A lithium-ion battery negative electrode sheet containing conductive coating and preparation method thereof

Abstract

The invention relates to the field of lithium batteries, and discloses a lithium-ion battery negative plate containing a conductive coating and a preparation method thereof. The negative electrode sheet includes a copper foil current collector, a conductive coating, and a negative electrode active material layer. The negative electrode active material layer is formed by solidifying the negative electrode slurry. The negative electrode slurry includes the following materials: 93-95 parts of graphite, 1.5-2.5 parts of conductive Carbon black SP, 1-2 parts of sodium carboxymethyl cellulose, 2-3 parts of styrene-butadiene rubber, 130-150 parts of deionized water; the conductive coating is cured by conductive paste, which includes the following Materials: 10-95 parts of composite carbon source, 5-50 parts of binder, 5-40 parts of dispersant, 450-550 parts of organic solvent. In the present invention, a layer of special conductive paste is coated on the current collector, which has a large specific surface area and low impedance, which can greatly improve the adhesion of the pole piece, enhance the conductivity, reduce the amount of binder and conductive agent added, and improve The energy density of the battery.

Description

Technical field[0001]The invention relates to the field of lithium batteries, in particular to a lithium ion battery negative electrode sheet containing a conductive coating and a preparation method thereof.Background technique[0002]At present, the negative electrode sheet of a lithium ion battery generally includes a current collector and a negative electrode active material coated on the current collector. The current collector of the negative electrode mainly adopts copper foil light foil. Due to the smooth surface of the light foil, the negative electrode active material has a weak interface binding force with the current collector during coating, resulting in poor binding force of the negative electrode active material, which is likely to cause problems such as electrode dropout in the later process. Therefore, the amount of conductive agent added must not be increased, and in order to ensure the adhesion of the electrode, it is necessary to add more binder to the slurry of the...

AI Technical Summary

Problems solved by technology

However, there are also some problems in the above-mentioned conductive coating: 1. Due to the addition of a layer of conductive coating, and the specific surface area of ​​the material in the conductive coating is not large enough, the impedance of the pole piece is increased; 2. Its adhesion to the current collector Still need to be further improved