The electrochemical properties of a composite electrode for the lithium-ion battery consisting of exfoliated MoO2 nanosheets were investigated. The cell exhibited a high capacity of ca. 400 mA h g(-1) in the cell voltage range of 3.0-0.1 V, even after several charge-discharge cycles. In situ X-ray analysis during the electrochemical test revealed that multiple injections of Li+ into the interlayers between the MoO2 nanosheets and subsequent delithiation from the material occurred reversibly at room temperature.