Nanosized CoSb2 powder was prepared by the solvothermal route and studied as a new candidate for anode material for secondary lithium-ion batteries. The powder was characterized by X-ray diffraction, transmission electron microscopy, and field emission scanning electron microscopy in conjunction with energy dispersive X-ray analyses. It was found that the reversible capacity of the nanosized CoSb2 in the first cycle reached 582 mA h g(-1) and a capacity of 355 mA h g(-1) was still maintained for more than 20 cycles. The experimental results of nanosized CoSb2 were compared with that of a micrometer-sized one prepared by the levitation-melting/ballmilling route, which exhibited lower reversible capacity and poor cycling behavior. The superior electrochemical performance of solvothermally prepared CoSb2 is related to the microstructure and nanoscaled particle size. (C) 2004 The Electrochemical Society.