Preparation and electrochemical performance of LiFePO_4/C cathode material

LiFePO4and LiFePO4/C composite cathodes were prepared by a sol-gel method using glycine as chelating agent and sucrose as carbon source.The thermostability,phase structure,surface morphology and electrochemical performance of LiFePO4and LiFePO4∕C composite were characterized by TG-DTG,XRD,SEM and galvanostatic charge-discharge respectively.The results show that LiFePO4 and LiFePO4/C are both simple pure phase olivine-type.Compared with pure phase LiFePO4,LiFePO4/C has smaller particle size and better electrochemical performance and the initial discharge capacity of LiFePO4/C are 157.5 mAh/g at 0.1 C,and 140.7 mAh/g at 0.2 C,which maintain discharge capacity of 152.4 mAh/g and 130.2 mAh/g after 20 cycles.