Dehydration system of lithium ion battery positive electrode material precursor and method for preparing positive electrode material precursor

Abstract

The invention provides a dehydration system of a lithium ion battery positive electrode material precursor and a method for preparing the positive electrode material precursor, a calcination rotary kiln is arranged in the dehydration system, and the calcination rotary kiln adopts a combined heat supply structure of external heating type heat supply and internal heating type heat supply. The positive electrode material precursor is calcined and dehydrated in two heat source modes of external heating type rotary kiln wall heating and high-temperature gas direct heating, gas serves as an efficient carrier for heat and mass transfer and is fully mixed and heated with the positive electrode material precursor in a calcining rotary kiln, heating is uniform, heat transfer is rapid, and the product quality is high. And the removal rate of the crystal water and the energy utilization efficiency are improved. The method for preparing the positive electrode material precursor comprises the following steps of: raising the temperature of the calcining rotary kiln and the hot gas supply device to a preset temperature by utilizing the dehydration system, and then feeding materials for continuous calcining dehydration; and various parameters of the dehydration system are regulated and controlled according to the monitored exhaust gas emission temperature in the hot gas supply device. According to the preparation method, the natural gas consumption required by each ton of finished product is greatly reduced.

Description

technical field [0001] The invention relates to a dehydration system of a lithium ion battery positive electrode material precursor and a method for preparing the positive electrode material precursor, and belongs to the technical field of lithium ion battery precursor material manufacturing. Background technique [0002] Due to the characteristics of low cost and good thermal stability, lithium iron phosphate lithium-ion batteries have become one of the new development directions in recent years. With the improvement of the synthesis quality and production stability of battery-grade iron phosphate, the application of lithium iron phosphate lithium-ion batteries is becoming more and more mature, and the market share is gradually rising. At present, lithium iron phosphate cathode materials are mainly synthesized from the precursors iron phosphate and lithium carbonate through high-temperature solid-phase reaction. In the past, lithium iron phosphate production enterprises ma...

AI Technical Summary

Problems solved by technology

In the past, lithium iron phosphate manufacturers mainly used iron phosphate dihydrate (FePO 4 2H 2 O) As a precursor material, however, the stability of the water content of ferric phosphate dihydrate is difficult to be guaranteed

Large fluctuations in the moisture content of iron phosphate dihydrate will affect the accuracy of production ingredients, and ultimately affect the quality of lithium iron phosphate products

The external heating rotary kiln dynamic calcination process is adopted and the materials in the kiln are stirred and heated, and the energy consumption of calcination and dehydration is reduced to a certain extent, but the natural gas consumption required for per ton of ferric phosphate dihydrate treatment is still as high as 400Nm 3 , much higher than the theoretical demand for natural gas; the heat treatment time is 4-8 hours, and the equipment capacity is low; these all lead to high production costs of anhydrous ferric phosphate and low production profits

Images