Synthesis and Electrochemical Properties of LiFePO_4/C by Sol-Gel Method

LiFePO4/ C samples were synthesized by sol-gel method using Fe( NO3)3·9H2O,NH4H2PO4and LiOH·H2O as raw materials and polyethylene glycol PEG-4000 as chelating agent and carbon source. The crystal structure, morphology and electrochemical properties of LiFePO4/ C were characterized by XRD, SEM and electrochemical performance tests. The results showed that PEG-4000 as chelating agent and carbon source made the sample being of small particle size and uniformly distributed. The LiFePO4/ C sample sintered for 18 h at 650 ℃ presented optimal electrochemical performance with the initial charge and discharge capacities of 152. 7 mAh / g and 150. 6 mAh / g at 0. 1C,a capacity of 146 mAh / g and a capacity decay rate of 3. 05% after 30 cycles.