WO2 modified LiFePO4/C composites were prepared by sol-gel method. The structures and compositions of LiFePO4/C samples containing 0-5 wt% WO2 were analyzed by X-ray diffraction, Raman spectroscopy, scanning electron microscopy and transmission electron microscopy. The electrochemical performances were also characterized with charge-discharge test and cyclic voltammetry. The WO2 modified LiFePO4/C samples showed improved specific capability and low-temperature performance and reduced the polarization of the cathode significantly. Their apparent lithium ion diffusion coefficients were in the range of 3×10−11 to 8×10−11 cm2/s depending on the WO2 content. Among the investigated samples, the one with 3 wt% WO2 exhibited the best electrochemical performance. This can be mainly attributed to the improvement of electrochemical kinetics by the modifying with WO2.
