Method for preparing lithium battery silicon carbide negative electrode composite material

Abstract

The invention discloses a method for preparing a lithium battery silicon carbide negative electrode composite material. The method comprises the following steps: ultrasonically cleaning silicon scrapsin a solvent to clean away surface dirt, and drying the cleaned silicon scraps to obtain a silicon material; crushing the obtained silicon material to a submicron level, and stirring and dispersing obtained silicon particles and a carbon source in a solvent to obtain a uniform turbid solution; carbonizing the obtained turbid solution a high temperature in an inert atmosphere to obtain a silicon carbide powder; and grinding the silicon carbide powder to obtain the lithium battery silicon carbide negative electrode composite material. Liquid state doping in the whole process is simple and is easy to implement; the obtained silicon carbide material is a porous spherical or spheroidal structure, and includes a porous Si-SiOx core and an amorphous carbon shell coating the surface of the core,so the volumetric effect of silicon is greatly improved, and the electrochemical stability is significantly improved; and the preparation method has the advantages of low preparation cost, simple andcontrollable process, and suitableness for large-scale industrial production.

Description

technical field [0001] The invention relates to an electrode material, in particular to a method for preparing a lithium battery silicon-carbon negative electrode composite material. Background technique [0002] With the gradual increase in the energy density of lithium batteries, the theoretical gram capacity of graphite, which is a traditional negative electrode material for lithium batteries, is 372MAH / g. The current actual gram capacity of graphite negative electrodes has exceeded 360MAH / g, which is close to the theoretical value and cannot meet the increasing demands. There is an increasing market demand, so it is urgent to find other new negative electrode materials. Silicon-based materials have attracted extensive research interest because of their high theoretical capacity and low lithium storage potential. However, silicon-based materials also have several disadvantages. Second, silicon itself is a semiconductor material with poor conductivity. These shortcomings ...

AI Technical Summary

Problems solved by technology

[0002] With the gradual improvement of the energy density of lithium batteries, the theoretical gram capacity of graphite, which is a traditional negative electrode material for lithium batteries, is 372MAH / g. The current actual gram capacity of graphite negative electrodes has exceeded 360MAH / g, which is close to the theoretical value and cannot meet the increasing demands. Growing market demand, so it is urgent to find other new negative electrode materials

Silicon-based materials have attracted extensive research interest because of their high theoretical capacity and low lithium storage potential. However, silicon-based materials also have several disadvantages. Second, silicon itself is a semiconductor material with poor conductivity. These shortcomings limit the development of silicon materials to a certain extent.

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