锂离子电池Li_(2)FeP_(2)O_(7)正极材料的制备及其电化学性能

Preparation and Electrochemical Performance of Li_(2)FeP_(2)O_(7) as Cathode Materials for Lithium-Ion Batteries

采用固相球磨法制备了Li_(2)FeP_(2)O_(7)/C正极材料,研究了烧结温度、碳包覆含量以及碳源对其结构、形貌以及电化学性能的影响。结果表明:高温固相烧结合成样品的适宜温度为680℃,以柠檬酸为碳源、碳包覆量为5%时,合成的Li_(2)FeP_(2)O_(7)/C晶型完整,晶粒较小且均匀,0.1C倍率下的放电比容量可达102.6 mAh/g,0.5C倍率下的初次放电比容量可达83.4 mAh/g,循环30次后放电比容量为80.7 mAh/g,展现了较好的循环性能以及倍率性能。

The cathode material of Li_(2)FeP_(2)O_(7)/C was prepared by solid-phase ball milling method,and the influences of sintering temperature,carbon coating content and carbon source on the phase structure,morphology and electrochemical properties were studied.The results indicate that the Li_(2)FeP_(2)O_(7)/C appropriately synthesized at 680℃,with citric acid as carbon source and carbon coating content of 5%,has a complete crystal shape with smaller and uniform grain.The Li_(2)FeP_(2)O_(7)/C exhibits an initial discharge capacity of 102.6 mAh/g at 0.1 C rate,and an initial discharge capacity of 83.4 mAh/g at 0.5 C rate,a reversible capacity of 80.7 mAh/g after 30 cycles at 0.5 C,showing better cycling and rate performance.