Preparation method of silicon-based negative electrode slurry

Abstract

The invention discloses a preparation method of silicon-based negative electrode slurry. The preparation method comprises the following steps OF: stirring a solvent, a thickening agent and a conductive agent in a glue preparation tank to obtain a conductive glue solution; uniformly mixing a silicon active material and a carbon active material to obtain a silicon-based composite material; uniformly stirring the silicon-based composite material and the conductive adhesive solution in a stirrer at a low speed, then completely adding the rest conductive adhesive solution into the stirrer, and performing uniform stirring and mixing under a high-speed vacuum condition to obtain mixed slurry; and adding an adhesive into the mixed slurry, continuing vacuum high-speed stirring, and finally discharging the negative electrode slurry. In the preparation process of the negative electrode slurry, the conductive glue solution and the silicon-based composite material are added in a spraying manner at the same time, so that the contact probability of the surfaces of active material particles in the silicon-based composite material and the conductive glue solution is greatly increased, the infiltration process of the glue solution on the surfaces of the active material particles is promoted, the dispersion efficiency of the active material particles is improved, the preparation time of theslurry is effectively shortened, and 20% of stirring time can be saved.

Description

technical field [0001] The invention relates to the field of lithium battery preparation, in particular to a method for preparing a silicon-based negative electrode slurry. Background technique [0002] At present, the anode material of lithium ion battery is mainly graphite material. Under the current technical conditions, the gram capacity of graphite anode materials is getting closer and closer to the theoretical gram capacity of graphite of 372mAh / g, making it increasingly difficult to increase the energy density of lithium-ion batteries. [0003] Silicon material is a new type of negative electrode material with broad application prospects. The theoretical gram capacity is 4200mAh / g, which is more than ten times that of graphite material. Silicon materials have a volume change of up to 300% during charge and discharge, which casts a shadow over the application of silicon materials in lithium-ion batteries. In order to promote the application of silicon materials in th...

AI Technical Summary

Problems solved by technology

In the process of slurry preparation, silicon-based particle powder and glue solution are added separately, which increases the difficulty of wetting the surface of silicon-based particles, which is not conducive to subsequent dispersion and slurry preparation efficiency, resulting in long slurry preparation time and energy consumption. Large, high cost, poor dispersion effect

This is mainly because the glue and active powder particles are added separately, which is not conducive to the infiltration of the surface of the active particles. If there are residual air bubbles, it is difficult to remove them in the subsequent dispersion process, resulting in poor dispersion effect and long slurry preparation cycle.

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