A preparation method of ternary tin-based compound sodium ion battery negative electrode material

Abstract

The application discloses a preparation method of a ternary tin-based compound sodium ion battery negative electrode material, which comprises the following steps: adding selenium powder and sodium borohydride into an ethanol solution, stirring and dissolving under ice bath condition to obtain solution A; adding a sulfur source and SnCl4*5H2O into an ethanol solution, stirring and dissolving under normal temperature condition to obtain solution B; adding solution B into solution A, stirring to obtain a mixed solution; adding the mixed solution into a reaction kettle, heating in a microwave field after being sealed, and obtaining a reaction product after cooling; and after cleaning and freeze-drying, the reaction product is obtained, thereby obtaining the ternary tin-based compound sodium ion battery negative electrode material. The preparation method has relatively mild conditions, can be synthesized by one step, has a simple process, controllable reaction conditions, a high yield, can prepare the ternary tin-based compound with uniform morphology and excellent electrochemical performance, and has excellent performance when used as the sodium ion battery negative electrode material, and has certain development potential in the field of new energy and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of sodium ion batteries, and particularly relates to a preparation method of a ternary tin-based compound sodium ion battery negative electrode material. BACKGROUND

[0002] The prices of non-renewable energy sources such as natural gas, coal and petroleum are soaring, and renewable energy sources such as hydrogen energy, solar energy and wind energy are attracting widespread attention. A revolution in energy is sweeping the world, and in order to cope with this recognized challenge, it is an important link to promote the energy revolution by efficiently, low-cost and durable energy storage conversion system to efficiently integrate renewable energy into the power grid and promote ground transportation energy transformation. The slow migration dynamics of sodium ions compared with lithium ions restricts the rapid charging and discharging capacity. The large molar mass and ion radius of Na + cause slow ion transport dynamics and huge structural deformation of the negative electrode material, which seriously limits its commercial application. Although great progress has been made in the past few years, it is still challenging to explore advanced sodium host electrode materials that can provide high capacity, fast charging and long life.

[0003] Transition metal dihalide compounds are widely studied due to their safe operation potential and high theoretical capacity. In particular, tin-based compounds have a good layered crystal structure, providing an ideal channel for Na + transport, but the common drawbacks include its inherent poor electronic conductivity and sharp volume expansion based on conversion and alloying mechanisms, resulting in slow reaction kinetics and severe structural collapse. Therefore, current research focuses on building heterostructures to regulate interface ion and electron conduction or coupling various types of carbon materials to improve electrical conductivity and buffer volume changes during the cycle process. However, these strategies are based on the two-dimensional interface level and have little effect on the intrinsic electrical conductivity and mechanical properties of the material.

[0004] Therefore, it is particularly necessary to study a strategy to improve the intrinsic ion / electron conduction characteristics and optimize the mechanical properties of the material to solve the above problems and achieve excellent electrochemical performance of the material. SUMMARY

[0005] The technical problem to be solved by the application is to provide a preparation method of a ternary tin-based compound sodium ion battery negative electrode material to solve the above problems of the prior art. The method forms a single-phase ternary metal dihalide by introducing an external anion ligand, which plays an atomic-level interface engineering role and provides an effective way to regulate the physicochemical properties of the material. Specifically, the SnSe 2-x S xThe open structure (0.6 < x < 1.2) realizes intrinsic ion / electron conduction characteristic regulation and mechanical property optimization, effectively improves the cycle stability in the charging and discharging process of the sodium ion battery negative electrode material, and solves the problems of complex preparation process of the single-phase ternary compound in the prior art, difficult product impurity removal, unstable structure after defect introduction and the like.

[0006] To solve the above technical problems, the technical scheme adopted by the present application is as follows: a preparation method of a ternary tin-based compound sodium ion battery negative electrode material, the method comprising the following steps:

[0007] S1, adding selenium powder and sodium borohydride into an ethanol solution, stirring and dissolving under ice bath conditions to obtain solution A;

[0008] S2, adding a sulfur source and SnCl4.5H2O into an ethanol solution, stirring and dissolving at normal temperature to obtain solution B; the sulfur source is thioacetamide or thiourea;

[0009] S3, adding solution B obtained in S2 into solution A obtained in S1 to stir and react, obtaining a mixed solution; transferring the mixed solution to a reaction kettle, sealing the reaction kettle, placing the reaction kettle in a microwave field, maintaining a rotation speed of 200-300 r / min, heating to 90-120 DEG C, then maintaining the temperature at 90-120 DEG C for 20-40 min, cooling to room temperature to obtain a reaction product; washing the reaction product with deionized water, and freeze-drying the washed product to obtain a ternary tin-based compound sodium ion battery negative electrode material with a molecular formula of SnSe 2-x S x , and the value range of x is 0.6 < x < 1.2.

[0010] Preferably, the molar ratio of sodium borohydride to selenium powder in S1 is 2:1; and the concentration of selenium powder in solution A is 0.1-0.8 mol / L.

[0011] Preferably, the stirring speed in S1 is 200-500 r / min, and the stirring time is 0.5-1 h.

[0012] Preferably, the molar ratio of selenium powder in S1 to the sulfur source in S2 is (0.5-2.0):1; and the amount of substance of SnCl4.5H2O in S2 is half of the sum of the amount of substance of the sulfur source and the amount of substance of the selenium source.

[0013] Preferably, the stirring speed in S2 is 200-500 r / min, and the stirring time is 0.1-0.5 h; and the concentration of SnCl4.5H2O in solution B is 0.05-0.5 mol / L.

[0014] Preferably, the volume ratio of the solution A and the solution B in S3 is 1:2, and the solution B is added to the solution A at a rate of 1.0-1.5 mL / min.

[0015] Preferably, the stirring speed in S3 is 200-500 r / min, and the stirring time is 0.1-0.5 h; and the power of the microwave field is 300 W.

[0016] Preferably, the number of times of washing the reaction product with deionized water in S3 is 3-6 times; the temperature of the freeze-drying is -50 to -30 DEG C, and the time is 6 h.

[0017] Preferably, the value of x in S3 is 0.87-1.

[0018] The sodium borohydride in the preparation method S1 of the application is a very stable and mild reducing agent, and the selenium powder is completely reduced into selenium ions under the ice bath (0 DEG C) environment and long time stirring; the sulfur source in S2 is thioacetamide or thiourea, and the addition amount of the sulfur source raw material determines the final product ternary tin-based compound SnSe 2-x S x Anion S 2- occupies a ratio of Se 2- ; the mixed solution in S3 is heated in a microwave field, under the high-temperature and high-pressure environment, Sn 4+ and S 2- , Se 2- generate SnSe 2-x S x through the combination of ions; meanwhile, due to the anion competition and different anion radii, SnSe 2-x S x generates part of anion vacancies during the generation process, which provides a channel for ion and electron diffusion in the sodium storage process; compared with the traditional solvothermal method (the reaction time is too long, and the internal heat distribution is uneven), the microwave-assisted solvothermal method of the application has more advantages, that is, the dielectric microwave heating provides a uniform nucleation environment and high-crystalline monodisperse nanocrystals are obtained in a short time, the microwave synthesis completes the reaction at a speed of thousands of times faster, shortens the reaction time, saves a large amount of energy, and significantly improves the reaction efficiency.

[0019] Compared with the prior art, the application has the following advantages:

[0020] 1. The preparation method of the application has mild conditions, simple one-step synthesis process, controllable reaction conditions, high yield, and can prepare a ternary tin-based compound with uniform morphology, excellent electrochemical performance and excellent performance as a negative electrode material of a sodium ion battery, which has certain development potential in the field of new energy and the like.

[0021] 2、The ternary tin-based compound material prepared by the application realizes the open structure rich in anion vacancies by introducing anion ligands in-situ, realizes the intrinsic ion / electron conduction characteristic regulation and mechanical property optimization, and exhibits high charge / discharge specific capacity, excellent rate performance and good cycle stability as a sodium ion battery negative electrode material.

[0022] 3、The ternary tin-based compound material rich in anion vacancies is obtained by introducing anion ligands in-situ, and the electric conductivity and ion diffusion rate of the ternary tin-based compound are significantly improved, and the ternary tin-based compound material exhibits better reaction kinetics and quite high reversible capacity as a sodium ion battery negative electrode material, and the electrochemical performance thereof is equivalent to that of the existing tin-based ternary alloy / carbon composite material, and the ternary tin-based compound material can be used as a sodium ion battery negative electrode material alone, and the cycle stability thereof can basically meet the requirements.

[0023] 4、The ternary tin-based compound obtained by the application exhibits higher elastic modulus by using the density functional theory calculation, and can better accommodate the volume change caused by Na + extraction / insertion during the charge / discharge process, avoids structure collapse and active material loss, and significantly improves the reversible capacity retention rate.

[0024] 5、The preparation method of the ternary tin-based compound material is simple and reliable, has good repeatability, strong operability, is environment-friendly and low in cost, and has important industrial value.

[0025] The technical solutions of the application will be further described in detail below with reference to the drawings and examples. DRAWINGS

[0026] Figure 1 is the SEM diagram of the ternary tin-based compound material SnSeS prepared in Example 1 of the application.

[0027] Figure 2 is the XRD diagram of the ternary tin-based compound material SnSeS prepared in Example 1 of the application.

[0028] Figure 3 is the cycle performance diagram of the sodium ion battery prepared by the ternary tin-based compound material SnSeS in Example 1 of the application. DETAILED DESCRIPTION

[0029] Example 1

[0030] The preparation method of the ternary tin-based compound sodium ion battery negative electrode material of the application comprises the following steps:

[0031] S1, 585 mg of selenium powder and 568 mg of sodium borohydride were added into 15 mL of ethanol solution, and stirred and dissolved under ice bath condition to obtain solution A; the stirring speed was 500 r / min, and the stirring time was 0.5 h;

[0032] S2, 611.5 mg of thiourea and 2.661 g of SnCl4·5H2O were added into 30 mL of ethanol solution, and stirred and dissolved at normal temperature to obtain solution B; the stirring speed was 500 r / min, and the stirring time was 0.1 h;

[0033] S3, solution B obtained in S2 was added into solution A obtained in S1 at a rate of 1.5 mL / min by using a peristaltic pump, and reacted under stirring at a speed of 500 r / min for 0.1 h to obtain a mixed solution; the volume ratio of solution A to solution B was 1:2; the mixed solution was transferred into a reaction kettle, and after being sealed, the reaction kettle was placed into a microwave field with a power of 300 W, and kept at a rotating speed of 200 r / min, and heated to 90℃, and kept at 90℃ for 40 min, and then cooled to room temperature to obtain a reaction product; the reaction product was washed with deionized water for 4 times, and the washed product was freeze-dried at a temperature of-50℃ for 6 h to obtain a ternary tin-based compound sodium ion battery negative electrode material with a molecular formula of SnSeS.

[0034] Example 2

[0035] The preparation method of the ternary tin-based compound sodium ion battery negative electrode material in this embodiment comprises the following steps:

[0036] S1, 108.5 mg of selenium powder and 104.1 mg of sodium borohydride were added into 15 mL of ethanol solution, and stirred and dissolved under ice bath condition to obtain solution A; the stirring speed was 250 r / min, and the stirring time was 0.8 h;

[0037] S2, 114.7 mg of thiourea and 503.1 mg of SnCl4·5H2O were added into 30 mL of ethanol solution, and stirred and dissolved at normal temperature to obtain solution B; the stirring speed was 250 r / min, and the stirring time was 0.4 h;

[0038] S3, the solution B obtained in S2 is added to the solution A obtained in S1 at a rate of 1.1 mL / min by using a peristaltic pump, and the reaction is carried out under the condition that the stirring speed is 250 r / min and the stirring time is 0.4 h to obtain a mixed solution, wherein the volume ratio of the solution A to the solution B is 1:2; the mixed solution is transferred into a reaction kettle, and after being sealed, the reaction kettle is placed into a microwave field with a power of 300 W, and kept at a rotating speed of 300 r / min and a temperature of 100 ℃ for 40 min, and then cooled to room temperature to obtain a reaction product; the reaction product is washed with deionized water for 5 times, and the washed product is freeze-dried at a temperature of -40 ℃ for 6 h to obtain a ternary tin-based compound sodium ion battery negative electrode material with a molecular formula of SnSeS.

[0039] Example 3

[0040] The preparation method of the ternary tin-based compound sodium ion battery negative electrode material in this example comprises the following steps:

[0041] S1, 234 mg of selenium powder and 227 mg of sodium borohydride are added into 15 mL of an ethanol solution, and dissolved under the condition of ice bath and stirring at a speed of 400 r / min for 0.6 h to obtain a solution A;

[0042] S2, 183.3 mg of thioacetamide and 936.5 mg of SnCl4·5H2O are added into 30 mL of an ethanol solution, and dissolved under the condition of stirring at a speed of 400 r / min for 0.2 h to obtain a solution B;

[0043] S3, the solution B obtained in S2 is added to the solution A obtained in S1 at a rate of 1.3 mL / min by using a peristaltic pump, and the reaction is carried out under the condition that the stirring speed is 400 r / min and the stirring time is 0.2 h to obtain a mixed solution, wherein the volume ratio of the solution A to the solution B is 1:2; the mixed solution is transferred into a reaction kettle, and after being sealed, the reaction kettle is placed into a microwave field with a power of 300 W, and kept at a rotating speed of 250 r / min and a temperature of 115 ℃ for 20 min, and then cooled to room temperature to obtain a reaction product; the reaction product is washed with deionized water for 3 times, and the washed product is freeze-dried at a temperature of -35 ℃ for 6 h to obtain a ternary tin-based compound sodium ion battery negative electrode material with a molecular formula of SnSe 1.13 S 0.87 .

[0044] Example 4

[0045] The preparation method of the ternary tin-based compound sodium ion battery negative electrode material in this example comprises the following steps:

[0046] S1, 234 mg of selenium powder and 227 mg of sodium borohydride were added into 15 mL of ethanol solution, and stirred and dissolved under ice bath condition to obtain solution A; the stirring speed was 200 r / min, and the stirring time was 1 h;

[0047] S2, 126 mg of thioacetamide and 731.8 mg of SnCl4·5H2O were added into 30 mL of ethanol solution, and stirred and dissolved at normal temperature to obtain solution B; the stirring speed was 200 r / min, and the stirring time was 0.5 h;

[0048] S3, solution B obtained in S2 was added into solution A obtained in S1 at a rate of 1.0 mL / min by using a peristaltic pump, and reacted under the condition of stirring at a speed of 200 r / min for 0.5 h to obtain a mixed solution; the volume ratio of solution A to solution B was 1:2; the mixed solution was transferred into a reaction kettle, and after being sealed, the reaction kettle was placed into a microwave field, and kept at a speed of 270 r / min, and heated to 120℃ at a power of 300 W; the reaction was kept at 120℃ for 20 min, and then cooled to room temperature to obtain a reaction product; the reaction product was washed with deionized water for 6 times, and the washed product was freeze-dried at a temperature of-30℃ for 6 h to obtain a ternary tin-based compound sodium ion battery negative electrode material with a molecular formula of SnSe 1.33 S 0.67 .

[0049] Example 5

[0050] The preparation method of the ternary tin-based compound sodium ion battery negative electrode material of the embodiment comprises the following steps:

[0051] S1, 585 mg of selenium powder and 568 mg of sodium borohydride were added into 15 mL of ethanol solution, and stirred and dissolved under ice bath condition to obtain solution A; the stirring speed was 300 r / min, and the stirring time was 0.7 h;

[0052] S2, 783.7 mg of thiourea and 3.092 g of SnCl4·5H2O were added into 30 mL of ethanol solution, and stirred and dissolved at normal temperature to obtain solution B; the stirring speed was 300 r / min, and the stirring time was 0.3 h;

[0053] S3. Solution B obtained in S2 is added to solution A obtained in S1 at a rate of 1.2 mL / min using a peristaltic pump. The mixture is stirred at 300 r / min for 0.3 h to obtain a mixed solution with a volume ratio of solution A to solution B of 1:2. The mixed solution is transferred to a reaction vessel, sealed, and placed in a microwave field with a power of 300 W. The microwave rotation speed is maintained at 280 r / min, and the temperature is raised to 110 °C. The mixture is held at 110 °C for 40 min and then cooled to room temperature to obtain the reaction product. The reaction product is washed four times with deionized water, and the washed product is freeze-dried at -45 °C for 6 h to obtain the product with the molecular formula SnSe. 0.85 S 1.15 Ternary tin-based compound sodium-ion battery anode material.

[0054] The ternary tin-based compound sodium-ion battery anode materials prepared in Examples 1-5 were mixed with a conductive agent (SuperP) and a binder (PVDF) in a mass ratio of 7:2:1 to prepare a negative electrode sheet. This negative electrode sheet was then assembled with the treated sodium sheet to form a CR2025 button-type sodium-ion battery, and its cycle performance was tested at 200 mA·g. -1 After 100 cycles at a given current density, their respective reversible capacity values ​​are shown in Table 1.

[0055] Table 1. Nanoscale SnSe prepared in Examples 1-5 2-x S x The negative electrode plate at 200mA·g -1 Table of reversible capacity values ​​after 100 cycles at current density

[0056] Item Volume Example 1 587 mAh-g -1 ]] Example 2 574 mAh-g -1 ]] Example 3 551 mAh-g -1 ]] Example 4 523 mAh-g -1 ]] Example 5 507 mAh-g -1 ]]

[0057] As shown in Table 1, the nano-sized SnSe prepared in Examples 1-5 2-x S x The negative electrode plate at 200mA·g -1 The reversible capacity remains at 507–587 mAh·g after 100 cycles at a current density. -1 Within the range.

[0058] like Figure 3 As shown, the nanoscale SnSeS ternary alloy prepared in Example 1 was subjected to a temperature of 200 mA·g. -1 After 100 cycles at a current density, the reversible capacity remains at ~587 mAh·g. -1 Its electrochemical performance is comparable to that of existing tin-based ternary alloy / carbon composite materials, and it can be used alone as a negative electrode material for sodium-ion batteries. Its cycle stability can basically meet the requirements.

[0059] Depend onFigure 1 It can be seen that after the introduction of S 2- , SnSeS presents sheet shape, with polygonal outline and thickness of 10-20 nm, which means greater specific surface area and active sites, higher contribution of pseudo-capacitance and better rate performance as negative active material of sodium ion battery. Figure 2 It can be seen that through simple one-step microwave solvothermal method, SnSeS ternary alloy can achieve good crystallinity without additional heat treatment process. Figure 3 The cycle performance of ternary tin-based compound SnSeS as negative electrode of sodium ion battery can be seen. SnSeS has open structure rich in anion vacancies, which is more conducive to realizing ion / electron conduction. In the first few cycles of activation process, it shows higher reversible charge / discharge specific capacity. At the same time, due to the regulation of sulfur source on mechanical properties, SnSeS electrode material can better accommodate the volume change caused by Na + extraction / insertion process in the charge / discharge process, avoid structure collapse and active material loss, and significantly improve the reversible capacity retention rate.

[0060] The elastic modulus of the ternary tin-based compound sodium ion battery negative electrode material of formula SnSeS prepared in Example 1 is calculated by using density functional theory, and the elastic modulus of the ternary tin-based compound sodium ion battery negative electrode material of SnSeS in Example 1 is 50.55 GPa, while the elastic modulus of the existing binary tin-based compound is 45.75 GPa. It can be seen that the ternary tin-based compound obtained in Example 1 shows higher elastic modulus, which can better accommodate the volume change caused by Na + extraction / insertion process in the charge / discharge process as a negative electrode material of sodium ion battery, avoid structure collapse and active material loss, and significantly improve the reversible capacity retention rate.

[0061] Comparative Example 1

[0062] The preparation method of the ternary tin-based compound sodium ion battery negative electrode material in this comparative example is exactly the same as the preparation method of the ternary tin-based compound sodium ion battery negative electrode material in Example 1, and the difference lies in that the solution A in S1 is mixed by selenium powder and hydrazine hydrate.

[0063] Comparative Example 2

[0064] The preparation method of the ternary tin-based compound sodium ion battery negative electrode material in this comparative example is exactly the same as the preparation method of the ternary tin-based compound sodium ion battery negative electrode material in Example 1, and the difference lies in that the selenium powder and sodium borohydride in S1 are dissolved at room temperature.

[0065] Comparative Example 3

[0066] The preparation method of the ternary tin-based compound sodium ion battery negative electrode material of the present comparative example is completely the same as the preparation method of the ternary tin-based compound sodium ion battery negative electrode material in Example 1, and the difference lies in that the rotation speed in the microwave field in S3 is 100 r / min.

[0067] Comparative Example 4

[0068] The preparation method of the ternary tin-based compound sodium ion battery negative electrode material of the present comparative example is completely the same as the preparation method of the ternary tin-based compound sodium ion battery negative electrode material in Example 1, and the difference lies in that the rotation speed in the microwave field in S3 is 500 r / min.

[0069] Comparative Example 5

[0070] The preparation method of the ternary tin-based compound sodium ion battery negative electrode material of the present comparative example is completely the same as the preparation method of the ternary tin-based compound sodium ion battery negative electrode material in Example 1, and the difference lies in that the rate of adding solution B to solution A in S3 is 2.0 mL / min.

[0071] Comparative Example 6

[0072] The preparation method of the ternary tin-based compound sodium ion battery negative electrode material of the present comparative example is completely the same as the preparation method of the ternary tin-based compound sodium ion battery negative electrode material in Example 1, and the difference lies in that the mixed solution in S3 is reacted by a solvothermal method, specifically: the mixed solution is transferred to a reaction kettle, heated to 90°C after being sealed, and kept at 90°C for 40 min, and other test conditions are the same.

[0073] Comparative Example 7

[0074] The preparation method of the ternary tin-based compound sodium ion battery negative electrode material of the present comparative example is completely the same as the preparation method of the ternary tin-based compound sodium ion battery negative electrode material in Example 1, and the difference lies in that the temperature in the microwave field in S3 is 80°C.

[0075] The ternary tin-based compound sodium ion battery negative electrode material prepared in Comparative Examples 1-7 is mixed with a conductive agent (Super P) and a binder (PVDF) in a mass ratio of 7:2:1 to prepare a negative electrode sheet, which is assembled with a treated sodium sheet to form a CR2025 button-type sodium ion battery for testing the cycle performance. After 100 cycles at a current density of 200 mA·g -1 -1, the reversible capacity values of each are shown in Table 2.

[0076] Table 2 Reversible capacity values of the negative electrode sheets prepared in Example 1 and Comparative Examples 1-7 after 100 cycles at a current density of 200 mA·g -1 -1

[0077] Item Volume Example 1 587 mAh-g -1 ]] Comparative Example 1 453 mAh-g -1 ]] Comparative Example 2 472 mAh-g -1 ]] Comparative Example 3 441 mAh-g -1 ]] Comparative Example 4 459 mAh-g -1 ]] Comparative Example 5 477 mAh g -1 ]] Comparative Example 6 355 mAh-g -1 ]] Comparative Example 7 495 mAh-g -1 ]]

[0078] It can be seen from Example 1, Comparative Examples 1, 2 that adjusting the reducing agent or reaction conditions affects the reduction degree of selenium powder, and ultimately affects the phase purity, and reduces the reversible capacity of the synthesis product as a negative material of a sodium ion battery; it can be seen from Example 1, Comparative Examples 3, 4 that too high a rotation speed in the microwave field forms nanosheets with too small a size, and the agglomeration phenomenon is very serious, while too low a rotation speed leads to uneven nanosheet sizes, which both seriously affect the reversible capacity of the active material; compared with Example 1, Comparative Example 5 shows that too fast a drop speed of solution B added to solution A cannot guarantee the uniform distribution of Sn 4+ , S 2- and Se 2- in the liquid phase, which seriously affects the uniformity of nanosheet nucleation; compared with Example 1, the test conditions in Comparative Example 6 show that the solvent thermal method has uneven heat distribution and slow reaction, and under the same temperature and time conditions, cannot form polygonal nanosheets with good crystallinity and complete morphology, which seriously affects the reversible capacity; compared with Example 1, reducing the microwave field reaction temperature in Comparative Example 7 affects the crystallinity of the ternary tin-based compound phase, and further affects the reversible capacity; the boiling point of ethanol is 78.3°C, and setting too high a microwave field temperature has certain safety hazards.

[0079] The above examples and comparative examples are only part of the experiments, in order to prove that the test conditions in the preparation method of the present application are obtained by a large number of experimental research and analysis by the inventors, and no prior art is referred to, and finally the protection scheme defined in the claims is obtained, the obtained ternary tin-based compound sodium ion battery negative material has excellent electrochemical performance, high charge and discharge specific capacity and good cycle stability and the like advantages, the above examples and comparative examples are not all the experiments done by the inventors, and the present application has also done hundreds of experiments.

[0080] The above is only a preferred embodiment of the present application, and does not limit the present application in any way. Any simple modification, change and equivalent change made according to the technical essence of the present application to the above examples are still within the protection scope of the technical scheme of the present application.

Claims

1. A method for preparing a ternary tin-based compound sodium-ion battery anode material, characterized in that, The method includes the following steps: S1. Selenium powder and sodium borohydride are added to an ethanol solution and stirred to dissolve under ice bath conditions to obtain solution A; S2. Add the sulfur source and SnCl4·5H2O to the ethanol solution and stir to dissolve at room temperature to obtain solution B; the sulfur source is thioacetamide or thiourea; S3. Add solution B obtained in S2 to solution A obtained in S1, stir to react, and obtain a mixture; transfer the mixture to a reaction vessel, seal it, and place the reaction vessel in a microwave field, maintaining a rotation speed of 200~300 r / min, heat to 90~120℃, then keep at 90~120℃ for 20~40 min, cool to room temperature, and obtain the reaction product; wash the reaction product with deionized water, and freeze-dry the washed product to obtain a sheet-like structure with the molecular formula SnSe. 2-x S x The ternary tin-based compound sodium-ion battery anode material, wherein the value of x ranges from 0.

6. <x<1.2。 2. The preparation method according to claim 1, characterized in that, The molar ratio of sodium borohydride and selenium powder in S1 is 2:1; the concentration of selenium powder in solution A is 0.1~0.8 mol / L.

3. The preparation method according to claim 1, characterized in that, The stirring speed described in S1 is 200-500 r / min and the stirring time is 0.5-1 h.

4. The preparation method according to claim 1, characterized in that, The molar ratio of the selenium powder in S1 to the sulfur source in S2 is (0.5~2.0):1; the amount of SnCl4·5H2O in S2 is half the sum of the amounts of the sulfur source and the selenium source.

5. The preparation method according to claim 1, characterized in that, The stirring speed in S2 is 200-500 r / min and the stirring time is 0.1-0.5 h; the concentration of SnCl4·5H2O in solution B is 0.05-0.5 mol / L.

6. The preparation method according to claim 1, characterized in that, In S3, the volume ratio of solution A to solution B is 1:2, and the rate at which solution B is added to solution A is 1.0~1.5 mL / min.

7. The preparation method according to claim 1, characterized in that, The stirring speed in S3 is 200-500 r / min and the stirring time is 0.1-0.5 h; the power of the microwave field is 300 W.

8. The preparation method according to claim 1, characterized in that, In step S3, the reaction product is washed with deionized water 3 to 6 times; the freeze-drying temperature is -50 to -30°C, and the time is 6 hours.

9. The preparation method according to claim 1, characterized in that, The value of x in S3 is 0.87~1.

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