The cobalt metal particles produced during lithium insertion into spinel, LiCoVO4, have been investigated by Co K-edge X-ray absorption spectroscopy (XAS) from the viewpoint of local and electronic structures around the Co atom. After electrochemical lithiation up to 0.01 V, extended X-ray absorption spectroscopy analysis showed an increasing Debye-Waller factor for the first neighbor interaction and disappearance of the second one. The simulated XAS by multiple scattering theory indicated that nanometer scale cobalt metal particles were produced with electrochemical reaction. It is suggested that the formation of nanometer scale cobalt particles leads to the high-rate performance of LiCoVO4 as the battery anode. (c) 2006 The Electrochemical Society.