Graphite anode material, its preparation method and use thereof

Abstract

The present invention relates to the field of carbon materials. A graphite negative electrode material, its preparation method and use are disclosed. The crystallite size L of the graphite negative electrode material in the c-axis direction obtained by XRD is c and the crystallite diameter L in the a-axis direction a However, under the following conditions, 30 nm ≦ L c ≦70 nm Formula (I) and 50 nm ≦ L a The graphite negative electrode material satisfies the following condition: 85≦graphitization degree≦93. The graphite negative electrode material has high charge / discharge capacity, high initial coulombic efficiency, and excellent rate capability, and can be prepared by a simple method at low cost.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of Chinese Patent Application No. 202110646868.9, filed on June 10, 2021, which is incorporated herein by reference.

[0002] The present invention relates to the field of carbon materials, in particular to graphite anode materials and their preparation methods and applications. [Background technology]

[0003] The negative electrode of a lithium-ion battery is primarily made of carbon materials, including amorphous carbon, natural graphite, and artificial graphite. Graphite has a regular layered structure, excellent electrical conductivity, and a theoretical specific capacity of 372 mAh / g, making it the mainstream negative electrode material today. Currently, the raw materials used to develop artificial graphite mainly include three types: isotropic coke, bitumen binder, and needle coke. Isotropic coke-based artificial graphite has low crystallinity, high isotropy, low capacity, and high power output. Needle coke-based artificial graphite has high capacity but relatively poor rate capability, while bitumen binder-based artificial graphite generally falls somewhere between the two.

[0004] CN104681786A discloses a coal-based anode material. The coal-based anode material is composed of an inner layer, a middle layer, and an outer layer formed by graphitizing the coal-based material. The preparation method of the material includes crushing the coal-based material, adding a binder or a mixture of a binder and a modifier, and then performing compression and high-temperature graphitization to obtain the final product.

[0005] CN109319757A discloses a method for preparing hollow-open onion carbon anode materials for lithium-ion batteries. Coal material is used as raw material, mixed with nickel salt or nickel elemental substance as catalyst, and heated, so that the nickel salt or nickel elemental substance is uniformly distributed on the surface of the coal-based material particles. After cooling, a layer of open-open graphite onion carbon is formed on the spherical surface. Finally, graphite onion carbon with a hollow-open sphere structure is obtained after acid-base treatment and purification.

[0006] CN107528053A discloses a negative electrode material for a lithium ion secondary battery, a negative electrode for a lithium ion secondary battery, and a lithium ion secondary battery. The negative electrode material for a lithium ion secondary battery contains a carbon material, and the carbon material has an average interplanar spacing d of 0.335 nm to 0.340 nm as determined by X-ray diffraction. 002 , volume average particle size (50% D) of 1 μm to 40 μm, maximum particle size D of less than 74 μm max and has at least two exothermic peaks within the temperature range of 300°C to less than 1,000°C, while conducting differential thermal analysis in a flowing air.

[0007] The negative electrode materials provided by the above prior art have complicated structures and methods, are expensive, and require the use of acids, bases, etc. for purification treatment, which is not environmentally friendly. More importantly, the rate capability of the single-phase graphite negative electrode material in the prior art is insufficient and cannot meet actual demand. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] CN104681786A [Patent Document 2] CN109319757A [Patent Document 3] CN107528053A Summary of the Invention [Problem to be solved by the invention]

[0009] To overcome the problems of prior art graphite anode materials, such as the complex structure, poor rate capability of single-phase graphite, complex preparation methods, and high costs, the present invention provides a coal-based graphite anode material, its preparation method, and applications. The coal-based graphite anode material has high charge / discharge capacity, high initial coulombic efficiency, and excellent rate capability, and its preparation method is simple and low cost. [Means for solving the problem]

[0010] In order to achieve the above object, one aspect of the present invention is to provide a graphite negative electrode material having a crystallite diameter L in the c-axis direction obtained by XRD. c and the crystallite diameter L in the a-axis direction a But under the following conditions, 30nm≦L c ≦70 nm Formula (I), and 50nm≦L a ≦120 nm Formula (II), and Satisfied, The graphitization degree of the graphite negative electrode material is as follows: 85≦degree of graphitization≦93 Formula (III) To provide a graphite negative electrode material that satisfies the above.

[0011] A second aspect of the present invention is a method for producing a cellulose acetate ester comprising the steps of: (1) crushing coal to obtain coal particles; (2) graphitizing the coal particles to obtain a graphite anode material; Including, Provided is a method for preparing a graphite negative electrode material, in which coal satisfies the following conditions: a vitrinite reflectance of 2 or more, a volatile component of 10 wt% or less, and an ash content of 10 wt% or less, and the graphitization conditions include controlling the actual maximum supply power of a graphitization furnace transformer to 3,000 kW or more, and the continuous transmission time of the actual maximum transmission power is 1 hour to 100 hours.

[0012] A third aspect of the present invention provides a graphite negative electrode material prepared by the above preparation method.

[0013] A fourth aspect of the present invention provides the application of the above graphite anode material in at least one of a lithium ion battery, an energy storage material, a mechanical component, and a graphite electrode.

[0014] According to the above technical solutions, the graphite negative electrode material and its preparation method and application provided by the present invention have the following beneficial effects: (1) The graphite anode material provided by the present invention has excellent electrochemical performance, and in particular, can significantly improve the rate capability of batteries containing the graphite anode material, provided that it maintains a relatively high charge / discharge capacity and a high initial coulombic efficiency, thereby achieving an optimal balance between these three. Specifically, the graphite anode material has a charge / discharge capacity of 330 mAh / g or more, an initial coulombic efficiency of 90% or more, and a capacity retention at 2C / 0.2C of 35% or more. (2) The graphite negative electrode material provided by the present invention has an I110 / I004 ratio of 0.30 or more, indicating that the graphite negative electrode material has high isotropy. Furthermore, the graphite negative electrode material has a small crystallite grain size, which further improves the rate capability of the graphite negative electrode material. (3) The cost of preparing the graphite negative electrode material of the present invention is low, the method is simple and easy to implement, and the raw materials are abundant and easy to obtain. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a TEM photograph of the graphite negative electrode material provided in Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0016] The range endpoints and any values ​​disclosed herein should be understood to be not limited to the exact range or value, but to include values ​​close to those ranges or values. For numerical ranges, one or more new numerical ranges can be obtained by combining the various range endpoints, the various range endpoints and individual point values, and the individual point values, and these numerical ranges should be considered to be specifically disclosed herein.

[0017] The first aspect of the present invention is to provide a graphite negative electrode material having a crystallite diameter L in the c-axis direction obtained by XRD. c and the crystallite diameter L in the a-axis direction a But under the following conditions, 30nm≦L c ≦70 nm Formula (I), and 50nm≦L a ≦120 nm Formula (II), and Satisfied, The graphite negative electrode material has a degree of graphitization that satisfies the following condition: 85≦degree of graphitization≦93 (expression (III)).

[0018] In the present invention, the graphite negative electrode material satisfying the above conditions has the characteristics of high isotropy and small crystallite grain size, which allows lithium ions to be inserted and extracted through many channels with short paths, and can significantly improve the rate capability of a battery containing the graphite negative electrode material, provided that a relatively high charge / discharge capacity and a high initial coulombic efficiency are maintained, thereby achieving the best balance between these three.

[0019] In the present invention, the graphite negative electrode material is a coal-based graphite negative electrode material.

[0020] In the present invention, the graphitization degree G of the graphite negative electrode material is calculated by the following formula: G=(0.344-d 002 ) / (0.344-0.3354) Calculation was performed according to the formula, where d 002 The value is calculated by Bragg's formula.

[0021] In the present invention, as shown in FIG. 1, the graphite negative electrode material is homogeneous.

[0022] Furthermore, 30 nm ≦ L c When it is ≦50 nm, the rate capability, charge / discharge capacity and initial coulombic efficiency of the graphite anode material are further improved.

[0023] Furthermore, 55 nm ≦ L a When it is ≦100 nm, the rate capability, charge / discharge capacity and initial coulombic efficiency of the graphite anode material are further improved.

[0024] Furthermore, when the degree of graphitization is 86≦degree≦92, the rate capability, charge / discharge capacity and initial coulombic efficiency of the graphite negative electrode material are further improved.

[0025] According to the present invention, the interplanar spacing d of the (002) crystal plane of the graphite negative electrode material obtained by XRD is 002 But under the following conditions, 0.3350nm≦d 002 ≦0.3380nm Formula (IV) Meet the following.

[0026] According to the present invention, the interplanar spacing d of the (002) crystal plane 002 However, 0.3360nm≦d 002 When the graphite anode material satisfies the condition of ≦0.3370 nm, the graphite anode material has better overall performance.

[0027] According to the present invention, the peak intensity I110 of the (110) crystal plane and the peak intensity I004 of the (004) crystal plane of the graphite negative electrode material obtained by XRD can be determined under the following conditions: I110 / I004 is 0.30 or more Formula (V) Meet the following.

[0028] In the present invention, the isotropy of the graphite negative electrode material that satisfies the above conditions is further increased, and as a result, the rate capability of the graphite negative electrode material is further improved.

[0029] Furthermore, when 0.35≦I110 / I004≦0.85, the graphite anode material has better rate capability.

[0030] According to the present invention, the ash content of the graphite anode material is less than or equal to 1000 ppm.

[0031] In the present invention, the ash content of the graphite negative electrode material is measured by the method in GB / T 3521. The graphite negative electrode material provided by the present invention has a low ash content, which can significantly improve the overall homogeneity of the graphite negative electrode material.

[0032] Furthermore, the ash content of the graphite negative electrode material is 500 ppm or less.

[0033] A second aspect of the present invention is a method for producing a cellulose acetate ester comprising the steps of: (1) crushing coal to obtain coal particles; (2) graphitizing the coal particles to obtain a graphite anode material; Including, Provided is a method for preparing a graphite negative electrode material, in which coal satisfies the following conditions: a vitrinite reflectance of 2 or more, a volatile component of 10 wt% or less, and an ash content of 10 wt% or less, and the graphitization conditions include controlling the actual maximum supply power of a graphitization furnace transformer to 3000 kW or more, and the continuous transmission time of the actual maximum transmission power is 1 hour to 100 hours.

[0034] In the present invention, the graphitization apparatus may be a graphitization apparatus commonly used in the industry, and specifically, the graphitization apparatus may be selected from at least one of an Acheson furnace, a box furnace, an inner-series furnace, a vertical graphitization furnace, and a horizontal graphitization furnace.

[0035] According to the present invention, a low-cost graphite anode material having a unique micro-nano structure is developed using coal as a raw material, and when the graphite anode material is prepared according to the method provided by the present invention, it is possible to achieve high-value-added utilization and clean and efficient diversion of coal.

[0036] In the present invention, when coal satisfying the above conditions is selected as the raw material for preparing a graphite negative electrode material, the prepared graphite negative electrode material has a medium degree of graphitization, a small crystallite size, and high isotropy, thereby significantly improving the rate capability, charge / discharge capacity, and initial coulomb efficiency of the graphite negative electrode material.

[0037] In the present invention, the vitrinite reflectance of coal is measured according to the national standard method GB / T 6948, and the volatile matter content and ash content of coal are both measured according to the national standard method GB / T 30732.

[0038] According to the present invention, the coal meets the following conditions: a vitrinite reflectance of 2.35 or more, a volatile content of 10 wt% or less, and an ash content of 6 wt% or less.

[0039] In the present invention, coal may be pulverized using conventional equipment in the art, such as a jet mill.

[0040] According to the present invention, in step (1), the particle size D of the coal particles 50 is 1 μm to 100 μm, preferably 5 μm to 30 μm.

[0041] According to the present invention, the method further comprises the step of shaping and / or screening the coal particles.

[0042] According to the present invention, step (2) comprises the following steps: (2-1) carbonizing coal particles to obtain an intermediate; (2-2) graphitizing the intermediate to obtain a graphite negative electrode material; Includes.

[0043] In the present invention, prior to the graphitization treatment, the volatile components or ash in the coal particles are removed by carbonization of the coal particles, which can avoid agglomeration caused by the outflow of volatile components or ash during the graphitization process, while improving the graphitization degree of the product. As a result, the charge / discharge capacity and initial coulombic efficiency of the battery including the graphite negative electrode material are increased, thereby achieving the best balance of capacity, efficiency, and rate capability.

[0044] According to the present invention, in the step (2-1), the carbonization conditions include a carbonization temperature of 400° C. to 1,800° C. and a carbonization time of 1 hour to 10 hours.

[0045] In the present invention, carbonization is carried out in the presence of an inert atmosphere.

[0046] According to the present invention, in step (2), the graphitization conditions include controlling the actual maximum supply power of the transformer in the graphitization apparatus to 5,000 kW to 50,000 kW, and the continuous transmission time of the actual maximum transmission power is 5 hours to 50 hours.

[0047] Furthermore, the graphitization conditions include controlling the actual maximum power supply of the transformer in the graphitization apparatus to 10,000 kW to 30,000 kW, and the continuous transmission time of the actual maximum transmission power is 8 hours to 40 hours.

[0048] A third aspect of the present invention provides a graphite negative electrode material prepared by the above preparation method.

[0049] A fourth aspect of the present invention provides the application of the above graphite anode material in at least one of a lithium ion battery, an energy storage material, a mechanical component, and a graphite electrode.

[0050] In the present invention, the lithium ion battery comprising the above graphite anode material has excellent electrochemical performance, specifically, the lithium ion battery comprising the above graphite anode material has a charge / discharge capacity of 330 mAh / g or more, an initial coulombic efficiency of 90% or more, and a capacity retention rate of 35% or more at 2C / 0.2C.

[0051] The present invention will be described in detail below using embodiments. (1)XRD analysis XRD analysis of graphite anode material Surface spacing d 002 , L a , L c All I110 / I004 samples were tested and analyzed using a Bruker AXS D8 Advance X-ray diffractometer. The XRD was calibrated using a silicon internal standard. 002 The value is calculated using the Bragg formula 2d sin Θ 002 = nλ, calculated by L a and L c was calculated using the Scherrer formula. (2) Particle size (D 10 , D 50 , D 90 ) D 50 was obtained by a Malvern Mastersizer 2000 laser particle sizer from Malvern Instruments. (3) The morphology of the graphite anode material was characterized by transmission electron microscopy (TEM). TEM photographs were obtained by examination through a JEOL ARM200F transmission electron microscope. (4)Battery performance The charge / discharge capacity and initial coulombic efficiency of the battery were tested by passing it through a CT2001A battery tester of the battery test system of Wuhan Land Electronics Co., Ltd., and subjected to a charge / discharge test at a current of 0.1C (1C=350mAh / g) and a voltage of 0V to 3V. (5) The vitrinite reflectance of the coal was measured according to the national standard method GB / T 6948, and the volatile matter content and ash content of the coal were both measured according to the national standard method GB / T 30732. [Example]

[0052] (1) Coal (vitrinite reflectance of 2.445, volatile content of 7.7 wt%, and ash content of 2.6 wt%) was crushed by a crusher to obtain a 10 μm D 50A powder having the above structure was obtained, and then the powder was screened to obtain coal particles. (2-1) Coal particles were carbonized at 1000°C in an inert gas for 2 hours to obtain an intermediate. (2-2) The intermediate was graphitized in a graphitization furnace. In the graphitization furnace, the actual maximum power supply of the transformer was 22,000 kW, and the continuous transmission time of the actual maximum transmission power was 20 hours. A graphite negative electrode material was obtained, and the graphite negative electrode material was sieved to obtain Product A1.

[0053] The TEM photograph of the graphite negative electrode material is shown in Figure 1. From Figure 1, it can be seen that Product A1 has high isotropy and small crystallite grain size. [Example]

[0054] (1) Coal (vitrinite reflectance of 2.445, volatile content of 7.7 wt%, and ash content of 2.6 wt%) was crushed by a crusher to obtain a 10 μm D 50 The coal powder having the formula (2-1) Coal particles were carbonized at 1000°C in an inert gas for 2 hours to obtain an intermediate. (2-2) The intermediate was graphitized in a graphitization furnace. In the graphitization furnace, the actual maximum power supply of the transformer was 22,000 kW, and the continuous transmission time of the actual maximum transmission power was 35 hours. A graphite negative electrode material was obtained, and the graphite negative electrode material was sieved to obtain Product A2. [Example]

[0055] (1) Coal (vitrinite reflectance of 2.445, volatile content of 7.7 wt%, and ash content of 2.6 wt%) was crushed by a crusher to obtain a 10 μm D 50 The coal powder having the formula (2-1) Coal particles were carbonized at 1,000°C in an inert gas atmosphere for 2 hours to obtain an intermediate. (2-2) The intermediate was graphitized in a graphitization furnace. In the graphitization furnace, the actual maximum power supply of the transformer was 22,000 kW, and the continuous transmission time of the actual maximum transmission power was 10 hours. A graphite negative electrode material was obtained, and the graphite negative electrode material was sieved to obtain Product A3. [Example]

[0056] (1) Coal (vitrinite reflectance of 2.445, volatile content of 7.7 wt%, and ash content of 2.6 wt%) was crushed by a crusher to obtain a 10 μm D 50 The coal powder having the formula (2-1) Coal particles were carbonized at 1000°C in an inert gas for 2 hours to obtain an intermediate. (2-2) The intermediate was graphitized in a graphitization furnace. In the graphitization furnace, the actual maximum power supply of the transformer was 10,000 kW, and the continuous transmission time of the actual maximum transmission power was 20 hours. A graphite negative electrode material was obtained, and the graphite negative electrode material was sieved to obtain Product A4. [Example]

[0057] (1) Coal (vitrinite reflectance of 2.269, volatile content of 6.83 wt%, and ash content of 9.3 wt%) was crushed in a crusher to obtain a 10 μm D 50 A powder having the above structure was obtained, and then the powder was screened to obtain coal particles. (2-1) Coal particles were carbonized at 1000°C in an inert gas for 2 hours to obtain an intermediate. (2-2) The intermediate was graphitized in a graphitization furnace. In the graphitization furnace, the actual maximum power supply of the transformer was 22,000 kW, and the continuous transmission time of the actual maximum transmission power was 20 hours. A graphite negative electrode material was obtained, and the graphite negative electrode material was sieved to obtain Product A5. [Example]

[0058] (1) Coal (vitrinite reflectance of 2.269, volatile content of 6.83 wt%, and ash content of 9.3 wt%) was crushed in a crusher to obtain a 10 μm D 50 A powder having the above structure was obtained, and then the powder was screened to obtain coal particles. (2-1) Coal particles were carbonized at 1000°C in an inert gas for 2 hours to obtain an intermediate. (2-2) The intermediate was graphitized in a graphitization furnace. In the graphitization furnace, the actual maximum power supply of the transformer was 5,000 kW, and the continuous transmission time of the actual maximum transmission power was 20 hours. A graphite negative electrode material was obtained, and the graphite negative electrode material was sieved to obtain Product A6. [Example]

[0059] (1) Coal (vitrinite reflectance of 2.269, volatile content of 6.83 wt%, and ash content of 9.3 wt%) was crushed in a crusher to obtain a 10 μm D 50 A powder having the above structure was obtained, and then the powder was screened to obtain coal particles. (2-1) Coal particles were carbonized at 1000°C in an inert gas for 2 hours to obtain an intermediate. (2-2) The intermediate was graphitized in a graphitization furnace. In the graphitization furnace, the actual maximum power supply of the transformer was 22,000 kW, and the continuous transmission time of the actual maximum transmission power was 5 hours. A graphite negative electrode material was obtained, and the graphite negative electrode material was sieved to obtain Product A7. [Example]

[0060] A graphite negative electrode material was prepared according to the method of Example 1, except that the carbonization conditions in step (2-1) were different from those in Example 1. Specifically, the carbonization temperature was 400°C and the time was 0.5 hours. [Example]

[0061] A graphite negative electrode material was prepared according to the method of Example 1, except that the carbonization conditions in step (2-1) were different from those in Example 1. Specifically, the carbonization temperature was 2200°C and the time was 15 hours. [Example]

[0062] (1) Coal (vitrinite reflectance of 2.445, volatile content of 7.7 wt%, and ash content of 2.6 wt%) was crushed by a crusher to obtain a 10 μm D 50 The coal powder having the formula (2) The coal particles were graphitized in a graphitization furnace. In the graphitization furnace, the actual maximum power supply of the transformer was 22,000 kW, and the continuous transmission time of the actual maximum transmission power was 20 hours. Graphite anode material was obtained, and the graphite anode material was sieved to obtain product A10.

[0063] Comparative Example 1 (1) Coal (vitrinite reflectance of 1.947, volatile content of 12.5 wt%, and ash content of 9.4 wt%) was pulverized by a jet mill to obtain a 10 μm D 50 The coal powder having the formula (2-1) Coal particles were carbonized at 1000°C in an inert gas for 2 hours to obtain an intermediate. (2-2) The intermediate was graphitized in a graphitization furnace. In the graphitization furnace, the actual maximum power supply of the transformer was 22,000 kW, and the continuous transmission time of the actual maximum transmission power was 20 hours. A graphite negative electrode material was obtained, and the graphite negative electrode material was sieved to obtain Product D1.

[0064] Comparative Example 2 (1) Coal (vitrinite reflectance of 2.445, volatile content of 7.7 wt%, and ash content of 2.6 wt%) was pulverized by a jet mill to obtain a 10 μm D 50 The coal powder having the formula (2-1) Coal particles were carbonized at 1000°C in an inert gas for 2 hours to obtain an intermediate. (2-2) The intermediate was graphitized in a graphitization furnace. In the graphitization furnace, the actual maximum power supply of the transformer was 600 kW, and the continuous transmission time of the actual maximum transmission power was 20 hours. A graphite negative electrode material was obtained, and the graphite negative electrode material was sieved to obtain Product D2.

[0065] Comparative Example 3 A negative electrode material D3 was prepared according to the method of Example 1, except that the coal was replaced with pitch coke.

[0066] The graphite anode materials prepared in the examples and comparative examples were characterized and the results can be seen in Table 1 below.

[0067] [Table 1]

[0068] Test Example The negative electrode materials prepared in the examples and comparative examples were uniformly mixed with conductive carbon black Super P and binder poly(vinylidene fluoride) (PVDF) in a mass ratio of 92:3:5, then solvent N-methylpyrrolidone (NMP) was added and stirred to form a uniform negative electrode slurry, which was uniformly coated on aluminum foil with a scraper and dried to obtain a negative electrode plate. The plate was cut into small pieces and then stored in an MBraun 2000 glove box (Ar atmosphere, HO and O concentrations of 0.1 × 10 -6 The resulting battery was then assembled into a button cell using a metallic lithium plate as a reference electrode. The electrochemical performance of the button cell was tested, and the test results can be seen in Table 2.

[0069] [Table 2]

[0070] From the results in Tables 1 and 2, it can be seen that the charge-discharge capacity and initial coulombic efficiency of the batteries manufactured using the coal-based negative electrode materials prepared in Examples 1 to 10 of the present invention are better, and it is possible to achieve the best balance between the charge-discharge capacity, initial coulombic efficiency, and rate capability of the battery.

[0071] Although the above are preferred embodiments of the present invention, the present invention is not limited to these embodiments. Within the scope of the technical concept of the present invention, many simple modifications can be made to the technical solutions of the present invention, including the combination of various technical features in any other suitable manner. These simple modifications and combinations are also considered to be the contents disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. The crystallite diameter L in the c-axis direction of the graphite negative electrode material obtained by XRD ｃ and the crystallite diameter L in the a-axis direction ａ But under the following conditions, 30 nm≦L ｃ ≦70 nm Formula (I) and 50 nm≦L ａ ≦120 nm Formula (II) and Satisfied, The graphitization degree of the graphite negative electrode material satisfies the following condition: 85%≦graphitization degree≦93% (Equation (III)), The graphite negative electrode material is characterized in that the peak intensity I110 of the (110) crystal plane and the peak intensity I004 of the (004) crystal plane obtained by XRD satisfy the following conditions: I110 / I004 is 0.30 or more; Formula (V), Meet the graphite negative electrode material.

2. 30 nm≦L ｃ 2. The graphite anode material of claim 1, wherein the average particle size is ≦50 nm.

3. 55 nm≦L ａ 3. The graphite anode material of claim 1, wherein the particle size is ≦100 nm.

4. 4. The graphite negative electrode material according to claim 1, wherein the degree of graphitization is 86%≦degree of graphitization≦92%.

5. The interplanar spacing d of the (002) crystal plane of the graphite negative electrode material obtained by XRD ００２ But under the following conditions, 0.3350nm≦d ００２ ≦0.3380nm Formula (IV) The graphite negative electrode material according to claim 1 , wherein

6. 0.35≦I110 / I004≦0.85 6. The graphite negative electrode material according to claim 1, wherein

7. 7. The graphite anode material of claim 1, wherein the ash content of the graphite anode material is 1000 ppm or less.

8. The following process: (1) crushing coal to obtain coal particles; (2) graphitizing the coal particles to obtain a graphite negative electrode material; Including, 8. The method for preparing a graphite negative electrode material according to claim 1, wherein the coal satisfies the following conditions: a vitrinite reflectance of 2 or more, a volatile content of 10 wt % or less, and an ash content of 10 wt % or less; and the graphitization conditions include controlling the actual maximum supply power of a transformer in a graphitization apparatus to 3,000 kW or more, and the continuous transmission time of the actual maximum transmission power is 1 hour to 100 hours.

9. 9. The method of claim 8, wherein the coal meets the following conditions: a vitrinite reflectance of 2.35 or greater, a volatile content of 10 wt. % or less, and an ash content of 6 wt. % or less.

10. In step (1), the particle diameter D of the coal particles ５０ The method according to claim 8 or 9, wherein the particle size is 1 μm to 100 μm.

11. Step (2) is the following step: (2-1) carbonizing the coal particles to obtain an intermediate; (2-2) graphitizing the intermediate to obtain the graphite negative electrode material; 11. The method of any one of claims 8 to 10, comprising:

12. The preparation method according to claim 11, wherein in step (2-1), the carbonization conditions include a carbonization temperature of 400°C to 1800°C and a carbonization time of 1 hour to 10 hours.

13. 13. The method according to any one of claims 8 to 12, wherein in step (2), the graphitization conditions include controlling an actual maximum supply power of a transformer in the graphitization apparatus to 5,000 kW to 50,000 kW, and the continuous transmission time of the actual maximum transmission power is 5 hours to 50 hours.

14. 8. Application of the graphite anode material according to any one of claims 1 to 7 in at least one of a lithium ion battery, an energy storage material, a machine component and a graphite electrode.

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