Preparation and electrochemical properties of LiFePO4/C nanocomposite using FePO4•2H2O nanoparticles by introduction of Fe3(PO4)2•8H2O at low cost

A LiFePO4/C composite was synthesized by a simple solid-state reaction method using stearic acid as reductive agent and carbon source and nano-sized FePO4 center dot 2H(2)O as precursor which was prepared from intermediate Fe-3(PO4)(2)center dot 8H(2)O using industrial FeSO4 center dot 7H(2)O and industrial NH4H2PO4 at a low cost. The structure, morphology and electrochemical performance of LiFePO4/C were investigated by Xray diffraction (XRD), scanning electron microscopy (SEM), galvanostatic charge-discharge tests, cyclic voltammograrn (CV) and electrochemical impedance spectroscopy (EIS). The results indicate that the LiFepO(4)/C has an olivine-type structure with nano-size and exhibits excellent electrochemical properties. The discharge capacities are 159 mAh g(-1), 148 mAh g(-1) and 113 mAh g(-1) at 0.1 C, 1 C and 10 C, respectively. Furthermore, the capacity retention rate is higher than 99% after 100 cycles at 1 C and 10 C. The excellent electrochemical performances of LiFePO4/C composite should be attributed to spherical nanoparticles as well as less impurity in FePO4 center dot 2H(2)O precursor. (C) 2013 Elsevier Ltd. All rights reserved.