Preparation Method and Application of a Sn-Based Composite Anode Material

Abstract

The present invention relates to a preparation method and application of an Sn-based composite anode material. The Sn-based composite anode material includes: Sn, InSb, and graphite. The Sn-based composite anode material provided by the present invention uses Sn as the main raw material, and InSb and graphite are added to Sn and ball-milled to form the anode material. Sn has a relatively low voltage plateau and a high theoretical specific capacity. The addition of InSb and graphite effectively improves the cycle stability and low-temperature performance of the composite anode material. The Sn-based composite anode material provided by the present invention still has a remaining capacity of 530 mAh / g after 50 cycles, and the capacity retention rate is 90.8% relative to 584 mAh / g in the second cycle, which is far superior to the pure Sn anode material. The Sn-based composite anode material provided by the present invention also has the characteristics of fast charge and discharge at low temperatures. The Sn-based composite anode material provided by the present invention has the characteristics of high capacity, high rate, and high stability.

Description

Technical Field

[0001] The present invention belongs to the technical field of lithium-ion battery manufacturing, and particularly relates to a preparation method and application of an Sn-based composite negative electrode material. Background Art

[0002] In the era of electronic information, devices driven by electricity can be seen everywhere, accompanied by a continuous increase in energy storage demand. Currently, commercial graphite used in lithium-ion batteries has faced problems such as low capacity, poor fast charging ability, and poor low-temperature performance. Therefore, there is an urgent need to find a new generation of negative electrode materials with properties such as high capacity, high lithium-ion diffusion ability, and moderate voltage platform.

[0003] Tin-based electrode materials have high specific capacity, moderate lithium intercalation potential, and fast lithium-ion transport ability, and are candidate negative electrode materials for lithium-ion batteries that have received much attention. The theoretical specific capacity of tin is as high as 994 mAh / g, far higher than that of commercial graphite negative electrodes. At the same time, lithium ions have an extremely high transport rate in the tin negative electrode, and tin materials can be used as fast transport conductors for lithium ions. However, as an alloying negative electrode material, the tin negative electrode has a large volume effect during charge and discharge processes, is prone to agglomeration, and seriously affects its cycle stability.

[0004] The allotrope α-Sn of Sn generated during the cycling process has a higher diffusion coefficient and impedance than β-Sn, and at the same time has better cycle stability and also has performance advantages at low temperatures. However, when pure tin undergoes solid-state phase transformation, it needs to experience a nucleation and growth process. At low temperatures, atomic movement is slow and energy fluctuations are small, so the nucleation process is extremely unstable. For this reason, the method of introducing artificial nucleating agents needs to be used to shorten the nucleation process. Since the InSb material with a zinc blende structure has a structure extremely similar to that of α-Sn, and the lattice misfit between the two is only 0.15%, InSb is the most suitable artificial nucleating agent. Moreover, different from traditional materials that store lithium through alloying, the InSb material has only a very small volume change during lithiation, so it has excellent cycle life. At the same time, the relatively large atomic spacing of the InSb material gives it excellent low-temperature rate performance, and it can still stably cycle at a current density of 1 A / g even under the harsh conditions of -50°C. Therefore, by adopting a suitable method to composite InSb and Sn, on the one hand, using InSb as a crystal nucleus to induce the occurrence of gray tin transformation, and on the other hand, using the stability and low-temperature high-rate performance of InSb itself to modify and optimize the Sn negative electrode, the low-temperature rate performance and cycle stability of the Sn alloy negative electrode can be improved from multiple aspects. The Sn-based negative electrode materials prepared according to this principle are expected to obtain high capacity, high rate, and high stability, so as to meet the requirements of fast charging and cycle stability of lithium ions. Summary of the Invention

[0005] The object of the present invention is to overcome the above deficiencies of the prior art and provide a preparation method and application of an Sn-based composite negative electrode material. By adding InSb and graphite to Sn and then compounding them into a negative electrode material, Sn has a high theoretical capacity and a high lithium ion transmission rate. The addition of InSb can improve the structural stability and low-temperature rate performance of the material, and the addition of graphite can provide the conductivity of the material. The prepared Sn-based composite negative electrode material has the characteristics of fast charge and discharge at low temperature, and at the same time has the advantages of high capacity, high rate and high stability.

[0006] To achieve the above invention object, the technical solution adopted by the present invention is as follows:

[0007] An Sn-based composite negative electrode material is prepared by using three powders of Sn, InSb and graphite as raw materials. The raw materials are mixed evenly according to the ratio and then ball-milled, wherein InSb is uniformly distributed in the Sn alloy matrix in the form of fine crystal particles.

[0008] Preferably, as a preferred embodiment, the mass percentage content of Sn in the Sn-based composite negative electrode material is 40-90%.

[0009] Preferably, as a preferred embodiment, the mass percentage content of InSb in the Sn-based composite negative electrode material is 10% to 50%.

[0010] Preferably, as a preferred embodiment, the mass percentage content of graphite in the Sn-based composite negative electrode material is 3% to 20%.

[0011] Preferably, as a preferred embodiment, the ratio of Sn, InSb and graphite in the Sn-based composite negative electrode material is 46.5:46.5:3.

[0012] Another object of the present invention is to provide a preparation method of an Sn-based composite negative electrode material. The preparation steps of the Sn-based composite negative electrode material are as follows:

[0013] S1: Prepare raw materials for the Sn-based composite negative electrode material, which at least include two materials of Sn and InSb. After mixing the raw materials, stir them evenly to obtain a mixed powder;

[0014] S2: Put the mixed powder into a can in an Ar atmosphere glove box and drop in a lubricant to assist ball milling.

[0015] S3: Perform planetary ball milling on the canned powder.

[0016] Preferably, as a preferred embodiment, the lubricant is anhydrous ethanol,

[0017] The addition amount of the anhydrous ethanol is 2 mL.

[0018] Preferably, as a better embodiment, the InSb powder is particles with a particle size of less than 150 microns, the Sn powder is particles with a particle size of less than 100 microns, and the graphite powder is particles with a particle size of less than 10 microns.

[0019] Preferably, as a better embodiment, the weight ratio of InSb, Sn and graphite powder in step S1 is 87.3:9.7:3. More preferably, the weight ratio is 46.5:46.5:3.

[0020] Preferably, as a better embodiment, the Ar gas in the glove box is argon with a purity of more than 99.99%.

[0021] Preferably, as a better embodiment, the absolute ethanol is absolute ethanol with a purity of more than 95%.

[0022] Preferably, as a better embodiment, the ball-to-material ratio of the planetary ball milling is 25 - 50:1.

[0023] Preferably, as a better embodiment, the rotation speed of the planetary ball milling is 300 - 400 r / min.

[0024] Preferably, as a better embodiment, the ball milling working mode is unidirectional / multidirectional operation for 20 - 40 h. Preferably, as a better embodiment, the ball milling tank and the bearing steel balls need to be cleaned before use to reduce the influence of surface stains and oxides on the material.

[0025] It should be noted that when the Sn-based composite anode material prepared by the planetary ball milling method is applied to a lithium-ion battery, the performance of the lithium-ion battery is significantly improved. After adding InSb, the cycle stability of the Sn anode is significantly improved. Even if only 10% InSb is added, the capacity of the material after 50 cycles can still remain at 530 mAh / g, and the capacity retention rate is 90.8%.

[0026] Another object of the present invention also lies in providing an application of the Sn-based composite anode material in the preparation of a battery.

[0027] Compared with the existing materials and technologies, the advantages of the present invention are as follows:

[0028] 1) The preparation method of the Sn-based composite anode material provided by the present invention is simple.

[0029] 2) The present invention accelerates the induction of the gray tin transformation by compounding InSb, and effectively shortens the nucleation process by introducing artificial nucleating agents.

[0030] 3) The present invention takes the lead in using sphalerite-structured InSb to modify the Sn-based alloy anode material, effectively improving the structural stability of the Sn-based anode and overcoming the drawback of large volume expansion rate of the alloying anode material during charge and discharge. Compared with the existing commercial graphite anode, this Sn-based composite anode material has extremely high capacity and maintains extremely high cycle stability.

[0031] 4) The Sn-based composite anode material of the present invention also has a high capacity retention rate at low temperatures, with extremely small capacity attenuation, overcoming the drawbacks of low charge and discharge efficiency and significant reduction in capacity of lithium-ion batteries at low temperatures, and at the same time combining the characteristics of high capacity and high cycle stability. Description of the Drawings

[0032] Figure 1 Scanning electron microscope image of the InSb-graphite composite anode material prepared in Example 1 of the present invention;

[0033] Figure 2 Initial charge-discharge curve of the InSb-graphite composite anode material prepared in Example 1 of the present invention;

[0034] Figure 3 Cycle-specific capacity performance curve of the InSb-graphite composite anode material prepared in Examples 1 and 2 of the present invention at 30 °C;

[0035] Figure 4 Cycle-specific capacity performance curve of the InSb-graphite composite anode material prepared in Example 1 of the present invention at -50 °C;

[0036] Figure 5 Scanning electron microscope image of the Sn-InSb-graphite composite anode material prepared in Example 5 of the present invention;

[0037] Figure 6 X-ray diffraction pattern of the Sn-InSb-graphite composite anode material prepared in Example 5 of the present invention;

[0038] Figure 7 Initial charge-discharge curve of the Sn-InSb-graphite composite anode material prepared in Example 5 of the present invention;

[0039] Figure 8 Cycle-specific capacity performance curve of the Sn-InSb-graphite composite anode material prepared in Examples 5 and 6 of the present invention at 30 °C;

[0040] Figure 9 Cycle-specific capacity performance curve of the Sn-InSb-graphite composite anode material prepared in Examples 5 and 6 of the present invention at -10 °C;

[0041] Figure 10 It is the scanning electron microscope image of the Sn-InSb-graphite composite anode material prepared in Example 6 of the present invention;

[0042] Figure 11 It is the X-ray diffraction spectrum of the Sn-InSb-graphite composite anode material prepared in Example 6 of the present invention;

[0043] Figure 12 It is the first charge-discharge curve of the Sn-InSb-graphite composite anode material prepared in Example 6 of the present invention. Detailed implementation manners

[0044] In order to make the technical problems to be solved, technical solutions and beneficial effects of the present invention clearer, the following further details the present invention with reference to embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but the implementation manners of the present invention are not limited thereto.

[0045] Unless otherwise defined, all professional terms used hereinafter have the same meaning as commonly understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments, and are not intended to limit the protection scope of the present invention.

[0046] I. Embodiment

[0047] 1. Embodiment 1

[0048] (1) Preparation and structure analysis of InSb-graphite composite anode material

[0049] After mixing InSb and graphite in a ratio of 97:3 and stirring evenly to obtain a mixed powder, canning is completed in an Ar atmosphere glove box, and 2 ml of absolute ethanol is dropped as a lubricant to assist ball milling. The ball-to-material ratio of planetary ball milling is 50:1, the rotation speed is 400 r / min, the ball milling working mode of one-way intermittent operation is adopted, the running time and the timing time are both 30 min, and the total ball milling running time is 20 h.

[0050] Figure 1 Shows the scanning electron microscope image of the InSb-graphite composite electron microscope material prepared in this embodiment. From Figure 1 it can be seen that the particle size of InSb particles after ball milling is all below 5 μm.

[0051] (2) Charge / discharge cycle performance test of InSb-graphite composite anode material

[0052] The InSb-graphite composite anode material powder prepared by planetary ball milling, conductive agent Super-P, and binder CMC were uniformly mixed at a mass ratio of 8:1:1, and then stirred with a stirring degassing machine for 30 min using deionized water as a solvent to make a slurry. The prepared slurry was uniformly coated on a battery-grade copper foil to make an electrode sheet. After surface drying the electrode sheet with an infrared baking lamp, it was placed in a vacuum drying oven and dried at 80 °C for 12 h. The dried electrode sheet was used as a working electrode for performance testing. Battery assembly was carried out in a glove box (Super 1220, Shanghai MIKRONA Electro-Mechanical Technology Co., Ltd.) with a high-purity Ar environment, and the water and oxygen content was less than 0.01 ppm. A pure lithium sheet was used as the counter electrode, and an electrolyte of 1 M LiPF6-EC:DEC:PC (1:1:1 by vol) with an additional 10 wt% FEC was used to assemble a coin cell for performance testing.

[0053] Test conditions: The charge-discharge current density was 0.1 A / g and 1.0 A / g, and the charge-discharge voltage range was 0.01 V to 2.0 V. The charge-discharge cycle test process was as follows: In the first cycle, the battery was first discharged at a constant current to 0.01 V, and then charged at a constant current to 2.0 V; starting from the second cycle, during discharge, it was discharged from 2.0 V to 0.01 V, and during charging, it was charged from 0.01 V to 2.0 V.

[0054] Through the above battery test conditions and steps for testing (the battery charge-discharge test system used was the LAND CT2001A battery test system, Wuhan Lanhe Electronics Co., Ltd.), as Figure 2 shown, the initial charge specific capacity of the prepared InSb-graphite composite anode material was 741.8 mAh / g. As Figure 3 shown, the InSb-graphite composite anode still had a capacity of 510.8 mAh / g after 1000 cycles at 30 °C, and the capacity retention rate was 89.9%. As Figure 4 shown, the InSb-graphite composite anode not only had excellent cycle stability at -50 °C but also could be cycled at a large current. When cycled at a current of 0.1 A / g for 100 cycles, the capacity was 596 mAh / g, and the capacity retention rate was as high as 103% compared to the capacity of 577 mAh / g in the second cycle. When the current density was increased to 1 A / g, after 700 cycles, the capacity decayed to 434.3 mAh / g, and the capacity retention rate was as high as 72.9%, showing excellent low-temperature high-rate performance.

[0055] 2. Example 2

[0056] (1) Preparation and structural analysis of InSb-graphite composite anode material

[0057] The preparation steps of the InSb-graphite composite anode material in this example are basically the same as those described in step (1) of Example 1, except that the ratio of InSb to graphite is 80:20.

[0058] (2) Charge / discharge cycle performance test of the InSb-graphite composite anode material

[0059] The first discharge performance test method and steps of the InSb-graphite composite anode material prepared in this example are the same as those described in step (2) of Example 1. According to this method, charge / discharge tests are carried out. As Figure 3 shown, the InSb-graphite composite anode still has a capacity of 457.0 mAh / g after 1000 cycles at 30 °C, and the capacity retention rate is 91.2%.

[0060] 3. Example 3

[0061] (1) Preparation and structural analysis of the InSb-graphite composite anode material

[0062] The preparation steps of the InSb-graphite composite anode material in this example are basically the same as those described in step (1) of Example 1, except that the total planetary ball milling time is 40 h.

[0063] (2) Charge / discharge cycle performance test of the InSb-graphite composite anode material

[0064] The first discharge performance test method and steps of the InSb-graphite composite anode material prepared in this example are the same as those described in step (2) of Example 1. According to this method, charge / discharge tests are carried out. The InSb-graphite composite anode still has a capacity of 468.7 mAh / g after 1000 cycles at 30 °C, and the capacity retention rate is 92.3%.

[0065] 4. Example 4

[0066] (1) Preparation and structural analysis of the InSb-graphite composite anode material

[0067] The preparation steps of the InSb-graphite composite anode material in this example are basically the same as those described in step (1) of Example 1, except that the planetary ball milling speed is 300 r / min.

[0068] (2) Charge / discharge cycle performance test of the InSb-graphite composite anode material

[0069] The first discharge performance test method and steps of the InSb-graphite composite anode material prepared in this example are the same as those described in step (2) of Example 1. According to this method, charge / discharge tests are carried out. The InSb-graphite composite anode still has a capacity of 481.1 mAh / g after 1000 cycles at 30 °C, and the capacity retention rate is 90.7%.

[0070] 5. Example 5

[0071] (1) Preparation and structural analysis of Sn-InSb-graphite composite anode material

[0072] The preparation steps of the Sn-InSb-graphite composite anode material in this example are basically the same as those described in step (1) of Example 1, except that the ratio of InSb, Sn, and graphite is 46.5:46.5:3.

[0073] Figure 5 The scanning electron microscope image of the Sn-InSb-graphite composite anode material prepared in this example is shown. It can be seen from the figure that the particle sizes of the two samples are approximately between 2 - 7 μm.

[0074] Figure 6 The X-ray diffraction pattern of the Sn-InSb-graphite composite anode material prepared in this example is shown. It can be seen from the figure that there are two phases in the ball-milled sample, namely InSb with a sphalerite structure and β-Sn with a body-centered tetragonal structure, and no phase transformation and formation of new intermetallic compounds occur during the ball-milling process.

[0075] (2) Charge / discharge cycle performance test of Sn-InSb-graphite composite anode material

[0076] The first discharge performance test method and steps of the Sn-InSb-graphite composite anode material prepared in this example are the same as those described in step (2) of Example 1. The charge / discharge test is carried out according to this method. As Figure 7 shown is the first charge / discharge curve of the Sn-InSb-graphite composite anode material. As Figure 8 shown is the cycle curve of the Sn-InSb-graphite composite anode material. After adding InSb, the cycle stability of the Sn anode is significantly improved. Even if only 10% InSb is added, the capacity of the material after 50 cycles can still remain at 530 mAh / g, and the capacity retention rate relative to the 584 mAh / g in the second cycle is 90.8%. As Figure 9 shown is the cycle curve of the InSb-graphite composite anode material under the condition of -10°C.

[0077] 6. Example 6

[0078] (1) Preparation and structural analysis of Sn-InSb-graphite composite anode material

[0079] The preparation steps of the Sn-InSb-graphite composite anode material in this example are basically the same as those described in step (1) of Example 1, except that the ratio of InSb, Sn, and graphite is 87.3:9.7:3.

[0080] Figure 10 The scanning electron microscope image of the Sn-InSb-graphite composite anode material prepared in this example is shown. It can be seen from the figure that the particle sizes of the two samples are approximately between 2 - 7 μm, slightly larger than those in Example 5. This is because the relatively low melting point of Sn makes it prone to cold welding during ball milling, bonding small particles to form large-sized particles.

[0081] Figure 11 The X-ray diffraction pattern of the Sn-InSb-graphite composite anode material prepared in this example is shown. It can be seen from the figure that there are two phases in the ball-milled sample, namely InSb with a sphalerite structure and β-Sn with a body-centered tetragonal structure. No phase transformation or formation of new intermetallic compounds occurred during ball milling. The peaks of InSb and β-Sn in the sample are close, and their ratio remains close to 1:1 after ball milling.

[0082] (2) Charge / discharge cycle performance test of the Sn-InSb-graphite composite anode material

[0083] The method and steps for the first discharge performance test of the InSb-graphite composite anode material prepared in this example are the same as those described in step (2) of Example 1. Charging and discharging tests are carried out according to this method. As Figure 12 shown is the first charge-discharge curve of the Sn-InSb-graphite composite anode material. As Figure 8 shown is the cycle curve of the Sn-InSb-graphite composite anode material. After adding InSb, the cycle stability of the Sn anode is significantly improved. As Figure 9 shown is the cycle curve of the InSb-graphite composite anode material under the condition of -10 °C.

[0084] 7. Example 7

[0085] (1) Preparation and structure analysis of the Sn-InSb-graphite composite anode material

[0086] The preparation steps of the Sn-InSb-graphite composite anode material in this example are basically the same as those described in step (1) of Example 1, except that the ratio of InSb, Sn, and graphite is 72:8:20.

[0087] (2) Charge / discharge cycle performance test of the Sn-InSb-graphite composite anode material

[0088] The method and steps for the first discharge performance test of the Sn-InSb-graphite composite anode material prepared in this example are the same as those described in step (2) of Example 1. Charging and discharging tests are carried out according to this method. The first charging capacity of the Sn-InSb-graphite composite anode is 515.7 mAh / g.

[0089] 8. Example 8

[0090] (1) Preparation and Structure Analysis of Sn-InSb-Graphite Composite Anode Material

[0091] The preparation steps of the Sn-InSb-graphite composite anode material in this example are basically the same as those described in step (1) of Example 1, except that the ratio of InSb, Sn, and graphite is 40:40:20.

[0092] (2) Charge / Discharge Cycle Performance Test of Sn-InSb-Graphite Composite Anode Material

[0093] The first discharge performance test method and steps of the InSb-graphite composite anode material prepared in this example are the same as those described in step (2) of Example 1. According to this method, the charge / discharge test is carried out, and the first charge capacity of the Sn-InSb-graphite composite anode is 515.7 mAh / g.

[0094] 9. Comparative Example

[0095] (1) Preparation and Structure Analysis of Sn-Graphite Composite Anode Material

[0096] After mixing Sn and graphite in a ratio of 97:3 and stirring evenly to obtain a mixed powder, canning is completed in an Ar atmosphere glove box, and 2 ml of anhydrous ethanol is dropped as a lubricant to assist ball milling. The ball-to-material ratio of planetary ball milling is 50:1, and the rotation speed is 400 r / min. The ball milling working mode of one-way intermittent operation is adopted, and both the running time and the timing time are 30 min. The total ball milling running time is 20 h.

[0097] (2) Charge / Discharge Cycle Performance Test of Sn-Graphite Composite Anode Material

[0098] After uniformly mixing the Sn-graphite composite anode material powder prepared by planetary ball milling, conductive agent Super-P, and binder CMC in a mass ratio of 8:1:1, deionized water is used as a solvent, and a stirring defoamer is used to stir for 30 min to make a slurry. The prepared slurry is uniformly coated on a battery-grade copper foil to make an electrode sheet. The electrode sheet is surface-dried with an infrared baking lamp and then placed in a vacuum drying oven at 80 °C for 12 h. The dried electrode sheet is used as a working electrode for performance testing, and battery assembly is carried out in a glove box (Super 1220, Shanghai MTI Co., Ltd.) with a high-purity Ar environment, and the water and oxygen content is less than 0.01 ppm. A pure lithium sheet is used as the counter electrode, and an electrolyte of 1 M LiPF6-EC:DEC:PC (1:1:1 by vol), plus 10 wt% FEC, is used to assemble a button cell for performance testing.

[0099] Test conditions: The charge-discharge current density is 0.1 A / g and 1.0 A / g, and the charge-discharge voltage range is 0.01 V to 2.0 V. The charge-discharge cycle test process is as follows: In the first cycle, the battery is first discharged at a constant current to 0.01 V, and then charged at a constant current to 2.0 V; starting from the second cycle, during discharge, it is discharged from 2.0 V to 0.01 V, and during charging, it is charged from 0.01 V to 2.0 V.

[0100] The test was carried out according to the above battery test conditions and steps (the battery charge-discharge test system used is the LAND CT2001A battery test system, Wuhan Lanhe Electronics Co., Ltd.). As Figure 8 、 Figure 9 shown, at room temperature, the capacity of the Sn-graphite composite anode material decays to nearly 0 after 30 cycles, while at -10 °C, the capacity of the Sn-graphite composite anode material decays to 150 mAh / g after 3 cycles, which is much lower than that of the Sn-InSb-graphite composite anode material in Example 5 and Example 6.

[0101] Through the comparison between Example 5 and the comparative example, it can be seen that the Sn-InSb-graphite composite anode material has better cycle stability and low-temperature performance compared with the Sn-graphite composite anode material. The Sn-InSb-graphite composite anode material has excellent performances such as high initial efficiency, high Coulomb efficiency, high rate performance, and high cycle stability.

[0102] As described above, the present invention can be preferably realized. The above embodiments are only partial embodiments of the present invention and are not used to limit the scope of implementation of the present invention; that is, all equivalent changes and modifications made according to the content of the present invention are covered by the scope protected by the claims of the present invention.

Claims

1. A Sn-based composite anode material, characterized in that, The Sn-based composite anode material includes: Sn, InSb, and graphite. InSb is uniformly distributed in the Sn alloy matrix in the form of fine crystal particles; the mass of Sn accounts for 40% - 90% of the total mass of the Sn-based composite anode material, the mass of InSb accounts for 10% - 50% of the total mass of the Sn-based composite anode material, and the mass of graphite accounts for 3% - 20% of the total mass of the Sn-based composite anode material; the Sn is in the form of particles with a particle size of less than 100 microns, the InSb is in the form of particles with a particle size of less than 150 microns, and the graphite is graphite particles with a particle size of less than 10 microns; the Sn-based composite anode material accelerates the induction of the transformation of gray tin by compounding InSb, shortening the nucleation process.

2. The preparation method of the Sn-based composite anode material according to claim 1, wherein Comprising the following steps S1: Prepare raw materials for the Sn-based composite anode material, which at least include two materials, Sn and InSb. After mixing the raw materials, stir evenly to obtain a mixed powder; S2: Put the mixed powder into a can in an Ar atmosphere glove box, and drop in a lubricant to assist ball milling; S3: Perform planetary ball milling on the canned powder to obtain the Sn-based composite anode material.

3. The preparation method of the Sn-based composite anode material according to claim 2, characterized in that: The grinding balls used in the planetary ball milling are made of bearing steel. The ball milling process is carried out in a high-purity Ar atmosphere, the ball-to-material ratio is 25 - 50:1, the ball milling speed is 300 - 400 r / min, and the ball milling mode is one-way / multi-way operation for 20 - 40 h.

4. The preparation method of the Sn-based composite anode material according to claim 3, wherein: The ball milling can and the bearing steel balls need to be cleaned before use.

5. The preparation method of the Sn-based composite anode material according to claim 2, wherein, The lubricant is absolute ethanol, and the addition amount of the absolute ethanol is 2 mL.

6. The application of the Sn-based composite anode material according to claim 1 or 2 in batteries and supercapacitors.

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