Characterization and Electrochemical Properties of LiFePO_4/C Composite with Carbon Core Structure

LiFePO4/C composite with carbon core structure was successfully synthesized by using epoxy resin as carbon source.The microstructure,morphology,surface composition of LiFePO4/C composite were characterized by X-ray diffraction(XRD),scanning electron microscope(SEM),transmission electron microscope(TEM) and X-ray photoelectron spectroscope(XPS).Their electrochemical properties were investigated in terms of galvanostatic charge-discharge and electrochemical impedance spectroscope(EIS) tests.The experimental results show that LiFePO4/C composite with carbon core structure is composed of amorphous carbon line core and nanometer LiFePO4 grains.The initial discharge capacity of LiFePO4/C composite is 166mAh/g at current density of 15mA/g.Its initial discharge capacity is 131mAh/g with capacity retention of 99.2% after 50 cycles at current density of 750mA/g.