A kind of artificial graphite negative electrode material and preparation method thereof, lithium ion battery

Abstract

The invention discloses a method for preparing a high-energy-density-magnification artificial graphite negative electrode material, which comprises the following steps: raw material coke is directly crushed and pulverized or pulverized after high-temperature modification after coarse crushing, and the primary particle A is obtained by shaping treatment; The primary granule A is kneaded with the organic carbon source, then dynamically thermally coated and sieved to obtain the primary granule B; the primary granule A and the binder are evenly mixed, then placed in a granulation reactor for granulation, and sieved to obtain the secondary granule B. Particle C; graphitize primary particle B and secondary particle C respectively, and sieve to obtain graphitized primary particle B and graphitized secondary particle C; graphitized primary particle B and graphitized secondary particle C are proportional Mix evenly and sieve to get the finished product. The preparation method has simple process and easy quality control; the artificial graphite negative electrode material prepared by the above method is applied to a lithium ion battery, and the lithium ion battery has high capacity, good cycle and excellent fast charging performance.

Description

technical field [0001] The invention relates to the technical field of negative electrode materials for lithium ion batteries, in particular to artificial graphite negative electrode materials, a preparation method thereof, and lithium ion batteries. Background technique [0002] As the most widely used driving force source for mobile digital terminals (mobile phones, tablets, notebooks) and new wearable devices, lithium-ion batteries have been maturely used for nearly 20 years. While people are pursuing ultra-long standby time of mobile devices, their charging time requirements are becoming more and more stringent. With the rapid development of electric vehicles, people are eager for electric vehicles to have fast charging performance while having long battery life. Therefore, the demand for high-capacity and high-rate lithium-ion batteries is increasing year by year. [0003] For a long time, increasing the capacity of artificial graphite, compacting, reducing expansion,...

AI Technical Summary

Problems solved by technology

Secondary particle coating carbonization can obtain high-capacity and high-rate materials, but there are problems such as poor coating uniformity, significant re-bonding phenomenon, and low yield, which seriously affect the processing performance of the material

[0004] In order to solve the above problems, the patent 201710683450.9 discloses a fast-charging graphite anode material and its preparation method, through mixing the graphite precursor with the coating material, low-temperature treatment and high-temperature graphitization treatment, but lacks the secondary granulation process and surface modification The improvement effect of ion diffusion path and interface is limited, the energy density is not high, and the improvement of fast charging performance is not obvious.

Patent 201711333907.X discloses a method for preparing a high-capacity and high-rate composite graphite anode material. By mixing graphite precursors with mesocarbon microspheres and co-granulating and graphitizing, although the kinetic level of the material is improved, However, the energy density is low and the preparation cost is high

Patent 201810939161.5 discloses a method for making high-rate fast-charging graphite anode materials. First, the graphite precursor is crushed and graphitized, and then fused with a binder for carbonization. Although the process is relatively simple, the coating of graphite monomer particles is not uniform. , there are many active sites in the carbonized structure, and the high temperature stability is insufficient

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