The intermetallic compound CoSb3 exhibits a larger Li-storage capacity compared with carbon-based materials, which are currently used as the anode materials in commercial lithium ion batteries. However, the CoSb3 electrode shows poor cycling stability during repetitive charge and discharge cycles. This behavior has precluded it from practical use in lithium ion batteries to date. In our present study, galvanostatic cycling, scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), and Fourier transition infra-red (FTIR) techniques were used to explore the capacity fade mechanism of CoSb3 electrodes. This preliminary study may supply a methodology for improving the electrochemical performances of the CoSb3 compound or other intermetallic compounds. (C) 2004 Elsevier B.V. All rights reserved.