Li[CrxLi(1/3-x/3)Mn(2/3-2x/3)]O-2 materials with x = 0.1, 0.15, and 0.2 are prepared by a solution method. The materials are calcined at 900 degreesC for 12 h in air, and then quenched to room temperature. The quenching procedure results in material with improved capacity and rate capability. In fact, layered Li1.27Cr0.2Mn0.53O2, not only shows a good cycle performance, but also exhibits an excellent discharge capacity of around 260 mA h g(-1). Cyclic voltammetry and a.c. impedance spectroscopy are also employed to characterize the reversibility and reactions of lithium insertion and extraction in Li[CrxLi(1/3-x/3)Mn(2/3-2x/3)]O-2 electrodes. (C) 2004 Elsevier B.V. All fights reserved.