A nano negative electrode material and a preparation method and application thereof

Abstract

The application discloses a kind of nano negative material and its preparation method and application, belong to electrode active substance.This method is by mechanical assistance to realize the nanocrystallization of material using ball milling process, including the following steps: (1) negative electrode raw material is refined to form raw material powder;(2) with the hardness greater than the water-soluble inorganic salt crystal of negative electrode raw material as grinding aid, the grinding aid is mixed with the raw material powder, and ball milling treatment is carried out at room temperature in inert atmosphere;After treatment, the product is washed, separated, dried, and the nano negative material is obtained.The process of the application is simple, low cost, and the nano negative material prepared has excellent ion storage performance, high specific capacity and coulomb efficiency, and good cycle performance.The material is applied to battery, which can significantly improve the performance of battery.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electrode active materials, in particular to a nano negative electrode material and a preparation method and application thereof. BACKGROUND

[0002] Fossil fuels are currently the most widely used energy source in the world. With the rapid development of productivity, energy consumption is growing rapidly, leading to a sharp decline in the reserves of fossil energy, which is difficult to meet the demand for industrial production in the coming decades. In addition, the large-scale use and production of fossil fuels have led to serious environmental pollution, and the energy crisis has emerged. In order to solve this problem, in recent years, researchers have carried out a lot of research on clean energy and renewable energy, such as the emergence of wind energy, solar energy, and tidal energy. The use of such energy can effectively reduce CO2 emissions, but these clean energy sources have the disadvantages of intermittency and instability. In contrast, rechargeable battery technology operating through reversible electrochemical reactions is considered an ideal energy storage mode. Among various energy storage technologies, secondary batteries such as lead-acid, nickel-hydrogen (Ni-MH), nickel-cadmium, zinc-silver, lithium-ion, and sodium-ion batteries are highly flexible and have high energy conversion efficiency, and are easy to maintain, making them a promising large-scale energy storage method.

[0003] Currently, lithium-ion batteries are the most frequently used secondary batteries. Lithium-ion batteries have high operating voltage, high energy density, good safety, good cycle performance, wide operating temperature range, no obvious self-discharge phenomenon, and no memory effect, etc. Therefore, current lithium-ion batteries have become the preferred energy storage battery. However, due to the high cost of the positive electrode material required for the current lithium-ion battery, and the uneven distribution and scarcity of lithium resources, the sustainability of lithium-ion batteries is limited. Therefore, other secondary ion batteries have also been developed. Among various energy storage technologies, secondary batteries (electrochemically rechargeable batteries) are a very critical component. They have a wide range of applications and strong connection capabilities with renewable energy power. From the perspective of applicable energy and power range, a variety of secondary batteries cover the technical needs of most energy storage applications. Secondary batteries are currently more mature in terms of positive electrode research, and there are many types of positive electrodes. However, research on negative electrodes is still not deep enough. The ability of negative electrode materials to insert and extract ions is a major factor affecting the capacity of secondary ion batteries.

[0004] As an important component of secondary ion battery, the negative electrode active material plays a vital role in the performance of secondary ion battery. At present, researchers have proposed a variety of negative electrode materials suitable for secondary ion battery, such as carbon-based materials, metal alloys, metal oxides / sulfides, etc. Among them, metal and alloy materials have attracted widespread attention due to their high capacity, wide raw material sources and low price. However, the volume expansion of metal and alloy materials during charging and discharging is too large, which leads to poor cycle performance. The common solutions include carbon coating, nanocrystallization, and construction of special structure, etc. Carbon coating will reduce the mass specific energy of the material, and the construction of special structure often takes a long time and is complicated.

[0005] Metal and alloy materials have high capacity and relatively low reaction potential, which have attracted the attention of researchers. However, these materials also have some shortcomings, such as poor reaction kinetics and large volume change after deintercalation of ions, which leads to material pulverization during the cycle process, and the specific capacity rapidly decays after the material loses electrical contact with the current collector. Nano-materials can significantly reduce the volume stress of material expansion and improve the wettability of electrolyte, so synthesizing negative electrode materials with nanostructure is a potential direction. SUMMARY

[0006] In view of the above-mentioned defects of the prior art, in the first aspect of the present application, a simple and low-cost preparation method of nano negative electrode material is provided, which realizes nanocrystallization of the material by mechanical assistance through ball milling process, including the following steps:

[0007] (1) The negative electrode raw material is refined to form a raw material powder;

[0008] (2) A water-soluble inorganic salt crystal with a hardness greater than that of the negative electrode raw material is used as a grinding aid, the grinding aid and the raw material powder are mixed, and ball milling treatment is carried out at room temperature in an inert atmosphere; after the treatment is completed, the product is washed, separated, and dried to obtain a nano negative electrode material.

[0009] Preferably, in the step (1), the negative electrode raw material includes at least one of copper, aluminum, zinc, iron, lead, tin, antimony, germanium, bismuth, cobalt, nickel, zinc, phosphorus, sulfur, silicon, boron.

[0010] Preferably, in the step (1), the negative electrode raw material is a micron-sized particle with a median particle size (D50) of 100-200 μm.

[0011] For the cost and difficulty of obtaining negative electrode raw materials, the use of micron-sized particles is a more appropriate choice. By means of refinement such as grinding, it can be processed into powder, which is more conducive to subsequent ball milling. The operation of refinement can be changed according to the actual process conditions, for example, in laboratory conditions, a small grinder or mortar can be used to complete the processing; while in industrial processing conditions, large grinding machines or grinding equipment can also achieve the same purpose.

[0012] Preferably, in the step (2), the grinding aid includes at least one of sodium chloride, aluminum chloride, potassium chloride, zinc chloride, magnesium chloride, calcium chloride, copper chloride, copper sulfate, sodium sulfate, sodium carbonate, sodium nitrate, sodium iodide, zinc sulfate, manganese sulfate, manganese chloride, and iron chloride.

[0013] Preferably, in the step (2), the mass ratio of the grinding aid to the raw material powder is 1-5:1.

[0014] Preferably, in the step (2), the grinding balls used in the ball milling process are graded in five levels of 12mm, 10mm, 8mm, 6mm, and 4mm in diameter; in terms of mass percentage, the grinding balls with diameters of 12mm and 10mm account for 30%-40%, the grinding balls with a diameter of 8mm account for 30%-40%, and the grinding balls with diameters of 6mm and 4mm account for 30% in total.

[0015] In the ball milling process in the art, the grinding balls function to impact the raw materials and are chemically inert and do not react with the raw materials. Therefore, the selection of the material type of the grinding balls is rich, for example, a person skilled in the art can use grinding balls made of materials such as cemented carbide, silicon oxide, zirconium oxide, aluminum oxide, zirconium silicate, stainless steel, agate, and ceramic to achieve the purpose of ball milling.

[0016] Preferably, in the step (2), the ball milling process lasts for 4-12h, and the ball milling frequency is 40-50Hz.

[0017] The washing, separation, and drying steps in the process can be carried out by general methods in the art, and the selection is diverse, and appropriate methods can be selected according to the actual processing conditions. For example, separation can be carried out by centrifugation, suction filtration, filtration, etc.

[0018] In the second aspect of the present application, a nano negative electrode material with high specific capacity and coulombic efficiency and good cycle performance is provided, which is prepared by the method of the first aspect of the present application.

[0019] In the third aspect of the present application, the application of the nano negative electrode material of the second aspect of the present application is provided, specifically the application as a negative active material in the preparation of a battery.

[0020] Based on the above technical solutions, the principles and design concepts of the present application will be described from the following two aspects. In one aspect, inorganic salt crystals are used as ball milling assistants. During the ball milling process, when the hardness (it should be understood as the general hardness definition in the art, including scratch hardness, indentation hardness, Rockwell hardness, Brinell hardness, microhardness, Leeb hardness, Shore hardness, Barcol hardness, Knoop hardness and Vickers hardness) of the selected inorganic salt is greater than that of the negative electrode raw material, the inorganic salt grains with finer microstructure will play a role like a cutting knife, further refining the particle size of the negative electrode raw material, and making it nanometerized. In another aspect, according to the use requirements of the finished product in the battery field, the interface isolation effect of the inorganic salt can block the severe agglomeration between the nanoparticles during the ball milling process, and the inorganic salt will form an extremely thin inorganic salt film on the surface of the nanoparticles in situ during the ball milling process (defects are generated in the raw material during ball milling, and the anions and cations of the salt are adsorbed, the ions adsorbed by electrostatic action are not detached by subsequent water washing, and after drying, the anions and cations combine to exist in the form of such a film), the rigid inorganic salt film plays a role like a solid electrolyte interface film (SEI film), which hinders the subsequent aggregation of nanoparticles, and at the same time inhibits the volume expansion of the nanoparticles during the cycle process when used as a secondary ion battery negative electrode material, thereby ensuring the structural integrity of the nanoparticles during the cycle process. Therefore, the nanoparticles obtained by ball milling using the process of the present application can exhibit very excellent electrochemical performance even without carbon coating.

[0021] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0022] The present application provides a preparation method of a nanometer negative electrode material, which realizes the nanometerization of the material by using a simple and low-cost process.

[0023] The present application provides a nanometer negative electrode material, which has excellent ion storage performance, high specific capacity and coulombic efficiency, and good cycle performance.

[0024] The present application also provides an application of a nanometer negative electrode material, which is used as a negative electrode active material in a battery, and can significantly improve the performance of the battery. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 X-ray diffraction (XRD) pattern of the nanometer negative electrode material prepared in Example 1;

[0026] Figure 2 The first cycle charge-discharge curve of the battery of Example 1 and Comparative Example 1;

[0027] Figure 3 The cycle curve of the battery of Example 1;

[0028] Figure 4 X-ray diffraction (XRD) pattern of the nano negative electrode material prepared in Example 2;

[0029] Figure 5 Charge-discharge curve of the first cycle of the battery of Example 2;

[0030] Figure 6 Cycle curve of the battery of Example 2 and Comparative Example 2;

[0031] Figure 7 Cycle curve of the battery of Example 3 and Comparative Example 3;

[0032] Figure 8 Transmission electron microscope (TEM) image of the nano negative electrode material prepared in Example 4;

[0033] Figure 9 Transmission electron microscope (TEM) image of the nano negative electrode material prepared in Example 5;

[0034] Figure 10 Scanning electron microscope (SEM) image of the nano negative electrode material prepared in Example 6. DETAILED DESCRIPTION

[0035] The present application is further illustrated by the following examples without thereby limiting the present application to the examples described. The experimental methods in the following examples, for which no specific conditions are indicated, are selected according to the conventional methods and conditions, or according to the instructions of the commercial products.

[0036] In the following examples:

[0037] In the ball milling process, the grinding balls are graded in five levels of Φ12 mm, Φ10 mm, Φ8 mm, Φ6 mm and Φ4 mm; the grinding balls with diameters of 12 mm and 10 mm (large balls, 1:1 w / w) account for 30% to 40% in mass percentage, the grinding balls with diameter of 8 mm (medium balls) account for 30%, and the grinding balls with diameters of 6 mm and 4 mm (small balls, 1:1 w / w) account for 30% in total;

[0038] The frequency of the ball milling equipment is controlled at 40 to 50 Hz.

[0039] Example 1

[0040] The preparation method of the nano negative electrode material is as follows:

[0041] (1) Grinding the metal tin raw material to obtain refined tin powder;

[0042] (2) with sodium fluoride as grinding aid, the grinding aid and the tin powder obtained were mixed in a mass ratio of 2:1, high-energy ball milling was carried out at room temperature under inert gas protection for 8 h, so that the tin powder was nanometerized; after the treatment was completed, the obtained powder was washed with deionized water, then was filtered by suction, and the washing was repeated for 3-5 times; then the obtained black powder was washed with deionized water, and then was centrifuged to separate the insoluble substances; the insoluble substances were placed in a vacuum oven at 80°C and dried for 12 h, to obtain the nanometer negative electrode material.

[0043] The nanometer negative electrode material obtained in the example was characterized by X-ray diffraction (XRD), and the results are shown in Figure 1 . As can be seen from Figure 1 , the characteristic peaks of the XRD pattern are consistent with the standard characteristic peaks of tin, indicating that the ball milling treatment of the application does not destroy the crystal structure of tin, which is beneficial to the application of the material in the battery.

[0044] The nanometer negative electrode material was applied as a negative active material in a battery, and its electrical performance was tested. Carboxymethyl cellulose (CMC) was used as a binder, Super P conductive carbon black was used as a conductive agent, and the nanometer negative electrode material was coated in a ratio of 1:1:8, and then was dried and sliced. A solution of NaPF6 dissolved in diethylene glycol dimethyl ether was used as an electrolyte, and a 2032 type sodium ion button cell was assembled in a glove box. In Comparative Example 1, metallic tin was used as a negative active material, and the same method was used to assemble a 2032 type sodium ion button cell. The cycle performance of the battery was tested by Neware software, first activated at 0.1C, and then cycled at a current density of 0.5C (1C=847mAh / g); the test results are shown in Figure 2 , 3 , and the effect comparison of Example 1 and Comparative Example 1 is shown in Table 1.

[0045] Table 1:

[0046]

[0047] From the above test results, it can be found that the capacity of the battery of Example 1 is very stable during the cycle of 200 cycles, and the capacity maintenance rate is as high as 99.5%, which shows that the cycle performance of nanometer tin in the sodium ion secondary battery is very excellent. The reason why nanometer tin has good cycle performance is that nanometerization reduces the volume strain and expansion stress during the cycle of the material, and nanometerization is beneficial to the conduction of sodium ions and the permeation of the material to the electrolyte, and the very thin sodium fluoride film coated on the surface of nanometer tin can play a role in interface isolation to inhibit the agglomeration of nanometer tin and maintain the structural integrity of the material.

[0048] Example 2

[0049] The preparation method of the nanometer negative electrode material is as follows:

[0050] (1) Grind the metallic antimony raw material to obtain fine antimony powder;

[0051] (2) Using sodium chloride as a grinding aid, the grinding aid and the obtained antimony powder were mixed at a mass ratio of 3:1 and ball-milled at room temperature for 8 hours under inert gas protection to make the antimony powder nano-sized. After the treatment, the obtained powder was washed with deionized water and then filtered. After washing 3 to 5 times, the obtained black powder was washed with deionized water and then centrifuged to separate the insoluble matter. It was then placed in an 80°C vacuum oven and dried for 12 hours to obtain the nano-anode material.

[0052] The nano-anode material obtained in this embodiment was characterized by X-ray diffraction (XRD), and the results are as follows: Figure 4 As shown. By Figure 4 As can be seen, the characteristic peaks of the XRD pattern are consistent with the standard characteristic peaks of antimony, which also indicates that the ball milling process of the present invention does not destroy the crystal structure of antimony.

[0053] The nano-anode material was used as the negative electrode active material in a battery, and its electrical performance was tested. Polyacrylic acid (PAA) was used as a binder, Super P conductive carbon black as a conductive agent, and the nano-anode material was coated in a 1:1:8 ratio, dried, and then sliced. NaPF6 was dissolved in a mixed solvent (1:1 v / v) of ethylene carbonate (EC) and diethyl carbonate (DEC), and 5% fluoroethylene carbonate (FEC) was added as an additive. The resulting solution was used as the electrolyte. A 2032-type sodium-ion coin cell was assembled in a glove box. Comparative Example 2 used antimony metal as the negative electrode active material and assembled a 2032-type sodium-ion coin cell using the same method. The cycle performance of the battery was tested using Neware software. It was first activated at 0.1C, then cycled at a current density of 0.5C (1C = 660 mAh / g). The test results are shown below. Figure 5 , 6 As shown in Table 2, the effects of Example 2 and Comparative Example 2 are compared.

[0054] Table 2:

[0055]

[0056] The test results above show that the battery in Example 2 maintains a very stable capacity during 200 cycles, with a capacity retention rate as high as 99%, demonstrating that nano-antimony has excellent cycle performance in sodium-ion secondary batteries.

[0057] Example 3

[0058] The preparation method of nano-anode materials includes the following steps:

[0059] (1) grinding the raw materials of metal tin and red phosphorus according to a molar ratio of 4:3 to obtain raw material powder;

[0060] (2) taking sodium chloride and sodium carbonate (2:1 w / w) as grinding aids, mixing the grinding aids with the obtained raw material powder at a mass ratio of 1:1, and performing high-energy ball milling under inert gas protection at room temperature for 12 h, so that the raw material powder is nano-sized and tin-phosphorus (Sn4P3) alloy is formed; after the treatment is completed, the obtained powder is washed with deionized water, then is subjected to suction filtration, and after repeating the washing for 3-5 times, the obtained black powder is washed with deionized water, then is centrifuged to separate insoluble substances, and the insoluble substances are placed in a vacuum oven at 80°C for drying for 12 h to obtain a nano negative electrode material.

[0061] The nano negative electrode material is applied as a negative electrode active material in a battery, and the electrical performance thereof is tested. Carboxymethyl cellulose (CMC) is used as a binder, Super P conductive carbon black is used as a conductive agent, and the nano negative electrode material is coated at a ratio of 1:2:7, and after drying and slicing, a solution in which NaPF6 is dissolved in diethylene glycol dimethyl ether is used as an electrolyte to assemble a 2032 type sodium ion button cell in a glove box. In Comparative Example 3, Sn4P3 alloy powder obtained by ball milling the raw materials of metal tin and red phosphorus under the same process conditions without adding a grinding aid for 12 h is used as a negative electrode active material, and a 2032 type sodium ion button cell is assembled by the same method. The cycle performance of the battery is tested by Neware software, first activated at 0.1C, and then cycled at a current density of 0.5C (1C=1300 mAh / g), and the test results are shown in Table 3. Figure 7 The effect comparison of Example 3 and Comparative Example 3 is shown in Table 3.

[0062] Table 3:

[0063]

[0064] The test results show that the capacity of the battery of the present embodiment is maintained very stably during the cycle of 200 cycles, and the capacity maintenance rate is as high as 98%.

[0065] Example 4

[0066] The preparation method of the nano negative electrode material is as follows:

[0067] (1) grinding the raw materials of metal tin and red phosphorus according to a molar ratio of 4:3 to obtain raw material powder;

[0068] (2) taking potassium chloride as a grinding aid, mixing the grinding aid with the obtained bismuth powder in a mass ratio of 5:1, high-energy ball-milling the mixture under inert gas protection at room temperature for 10 h, so as to complete the nanocrystallization of the bismuth powder; after the treatment is completed, the obtained powder is washed with deionized water, and then is subjected to suction filtration; after the washing is repeated for 3-5 times, the obtained black powder is washed with deionized water, and then is subjected to centrifugal separation of insoluble substances; the insoluble substances are placed in a vacuum oven at 80°C for drying for 12 h, so as to obtain the nanometer negative electrode material.

[0069] The micro-morphology of the nanometer negative electrode material of the present embodiment is observed by using a transmission electron microscope (TEM), and an image thereof is shown in FIG. 2. Figure 8 The TEM image shows that the particle size of the material reaches about 200 nm after the potassium chloride-assisted ball-milling, the particle size of the material is uniform, and a layer of obvious film, i.e., the potassium chloride film, can be seen on the surface of the material.

[0070] The nanometer negative electrode material is applied as a negative active material to a battery, and the electrical performance thereof is tested. Carboxymethyl cellulose (CMC) is used as a binder, Super P conductive carbon black is used as a conductive agent, and the nanometer negative electrode material is coated in a proportion of 1:2:7, and after drying, the slice is cut, a solution in which NaPF6 is dissolved in diethylene glycol dimethyl ether is used as an electrolyte, and a 2032 type sodium ion button cell is assembled in a glove box. In Comparative Example 4, metallic bismuth is used as a negative active material, and the same method is used to assemble a 2032 type sodium ion button cell. The cycle performance of the battery is tested by using Neware software, first activated at 0.1C, and then cycled at a current density of 0.5C (1C=385 mAh / g), and the effect comparison of the test results of Example 4 and Comparative Example 4 is shown in Table 4.

[0071] Table 4:

[0072]

[0073] The test results show that the capacity of the battery of the present embodiment is maintained very stably during the cycle of 150 times, and the capacity maintenance rate is as high as 90%.

[0074] Example 5

[0075] The preparation method of the nanometer negative electrode material is as follows:

[0076] (1) grinding the metallic germanium raw material to obtain refined germanium powder;

[0077] (2) with sodium carbonate as grinding aid, the grinding aid and the obtained germanium powder are mixed in a mass ratio of 3.5:1, high-energy ball milling is carried out under inert gas protection at room temperature for 10 h, so that the germanium powder is nanometerized; after the treatment is completed, the obtained powder is washed with deionized water, then filtration is carried out, the washing is repeated for 3-5 times, then the obtained black powder is washed with deionized water, then the insoluble substances are centrifuged and separated, and the insoluble substances are placed in a vacuum oven at 80°C for drying for 12 h, so that the nanometer negative electrode material is obtained.

[0078] The microstructure of the nanometer negative electrode material of the embodiment is observed by a transmission electron microscope (TEM), and the image is as shown in FIG. 2. Figure 9 The TEM image shows that the particle size of the material after ball milling is about 50 nm, and the nanometerization of the raw material is completed.

[0079] The nanometer negative electrode material is applied as a negative electrode active material in a battery, and the electrical performance thereof is tested. Carboxymethyl cellulose (CMC) is used as a binder, Super P conductive carbon black is used as a conductive agent, and the nanometer negative electrode material is coated in a proportion of 1:2:7, then the slice is dried, a solution in which NaPF6 is dissolved in diethylene glycol dimethyl ether is used as an electrolyte, and a 2032 type sodium ion button cell is assembled in a glove box. In Comparative Example 5, the metal germanium raw material is used as a negative electrode active material, and the same method is used to assemble a 2032 type sodium ion button cell. The cycle performance of the battery is tested by Neware software, first 0.1C activation is carried out, then 0.5C current density is used for cycle (1C=370 mAh / g), and the effect comparison of the test results of Example 5 and Comparative Example 5 is shown in Table 5.

[0080] Table 5:

[0081]

[0082] The test results show that the capacity of the battery of the embodiment is maintained very stably in the process of 300 cycles, and the capacity maintenance rate is as high as 87%.

[0083] Example 6

[0084] The preparation method of the nanometer negative electrode material is as follows:

[0085] (1) the silicon raw material is ground to obtain fine silicon powder;

[0086] (2) with lithium fluoride as a grinding aid, the grinding aid and the obtained silicon powder are mixed in a mass ratio of 4.5:1, high-energy ball milling is carried out under inert gas protection at room temperature for 10 h, so that the silicon powder is nanometerized; after the treatment is completed, the obtained powder is washed with deionized water, then filtration is carried out, the washing is repeated for 3-5 times, then the obtained black powder is washed with deionized water, then the insoluble substances are centrifuged and separated, and the insoluble substances are placed in a vacuum oven at 80°C for drying for 12 h, so that the nanometer negative electrode material is obtained.

[0087] The microstructure of the nanometer negative electrode material of the embodiment is observed by a scanning electron microscope (SEM), and the image is shown in FIG. 1. Figure 10 The SEM image shows that the particle size of the material is uniform after ball milling, about 200 nm, and nanometer is successfully achieved.

[0088] The nanometer negative electrode material is applied as a negative active material in a battery, and its electrical performance is tested. Polyacrylic acid (PAA) is used as a binder, Super P conductive carbon black is used as a conductive agent, and the nanometer negative electrode material is coated at a ratio of 1:2:7, and after drying, the slice is cut, and a solution of NaPF6 dissolved in diethylene glycol dimethyl ether is used as an electrolyte, and a 2032 type sodium ion button cell is assembled in a glove box. Comparative Example 6 uses silicon raw materials as a negative active material, and is assembled into a 2032 type sodium ion button cell by the same method. The cycle performance of the battery is tested by Neware software, first activated at 0.1C, and then cycled at a current density of 0.5C (1C = 1000 mAh / g). The comparison of the test results of Example 6 and Comparative Example 6 is shown in Table 6.

[0089] Table 6:

[0090]

[0091] The test results show that the capacity of the battery of the embodiment is very stable during the 50 cycles, and the capacity retention rate is as high as 81%.

[0092] The above describes the preferred embodiments of the application in detail. It should be understood that those skilled in the art can make many modifications and changes without creative labor according to the concept of the application. Therefore, any technical solution obtained by logical analysis, reasoning or limited experiment based on the prior art according to the concept of the application shall be within the protection scope determined by the claims.

Claims

1. A method for preparing a nano-anode material, employing a ball milling process, characterized in that, Includes the following steps: (1) The negative electrode raw material is refined to form raw material powder; The negative electrode material includes at least one of copper, aluminum, zinc, iron, lead, tin, antimony, germanium, bismuth, cobalt, nickel, zinc, phosphorus, sulfur, silicon, and boron. (2) Using water-soluble inorganic salt crystals with a hardness greater than that of the anode material as a grinding aid, the grinding aid is mixed with the raw material powder and ball-milled at room temperature in an inert atmosphere; after the treatment, the product is washed, separated and dried to obtain nano anode material. The grinding aid includes at least one of the following: sodium chloride, aluminum chloride, potassium chloride, zinc chloride, magnesium chloride, calcium chloride, copper chloride, copper sulfate, sodium sulfate, sodium carbonate, sodium nitrate, sodium iodide, zinc sulfate, manganese sulfate, manganese chloride, and ferric chloride. In the ball milling process, the grinding balls are graded into five sizes with diameters of 12mm, 10mm, 8mm, 6mm, and 4mm. By mass percentage, grinding balls with diameters of 12mm and 10mm account for 30% to 40%, grinding balls with diameters of 8mm account for 30% to 40%, and grinding balls with diameters of 6mm and 4mm account for 30%. The ball milling process lasts for 4 to 12 hours, and the ball milling frequency is 40 to 50 Hz.

2. The method according to claim 1, characterized in that: In step (1), the negative electrode material is micron-sized particles with a median particle size of 100~200μm.

3. The method according to claim 1, characterized in that: In step (2), the mass ratio of the grinding aid to the raw material powder is 1~5:

1.

4. A nano-anode material, characterized in that: It is prepared by the method described in any one of claims 1 to 3.

5. An application of the nano-anode material as described in claim 4, characterized in that: Application of it as a negative electrode active material in battery manufacturing.

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