Negative plate and lithium ion battery

Abstract

The invention discloses a negative plate and a lithium ion battery, and belongs to the technical field of lithium ion batteries. The negative plate comprises a negative current collector and a film coated on the negative current collector; the film is divided into two layers, the first layer of coating is a bottom graphite coating close to the negative current collector, and the second layer of coating is a top silicon-containing coating layer far away from a copper foil. By adopting the technology of dual-layer coating, two types of slurry coats the negative current collector at the same time, after a dual-layer paste coating structure is formed on the same side of the negative current collector, a dual-layer coated negative plate with a silicon-containing coating on the top layer and a silicon-free pure graphite layer on the bottom layer is prepared, and the prepared negative plate has high compaction and high capacity performance, and the preparation method is simple and convenientin process; and the prepared lithium ion battery has the advantages of the high energy density and the good cycle performance, and can avoid lithium precipitation on the surface of the negative plateunder the condition of high-rate quick charging, so that the industrial application requirements are met.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a negative electrode sheet and a lithium ion battery. Background technique [0002] In recent years, with the continuous expansion of the industrial scale of lithium-ion batteries and the continuous development of related technologies, lithium-ion batteries have become energy storage devices for mainstream electronic products, and the uses of lithium-ion batteries have been greatly expanded. At the same time, people's performance requirements for lithium-ion batteries have also been further improved, requiring lithium-ion batteries to have high energy density and long cycle life. [0003] At present, one of the methods for improving the energy density of the negative electrode is to adopt technologies such as the combination of large and small particles to improve the compaction of the negative electrode, but high pressure compaction will lead to low por...

AI Technical Summary

Problems solved by technology

[0004] The object of the present invention is to solve the problem of poor cycle performance caused by the volume effect of the silicon-based negative electrode, and provide a negative electrode sheet and a lithium ion battery. The negative electrode sheet has high compaction and high capacity performance, and the preparation process is simple and convenient. The obtained lithium-ion battery has the advantages of high energy density and good cycle performance. At the same time, it can avoid lithium deposition on the surface of the negative electrode sheet under high-rate fast charging, which meets the needs of industry applications.

Images