Drying method for lithium ion battery manufacture

Abstract

The invention provides a drying method for electrode materials, pole pieces or electric cores in lithium ion battery manufacture. The method includes soaking or rinsing articles to be dried in or with solvent with boiling point lower than that of water and intersoluble with water; drying the to-be-dried articles treated in the last step at the temperature not lower than the boiling point of the solvent. The drying method can achieve better drying effect at the lower temperature and in shorter drying time.

Description

technical field [0001] The invention relates to a drying method, in particular to a drying method for lithium ion electrode materials, pole pieces or electric cores. Background technique [0002] In the manufacturing process of lithium-ion batteries, moisture control is one of the important factors affecting the quality and performance of batteries. Therefore, in the preparation process of lithium-ion batteries, it is not only necessary to strictly control the environmental humidity in the production workshop, but also to dry the electrode materials, pole pieces or batteries. The existing technology generally adopts the method of vacuum baking to dry the electrode material, the electrode piece or the electric core. In operation, after putting the electrode material, pole piece or cell into the vacuum oven, it is dried and dehumidified by heating, inflating and vacuuming for many times. However, the efficiency of vacuum baking is low, especially when the moisture content of...

AI Technical Summary

Problems solved by technology

However, the efficiency of vacuum baking is low, especially when the moisture content of the battery electrode sheet needs to be controlled at a very low level (such as below 50ppm), and vacuum baking often takes several days or even longer (ten days) to achieve Moisture Control Requirements

This kind of long-term baking not only consumes a lot of energy and takes a long time, but also easily brings other quality problems, such as excessive shrinkage of the separator during the drying process of the battery cell, resulting in a change in porosity, which affects the battery's electrical capacity. Chemical properties and pass rate

[0003] In the prior art, methods such as vacuum baking and blast drying are mainly used to dry lithium-ion electrode materials, pole pieces or batteries. This method can obtain better results for ordinary electrode materials or pole pieces, but for lithium titanate (LTO) similar composite oxide materials or pole pieces prepared using this material, it is difficult to obtain the ideal drying effect by simple vacuum and blast drying

Images