Improved high-rate charge/discharge performances of LiFePO4/C via V-doping

V-doped LiFePO4/C cathode materials were prepared through a carbothermal reduction route. The microstructure was characterized by X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy. The electrochemical Li+ intercalation performances of V-doped LiFePO4/C were compared with those of undoped one through galvanostatic intermittent titration technique, cyclic voltamperometry, and electrochemical impedance spectrurn. V-doped LiFePO4/C showed a high discharge capacity of similar to 70 mAh g(-1) at the rate of 20 C (3400 mA g(-1)) at room temperature. The significantly improved high-rate charge/discharge capacity is attributed to the increase of Li+ ion "effective" diffusion capability. (C) 2009 Elsevier B.V. All rights reserved.