Application research of recycled cathode material LiFePO4 from lithium-ion battery.

With the hasten development of the new energy industry, the recycle of power and energy storage lithium-ion batteries began to be gradually valued. In order to ensure the cleanliness and environmental protection of the whole life cycle of lithium-ion batteries, the feasibility of recycling the positive and negative core materials in lithium-ion batteries needs to be further evaluated, so as to achieve the closed loop of the new energy industry chain with lithium-ion batteries as the core. The properties of a recycled LiFePO₄ cathode material are verified, and the effect of changes in physical and chemical indexes of the material on the processing performance and the impact of the electrical performance after processing into a battery are evaluated. The results show that the main physical properties of recycled LiFePO₄ obtained by physical drying method can meet the requirements of battery manufacturing grade. ICP test results show that the Al content is high, magnetic impurities, gram capacity and recovery powder particle size distribution and other physical and chemical indicators are not significantly abnormal, but there is still a large room for improvement, by following the process processing performance of the recovery of LiFePO₄, the direct current resistance of the pole is fluctuates. The results of charge storage at room temperature test show that the capacity retention rate of the cell after 28 days has reached more than 92%, recovery rate more than 93%, which meets the requirements of the national standard, indicating that the necessary demagnetization operation to increase the powder and slurry plays a certain role in reducing the risk of self-discharge of the final finished battery. The cell cycle test results show that the capacity retention rate of 0.2 C for 100 cycles is more than 95%, which is comparable to the normal LiFePO₄ processing of the cell cycle performance level. [ABSTRACT FROM AUTHOR]