Drying process of lithium iron phosphate

Abstract

The invention discloses a drying process of lithium iron phosphate. The drying process comprises the following steps of automatically performing overturn and bowl-discharging of a lithium iron phosphate material by an overturn and bowl-discharging machine, and transmitting the lithium iron phosphate material to a raw material storage bin; taking heated nitrogen as a smashing and drying air source, smashing the material, and performing counter jet flow instant drying on the material; transmitting the smashed lithium iron phosphate material to a dust catcher through the nitrogen, introducing the lithium iron phosphate material to a supersonic-speed vibration screening machine for screening; and transmitting the screened lithium iron phosphate to a package system for package. According to the drying process, the high-temperature nitrogen at 100-170 DEG C is taken as the smashing and drying air source, the lithium iron phosphate with high moisture content is simultaneously smashed and dried by the high-temperature nitrogen, the lithium iron phosphate material is effectively prevented from being oxidized in a high temperature, meanwhile, the material is prevented from being in contact with moisture, and a lithium iron phosphate product with moderate grain size and the moisture content less than or equal to 500ppm is obtained. By the drying process, the output time of the lithium iron phosphate product is shortened, the energy consumption is reduced, and the production efficiency is improved.

Description

technical field [0001] The invention relates to a post-treatment method for a positive electrode material of a lithium ion battery, in particular to a drying process for lithium iron phosphate. Background technique [0002] Since the water content of the positive electrode material lithium iron phosphate directly affects the electrochemical performance of the battery, the water content of lithium iron phosphate must be strictly controlled, generally within 500ppm. Due to the fine particles and large specific surface area of ​​lithium iron phosphate powder, it has strong water absorption. If it is exposed in the air for a long time or the ambient humidity is high, its moisture content will exceed 1000ppm. In order to control the moisture content of lithium iron phosphate, most manufacturers adopt the method of adding baking and drying equipment before packaging, or adding material baking equipment before the battery manufacturing and pulping process, and some manufacturers s...

AI Technical Summary

Problems solved by technology

In order to control the moisture content of lithium iron phosphate, most manufacturers adopt the method of adding baking and drying equipment before packaging, or adding material baking equipment before the battery manufacturing and pulping process, and some manufacturers set airflow crushing, mixing, and packaging processes to Control the moisture absorption of materials in the drying room. These methods are not only cumbersome, but also time-consuming and energy-consuming, and the moisture content is not easy to control

Images