Synthesis and Characterization of LiFePO₄ / PPy Composite Powders

Abstract

A series of lithium iron phosphate /polypyrrole (LiFePO4/PPy) composite powders were synthesized by chemical oxidation method with different doping agent and oxidation agent. The composite powders were characterized by scanning electron microscopy (SEM), Fourier Transform Infrared Spectrum (FTIR), and X-ray diffraction (XRD). The results showed that the composite powders composed of PPy and LiFePO4. And the doping of polypyrrole in LiFePO4 could weaken the XRD intensity of LiFePO4 , but could not destroy its crystallization. With the increase of pyrrole in LiFePO4/ PPy composite powders, the polypyrrole on the surface of LiFePO4 increased and dispersed more homogeneously. Thermogravimetric analysis (TGA) data indicated the heat-stability of LiFePO4/PPy was very good that the composite powders would not oxidate till 300°C in the air flow.