Li0.33MnO2 was prepared by solid-state reaction of CMD oxide and a lithium salt. The structure was studied by X-ray diffraction and Raman scattering during electrochemical discharging. The possibility of application as a positive electrode in rechargeable lithium batteries was investigated. The electrochemical properties of Li//Li0.33MnO2 cells were studied as a function of temperature in the range 25–55°C. The electrode material delivers an initial capacity of 194mAhg−1 and shows good reversibility at room temperature. Finally, the lithium insertion mechanism was examined by the determination of the ion kinetics.