Porous pole piece and preparation method thereof and lithium ion battery

Abstract

The invention is suitable for the field of lithium ion batteries, and provides a preparation method of a porous pole piece. The preparation method comprises the following steps: mixing a pore forming material and slurry to obtain a mixture, and coating a pole piece with the mixture; and baking the pole piece at 100 to 150 DEG C to obtain a porous pole piece, wherein the porosity of the pole piece is 35 to 45 percent. The invention also provides a lithium ion battery containing the porous pole piece. The porous pole piece has higher porosity and further has higher liquid preserving capacity. The lithium ion battery containing the pole piece has higher multiplying power performance and higher cycling performance. Meanwhile, the formed pores are convenient for discharging gases, so that the service life of the battery is prolonged. According to the porous pole piece and the preparation method thereof and the lithium ion battery containing the porous pole piece, the preparation method is simple, the operation is simple and convenient, and the industrialized production can be realized.

Description

technical field [0001] The invention belongs to the field of lithium ion batteries, and in particular relates to a porous pole piece, a preparation method thereof, and a lithium ion battery comprising the porous pole piece. Background technique [0002] With the rapid development of society, the existing lithium-ion batteries are mainly developed in the direction of high rate. At present, the industry mainly reduces the diffusion path of lithium ions, increases the flow area, and improves the high-current charge and discharge performance of the battery through nano-materialization, porosity, reduction of the surface density of the pole piece, and end-face welding structure. However, with the nanometerization of materials, the process requirements are more stringent, and the processing performance requirements of materials are also significantly improved. The thin surface density requires higher precision of the coating machine and higher cost of end welding. Therefore, if t...

AI Technical Summary

Problems solved by technology

However, with the nanometerization of materials, the process requirements are more stringent, and the processing performance requirements of materials are also significantly improved. The thin surface density requires higher precision of the coating machine and higher cost of end welding

Therefore, if the above method is fully adopted, it is still difficult to continue to improve the rate performance to meet the needs.

Especially for cylindrical batteries, at high rates, there will be problems such as rate temperature rise, long-cycle electrolyte decomposition, and cycle life attenuation.

This is because although the above-mentioned method improves the material’s deintercalation of lithium ions and accelerates the current speed, the structural characteristics of the battery pole piece itself hinders the diffusion rate of lithium ions, so that the rate performance and cycle performance of the battery cannot be further improved.