Electrochemical performance of LiFePO4/(C+Fe2P) composite cathode material synthesized by sol-gel me

A LiFePO4/(C+Fe2P) composite cathode material was prepared by a sol-gel method using Fe(NO3)3·9H2O,LiAc·H2O,NH4H2PO4 and citric acid as raw materials,and the physical properties and electrochemical performance of the composite cathode material were investigated by X-ray diffractometry (XRD),scanning electron microscopy (SEM),transmission electron microscopy (TEM) and electrochemical tests.The Fe2P content,morphology and electrochemical performance of LiFePO4/(C+Fe2P) composite depend on the calcination temperature.The optimized LiFePO4/(C+Fe2P) composite is prepared at 650 ℃ and the optimized composite exhibits sphere-like morphology with porous structure and Fe2P content of about 3.2％ (mass fraction).The discharge capacity of the optimized LiFePO4/(C+Fe2P) at 0.1C is 156 and 161 mA·h/g at 25 and 55 ℃,respectively,and the corresponding capacity retentions are 96％ after 30 cycles; while the capacity at 1C is 142 and 149 mA·h/g at 25 and 55 ℃,respectively,and thecapacity still remains 135 and 142 mA·h/g after 30 cycles at 25 and 55 ℃,respectively.