining high-performance sodium storage anode materials.

[0015] In the above preparation process, this invention uses cobalt hydroxytin oxide and a polymer as solutes, dissolves them in an organic solvent to form a uniform spinning solution, and successfully prepares a cobalt hydroxytin oxide-derived carbon fiber composite film through electrospinning. To enhance the structural stability of the fiber in subsequent high-temperature treatment, it is first pre-oxidized in an air atmosphere. Subsequently, high-temperature carbonization is used to achieve in-situ reduction of cobalt-tin bimetallic salt to cobalt-tin alloy. Polyacrylonitrile and the channel forming agent have good compatibility in N,N-dimethylformamide, resulting in higher stability of the spinning solution and ensuring uniform dispersion of cobalt-tin sulfide particles. During this process, polyacrylonitrile thermally decomposes to form a nitrogen-doped carbon framework, while the channel forming agent decomposes to generate abundant porous channels. This porous structure not only increases the contact interface between the electrode material and the electrolyte, promoting rapid electrolyte penetration, but also provides more pathways for ion transport, which helps to achieve rapid ion migration under high-rate charge and discharge conditions, thereby significantly improving the rate performance of the material. In addition, the porous carbon framework can effectively buffer the volume expansion of metal sulfides during charge and discharge, enhancing structural stability. The generation of nitrogen-doped carbon further enhances the graphitization degree and overall conductivity of the carbon material. Finally, through gas-phase sulfidation, sulfur powder is sublimated at high temperature and reacted with a cobalt-tin alloy to generate cobalt disulfide / tin disulfide composite carbon nanofibers. Excess sulfur remains within the carbon fibers as a dopant, further optimizing the material's conductivity. This method features a simple process flow, easily controllable reaction conditions, and good repeatability and controllability.

[0016] More preferably, in step one, the tin source is any one or more of tin tetrachloride pentahydrate, anhydrous tin tetrachloride, sodium hexahydroxystannate, tin tetrafluoride, and dibutyltin dilaurate; the cobalt source is any one or more of cobalt chloride hexahydrate, cobalt sulfate heptahydrate, and cobalt oxalate dihydrate; and the dispersant is any one or more of trisodium citrate dihydrate, sodium tartrate, sodium oxalate, and ammonium oxalate.

[0017] This invention reveals that in traditional coprecipitation methods, the absence of a dispersant results in poorly dispersed nanocubes and impurity particles due to uncontrolled nucleation and rapid crystal growth. Therefore, selecting a suitable dispersant can lead to the formation of discrete and uniform nanocubes.

[0018] More preferably, in step one, the molar ratio of cobalt source, tin source and dispersant in the mixed solution A is (1~7):(1~7):(1~10), and the volume ratio of water to anhydrous ethanol is (4~9):1.

[0019] More preferably, in step two, the concentration of the sodium hydroxide aqueous solution is 1~5 M; the volume ratio of the sodium hydroxide aqueous solution to mixed solution A is 1:(5~10); the stirring time is 20~40 min; and the standing time is 1~3 h.

[0020] More preferably, in step three, the alkaline etching involves adding an alkaline etching solution dropwise into suspension B at a rate of 0.3~0.6 mL·min. -1 The etching solution is left to stand for 10-25 minutes; the alkaline etching solution is any one or more of sodium hydroxide aqueous solution and potassium hydroxide aqueous solution, with a concentration of 3-10 M.

[0021] This invention discovers that perovskite-type cobalt hydroxytin oxide first undergoes rapid stoichiometric co-precipitation of Sn in the presence of a dispersant. 4+ Co 2+ and OH - Prepared in aqueous solution. Its intrinsic cubic structure promotes the spontaneous formation of single-crystal nanocubes. Due to its amphoteric properties, cobalt hydroxytinide nanocubes can react with excess OH... - It coordinates and gradually dissolves in concentrated alkaline solution at room temperature to form soluble [Co(OH)4]. 2- and [Sn(OH)6] 2- During this process, due to [Co(OH)4] 2- Due to thermodynamic dominance and oxidation in air, insoluble Co(III) species boundary layers easily form on the surface of cobalt hydroxyl oxidase crystals. This passivation layer makes the outer surface of the cobalt hydroxyl oxidase cube less reactive than the newly exposed inner surface during alkaline etching. By continuously removing the core material through the shell, a hollow cobalt hydroxyl oxidase nanobox with high crystallinity is eventually formed. By repeatedly depositing cobalt hydroxyl oxidase layers onto pre-formed cobalt hydroxyl oxidase particles (such as nanocubes or nanoboxes) and performing continuous alkaline etching, cobalt hydroxyl oxidase materials with complex internal structures (including eggshell particles and multi-shell nanoboxes) can be prepared while maintaining single crystallinity. In this process, the alkaline etching solution cannot be added all at once, otherwise it is easy to cause localized severe reactions, structural collapse, or uneven corrosion. Continuous and slow drop-feeding can control the OH content. -A gradual increase in concentration allows etching to begin from the core, which is beneficial for forming hollow or core-shell structures. Furthermore, excessively long etching times or excessively high alkaline etching solution concentrations can easily lead to the formation of impurity phases and significant loss of active materials; conversely, excessively short etching times or excessively low alkaline etching solution concentrations can result in incomplete reactions and failure to form hollow structures. Therefore, controlling the appropriate alkaline etching solution drop rate and etching time is crucial for ensuring the formation of hollow cobalt hydroxytinide structures and phases.

[0022] More preferably, in step four, the polymer is a mixture of polyacrylonitrile and channel forming agent in a mass ratio of 1:(0.25~2), and the channel forming agent is any one or more of polymethyl methacrylate, polyvinyl alcohol, and polyoxyethylene-polyoxypropylene block copolymer; the mass ratio of the cobalt hydroxytin oxide material, the polymer and N,N dimethylformamide is 1:(1~3):(1~10).

[0023] More preferably, in step four, the electrospinning conditions are as follows: the vertical distance from the nozzle to the receiver is 10-20 cm, the spinning voltage is 10-18 kV, and the feed rate is 0.5-1 mL·h. -1 The spinning temperature is 25~30 ℃, and the relative humidity of the air is 20~45%.

[0024] More preferably, in step five, the pre-oxidation conditions are: 1~5 °C·min in an air atmosphere. -1 The temperature is increased to 200-300 °C at a rate of [missing information], and held for 1-3 h; the carbonization conditions are: [missing information] in an inert atmosphere at a rate of 2-10 °C / min. -1 The temperature is increased to 600~1000 ℃ at a rate of 1~3 h and held for 1~3 h.

[0025] More preferably, in step six, the sulfidation treatment involves exposing the carbonized film and sulfur powder to an inert atmosphere at 2~10 °C·min. -1 The temperature is increased to 400~600 ℃ at a rate of 1~3 h and held for 1~3 h; the mass ratio of the carbonized film to sulfur powder is 1:(4~6).

[0026] The second technical solution of the present invention: the application of a cobalt hydroxytin derivative sulfide carbon composite material based on electrospinning as a negative electrode material for sodium-ion batteries.

[0027] A further preferred embodiment is that a sodium-ion battery is assembled from a cobalt hydroxytin sulfide-derived carbon composite material. The battery assembly method is as follows: first, the cobalt hydroxytin sulfide-derived carbon composite material is mixed with conductive carbon black and a binder in a certain proportion. Then, N-methylpyrrolidone is added and mixed evenly to obtain a negative electrode slurry. The negative electrode slurry is then evenly coated onto a copper foil, and the negative electrode sheet is obtained by rolling and drying. A sodium metal sheet is used as the counter electrode, a sodium hexafluorophosphate diethylene glycol dimethyl ether solution (1 M NaPF6 in GIGLYME = 100 Vol%) is used as the electrolyte, and glass fiber is used as the battery separator. The battery assembly is completed in a glove box filled with argon atmosphere.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] (1) This invention prepares cobalt hydroxytin derivative sulfide carbon composite material by improving the co-precipitation method combined with electrospinning technology. Compared with the traditional preparation method, it is simple and efficient, highly repeatable, low in cost, and more suitable for large-scale production.

[0030] (2) The present invention uses cobalt hydroxytin as a precursor to derive bimetallic sulfides. A heterojunction is formed between the two phase components. The built-in electric field reduces the ion diffusion barrier, accelerates ion transport, and significantly improves sodium storage performance.

[0031] (3) By introducing the transition metal Co, the present invention can change the electronic structure of Sn, increase the carrier concentration, and thus improve the intrinsic conductivity of the material.

[0032] (4) The present invention prepares composite fibers with multi-channel structure by electrospinning polymer precursors with different surface tensions and calcining them at high temperature, which inhibits the aggregation between metal sulfides, effectively alleviates the volume expansion during charging and discharging, and improves the electrochemical performance of the material. Attached Figure Description

[0033] Figure 1 This is a scanning electron microscope image of the surface of the cobalt hydroxytin sulfide-derived carbon composite material prepared in Example 1;

[0034] Figure 2 This is a rate performance diagram of the cobalt hydroxytinide-derived sulfide carbon composite material prepared in Example 1;

[0035] Figure 3 This is a scanning electron microscope image of the cross section of the cobalt hydroxytinide-derived sulfide carbon composite material prepared in Example 2;

[0036] Figure 4 This is a transmission electron microscope (TEM) image of the cobalt hydroxytinide-derived sulfide carbon composite material prepared in Example 2;

[0037] Figure 5 The X-ray diffraction pattern of the cobalt hydroxytin sulfide-derived carbon composite material prepared in Example 3;

[0038] Figure 6 The graph shows the cycling performance of the cobalt hydroxytin sulfide-derived sulfide carbon composite material prepared in Example 4.

[0039] Figure 7 The image shows a scanning electron microscope (SEM) image of cobalt hydroxytinide prepared in Comparative Example 1.

[0040] Figure 8 The cycling performance diagram is shown for the cobalt hydroxytin sulfide-derived sulfide material prepared in Comparative Example 3.

[0041] Figure 9 Here is a scanning electron microscope image of the cobalt hydroxytin sulfide-derived sulfide material prepared in Comparative Example 6;

[0042] Figure 10 This is a scanning electron microscope image of the cobalt hydroxytin derivative sulfide material prepared in Comparative Example 3. Detailed Implementation

[0043] The following description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0044] Example 1

[0045] Step 1: Dissolve 1 mmol of tin tetrachloride pentahydrate in 5 mL of anhydrous ethanol and stir at room temperature until completely dissolved to obtain a tin source solution; dissolve 1 mmol of cobalt chloride hexahydrate and 1 mmol of disodium citrate trihydrate in 35 mL of deionized water and stir at room temperature until completely dissolved to obtain a cobalt source solution; quickly pour the tin source solution into the cobalt source solution to obtain mixed solution A.

[0046] Step 2: Prepare 5 mL of 2 M NaOH aqueous solution. Slowly add the 2 M NaOH aqueous solution dropwise into mixed solution A, stir at room temperature for 30 min, and let stand for 1 h to obtain suspension B.

[0047] Step 3: Prepare 20 mL of alkaline etching solution (8 M NaOH aqueous solution), and dissolve the alkaline etching solution at a rate of 0.5 mL / min. -1 The suspension B was added dropwise at a certain rate, and after standing at room temperature for 15 min, it was centrifuged, washed, and dried to obtain cobalt hydroxytinide material.

[0048] Step 4: Add 0.3 g of cobalt hydroxytin to 4 g of DMF and disperse it evenly by ultrasonication. Then add 0.4 g of polyacrylonitrile and 0.4 g of polymethyl methacrylate and stir vigorously until homogeneous to obtain the spinning solution.

[0049] Step 5: Pour the spinning solution into a 5 mL syringe and spin using an electrospinning device at a temperature of 35 ℃ and a humidity of 30%. Specific spinning parameters are: the distance from the syringe needle to the receiver is 15 cm, the applied voltage is 15 kV, and the propulsion device is at a rate of 0.6 mL / h. -1 The propulsion speed pushes the spinning solution in the 5 mL syringe to the needle tip, where it is collected on the tin foil collector under the action of the electric field to obtain a fiber film.

[0050] Step Six: Place the fiber film flat in a muffle furnace and heat it in air at 1 °C·min. -1 The temperature was increased to 260 °C at a heating rate and held for 1.5 h. After the pre-oxidation process was completed, the temperature was increased to 2 °C·min under a nitrogen atmosphere. -1 The temperature was increased to 800 °C and held for 2 h to obtain a carbonized thin film.

[0051] Step 7: Place the carbonized film and sulfur powder at a mass ratio of 1:5 at both ends of a quartz boat, and incubate under argon protection at 3 °C·min. -1 The temperature was increased to 500 °C and held for 1.5 h to obtain a cobalt hydroxytin derivative sulfide carbon composite material.

[0052] Example 2

[0053] Step 1: Dissolve 1 mmol of tin tetrachloride pentahydrate in 5 mL of anhydrous ethanol and stir at room temperature until completely dissolved to obtain a tin source solution; dissolve 1 mmol of cobalt chloride hexahydrate and 1 mmol of disodium citrate trihydrate in 35 mL of deionized water and stir at room temperature until completely dissolved to obtain a cobalt source solution; quickly pour the tin source solution into the cobalt source solution to obtain mixed solution A.

[0054] Step 2: Prepare 5 mL of 2 M NaOH aqueous solution. Slowly add the 2 M NaOH aqueous solution dropwise into mixed solution A, stir at room temperature for 30 min, and let stand for 1 h to obtain suspension B.

[0055] Step 3: Prepare 20 mL of alkaline etching solution (4 M NaOH aqueous solution), and dissolve the alkaline etching solution at a rate of 0.5 mL / min. -1 The suspension B was added dropwise at a certain rate, and after standing at room temperature for 15 min, it was centrifuged, washed, and dried to obtain cobalt hydroxytinide material.

[0056] Step 4: Add 0.3 g of cobalt hydroxytin to 4 g of DMF and disperse it evenly by ultrasonication. Then add 0.4 g of polyacrylonitrile and 0.4 g of polymethyl methacrylate and stir vigorously until homogeneous to obtain the spinning solution.

[0057] Step 5: Pour the spinning solution into a 5 mL syringe and spin using an electrospinning device at a temperature of 35 ℃ and a humidity of 30%. Specific spinning parameters are: the distance from the syringe needle to the receiver is 15 cm, the applied voltage is 15 kV, and the propulsion device is at a rate of 0.6 mL / h. -1 The propulsion speed pushes the spinning solution in the 5 mL syringe to the needle tip, where it is collected on the tin foil collector under the action of the electric field to obtain a fiber film.

[0058] Step Six: Place the fiber film flat in a muffle furnace and heat it in air at 1 °C·min. -1 The temperature was increased to 260 °C at a heating rate and held for 1.5 h. After the pre-oxidation process was completed, the temperature was increased to 2 °C·min under a nitrogen atmosphere. -1 The temperature was increased to 800 °C and held for 2 h to obtain a carbonized thin film.

[0059] Step 7: Place the carbonized film and sulfur powder at a mass ratio of 1:5 at both ends of a quartz boat, and incubate under argon protection at 3 °C·min. -1 The temperature was increased to 500 °C and held for 1.5 h to obtain a cobalt hydroxytin derivative sulfide carbon composite material.

[0060] Example 3

[0061] Step 1: Dissolve 2 mmol of tin tetrachloride pentahydrate in 5 mL of anhydrous ethanol and stir at room temperature until completely dissolved to obtain a tin source solution; dissolve 1 mmol of cobalt chloride hexahydrate and 1 mmol of disodium citrate trihydrate in 35 mL of deionized water and stir at room temperature until completely dissolved to obtain a cobalt source solution; quickly pour the tin source solution into the cobalt source solution to obtain mixed solution A.

[0062] Step 2: Prepare 5 mL of 2 M NaOH aqueous solution. Slowly add the 2 M NaOH aqueous solution dropwise into mixed solution A, stir at room temperature for 30 min, and let stand for 1 h to obtain suspension B.

[0063] Step 3: Prepare 20 mL of alkaline etching solution (8 M NaOH aqueous solution), and dissolve the alkaline etching solution at a rate of 0.5 mL / min. -1 The suspension B was added dropwise at a certain rate, and after standing at room temperature for 15 min, it was centrifuged, washed, and dried to obtain cobalt hydroxytinide material.

[0064] Step 4: Add 0.3 g of cobalt hydroxytin to 4 g of DMF and disperse it evenly by ultrasonication. Then add 0.4 g of polyacrylonitrile and 0.4 g of polymethyl methacrylate and stir vigorously until homogeneous to obtain the spinning solution.

[0065] Step 5: Pour the spinning solution into a 5 mL syringe and spin using an electrospinning device at a temperature of 35 ℃ and a humidity of 30%. Specific spinning parameters are: the distance from the syringe needle to the receiver is 15 cm, the applied voltage is 15 kV, and the propulsion device is at a rate of 0.6 mL / h. -1 The propulsion speed pushes the spinning solution in the 5 mL syringe to the needle tip, where it is collected on the tin foil collector under the action of the electric field to obtain a fiber film.

[0066] Step Six: Place the fiber film flat in a muffle furnace and heat it in air at 1 °C·min. -1 The temperature was increased to 260 °C at a heating rate and held for 1.5 h. After the pre-oxidation process was completed, the temperature was increased to 2 °C·min under a nitrogen atmosphere. -1 The temperature was increased to 800 °C and held for 2 h to obtain a carbonized thin film.

[0067] Step 7: Place the carbonized film and sulfur powder at a mass ratio of 1:5 at both ends of a quartz boat, and incubate under argon protection at 3 °C·min. -1 The temperature was increased to 500 °C and held for 1.5 h to obtain a cobalt hydroxytin derivative sulfide carbon composite material.

[0068] Example 4

[0069] Step 1: Dissolve 1 mmol of tin tetrachloride pentahydrate in 5 mL of anhydrous ethanol and stir at room temperature until completely dissolved to obtain a tin source solution; dissolve 1 mmol of cobalt chloride hexahydrate and 1 mmol of sodium tartrate in 35 mL of deionized water and stir at room temperature until completely dissolved to obtain a cobalt source solution; quickly pour the tin source solution into the cobalt source solution to obtain mixed solution A.

[0070] Step 2: Prepare 5 mL of 2 M NaOH aqueous solution. Slowly add the 2 M NaOH aqueous solution dropwise into mixed solution A, stir at room temperature for 30 min, and let stand for 1 h to obtain suspension B.

[0071] Step 3: Prepare 20 mL of alkaline etching solution (8 M NaOH aqueous solution), and dissolve the alkaline etching solution at a rate of 0.5 mL / min. -1 The suspension B was added dropwise at a certain rate, and after standing at room temperature for 15 min, it was centrifuged, washed, and dried to obtain cobalt hydroxytinide material.

[0072] Step 4: Add 0.3 g of cobalt hydroxytin to 4 g of DMF and disperse it evenly by ultrasonication. Then add 0.4 g of polyacrylonitrile and 0.4 g of polymethyl methacrylate and stir vigorously until homogeneous to obtain the spinning solution.

[0073] Step 5: Pour the spinning solution into a 5 mL syringe and spin using an electrospinning device at a temperature of 35 ℃ and a humidity of 30%. Specific spinning parameters are: the distance from the syringe needle to the receiver is 15 cm, the applied voltage is 15 kV, and the propulsion device is at a rate of 0.6 mL / h. -1 The propulsion speed pushes the spinning solution in the 5 mL syringe to the needle tip, where it is collected on the tin foil collector under the action of the electric field to obtain a fiber film.

[0074] Step Six: Place the fiber film flat in a muffle furnace and heat it in air at 1 °C·min. -1 The temperature was increased to 260 °C at a heating rate and held for 1.5 h. After the pre-oxidation process was completed, the temperature was increased to 2 °C·min under a nitrogen atmosphere. -1 The temperature was increased to 800 °C and held for 2 h to obtain a carbonized thin film.

[0075] Step 7: Place the carbonized film and sulfur powder at a mass ratio of 1:5 at both ends of a quartz boat, and incubate under argon protection at 3 °C·min. -1 The temperature was increased to 500 °C and held for 1.5 h to obtain a cobalt hydroxytin derivative sulfide carbon composite material.

[0076] Comparative Example 1

[0077] Step 1: Dissolve 1 mmol of tin tetrachloride pentahydrate in 5 mL of anhydrous ethanol and stir at room temperature until completely dissolved to obtain a tin source solution; dissolve 1 mmol of cobalt chloride hexahydrate and 1 mmol of disodium citrate trihydrate in 35 mL of deionized water and stir at room temperature until completely dissolved to obtain a cobalt source solution; quickly pour the tin source solution into the cobalt source solution to obtain mixed solution A.

[0078] Step 2: Prepare 5 mL of 2 M NaOH aqueous solution. Slowly add the 2 M NaOH aqueous solution dropwise into mixed solution A, stir at room temperature for 30 min, and let stand for 1 h to obtain suspension B.

[0079] Step 3: Prepare 20 mL of alkaline etching solution (8 M NaOH aqueous solution), and dissolve the alkaline etching solution at a rate of 0.5 mL / min. -1 The suspension B was added dropwise at a certain rate, and after standing at room temperature for 30 min, it was centrifuged, washed, and dried to obtain cobalt hydroxytinide material.

[0080] Step 4: Add 0.3 g of cobalt hydroxytin to 4 g of DMF and disperse it evenly by ultrasonication. Then add 0.4 g of polyacrylonitrile and 0.4 g of polymethyl methacrylate and stir vigorously until homogeneous to obtain the spinning solution.

[0081] Step 5: Pour the spinning solution into a 5 mL syringe and spin using an electrospinning device at a temperature of 35 ℃ and a humidity of 30%. Specific spinning parameters are: the distance from the syringe needle to the receiver is 15 cm, the applied voltage is 15 kV, and the propulsion device is at a rate of 0.6 mL / h. -1 The propulsion speed pushes the spinning solution in the 5 mL syringe to the needle tip, where it is collected on the tin foil collector under the action of the electric field to obtain a fiber film.

[0082] Step Six: Place the fiber film flat in a muffle furnace and heat it in air at 1 °C·min. -1 The temperature was increased to 260 °C at a heating rate and held for 1.5 h. After the pre-oxidation process was completed, the temperature was increased to 2 °C·min under a nitrogen atmosphere. -1 The temperature was increased to 800 °C and held for 2 h to obtain a carbonized thin film.

[0083] Step 7: Place the carbonized film and sulfur powder at a mass ratio of 1:5 at both ends of a quartz boat, and incubate under argon protection at 3 °C·min. -1 The temperature was increased to 500 °C and held for 1.5 h to obtain a cobalt hydroxytin derivative sulfide carbon composite material.

[0084] Comparative Example 2

[0085] Step 1: Dissolve 1 mmol of tin tetrachloride pentahydrate in 5 mL of anhydrous ethanol and stir at room temperature until completely dissolved to obtain a tin source solution; dissolve 1 mmol of cobalt chloride hexahydrate and 1 mmol of disodium citrate trihydrate in 35 mL of deionized water and stir at room temperature until completely dissolved to obtain a cobalt source solution; quickly pour the tin source solution into the cobalt source solution to obtain mixed solution A.

[0086] Step 2: Prepare 5 mL of 2 M NaOH aqueous solution, slowly add the 2 M NaOH aqueous solution dropwise into mixed solution A, stir at room temperature for 30 min, let stand for 1 h, centrifuge, wash, and dry to obtain cobalt hydroxytinide material.

[0087] Step 3: Add 0.3 g of cobalt hydroxytin to 4 g of DMF and disperse it evenly by ultrasonication. Then add 0.4 g of polyacrylonitrile and 0.4 g of polymethyl methacrylate and stir vigorously until homogeneous to obtain the spinning solution.

[0088] Step 4: Pour the spinning solution into a 5 mL syringe and spin using an electrospinning device at a temperature of 35 ℃ and a humidity of 30%. Specific spinning parameters are: the distance from the syringe needle to the receiver is 15 cm, the applied voltage is 15 kV, and the propulsion device moves at a rate of 0.6 mL / h. -1 The propulsion speed pushes the spinning solution in the 5 mL syringe to the needle tip, where it is collected on the tin foil collector under the action of the electric field to obtain a fiber film.

[0089] Step 5: Place the fiber film flat in a muffle furnace and heat it in air at 1 °C·min. -1 The temperature was increased to 260 °C at a heating rate and held for 1.5 h. After the pre-oxidation process was completed, the temperature was increased to 2 °C·min under a nitrogen atmosphere. -1 The temperature was increased to 800 °C and held for 2 h to obtain a carbonized thin film.

[0090] Step Six: Place the carbonized film and sulfur powder at a mass ratio of 1:5 at both ends of a quartz boat, and incubate under argon protection at 3 °C·min. -1 The temperature was increased to 500 °C and held for 1.5 h to obtain a cobalt hydroxytin derivative sulfide carbon composite material.

[0091] Comparative Example 3

[0092] Step 1: Dissolve 1 mmol of tin tetrachloride pentahydrate in 5 mL of anhydrous ethanol and stir at room temperature until completely dissolved to obtain a tin source solution; dissolve 1 mmol of cobalt chloride hexahydrate and 1 mmol of disodium citrate trihydrate in 35 mL of deionized water and stir at room temperature until completely dissolved to obtain a cobalt source solution; quickly pour the tin source solution into the cobalt source solution to obtain mixed solution A.

[0093] Step 2: Prepare 5 mL of 2 M NaOH aqueous solution. Slowly add the 2 M NaOH aqueous solution dropwise into mixed solution A, stir at room temperature for 30 min, and let stand for 1 h to obtain suspension B.

[0094] Step 3: Prepare 20 mL of alkaline etching solution (8 M NaOH aqueous solution), and dissolve the alkaline etching solution at a rate of 0.5 mL / min. -1 The suspension B was added dropwise at a certain rate, and after standing at room temperature for 15 min, it was centrifuged, washed, and dried to obtain cobalt hydroxytinide material.

[0095] Step 4: Place the cobalt hydroxytinide material and sulfur powder at a mass ratio of 1:5 at both ends of a quartz boat, and incubate under argon protection at 3 °C·min. -1 The temperature was increased to 500 °C and held for 1.5 h to obtain a cobalt hydroxytin derivative sulfide carbon composite material.

[0096] Comparative Example 4

[0097] Step 1: Dissolve 1 mmol of tin tetrachloride pentahydrate in 5 mL of anhydrous ethanol and stir at room temperature until completely dissolved to obtain a tin source solution; dissolve 1 mmol of cobalt chloride hexahydrate and 1 mmol of disodium citrate trihydrate in 35 mL of deionized water and stir at room temperature until completely dissolved to obtain a cobalt source solution; quickly pour the tin source solution into the cobalt source solution to obtain mixed solution A.

[0098] Step 2: Prepare 5 mL of 2 M NaOH aqueous solution. Slowly add the 2 M NaOH aqueous solution dropwise into mixed solution A, stir at room temperature for 30 min, and let stand for 1 h to obtain suspension B.

[0099] Step 3: Prepare 20 mL of alkaline etching solution (8 M NaOH aqueous solution), and dissolve the alkaline etching solution at a rate of 5 mL / min. -1 The suspension B was added dropwise at a certain rate, and after standing at room temperature for 15 min, it was centrifuged, washed, and dried to obtain cobalt hydroxytinide material.

[0100] Step 4: Add 0.3 g of cobalt hydroxytin to 4 g of DMF and disperse it evenly by ultrasonication. Then add 0.4 g of polyacrylonitrile and 0.4 g of polymethyl methacrylate and stir vigorously until homogeneous to obtain the spinning solution.

[0101] Step 5: Pour the spinning solution into a 5 mL syringe and spin using an electrospinning device at a temperature of 35 ℃ and a humidity of 30%. Specific spinning parameters are: the distance from the syringe needle to the receiver is 15 cm, the applied voltage is 15 kV, and the propulsion device is at a rate of 0.6 mL / h. -1 The propulsion speed pushes the spinning solution in the 5 mL syringe to the needle tip, where it is collected on the tin foil collector under the action of the electric field to obtain a fiber film.

[0102] Step Six: Place the fiber film flat in a muffle furnace and heat it in air at 1 °C·min. -1 The temperature was increased to 260 °C at a heating rate and held for 1.5 h. After the pre-oxidation process was completed, the temperature was increased to 2 °C·min under a nitrogen atmosphere. -1 The temperature was increased to 800 °C and held for 2 h to obtain a carbonized thin film.

[0103] Step 7: Place the carbonized film and sulfur powder at a mass ratio of 1:5 at both ends of a quartz boat, and incubate under argon protection at 3 °C·min. -1 The temperature was increased to 500 °C and held for 1.5 h to obtain a cobalt hydroxytin derivative sulfide carbon composite material.

[0104] Comparative Example 5

[0105] Step 1: Dissolve 10 mmol of tin tetrachloride pentahydrate in 5 mL of anhydrous ethanol and stir at room temperature until completely dissolved to obtain a tin source solution; dissolve 1 mmol of cobalt chloride hexahydrate and 1 mmol of disodium citrate trihydrate in 35 mL of deionized water and stir at room temperature until completely dissolved to obtain a cobalt source solution; quickly pour the tin source solution into the cobalt source solution to obtain mixed solution A.

[0106] Step 2: Prepare 5 mL of 2M NaOH aqueous solution. Slowly add the 2M NaOH aqueous solution dropwise into mixed solution A. Stir at room temperature for 30 min and let stand for 1 h to obtain suspension B.

[0107] Step 3: Prepare 20 mL of alkaline etching solution (8 M NaOH aqueous solution), and dissolve the alkaline etching solution at a rate of 0.5 mL / min. -1 The suspension B was added dropwise at a certain rate, and after standing at room temperature for 15 min, it was centrifuged, washed, and dried to obtain cobalt hydroxytinide material.

[0108] Step 4: Add 0.3g of cobalt hydroxytin to 4g of DMF and disperse it evenly by ultrasonication. Then add 0.4g of polyacrylonitrile and 0.4g of polymethyl methacrylate and stir vigorously until evenly mixed to obtain the spinning solution.

[0109] Step 5: Pour the spinning solution into a 5 mL syringe and spin using an electrospinning device at a temperature of 35 ℃ and a humidity of 30%. Specific spinning parameters are: the distance from the syringe needle to the receiver is 15 cm, the applied voltage is 15 kV, and the propulsion device is at a rate of 0.6 mL / h. -1 The propulsion speed pushes the spinning solution in the 5 mL syringe to the needle tip, where it is collected on the tin foil collector under the action of the electric field to obtain a fiber film.

[0110] Step Six: Place the fiber film flat in a muffle furnace and heat it in air at 1 °C·min. -1 The temperature was increased to 260 °C at a heating rate and held for 1.5 h. After the pre-oxidation process was completed, the temperature was increased to 2 °C·min under a nitrogen atmosphere. -1 The temperature was increased to 800 °C and held for 2 h to obtain a carbonized thin film.

[0111] Step 7: Place the carbonized film and sulfur powder at a mass ratio of 1:5 at both ends of a quartz boat, and incubate under argon protection at 3 °C·min. -1 The temperature was increased to 500 °C and held for 1.5 h to obtain a cobalt hydroxytin derivative sulfide carbon composite material.

[0112] Comparative Example 6

[0113] Step 1: Dissolve 1 mmol of tin tetrachloride pentahydrate in 5 mL of anhydrous ethanol and stir at room temperature until completely dissolved to obtain a tin source solution; dissolve 1 mmol of cobalt chloride hexahydrate and 1 mmol of disodium citrate trihydrate in 35 mL of deionized water and stir at room temperature until completely dissolved to obtain a cobalt source solution; quickly pour the tin source solution into the cobalt source solution to obtain mixed solution A.

[0114] Step 2: Prepare 5 mL of 2 M NaOH aqueous solution. Slowly add the 2 M NaOH aqueous solution dropwise into mixed solution A, stir at room temperature for 30 min, and let stand for 1 h to obtain suspension B.

[0115] Step 3: Prepare 20 mL of alkaline etching solution (8 M NaOH aqueous solution), and dissolve the alkaline etching solution at a rate of 0.5 mL / min. -1 The suspension B was added dropwise at a certain rate, and after standing at room temperature for 15 min, it was centrifuged, washed, and dried to obtain cobalt hydroxytinide material.

[0116] Step 4: Add 0.3 g of cobalt hydroxytin to 4 g of DMF, disperse evenly by ultrasonication, then add 0.4 g of polyacrylonitrile and stir vigorously until uniform to obtain the spinning solution.

[0117] Step 5: Pour the spinning solution into a 5 mL syringe and spin using an electrospinning device at a temperature of 35 ℃ and a humidity of 30%. Specific spinning parameters are: the distance from the syringe needle to the receiver is 15 cm, the applied voltage is 15 kV, and the propulsion device is at a rate of 0.6 mL / h. -1 The propulsion speed pushes the spinning solution in the 5 mL syringe to the needle tip, where it is collected on the tin foil collector under the action of the electric field to obtain a fiber film.

[0118] Step Six: Place the fiber film flat in a muffle furnace and heat it in air at 1 °C·min. -1 The temperature was increased to 260 °C at a heating rate and held for 1.5 h. After the pre-oxidation process was completed, the temperature was increased to 2 °C·min under a nitrogen atmosphere. -1 The temperature was increased to 800 °C and held for 2 h to obtain a carbonized thin film.

[0119] Step 7: Place the carbonized film and sulfur powder at a mass ratio of 1:5 at both ends of a quartz boat, and incubate under argon protection at 3 °C·min. -1 The temperature was increased to 500 °C and held for 1.5 h to obtain a cobalt hydroxytin derivative sulfide carbon composite material.

[0120] Performance testing

[0121] The final products obtained in each embodiment and comparative example were used to prepare sodium-ion battery anodes: 0.08g of cobalt hydroxytin derivative sulfide carbon composite material, 0.01g of carbon black, and 0.01g of polyvinylidene fluoride were weighed and ground in a mortar for 20min. Then, the mixture was transferred to a weighing bottle and 50μL of N-methylpyrrolidone was added and stirred to obtain a slurry. The slurry was coated onto copper foil using a coating device. After drying at a constant temperature of 60℃ for 12h, the electrode was punched into a disc with a diameter of 12mm to obtain the sodium-ion battery anode.

[0122] Then, the sodium-ion battery negative electrode was assembled to form a half-cell, using glass fiber as the separator, a sodium metal sheet as the counter electrode, and a sodium hexafluorophosphate solution in diethylene glycol dimethyl ether (1 M NaPF6 in GIGLYME = 100 Vol%) as the electrolyte. Battery assembly was performed in an argon-filled glove box, proceeding from bottom to top in the following order: positive electrode shell, negative electrode, separator, electrolyte, sodium metal sheet, nickel foam, and negative electrode shell. The assembled sodium-ion half-cell was allowed to stand for 24 hours, and then constant current charge-discharge tests were conducted within the range of 0.01–3V.

[0123] Table 1

[0124]

[0125] Based on the data in Table 1, the following conclusions can be drawn: It can be clearly observed that the capacity retention rate of Example 1 is significantly higher than that of Comparative Example 2 in the application test, and the cycle stability and lifespan are increased. This is because the cobalt hydroxyl tin oxide material in Comparative Example 2 was not etched with an alkaline, while the etched precursor will form a hollow cube, which alleviates the volume change during the cycle and reduces the diffusion distance of sodium ions.

[0126] like Figure 1 The image shown is a scanning electron microscope (SEM) image of the cobalt hydroxytin sulfide-derived carbon composite material prepared in Example 1. It can be seen that the nanofibers have a diameter of approximately 2 μm, encapsulating cubic cobalt hydroxytin sulfide particles, which are uniformly distributed on the fibers without aggregation, indicating good bonding between the cobalt tin sulfide and the carbon nanofibers. Furthermore, as... Figure 3 , Figure 4 As shown in the figure, the cross-section of the fiber and the transmission electron microscope image reveal that carbon nanofibers have a multi-channel structure, which is beneficial for alleviating volumetric stress in subsequent applications.

[0127] like Figure 2 The figure shown is a rate performance test graph of Example 1. It can be seen that the composite material of the present invention exhibits performance at 0.2 A·g -1 0.5A·g -1 1A·g -1 2A·g -1 5A·g-1 And restore 0.2A·g -1 The specific capacity at the current density is 742 mAh·g -1 698mAh·g -1 651mAh·g -1 609mAh·g -1 516mAh·g -1 726mAh·g -1 It exhibits excellent rate performance.

[0128] like Figure 5 The X-ray diffraction pattern of Example 3 is shown. The presence of cobalt disulfide (JCPDS No. 99-000-0611) and tin disulfide (JCPDS No. 99-000-0337) in the pattern confirms the formation of a cobalt-tin sulfide heterojunction.

[0129] like Figure 6 The diagram shown is a cycle performance graph for Example 4, compared to... Figure 8 The cycling performance graph of Comparative Example 3 shows that the specific capacity and cycling stability of Example 4 are significantly improved. Comparative Example 3 did not undergo electrospinning and carbonization treatment, while the volume expansion of the hydroxyl tin sulfide-derived sulfide coated with multi-channel carbon nanofibers in Example 4 is significantly alleviated.

[0130] like Figure 7 The image shown is a scanning electron microscope (SEM) image of the cobalt hydroxytinide material prepared in Comparative Example 1. It is clearly visible that a large amount of active material is lost inside the cube, and the structure tends to collapse, which is caused by excessive etching time. In Comparative Example 4, the excessively rapid drop rate of the alkaline etching solution leads to uneven etching and a tendency for structural collapse, thus also resulting in poor electrochemical performance. In Comparative Example 5, the excessive addition of tin source reduces the complementary synergistic effect between cobalt and tin, which is detrimental to obtaining good electrochemical performance.

[0131] Figure 9 , Figure 10 The images shown are scanning electron microscope (SEM) images of Comparative Example 6 and Comparative Example 3, respectively. From the SEM images, it can be seen that the composite fiber material in Comparative Example 6 without added polymethyl methacrylate has a diameter of approximately 200–400 nm. Figure 1 Compared to Example 1, the surface agglomeration was severe, and the number of pores was significantly reduced without the pore-forming agent, resulting in poor electrolyte wettability and a slower response rate at high current densities. The material obtained in Comparative Example 3 clearly shows that cobalt tin hydroxide compounds easily release flake-like metal sulfides after high-temperature sulfidation of uncoated carbon materials, leading to easy pulverization of the corresponding material and a significant decrease in capacity after long-term cycling.

[0132] In summary, the cobalt hydroxytinide-derived sulfide carbon composite material prepared by the improved co-precipitation method combined with electrospinning technology exhibits good electrochemical performance. Furthermore, this invention boasts high production efficiency, low cost, and ease of commercialization, making it a viable and effective method for the preparation of sodium-ion battery materials.

[0133] Unless otherwise specified, the raw materials and equipment used in this invention are all commonly used in the field; unless otherwise specified, the methods used in this invention are all conventional methods in the field.

[0134] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, alterations, and equivalent transformations made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for preparing a cobalt hydroxytinide-derived sulfide carbon composite material based on electrospinning, characterized in that, Includes the following steps: Step 1: Add the tin source to anhydrous ethanol and stir until completely dissolved to obtain a tin source solution; add the cobalt source and dispersant to water and stir until completely dissolved to obtain a cobalt source solution; at room temperature, pour the tin source solution into the cobalt source solution and mix thoroughly to obtain mixed solution A; Step 2: Add sodium hydroxide aqueous solution dropwise to mixed solution A, stir, and let stand for a period of time to obtain suspension B; Step 3: Alkali etching is performed on suspension B, followed by centrifugation, washing, and drying to obtain cobalt hydroxytin bromide material; Step 4: Dissolve cobalt hydroxytin oxide material and polymer in N,N-dimethylformamide to form a spinning solution; perform electrospinning to obtain a fiber film; Step 5: The fiber film is subjected to pre-oxidation and carbonization in sequence to obtain a carbonized film; Step 6: The carbonized film is subjected to sulfurization treatment to obtain a carbon composite material of cobalt hydroxytin derivative sulfide.

2. The method for preparing cobalt hydroxytinide-derived sulfide carbon composite material based on electrospinning as described in claim 1, characterized in that, In step one, the tin source is any one or more of tin tetrachloride pentahydrate, anhydrous tin tetrachloride, sodium hexahydroxystannate, tin tetrafluoride, and dibutyltin dilaurate; the cobalt source is any one or more of cobalt chloride hexahydrate, cobalt sulfate heptahydrate, and cobalt oxalate dihydrate; and the dispersant is any one or more of trisodium citrate dihydrate, sodium tartrate, sodium oxalate, and ammonium oxalate.

3. The method for preparing cobalt tin hydroxylide-derived sulfide carbon composite material based on electrospinning as described in claim 1 or 2, characterized in that, In step one, the molar ratio of cobalt source, tin source and dispersant in the mixed solution A is (1~7):(1~7):(1~10), and the volume ratio of water to anhydrous ethanol is (4~9):

1.

4. The method for preparing cobalt hydroxytinide-derived sulfide carbon composite material based on electrospinning as described in claim 1, characterized in that, In step two, the concentration of the sodium hydroxide aqueous solution is 1-5 M; the volume ratio of the sodium hydroxide aqueous solution to mixed solution A is 1:(5-10); the stirring time is 20-40 min; and the standing time is 1-3 h.

5. The method for preparing cobalt tin sulfide-derived carbon composite material based on electrospinning as described in claim 1 or 4, characterized in that, In step three, the alkaline etching involves adding an alkaline etching solution dropwise into suspension B at a rate of 0.3–0.6 mL / min. -1 The etching solution is left to stand for 10-25 minutes; the alkaline etching solution is any one or more of sodium hydroxide aqueous solution and potassium hydroxide aqueous solution, with a concentration of 3-10 M.

6. The method for preparing cobalt hydroxytinide-derived sulfide carbon composite material based on electrospinning as described in claim 1, characterized in that, In step four, the polymer is a mixture of polyacrylonitrile and channel forming agent in a mass ratio of 1:(0.25~2), and the channel forming agent is any one or more of polymethyl methacrylate, polyvinyl alcohol, and polyoxyethylene-polyoxypropylene block copolymer; the mass ratio of the cobalt hydroxytin oxide material, the polymer and N,N dimethylformamide is 1:(1~3):(1~10).

7. The method for preparing cobalt hydroxytinide-derived sulfide carbon composite material based on electrospinning as described in claim 1 or 6, characterized in that, In step four, the electrospinning conditions are as follows: the vertical distance from the nozzle to the receiver is 10-20 cm, the spinning voltage is 10-18 kV, and the feed rate is 0.5-1 mL·h. -1 The spinning temperature is 25~30 ℃ and the relative humidity of the air is 20~45%.

8. The method for preparing cobalt hydroxytinide-derived sulfide carbon composite material based on electrospinning as described in claim 1, characterized in that, In step five, the pre-oxidation conditions are as follows: at 1~5 °C / min in an air atmosphere. -1 The temperature is increased to 200-300 °C at a rate of [missing information], and held for 1-3 h; the carbonization conditions are: [missing information] in an inert atmosphere at a rate of 2-10 °C / min. -1 The temperature is increased to 600~1000 ℃ at a rate of 1~3 h and held for 1~3 h.

9. The method for preparing cobalt hydroxytinide-derived sulfide carbon composite material based on electrospinning as described in claim 1 or 8, characterized in that, In step six, the sulfidation treatment involves exposing the carbonized film and sulfur powder to an inert atmosphere at 2-10 °C / min. -1 The temperature is increased to 400~600 ℃ at a rate of 1~3 h and held for 1~3 h; the mass ratio of the carbonized film to sulfur powder is 1:(4~6).

10. The application of a cobalt tin oxide-derived sulfide carbon composite material based on electrospinning, obtained by any one of claims 1 to 9, as a negative electrode material for sodium-ion batteries.

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