A method for preparing a negative electrode sheet, the negative electrode sheet

Abstract

This application belongs to the field of battery manufacturing technology and provides a method for preparing a negative electrode sheet and the negative electrode sheet itself. The preparation method includes: sequentially coating an ion-conducting layer slurry and a bonding layer slurry on the surface of a thinned region of the negative electrode substrate, and coating the bonding layer slurry while the wet film of the ion-conducting layer is not completely dry; after heat treatment, a functional layer is integrally formed on the surface of the thinned region. The outer surface of this functional layer is flush with the main body region, and its interior includes an ion-conducting layer, a bonding layer, and a transition structure where the two layers interpenetrate at their interface. The negative electrode sheet includes the aforementioned functional layer. This application, through a wet film stacking process and heat treatment, constructs an integrated functional layer in the thinned region that combines a highly efficient ion transport channel and a strong mechanical bonding interface, solving the problems of uneven ion transport and weak interface bonding in this region, suppressing local lithium plating and interface peeling, and effectively improving the cycle life and safety of the battery.

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