Preparation method of graphite negative electrode material as well as product and application of graphite negative electrode material

A graphite negative electrode and graphite technology, applied in the direction of negative electrodes, chemical instruments and methods, battery electrodes, etc., can solve the problems of capacity attenuation, intensified side reactions, and serious polarization of negative electrodes, and achieve lower OI value, long cycle life, and reduced or defect effect

Active Publication Date: 2022-05-13
HUIZHOU LIWINON NEW ENERGY TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The existence of defects will lead to the intensification of side reactions of graphite in the late cycle of the battery, especially the high temperature cycle, resulting in serious polarization of the negative electrode and rapid capacity decay

Method used

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  • Preparation method of graphite negative electrode material as well as product and application of graphite negative electrode material
  • Preparation method of graphite negative electrode material as well as product and application of graphite negative electrode material
  • Preparation method of graphite negative electrode material as well as product and application of graphite negative electrode material

Examples

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preparation example Construction

[0025] The first aspect of the present invention aims to provide a preparation method of graphite negative electrode material, comprising the following steps:

[0026] S1. Choose graphite raw material with D50 of 5-9μm, mix it with oily organic matter, then raise the temperature to 300-400°C at a rate of 2-4°C / min, keep it warm for 70-100min, and then heat it at 2-4°C Raise the temperature at a rate of 620-650°C at a rate of 1 / min, and keep it warm for 60-90 minutes to obtain the coated graphitized precursor;

[0027] S2. Graphitizing the graphitized precursor obtained in step S1 at 2800-3000° C. for 40-55 hours in an inert atmosphere to obtain a graphitized product;

[0028] S3, mixing and granulating the graphitized product obtained in step S2 with pitch to obtain secondary granules;

[0029] S4. Carbonize the secondary particles obtained in step S3 at 1050-1150° C., and then sieve to obtain the graphite negative electrode material.

[0030] Among them, the preparation met...

Embodiment 1

[0050] A preparation method of graphite negative electrode material, comprising the following steps:

[0051] S1. After crushing, grinding and grading the needle-shaped forged coke, obtain graphite raw material with a D50 of 6-8 μm, stir and mix it with coal tar in a horizontal reactor, and the weight of coal tar is 8% of the weight of graphite raw material. %, then at a stirring rate of 15Hz, the temperature was raised to 350°C at a rate of 2-4°C / min, and kept at a temperature of 70-100 minutes, and then the temperature was raised to 640°C at a rate of 2-4°C / min, and held at a rate of 60-90 minutes. obtain the coated graphitized precursor;

[0052] S2. Sieve the graphitized precursor, then put it into a graphite crucible for graphitization treatment, and treat it at 3000° C. for 48 hours in an inert atmosphere to obtain a graphitized product;

[0053] S3. Mix and granulate the obtained graphitized product and low-temperature pitch. The weight of the pitch is 15% of the weigh...

Embodiment 2

[0056] The difference from Example 1 is step S1, the weight of coal tar added in this embodiment is 15% of the weight of graphite raw material.

[0057] The rest are the same as in Embodiment 1, and will not be repeated here.

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Abstract

The invention provides a preparation method of a graphite negative electrode material as well as a product and application of the graphite negative electrode material, the preparation method of firstly coating, then graphitizing and then granulating and carbonizing is adopted, a graphite raw material is subjected to coating treatment in the earlier stage of preparation, coating modification is carried out under specific conditions, and after coating, oil organic matters can be filled in convex-concave corner defects on the surface of the graphite raw material, so that the graphite negative electrode material is prepared. Then graphitization is carried out to convert into a graphite-like crystal structure, so that the purpose of greatly reducing or eliminating defects is achieved, and the subsequent high-temperature cycle performance is ensured; then the graphitized product with few defects and asphalt are granulated, the asphalt can serve as a few binder to guarantee the granulation strength, meanwhile, a secondary coating layer can be formed on the surface of the graphitized product, the OI value of the material is reduced, and the graphite negative electrode material with good charging performance and long cycle life can be obtained after carbonization; therefore, the problem of corner defect of the existing graphite material is solved.

Description

technical field [0001] The invention relates to the field of secondary batteries, in particular to a method for preparing a graphite negative electrode material and its products and applications. Background technique [0002] Lithium-ion batteries have been widely used since their commercialization because of their high energy density, long cycle life, and no memory effect. Graphite has a low lithium intercalation potential and a stable layered structure, and is the most widely used negative electrode material for lithium-ion batteries. With the increasing demand of consumers for lithium-ion batteries with high specific capacity and long cycle life, graphite negative electrodes must also meet the requirements of long cycle life and high capacity. [0003] Generally, high-capacity graphite materials use needle-shaped forged coke as raw material, and the dynamic performance of forged coke is limited. In order to improve good kinetics, the aggregate particle size is usually re...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B32/205H01M4/133H01M4/583H01M10/0525
CPCC01B32/205H01M4/583H01M4/133H01M10/0525C01P2004/03C01P2006/40H01M2004/027Y02E60/10
Inventor 陈杰杨山其他发明人请求不公开姓名
Owner HUIZHOU LIWINON NEW ENERGY TECH CO LTD
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