A graphite negative electrode material, its preparation method and use

Abstract

The present invention provides a graphite anode material, a preparation method thereof and uses thereof. The preparation method comprises the following steps: mixing a first petroleum coke raw material and a second petroleum coke raw material, granulating, graphitizing, and carbon coating to obtain the graphite anode material; wherein, the content of aromatic phenol in the first petroleum coke raw material is 30-50%, and the content of volatile matter is 2-5%; the polarized light photograph of the first petroleum coke raw material satisfies that the volume proportion of the watershed structure is 70-90%. By defining the watershed structure in the petroleum coke raw material, the graphitized anode material has better isotropy, faster lithium ion insertion and extraction, and better fast charging performance. The content of aromatic phenol ensures the capacity level of the anode material, and the content of volatile matter ensures the appropriate porosity of the anode material, greatly reducing the treatment of the subsequent process; at the same time, the petroleum coke with high volatile matter is used as a binder for granulation, reducing the capacity loss of the material and ensuring the fast charging performance of the material.

Description

Technical Field

[0001] The present invention belongs to the technical field of graphite anode materials, and relates to a graphite anode material, a preparation method thereof and uses thereof. Background Art

[0002] With the continuous development of lithium-ion battery technology and the continuous expansion of application fields, higher requirements are put forward for battery technology. At present, the development of high specific energy and high power lithium-ion batteries has become an irresistible social trend. The main reasons are as follows: To provide battery technology for the rapidly growing new energy vehicles, the battery performance is required to meet the requirements of fast charging, high power, long cruising range, safety, etc. for automobiles; the incentive policies and higher standards for the energy density of power lithium-ion batteries have further promoted the development of high energy density and high power battery technology.

[0003] At present, one of the problems in replacing traditional fuel vehicles with new energy vehicles is time. Traditional fuel vehicles can drive away immediately after refueling, while new energy vehicles have a long charging time, which greatly limits the universality and convenience of new energy vehicles. Therefore, the anode of fast-charging lithium-ion batteries plays an irreplaceable role in batteries. Most scientific researchers improve the fast-charging performance of anode materials from the following aspects: 1. Particle refinement: reducing the particle size of the anode particles to a small enough size to shorten the transmission path of lithium ions and improve the embedding speed of lithium ions, thereby improving the fast-charging performance of the material; 2. Carbon coating: coating a layer of amorphous carbon on the surface of the anode material to prevent direct contact between the graphite active material and the electrolyte, thereby reducing the occurrence of side reactions and improving the rate performance of the material; in addition, carbon coating can also improve the OI value of the material and increase the isotropy of the material, that is, increase the lithium ion embedding channels and improve the fast-charging performance of the material; 3. Granulation: refining the particles and then bonding each part with pitch to improve the isotropy of the material, thereby improving the fast-charging performance of the material. These traditional improvement methods have great defects. In the actual application process, the fast-charging performance of the material is improved, but the capacity of the material is sacrificed, resulting in a significant reduction in the energy density of the battery; in addition, when the fast-charging requirements are raised higher, such as charging at 5C, 6C, etc., these improvement means far cannot meet the requirements and cannot reach the target value.

[0004] JP10294111 and CN105024043A both use natural graphite as raw materials and improve the fast-charging performance of graphite anodes by coating and granulation respectively. However, the cycle performance of natural graphite itself is inferior to that of artificial graphite, so its scope of application is small. CN106981632A uses pitch coke or petroleum coke as raw materials and obtains a fast-charging graphite anode material by granulating first and then coating. This material also avoids the problem of poor cycle performance of natural graphite. However, this process has complicated steps and high production costs, and is only applicable to high-end lithium-ion batteries.

[0005] CN108328614A discloses a graphite anode material for fast-charging lithium-ion batteries and a preparation method thereof. After mixing, kneading, carbonizing, and subjecting a carbon material and pitch to high-temperature graphitization treatment, a composite graphite material with a secondary particle structure is obtained. Since the surface of the particles becomes highly ordered after graphitization treatment, it has a negative impact on the fast-charging performance.

[0006] Therefore, how to improve the fast-charging performance of the graphite anode material while ensuring the stability of other electrochemical properties is a technical problem to be urgently solved. Summary of the Invention

[0007] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a graphite anode material, a preparation method thereof, and uses thereof. By defining the zonal structure in the petroleum coke raw material, the obtained anode material after graphitization has better isotropy, faster lithium-ion insertion and extraction, and better fast-charging performance. The content of aromatic phenols ensures the capacity level of the anode material, and the content of volatile matter ensures an appropriate porosity of the anode material, significantly reducing the processing of the subsequent process; at the same time, using petroleum coke with a high volatile content as a binder for granulation reduces the capacity loss of the material while ensuring the fast-charging performance of the material.

[0008] To achieve this purpose, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a preparation method of a graphite anode material, the preparation method comprising the following steps:

[0010] Mixing a first petroleum coke raw material and a second petroleum coke raw material, granulating, subjecting to graphitization treatment, and carbon coating to obtain the graphite anode material;

[0011] Wherein, the content of aromatic phenols in the first petroleum coke raw material is 30-50%, such as 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49% or 50%, etc., and the content of volatile matter is 2-5%, such as 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5%, etc.;

[0012] The polarized light photograph of the first petroleum coke raw material satisfies that the volume ratio of the zonal structure is 70-90%, such as 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89% or 90%, etc.

[0013] In the present invention, the polarized light photograph structure of the petroleum coke raw material can refer to the literature: Discussion on the Method of Quantitative Analysis of the Microstructure of Needle Coke by Polarized Light Microscopy by Tian Lingyan et al. [J]. Carbon Technology, 2010, 2(29)..

[0014] In the present invention, by defining the zonal structure in the petroleum coke raw material, the graphitized anode material has better isotropy, faster lithium ion insertion and extraction, better fast charging performance. The content of aromatic phenols ensures the capacity level of the anode material, and the content of volatile matter ensures the appropriate porosity of the anode material, greatly reducing the treatment of the subsequent process; at the same time, using petroleum coke with high volatile matter as the binder for granulation reduces the capacity loss of the material and also ensures the fast charging performance of the material.

[0015] In the present invention, selecting the petroleum coke raw material can better achieve the fast charging performance of the material. If other types of coke materials, such as needle coke, are selected, problems such as rapid capacity decay and lithium deposition on the cross-section will occur during high-rate charging.

[0016] In the present invention, if the asphalt material is used to replace the second petroleum coke raw material, it is difficult to achieve the affinity between petroleum cokes and the problem of poor coating effect.

[0017] Preferably, the median particle size of the first petroleum coke raw material is 7 - 10 μm, such as 7 μm, 8 μm, 9 μm or 10 μm, etc.

[0018] Preferably, the polarized light photograph of the first petroleum coke raw material further satisfies that the volume fraction of the mosaic structure is 10 - 15%, such as 10%, 11%, 12%, 13%, 14% or 15%, etc., and the volume fraction of the fibrous tissue structure is 10 - 15%, such as 10%, 11%, 12%, 13%, 14% or 15%, etc.

[0019] In the present invention, the polarized light photograph of the first petroleum coke raw material further satisfies that the volume fraction of the mosaic structure is 10 - 15% and the volume fraction of the fibrous tissue structure is 10 - 15%, which can better improve the fast charging performance of the material on the basis of ensuring the capacity of the anode material;

[0020] In the present invention, the mosaic structure is beneficial to the long cycle performance; the fibrous tissue structure plays a role in ensuring the capacity level. If the fibrous tissue structure is too small, the fast charging performance will be extremely good but the capacity of the material will be extremely low, resulting in an extremely low energy density of the battery.

[0021] Preferably, the content of volatile matter in the second petroleum coke raw material is 9 - 15%, such as 9%, 10%, 11%, 12%, 13%, 14% or 15%, etc.

[0022] In the present invention, if the content of volatile matter in the second petroleum coke raw material is too small, it is not conducive to the coating of the material; if it is too large, it will lead to the inversion of primary and secondary, and the fast charging effect cannot be achieved.

[0023] Preferably, the median particle size of the second petroleum coke raw material is 4 - 9 μm, such as 4 μm, 5 μm, 6 μm, 7 μm, 8 μm or 9 μm, etc.

[0024] In the present invention, small particle-sized petroleum coke raw materials can better achieve the fast charging performance of the finally obtained graphite anode material. Whether it is the first petroleum coke raw material or the second petroleum coke raw material, if the particle size is too large, it will affect the transmission of lithium ions, and the effect of high-rate fast charging cannot be achieved.

[0025] Preferably, the mass ratio of the first petroleum coke raw material to the second petroleum coke raw material is 9:(1 - 3), such as 9:1, 9:1.5, 9:2, 9:2.5 or 9:3, etc.

[0026] In the present invention, if the mass ratio of the first petroleum coke raw material to the second petroleum coke raw material is too large, that is, the second petroleum coke raw material is too little, it will lead to uneven coating, the coating layer is too thin, and the effect of high-rate charging cannot be achieved. If the mass ratio is too small, that is, the second petroleum coke raw material is too much, it is not conducive to the performance of the capacity of the main material.

[0027] Preferably, the temperature of granulation is 900 - 1200 °C, such as 900 °C, 930 °C, 950 °C, 980 °C, 1000 °C, 1030 °C, 1050 °C, 1080 °C, 1100 °C, 1120 °C, 1150 °C, 1180 °C or 1200 °C, etc.

[0028] In the present invention, under the condition that the volatile matter in the second petroleum coke raw material is 9 - 15%, the granulation temperature cannot be too low. If it is too low, the volatile matter cannot be discharged, the adhesiveness of the material becomes poor, and the coating effect becomes poor. That is, the content of volatile matter in the second petroleum coke raw material and the granulation temperature jointly affect the final coating effect through a synergistic effect.

[0029] Preferably, the time of granulation is 6 - 10 h, such as 6 h, 7 h, 8 h, 9 h or 10 h, etc.

[0030] Preferably, the temperature of graphitization treatment is 2800 - 3000 °C, such as 2800 °C, 2900 °C, 3000 °C, 3100 °C or 3200 °C, etc.

[0031] Preferably, the time of graphitization treatment is 10 - 15 h, such as 10 h, 11 h, 12 h, 13 h, 14 h or 15 h, etc.

[0032] Preferably, the method of carbon coating is liquid-phase carbon coating.

[0033] Preferably, the method for liquid-phase carbon coating includes:

[0034] Mixing the granulated material with a liquid-phase carbon source, spray drying, and carbonizing.

[0035] In the present invention, further coating an amorphous carbon layer on the outer layer of the graphitized product further improves the fast charging performance of the material. At the same time, during the spray drying process, in addition to drying the moisture, the material is also spheroidized, further improving the isotropy of the material and being more conducive to the fast charging performance of the anode material.

[0036] Preferably, the liquid-phase carbon source includes a resin-based carbon source.

[0037] Preferably, the residual carbon content of the resin-based carbon source is 10-30%, such as 10%, 12%, 15%, 18%, 20%, 23%, 25%, 28% or 30%, etc.

[0038] In the present invention, selecting a resin-based carbon source, especially a resin-based carbon source with a residual carbon content of 10-30%, can better achieve the coating of the hard carbon layer.

[0039] Preferably, the temperature of the carbonization is 900-1300 °C, such as 900 °C, 1000 °C, 1100 °C, 1200 °C or 1300 °C, etc.

[0040] Preferably, the time of the carbonization is 7-10 h, such as 7 h, 8 h, 9 h or 10 h, etc.

[0041] As a preferred technical solution, the preparation method includes:

[0042] Mixing a first petroleum coke raw material with a median particle size of 7-10 μm and a second petroleum coke raw material with a median particle size of 4-9 μm at a mass ratio of 9:(1-3), granulating at 900-1200 °C for 6-10 h, performing graphitization treatment at 2800-3000 °C for 10-15 h, mixing with a resin-based carbon source with a residual carbon content of 10-30% and the granulated material, spray drying, and carbonizing at 900-1300 °C for 7-10 h to obtain the graphite anode material;

[0043] Among them, the content of aromatic phenols in the first petroleum coke raw material is 30-50%, and the content of volatile components is 2-5%; the polarized light photograph of the first petroleum coke raw material satisfies that the volume ratio of the zonal structure is 70-90%, the volume ratio of the mosaic structure is 10-15%, and the volume ratio of the fibrous tissue structure is 10-15%; the content of volatile components in the second petroleum coke raw material is 9-15%.

[0044] In a second aspect, the present invention provides a graphite anode material, which is prepared by the preparation method of the graphite anode material as described in the first aspect.

[0045] In a third aspect, the present invention further provides a lithium-ion battery, which includes the graphite anode material as described in the second aspect.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] By defining various organizational structures in the polarized light photograph of the petroleum coke raw material, the present invention makes the graphitized anode material more isotropic, the lithium ions are embedded and extracted faster, the fast charging performance is better, the content of aromatic phenol ensures the capacity level of the anode material, and the content of volatile matter ensures the appropriate porosity of the anode material, greatly reducing the treatment of the subsequent process; at the same time, using small-particle-size petroleum coke with high volatile matter as the binder for granulation reduces the capacity loss of the material and also ensures the fast charging performance of the material. With the addition of amorphous carbon layer coating, the isotropy of the material is improved, which is more conducive to the fast charging performance of the anode material. The first discharge capacity of the battery provided by the present invention can reach more than 345 mAh / g at 0.2C; the capacity retention rate can reach more than 79% after the first cycle at 0.2C and then cycling 500 times at 1C; the capacity retention rate can reach more than 73% after the first cycle at 0.2C and then cycling 200 times at 3C; the capacity retention rate can reach more than 70% after the first cycle at 0.2C and then cycling 50 times at 5C. Specific Embodiments

[0048] The technical solutions of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0049] Example 1

[0050] This example provides a preparation method of a graphite anode material, and the preparation method is as follows:

[0051] Put the first petroleum coke raw material (median particle size of 7.5 μm) and the second petroleum coke raw material (median particle size of 5 μm) into a horizontal reaction kettle in a mass ratio of 9:2, granulate at 900 °C, keep warm for 10 h, then carry out graphitization treatment at a graphitization temperature of 2800 °C for 15 h, and then mix with the granulated material using phenolic resin with a residual carbon content of 15%, spray dry, and carbonize at 1000 °C for 8 h to obtain the graphite anode material;

[0052] Among them, the content of aromatic phenol in the first petroleum coke raw material is 40%, and the content of volatile matter is 5%; the polarized light photograph of the first petroleum coke raw material satisfies that the volume ratio of the basin structure is 80%, the volume ratio of the mosaic structure is 10%, and the volume ratio of the fiber tissue structure is 10%; the content of volatile matter in the second petroleum coke raw material is 9%.

[0053] Example 2

[0054] This example provides a preparation method of a graphite anode material, and the preparation method is as follows:

[0055] Put the first petroleum coke raw material (median particle size is 10 μm) and the second petroleum coke raw material (median particle size is 9 μm) into a horizontal reactor in a mass ratio of 9:3, granulate at 1200 °C, keep warm for 6 h, then carry out graphitization treatment at a graphitization temperature of 3000 °C for 15 h, and then mix with the granulated material with an epoxy resin having a residual carbon content of 30%, spray dry, and carbonize at 1300 °C for 7 h to obtain the graphite anode material;

[0056] Among them, the content of aromatic phenol in the first petroleum coke raw material is 30%, and the content of volatile matter is 4%; the polarized light photograph of the first petroleum coke raw material satisfies that the volume ratio of the basin structure is 70%, the volume ratio of the mosaic structure is 15%, and the volume ratio of the fiber tissue structure is 15%; the content of volatile matter in the second petroleum coke raw material is 13%.

[0057] Example 3

[0058] This example provides a preparation method of a graphite anode material, and the preparation method is as follows:

[0059] Put the first petroleum coke raw material (median particle size is 7 μm) and the second petroleum coke raw material (median particle size is 4 μm) into a horizontal reactor in a mass ratio of 9:1, granulate at 1100 °C, keep warm for 8 h, then carry out graphitization treatment at a graphitization temperature of 3100 °C for 13 h, and then mix with the granulated material with an epoxy resin having a residual carbon content of 17%, spray dry, and carbonize at 1300 °C for 10 h to obtain the graphite anode material;

[0060] Among them, the content of aromatic phenol in the first petroleum coke raw material is 50%, and the content of volatile matter is 3%; the polarized light photograph of the first petroleum coke raw material satisfies that the volume ratio of the basin structure is 90%, the volume ratio of the mosaic structure is 5%, and the volume ratio of the fiber tissue structure is 5%; the content of volatile matter in the second petroleum coke raw material is 15%.

[0061] Example 4

[0062] The difference between this embodiment and Embodiment 1 is that in this embodiment, the mass ratio of the first petroleum coke raw material to the second petroleum coke raw material is 9:0.5.

[0063] The remaining preparation methods and parameters are the same as those in Embodiment 1.

[0064] Embodiment 5

[0065] The difference between this embodiment and Embodiment 1 is that in this embodiment, the mass ratio of the first petroleum coke raw material to the second petroleum coke raw material is 9:4.

[0066] The remaining preparation methods and parameters are the same as those in Embodiment 1.

[0067] Embodiment 6

[0068] The difference between this embodiment and Embodiment 1 is that in this embodiment, the volatile content of the second petroleum coke raw material is 5%.

[0069] The remaining preparation methods and parameters are the same as those in Embodiment 1.

[0070] Embodiment 7

[0071] The difference between this embodiment and Embodiment 1 is that in this embodiment, the granulation temperature is 800 °C.

[0072] The remaining preparation methods and parameters are the same as those in Embodiment 1.

[0073] Embodiment 8

[0074] The difference between this embodiment and Embodiment 1 is that in this embodiment, the volume ratio of the fibrous tissue structure is 8%.

[0075] The remaining preparation methods and parameters are the same as those in Embodiment 1.

[0076] Comparative Example 1

[0077] The difference between this comparative example and Embodiment 1 is that in this comparative example, the second petroleum coke raw material is replaced with petroleum pitch.

[0078] The remaining preparation methods and parameters are the same as those in Embodiment 1.

[0079] Comparative Example 2

[0080] The difference between this comparative example and Embodiment 1 is that in this comparative example, the first petroleum coke raw material is replaced with a needle coke raw material.

[0081] The remaining preparation methods and parameters are the same as those in Embodiment 1.

[0082] Comparative Example 3

[0083] The difference between this comparative example and Embodiment 1 is that in this comparative example, the volume ratio of the watershed structure is 50%.

[0084] The remaining preparation methods and parameters are the same as those in Example 1.

[0085] Using the graphite anode materials provided in Examples 1-8 and Comparative Examples 1-3 as the anode active materials, they were mixed with polyvinylidene fluoride in a mass ratio of 98:2, and N-methylpyrrolidone was added to obtain the anode slurry. Then, it was coated on the surface of the copper foil, dried and roll-pressed to obtain the anode electrode sheet, and a coin cell was assembled with a lithium sheet as the counter electrode. A battery with fast-charging graphite as the anode and a lithium sheet as the counter electrode was obtained.

[0086] The batteries of Examples 1-8 and Comparative Examples 1-3 were tested for fast-charging performance, and the test conditions were as follows:

[0087] The voltage range was 0-2V, the initial charge-discharge current was 0.2C, and cycling was carried out at 1C, 3C, and 5C respectively. The results are shown in Table 1.

[0088] Table 1

[0089]

[0090] From the data results of Example 1 and Examples 4 and 5, it can be seen that if the mass ratio of the above-mentioned first petroleum coke raw material to the second petroleum coke raw material is too large, that is, the second petroleum coke raw material is too little, it will lead to uneven coating layer and too thin coating layer, and large-rate charging cannot be carried out. If the mass ratio is too small, that is, the second petroleum coke raw material is too much, it is not conducive to the capacity utilization of the main material.

[0091] From the data results of Example 1 and Example 6, it can be seen that if the content of volatile matter in the second petroleum coke raw material is too low, it is not conducive to the coating of the main material. When the volatile matter is low, the bonding performance during granulation of the material is low, which is not conducive to the coating between the two.

[0092] From the data results of Example 1 and Example 7, it can be seen that if the granulation temperature is too low, it is difficult to discharge the volatile matter, and the coating effect of the material also deteriorates.

[0093] From the data results of Example 1 and Example 8, it can be seen that when the volume ratio of the fibrous tissue structure of the first petroleum coke raw material is too small, although the fast-charging performance can be improved, the capacity level of the material is low and cannot meet the energy density requirements of the battery.

[0094] From the data results of Example 1 and Comparative Example 1, it can be seen that replacing the second petroleum coke raw material with pitch cannot achieve a better coating effect of the material, and the fast-charging performance of the material becomes poor.

[0095] From the data results of Example 1 and Comparative Example 2, it can be seen that replacing the first petroleum coke raw material with a needle coke raw material will cause a problem of rapid deterioration of the fast-charging performance.

[0096] From the data results of Example 1 and Comparative Example 3, it can be seen that the zonal structure of the first petroleum coke raw material is too small, making it difficult to meet the fast charging requirements of the material.

[0097] In summary, by defining various tissue structures in the polarized light photograph of the petroleum coke raw material, the present invention makes the graphitized anode material more isotropic, the lithium ions can be embedded and extracted faster, and the fast charging performance is better. The content of aromatic phenol ensures the capacity level of the anode material, and the content of volatile matter ensures the appropriate porosity of the anode material, greatly reducing the treatment of the backend process; at the same time, small particle size petroleum coke with high volatile matter is used as a binder for granulation, reducing the capacity loss of the material and also ensuring the fast charging performance of the material. Supplementary amorphous carbon layer coating improves the isotropic property of the material and is more conducive to the fast charging performance of the anode material. The first discharge capacity of the battery provided by the present invention can reach more than 345 mAh / g at 0.2C; the capacity retention rate can reach more than 79% after the first cycle at 0.2C and then 500 cycles at 1C; the capacity retention rate can reach more than 73% after the first cycle at 0.2C and then 200 cycles at 3C; the capacity retention rate can reach more than 70% after the first cycle at 0.2C and then 50 cycles at 5C.

[0098] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A preparation method of a graphite anode material, characterized in that, The preparation method includes the following steps: Mix the first petroleum coke raw material and the second petroleum coke raw material, granulate, graphitize, and perform carbon coating to obtain the graphite anode material; Among them, the content of aromatic phenol in the first petroleum coke raw material is 30-50%, and the content of volatile matter is 2-5%; the content of volatile matter in the second petroleum coke raw material is 9-15%; The polarized light photograph of the first petroleum coke raw material satisfies that the volume ratio of the basin structure is 70-90%, the volume ratio of the mosaic structure is 10-15%, and the volume ratio of the fibrous tissue structure is 10-15%.

2. The preparation method of the graphite anode material according to claim 1, characterized in that, The median particle size of the first petroleum coke raw material is 7-10 μm.

3. The preparation method of the graphite negative electrode material according to claim 1, wherein, The median particle size of the second petroleum coke raw material is 4-9 μm.

4. The preparation method of the graphite negative electrode material according to claim 1, wherein, The mass ratio of the first petroleum coke raw material to the second petroleum coke raw material is 9:(1-3).

5. The preparation method of the graphite negative electrode material according to claim 1, wherein The temperature of the granulation is 900-1200 °C.

6. The preparation method of the graphite anode material according to claim 1, characterized in that, The time of the granulation is 6-10 h.

7. The preparation method of the graphite anode material according to claim 1, wherein, The temperature of the graphitization treatment is 2800-3000 °C.

8. The preparation method of the graphite anode material according to claim 1, characterized in that, The time of the graphitization treatment is 10-15 h.

9. The preparation method of the graphite anode material according to claim 1, wherein, The method of the carbon coating is liquid-phase carbon coating.

10. The preparation method of the graphite anode material according to claim 9, characterized in that, The method of the liquid-phase carbon coating includes: Mix the granulated material with a liquid-phase carbon source, spray dry, and carbonize.

11. The preparation method of the graphite anode material according to claim 10, characterized in that, The liquid-phase carbon source includes a resin-based carbon source.

12. The preparation method of the graphite anode material according to claim 11, wherein The residual carbon content of the resin-based carbon source is 10-30%.

13. The preparation method of the graphite anode material according to claim 10, wherein, The temperature of the carbonization is 900-1300 °C.

14. The preparation method of the graphite negative electrode material according to claim 10, characterized in that, The time of the carbonization is 7-10 h.

15. The preparation method of the graphite negative electrode material according to claim 1, characterized in that, The preparation method includes: Mix a first petroleum coke raw material with a median particle size of 7-10 μm and a second petroleum coke raw material with a median particle size of 4-9 μm at a mass ratio of 9:(1-3), granulate at 900-1200 °C for 6-10 h, perform graphitization treatment at 2800-3000 °C for 10-15 h, mix the granulated material with a resin-based carbon source with a residual carbon content of 10-30%, spray dry, and carbonize at 900-1300 °C for 7-10 h to obtain the graphite anode material; Among them, the content of aromatic phenol in the first petroleum coke raw material is 30-50%, and the content of volatile matter is 2-5%; the polarized light photograph of the first petroleum coke raw material satisfies that the volume ratio of the basin structure is 70-90%, the volume ratio of the mosaic structure is 10-15%, and the volume ratio of the fibrous tissue structure is 10-15%; the content of volatile matter in the second petroleum coke raw material is 9-15%.

16. A graphite anode material, characterized in that, The graphite anode material is prepared by the preparation method of the graphite anode material according to any one of claims 1-15.

17. A lithium-ion battery, characterized in that, The lithium-ion battery includes the graphite anode material according to claim 16.

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