Synthesis and Properties of Nano-LiFePO4/C Composites

FePO4· H2O precursor was synthesized by the co-precipitation method from raw materials Fe (NO3)3· 9H2O, H3PO4 and NH3· H2O, which then was modified by surfactants hexadecyl trim ethyl ammonium bromide (CTAB) and polyethylene glycol (PEG). Finally LiFePO4 /C composites were synthesized with the as-prepared FePO4· 2H2O, Li2CO3 and sucrose as raw materials. The LiFePO4 /C composites were characterized by means of Xray diffractormeter (XRD) and scanning electron microscope (SEM). Their performance was determined by cyclic voltammograms (CV) and electrochemical measurement.. The results show that the presence of surfactants CTAB and PEG may be beneficial to suppressing the agglomeration of the particles of the composites; thereby their electrochemical properties were enhanced. The LiFePO4/C particles synthesized with surfactant CTAB modified FePO4·2H2O exhibit excellent dispersive ability with particle mean size 170nm and excellent cycle performance and rate properties i.e. a discharge specific capacity 159.8 mAh·g at 0.1C as well as a value higher than 132.4 mAh·g even at 10C.