Synthesis and characterization of LiFePO4/(C + Fe2P) composite cathodes

LiFePO4/(C + Fe2P) composite cathode with composite conductive webs structure was synthesized by modified carbothermal reduction method from the amorphous gel precursor at a heat-treatment temperature of 700 °C. The composite material exhibits an improved discharge capacity. Discharge capacities at 1 C rate were improved from 121.4 mAh g− 1 of LiFePO4/C to 140.8 mAh g− 1 of LiFePO4/(C + Fe2P) composite materials synthesized by two different routes using the same gel precursor, which could be, at least in part, attributed to the improved conductivity through the in situ formed Fe2P phase by the method. Electrochemical impedance measurements show that coexistence of the carbon and Fe2P phase with LiFePO4 could decrease the charge transfer resistance and increase surface electronic conductivity of the LiFePO4/(C + Fe2P) composite cathode.