Synthesis of high density LiFePO_4/C composite by stepwise carbon-coating

LiFePO4/C composite was synthesized by stepwise carbon-coating.First,the precursor Fe2P2O7/C was obtained by solid state reaction with Fe2O3,NH4H2PO4 and glucose,then,LiFePO4/C was synthesized by mixing the precursor,Li2CO3 and glucose through stepwise carbon-coating process.The effect of synthesis temperature on the electrochemical performances of LiFePO4/C composites was studied.The product were characterized by XRD,SEM,DSC-TGA,EIS and charge-discharge test.The results show that the LiFePO4/C composites synthesized with Fe2P2O7 as the precursor have excellent physics and electrochemical performance,the tap density of product reaches 1.26 g/cm3,and it has discharge capacities of 158.3 mA·h/g at 0.1C and 140 mA·h/g at 1C.