Cl-cloped LiFePO4/C cathode materials were synthesized through a carbothermal reduction route, and the microstructure and electrochemical performances were systematically studied. Cl-cloped LiFePO4/C cathode materials presented a high discharge capacity of similar to 90mAh g(-1) atthe rateof 20C(3400 mA g(-1)) at room temperature. Electrochemical impedance spectroscopy and cyclic voltamperometry indicated the optimized electrochemical reaction and Li+ diffusion in the bulk of LiFePO4 due to Cl-doping. The improved Li+ diffusion capability is attributed to the microstructure modification of LiFePO4 via Cl-cloping. (C) 2009 Elsevier B.V. All rights reserved.