Method for preparing lithium negative electrode material by using anthracite and application thereof

Abstract

The application discloses a method for preparing a lithium battery negative electrode material from anthracite and application thereof and belongs to the field of new energy sources.The method comprises the following steps: S1, crushing anthracite to a set particle size to obtain finely crushed anthracite; S2, mixing the finely crushed anthracite obtained in step S1 with an alkaline additive and placing the mixture into a vacuum furnace to perform vacuum roasting to obtain a roasted sample; S3, performing acid immersion and impurity removal on the roasted sample obtained in step S2 to obtain high-purity anthracite; and S4, mixing the high-purity anthracite obtained in step S3 with a catalyst and performing graphitization treatment to obtain a lithium battery negative electrode material. Through the above method, efficient removal of ash in anthracite is realized, the influence of impurity components on electrochemical performance is avoided, and the nucleation and growth of a graphite layer are promoted, so that the electrochemical performance is enhanced.

Description

Technical Field

[0001] This invention relates to the field of new energy, specifically to a method for preparing lithium battery anode materials using anthracite and its application. Background Technology

[0002] Faced with the increasing depletion of traditional fossil fuels, developing green new energy sources and upgrading energy storage and conversion equipment are crucial directions for achieving sustainable global economic and social development. With the widespread application of lithium-ion batteries, while stringent requirements are placed on electrode material performance, controlling the manufacturing cost of these materials is equally important. As a core component of lithium-ion batteries, the anode material affects battery capacity and cycle performance, directly limiting their electrochemical performance. Currently, commercially available lithium-ion battery anode materials are primarily graphite-based. With the increasing depletion of natural graphite resources, artificial graphite has attracted widespread attention as an important supplement to anode materials. Although artificial graphite anodes exhibit excellent electrochemical performance, their high manufacturing cost limits their commercial application. Therefore, replacing existing anode materials with lower manufacturing costs and superior electrochemical performance is urgently needed.

[0003] In the field of new energy materials, anthracite can replace (or partially replace) needle coke, petroleum coke, and other raw materials in the preparation of lithium-ion battery anode materials, thereby expanding the application of high-quality anthracite in high-value-added industries. However, due to inherent defects in anthracite itself, it cannot be directly used as electrode material, as impurities in anthracite severely affect the electrochemical performance of anode materials. Advanced anthracite purification processes are one of the keys to eliminating the adverse effects of impurities on the performance of anode materials.

[0004] Chinese patent (CN115621462 A) discloses a method for preparing coal-derived carbon nanosheets as lithium-ion battery anode materials. Using amorphous carbon as a raw material, the method employs a chloride-activated carbonization process to prepare coal-derived amorphous carbon nanomaterials. This patent uses chloride as a catalyst; during the chloride-activated carbonization process, not only are the layered macromolecules continuously assembled into nanosheet structures, but the carbon atoms also undergo disordered arrangement during assembly, forming an amorphous phase structure. However, no impurity removal treatment is performed, resulting in poor conductivity and affecting the subsequent electrochemical performance of the lithium-ion battery material.

[0005] Chinese patent (CN118993056A) discloses a fast-charging coal-based graphite material and its preparation and application methods. The steps are as follows: Coal powder with a particle size of 0.5~3.0 mm is physically sorted and dried to obtain a sorted coal sample; secondary crushing and sieving are performed to obtain coal powder with a particle size less than 0.074 mm; acid washing, water washing until neutral, and drying are performed to obtain an ultrapure coal sample with an ash content of less than 0.5 wt%; the ultrapure coal sample is graphitized under a micro-positive pressure of 20~30 kPa and an inert atmosphere to obtain the coal-based graphite material. This process has a short flow rate, but it suffers from problems such as high acid consumption and difficulty in treating waste liquid.

[0006] In existing technologies, the graphitization of finely crushed anthracite coal directly results in a graphitized product with a fixed carbon content of only about 98% and a high ash content, which reduces the material's electrical conductivity. During the graphitization process, impurities may induce side reactions, reducing the initial coulombic efficiency and charge / discharge capacity. At the same time, the graphite layer is not fully developed, and the electron and ion transport channels are not ideal, resulting in the electrochemical performance of lithium batteries being inferior to that of soft carbon materials such as needle coke. Summary of the Invention

[0007] To address the technical problems in existing technologies, such as the fact that "the fixed carbon content of the product after graphitization of finely crushed anthracite is only around 98%, the ash content is too high, reducing the conductivity stability of the material, and impurities may induce side reactions during graphitization, reducing the initial coulombic efficiency and charge / discharge capacity; at the same time, the graphite layer is not fully developed, the electron and ion transport channels are not ideal, and the electrochemical performance of the prepared lithium battery is not as good as that of soft carbon materials such as needle coke," the purpose of this invention is to provide a method for preparing lithium battery anode materials using anthracite and its application. The above method achieves efficient removal of anthracite ash, avoids the influence of impurities on electrochemical performance, promotes the nucleation and growth of the graphite layer, and thus enhances its electrochemical performance.

[0008] This invention uses anthracite as raw material. First, it refines particle size, increases specific surface area, and shortens mass transfer paths through crushing, providing favorable conditions for subsequent vacuum roasting and impurity removal. Then, vacuum roasting is performed under the action of alkaline additives, activating, loosening, or transforming mineral impurities in the coal, while simultaneously promoting volatile matter removal and preliminary carbon structure remodeling. After acid leaching, the inorganic ash exposed or activated during roasting is further dissolved and removed, effectively reducing impurity content, increasing fixed carbon content, and creating space for subsequent carbon microcrystalline structure reconstruction. Finally, high-temperature graphitization is performed under the catalysis of direct reduced iron, reduced iron powder, or nickel powder, promoting carbon atom migration and the nucleation and growth of graphite layers, improving the orderliness and conductivity of the carbon material's microcrystalline structure, thereby improving its lithium storage performance, charge / discharge capacity, and coulombic efficiency.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] This invention provides a method for preparing lithium-ion battery anode materials using anthracite and its application, comprising the following steps:

[0011] S1. Crush the anthracite to a set particle size to obtain finely crushed anthracite;

[0012] S2. The finely crushed anthracite obtained in step S1 is mixed with alkaline additives and placed in a vacuum furnace for vacuum roasting to obtain a roasted sample.

[0013] S3. The roasted sample obtained in step S2 is subjected to acid leaching to remove impurities, and high-purity anthracite is obtained.

[0014] S4. The high-purity anthracite obtained in step S3 is mixed with the catalyst and graphitized to obtain the lithium battery anode material.

[0015] In a preferred embodiment, in step S2, the alkaline additive is one or more of sodium hydroxide, sodium carbonate, potassium hydroxide, and potassium carbonate, and the amount added is 10-20 wt.% of the anthracite.

[0016] In the preferred embodiment, in step S4, the catalyst is one or more of direct reduced iron (DRI), reduced iron powder, and nickel powder, and its addition amount is 10-20 wt.% of high-purity anthracite.

[0017] In the preferred embodiment, step S1 involves a two-stage crushing process for anthracite coal, specifically as follows:

[0018] The first stage of crushing is coarse crushing, using a jaw crusher to crush the anthracite, with the particle size controlled at -3 mm. The coarsely crushed anthracite is then further crushed by a high-pressure roller mill, with the particle size of the finely crushed anthracite controlled at D... max ≤70 μm, D 50 ≤20 μm.

[0019] In the preferred embodiment, in step S2, the vacuum calcination temperature is 850~950 ℃, the vacuum degree is less than 50 Pa, and the calcination time is 60~120 min.

[0020] In the preferred embodiment, in step S3, the acid added during the acid leaching process is one or more of hydrochloric acid, phosphoric acid, and nitric acid, and the acid concentration is 10~20 wt.%.

[0021] In the preferred embodiment, in step S3, the acid leaching temperature is 70~90 ℃, the acid leaching time is 30~120 min, and the liquid-solid mass ratio is 3~10 ml / g.

[0022] In the preferred embodiment, in step S4, the graphitization temperature is 2400~2800 ℃, the graphitization time is 90~240 min, the atmosphere is argon, and the pressure is controlled at 2.0~4.0 kPa.

[0023] The present invention also provides the application of the lithium battery anode material product, which is used to prepare lithium battery anodes.

[0024] Compared with the prior art, the advantages of the present invention are as follows:

[0025] 1) This invention discloses a method for preparing lithium battery anode materials using anthracite and its application. The method uses a high-pressure roller mill to finely crush the anthracite, thereby increasing its specific surface area and surface activity. In addition, the microcracks generated are beneficial to the subsequent vacuum roasting-acid leaching process for removing impurities.

[0026] 2) This invention discloses a method for preparing lithium-ion battery anode materials using anthracite and its application. The method employs an "alkaline additive + vacuum roasting" process to pretreat finely crushed anthracite. The alkaline additive reacts with components such as Al2O3, SiO2, and Fe2O3 in the ash to generate acid-soluble aluminates, silicates, and ferrates. Simultaneously, it disrupts the morphology of inclusions, facilitating subsequent leaching. Vacuum roasting effectively reduces the required oxygen partial pressure and induces changes in mineral composition, structural activation, and porosity reconstruction. Furthermore, vacuum roasting effectively reduces carbon loss and increases yield.

[0027] 3) This invention discloses a method for preparing lithium-ion battery anode materials using anthracite and its application. Direct reduced iron (DRI), reduced iron powder, and nickel powder are used as catalysts. At high temperatures, the reduced iron and nickel powder promote the transformation of disordered carbon in the anthracite into ordered graphitic microcrystals, increasing graphitization and conductivity, thereby improving lithium storage performance. During the heating process, DRI can come into close contact with the anthracite, promoting carbon structure rearrangement. The catalyst eventually volatilizes at high temperatures. Simultaneously, DRI often has a porous structure, which improves the contact area and local mass transfer. Its advantages include low cost, wide availability, and good industrial scale-up potential. Attached Figure Description

[0028] Figure 1 This is a process flow diagram of the present invention for preparing lithium battery anode materials using anthracite;

[0029] Figure 2 The images shown are SEM and TEM images of the negative electrode material in Example 1.

[0030] Wherein, (a): SEM, (b): TEM;

[0031] Figure 3 Here are the XRD and Raman spectroscopy images of the negative electrode material in Example 1:

[0032] Where, (a): XRD, (b): Raman;

[0033] Figure 4This is a rate performance diagram of the lithium battery in Example 1. Detailed Implementation

[0034] To further illustrate the content of this invention, the following description will be made more fully and in detail with reference to preferred embodiments, but the scope of protection of this invention is not limited to the following specific embodiments.

[0035] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0036] In the following comparative examples and embodiments, the raw material used was Taixi anthracite, with a fixed carbon content of 88.92%, volatile matter of 6.97%, and ash content of 2.44%. The lump anthracite was crushed to a particle size of -3 mm using a jaw crusher, and then processed by a high-pressure roller mill to obtain D... max It is 68.21 μm, D 50 It is a powdery anthracite with a particle size of 19.87 μm.

[0037] The present invention will be further described below with reference to specific embodiments and accompanying drawings:

[0038] Comparative Example 1: Direct Processing of Raw Coal

[0039] Powdered anthracite was used as raw material and directly graphitized at a temperature of 2800℃ for 120 min under an argon atmosphere at a pressure of 3.0 kPa to obtain lithium-ion battery anode material. Industrial analysis and graphitization degree testing revealed an ash content of 1.64% and a graphitization degree of 63%.

[0040] Lithium-ion battery anode material, acetylene black, and PVDF were mixed uniformly in an 8:1:1 ratio using NMP as the solvent. The positive electrode was coated onto a flat aluminum foil (the negative electrode onto a copper foil), and vacuum dried at 80°C for at least 12 hours. The resulting sheets were then punched into 12mm diameter plates. The active material loading was calculated by weighing. CR2032 coin cells were assembled in a high-purity argon glove box, using lithium-ion sheets as the counter electrode, Celgard 2400 polymer membrane as the separator, and 1mol / L LiPF6 (EC:DMC:DEC = 1:1:1) as the electrolyte. After standing for 12 hours, the cells were tested. With a theoretical capacity of 372 mAh / g, measured at a current density of 0.1C, the initial discharge specific capacity was 309.43 mAh / g, the initial charge / discharge efficiency was 81.98%, and the 10C discharge specific capacity was 32.04 mAh / g.

[0041] Comparative Example 2: Raw coal + vacuum roasting

[0042] Using the aforementioned powdered anthracite as raw material, the material was first subjected to vacuum roasting at 900℃, a vacuum degree of 45 Pa, and a roasting time of 120 min. Then, it underwent graphitization treatment at 2800℃ for 120 min in an argon atmosphere at a controlled pressure of 3.0 kPa to obtain the lithium-ion battery anode material. Industrial analysis and graphitization degree testing revealed an ash content of 1.53% and a graphitization degree of 82%.

[0043] Lithium-ion battery anode material, acetylene black, and PVDF were mixed uniformly in an 8:1:1 ratio using NMP as the solvent. The positive electrode was coated onto a flat aluminum foil (the negative electrode onto a copper foil), and vacuum dried at 80°C for at least 12 hours. The resulting electrode sheets were then punched into 12 mm diameter sheets. The active material loading was calculated by weighing. CR2032 coin cells were assembled in a high-purity argon glove box, using lithium foil as the counter electrode, Celgard 2400 polymer membrane as the separator, and 1 mol / L LiPF6 (EC:DMC:DEC = 1:1:1) as the electrolyte. After standing for 12 hours, the cells were tested. With a theoretical capacity of 372 mAh / g, the initial discharge specific capacity was measured at a current density of 0.1C: 291.53 mAh / g, the initial charge / discharge efficiency was 82.02%, and the 10C discharge specific capacity was 27.90 mAh / g.

[0044] Example 1

[0045] Using the above-mentioned powdered anthracite as raw material, 10 wt.% NaOH was added, and after thorough mixing, the mixture was placed in a vacuum furnace for roasting at a temperature of 900℃, a vacuum degree of 38 Pa, and a roasting time of 120 min. The roasted sample was then acid-washed with a 20 wt.% hydrochloric acid solution to remove impurities at a temperature of 90℃ for 120 min, with a liquid-to-solid mass ratio of 8 ml / g. The purified sample was then placed in a vacuum oven and dried to constant weight at 60℃. After drying, 10 wt.% direct reduced iron (particle size D) was added to the sample. max The material (74.5 μm, Fe content 94 wt.%) was thoroughly mixed and then graphitized at 2800℃ for 120 min under argon atmosphere and pressure of 3.0 kPa to obtain the lithium-ion battery anode material. Industrial analysis and graphitization degree testing revealed an ash content of 0.05% and a graphitization degree of 90%.

[0046] Lithium-ion battery anode material, acetylene black, and PVDF were mixed uniformly in an 8:1:1 ratio using NMP as the solvent. The positive electrode was coated onto a flat aluminum foil (the negative electrode onto a copper foil), and vacuum dried at 80°C for at least 12 hours. The resulting sheets were then punched into 12 mm diameter plates. The active material loading was calculated by weighing. CR2032 coin cells were assembled in a high-purity argon glove box, using lithium-ion sheets as the counter electrode, Celgard 2400 polymer membrane as the separator, and 1 mol / L LiPF6 (EC:DMC:DEC = 1:1:1) as the electrolyte. After standing for 12 hours, the cells were tested. With a theoretical capacity of 372 mAh / g, the initial discharge specific capacity was measured at a current density of 0.1C: 338.22 mAh / g, the initial charge / discharge efficiency was 86.46%, and the 10C discharge specific capacity was 29.96 mAh / g.

[0047] Example 2

[0048] Using the above-mentioned powdered anthracite as raw material, 15 wt.% NaOH was added, and after thorough mixing, the mixture was placed in a vacuum furnace for roasting at a temperature of 900℃, a vacuum degree of 42 Pa, and a roasting time of 120 min. The roasted sample was then acid-washed with a 20 wt.% nitric acid solution to remove impurities at a temperature of 90℃ for 120 min, with a liquid-to-solid mass ratio of 8 ml / g. The purified sample was then placed in a vacuum oven and dried to constant weight at 60℃. After drying, 20 wt.% reduced iron powder (particle size D) was added to the sample. max The material (74.5 μm, Fe content 99 wt.%) was thoroughly mixed and then graphitized at 2800℃ for 240 min under argon atmosphere and pressure of 3.0 kPa to obtain the lithium-ion battery anode material. Industrial analysis and graphitization degree testing revealed an ash content of 0.01% and a graphitization degree of 92%.

[0049] Lithium-ion battery anode material, acetylene black, and PVDF were mixed uniformly in an 8:1:1 ratio using NMP as solvent. The positive electrode was coated onto a flat aluminum foil (the negative electrode onto a copper foil), and vacuum dried at 80°C for at least 12 hours. The resulting sheets were then punched into 12 mm diameter plates. The active material loading was calculated by weighing. CR2032 coin cells were assembled in a high-purity argon glove box, using lithium-ion sheets as the counter electrode, Celgard 2400 polymer membrane as the separator, and 1 mol / L LiPF6 (EC:DMC:DEC = 1:1:1) as the electrolyte. After standing for 12 hours, the cells were tested. With a theoretical capacity of 372 mAh / g, the initial discharge specific capacity was measured at a current density of 0.1C: 341.21 mAh / g, the initial charge / discharge efficiency was 86.91%, and the 10C discharge specific capacity was 37.21 mAh / g.

[0050] Example 3

[0051] Using the above-mentioned powdered anthracite as raw material, 15 wt.% KOH was added, and after thorough mixing, the mixture was placed in a vacuum furnace for roasting at a temperature of 900℃, a vacuum degree of 30 Pa, and a roasting time of 120 min. The roasted sample was then acid-washed to remove impurities using a 20 wt.% phosphoric acid solution + hydrochloric acid solution (phosphoric acid: hydrochloric acid = 1:4) at a temperature of 90℃ for 120 min, with a liquid-to-solid mass ratio of 8 ml / g. The purified sample was then placed in a vacuum oven and dried to constant weight at 60℃. After drying, 15 wt.% direct reduced iron (particle size D) was added to the sample. max The material (74.5 μm, Fe content 98 wt.%) was thoroughly mixed and then graphitized at 2600℃ for 90 min under argon atmosphere and pressure of 3.0 kPa to obtain the lithium-ion battery anode material. Industrial analysis and graphitization degree testing revealed an ash content of 0.04% and a graphitization degree of 90%.

[0052] Lithium-ion battery anode material, acetylene black, and PVDF were mixed uniformly in an 8:1:1 ratio using NMP as the solvent. The positive electrode was coated onto a flat aluminum foil (the negative electrode onto a copper foil), and vacuum dried at 80°C for at least 12 hours. The resulting sheets were then punched into 12 mm diameter plates. The active material loading was calculated by weighing. CR2032 coin cells were assembled in a high-purity argon glove box, using lithium foil as the counter electrode, Celgard 2400 polymer membrane as the separator, and 1 mol / L LiPF6 (EC:DMC:DEC = 1:1:1) as the electrolyte. After standing for 12 hours, the cells were tested. With a theoretical capacity of 372 mAh / g, the initial discharge specific capacity was measured at a current density of 0.1C: 339.15 mAh / g, the initial charge / discharge efficiency was 87.03%, and the 10C discharge specific capacity was 33.56 mAh / g.

[0053] Example 4

[0054] Using the above-mentioned powdered anthracite as raw material, 10 wt.% NaOH was added, and after thorough mixing, the mixture was placed in a vacuum furnace for roasting at a temperature of 900℃, a vacuum degree of 38 Pa, and a roasting time of 120 min. The roasted sample was then acid-washed with a 15 wt.% phosphoric acid solution to remove impurities at a temperature of 90℃ for 120 min, with a liquid-to-solid mass ratio of 8 ml / g. The purified sample was then placed in a vacuum oven and dried to constant weight at 60℃. After drying, 20 wt.% nickel powder (particle size D) was added to the sample. maxThe material (74.5 μm, Ni content 99.5 wt.%) was thoroughly mixed and then graphitized at 2650℃ for 180 min under argon atmosphere and pressure of 3.0 kPa to obtain the lithium-ion battery anode material. Industrial analysis and graphitization degree testing revealed an ash content of 0.05% and a graphitization degree of 90%.

[0055] Lithium-ion battery anode material, acetylene black, and PVDF were mixed uniformly in an 8:1:1 ratio using NMP as the solvent. The positive electrode was coated onto a flat aluminum foil (the negative electrode onto a copper foil), and vacuum dried at 80°C for at least 12 hours. The resulting sheets were then punched into 12 mm diameter plates. The active material loading was calculated by weighing. CR2032 coin cells were assembled in a high-purity argon glove box, using a lithium-ion sheet as the counter electrode, a Celgard 2400 polymer membrane as the separator, and 1 mol / L LiPF6 (EC:DMC:DEC = 1:1:1) as the electrolyte. After standing for 12 hours, the cells were tested. With a theoretical capacity of 372 mAh / g, the initial discharge specific capacity was measured at a current density of 0.1C: 337.94 mAh / g, the initial charge / discharge efficiency was 85.78%, and the 10C discharge specific capacity was 36.86 mAh / g.

[0056] Example 5

[0057] Using the above-mentioned powdered anthracite as raw material, 20 wt.% NaOH was added, and after thorough mixing, the mixture was placed in a vacuum furnace for roasting at a temperature of 900℃, a vacuum degree of 38 Pa, and a roasting time of 120 min. The roasted sample was then acid-washed with a 10 wt.% hydrochloric acid solution to remove impurities at a temperature of 90℃ for 120 min, with a liquid-to-solid mass ratio of 8 ml / g. The purified sample was then placed in a vacuum oven and dried to constant weight at 60℃. After drying, 20 wt.% direct reduced iron + nickel powder (reduced iron powder: nickel powder = 8:2) (particle size D) was added to the sample. max The nickel powder (74.5 μm, Fe content 98 wt.%; Ni content 99.5%) was thoroughly mixed and then graphitized at 2400℃ for 240 min under argon atmosphere and pressure controlled at 3.0 kPa to obtain the lithium-ion battery anode material. Industrial analysis and graphitization degree testing revealed an ash content of 0.05% and a graphitization degree of 93%.

[0058] Lithium-ion battery anode material, acetylene black, and PVDF were mixed uniformly in an 8:1:1 ratio using NMP as the solvent. The positive electrode was coated onto a flat aluminum foil (the negative electrode onto a copper foil), and vacuum dried at 80°C for at least 12 hours. The resulting sheets were then punched into 12 mm diameter plates. The active material loading was calculated by weighing. CR2032 coin cells were assembled in a high-purity argon glove box, using lithium-ion sheets as the counter electrode, Celgard 2400 polymer membrane as the separator, and 1 mol / L LiPF6 (EC:DMC:DEC = 1:1:1) as the electrolyte. After standing for 12 hours, the cells were tested. With a theoretical capacity of 372 mAh / g, the initial discharge specific capacity was measured at a current density of 0.1C: 343.33 mAh / g, the initial charge / discharge efficiency was 87.54%, and the 10C discharge specific capacity was 31.23 mAh / g.

[0059] Table 1 Electrochemical performance of lithium batteries in Comparative Examples 1-2 and Examples 1-5

[0060] 0.1C initial discharge specific capacity (mAh / g) First charge and discharge efficiency 10C discharge specific capacity (mAh / g) Comparative Example 1 309.43 81.98% 32.04 Comparative Example 2 291.53 82.02% 27.90 Example 1 338.22 86.46% 29.96 Example 2 341.21 86.91% 37.21 Example 3 339.15 87.03 % 33.56 Example 4 337.94 85.78% 36.86 Example 5 343.33 87.54% 31.23

[0061] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing lithium-ion battery anode materials using anthracite, characterized in that, Includes the following steps: S1. Crush the anthracite to a set particle size to obtain finely crushed anthracite; S2. The finely crushed anthracite obtained in step S1 is mixed with alkaline additives and placed in a vacuum furnace for vacuum roasting to obtain a roasted sample. S3. The roasted sample obtained in step S2 is subjected to acid leaching to remove impurities, and high-purity anthracite is obtained. S4. The high-purity anthracite obtained in step S3 is mixed with the catalyst and graphitized to obtain the lithium battery anode material.

2. The method for preparing lithium battery anode materials using anthracite according to claim 1, characterized in that, In step S2, the alkaline additive is one or more of sodium hydroxide, sodium carbonate, potassium hydroxide, and potassium carbonate, and its addition amount is 10-20 wt.% of anthracite.

3. The method for preparing lithium battery anode materials using anthracite according to claim 1, characterized in that, In step S4, the catalyst is one or more of direct reduced iron (DRI), reduced iron powder, and nickel powder, and its addition amount is 10-20 wt.% of high-purity anthracite.

4. The method for preparing lithium battery anode materials using anthracite according to claim 1, characterized in that, In step S1, the anthracite crushing adopts a two-stage crushing process, specifically as follows: The first stage of crushing is coarse crushing, using a jaw crusher to crush the anthracite, with the particle size controlled at -3 mm. The coarsely crushed anthracite is then further crushed by a high-pressure roller mill, with the particle size of the finely crushed anthracite controlled at D... max ≤70 μm, D 50 ≤20 μm.

5. The method for preparing lithium battery anode materials using anthracite according to claim 1, characterized in that, In step S2, the vacuum calcination temperature is 850~950 ℃, the vacuum degree is less than 50 Pa, and the calcination time is 60~120 min.

6. The method for preparing lithium battery anode materials using anthracite according to claim 1, characterized in that, In step S3, the acid added during the acid leaching process is one or more of hydrochloric acid, phosphoric acid, and nitric acid, and the acid concentration is 10~20 wt.%.

7. The method for preparing lithium battery anode materials using anthracite according to claim 1, characterized in that, In step S3, the acid leaching temperature is 70~90 ℃, the acid leaching time is 30~120 min, and the liquid-to-solid mass ratio is 3~10 ml / g.

8. The method for preparing lithium battery anode materials using anthracite according to claim 1, characterized in that, In step S4, the graphitization temperature is 2400~2800 ℃, the graphitization time is 90~240 min, the atmosphere is argon, and the pressure is controlled at 2.0~4.0 kPa.

9. A lithium-ion battery anode material product, characterized in that, It is prepared using the method for preparing lithium battery anode materials from anthracite as described in any one of claims 1 to 8.

10. The application of the lithium-ion battery anode material product according to claim 9, characterized in that, It is used to prepare lithium battery anodes.

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