关键词: 磷酸铁锂, 气流粉碎分级, 全电池, 电化学性能

Abstract: The carbon coated lithium iron phosphate (LiFePO₄/C) composite cathode material was prepared by using iron phosphate process. The effects of jet milling and classifying process on the electrochemical performance of LiFePO₄/C cathode material in full batteries were investigted. Scanning electron microscopic analyses suggested that the globose secondary particles were crustily crushed during the jet milling and classifying process, which would further result in lower tap density and carbon content. The LiFeP₄/C composite cathode materials with different physical characteristics were further tested in full batteries to evaluate the electrochemical properties. The results showed no obvious differences in capacity, AC resistance, DC resistance and power density. However, the globose LiFePO₄/C exhibited far better performances in low temperature discharge capacity retention rate and high temperature cycle retention than that of granulated composite cathode, which probably arisen from the certain delamination and destruction of conductive network during the jet milling and classifying process.

Key words: LiFePO₄/C, jet milling and classifying, full battery, electrochemical performance.