Effect of Pyrrole Additive on Structure and Properties of LiFePO_4/C Cathode Materials Prepared by in situ Polymerization Restriction Method

Nano-sized LiFePO4/C cathode materials were synthesized with mesoporous FePO4/PPy precursor prepared by in-situ polymerization restriction method.Effect of pyrrole additive on the structure,morphology and electrochemical properties of LiFePO4/C samples were characterized by X-ray diffraction,scanning electron microscopy,transmission electron microscopy,galvanostatic charge-discharge tests and electrochemical impedance spectroscopy(EIS),respectively.The results show that LiFePO4/C and FePO4/PPy have the similar morphology and pyrrole additive affect the electrochemical properties of LiFePO4/C.The LiFePO4/C samples synthesized at a pyrrole addition of 1.0 mL had the smaller particles with the uniform particle size distribution and superior electrochemical properties.The initial discharge capacity of the sample was 149.0 mA h/g in the voltage window range of 2.5-4.1 V at 0.1 C rate and the capacity retention was superior.