The Li[Li(1/3-x/3)CrxMn(2/3-2x/3)]O-2 (0.15 <= x <= 0.3) cathode materials were synthesized by sol-gel process using aqueous solutions of metal acetates and citric acid as the chelating agent. The precipitate of metal citrate was dried in a vacuum In oven for 10 degrees at 100 degrees C. After drying, the gel precursor was calcined at 300 degrees C for about 10h. The resulted powder was ground and heated at 900 degrees C. The structural characterization was carried out by fitting the XRD data with Rietveld program. The samples exhibited a well defined layered Structure and the unit cell parameters linearly increased with increasing chromium contents in Li[Li(1/3-x/3)CrxMn(2/3-2x/3)]O-2 Surface morphology was determined by SEM and HRTEM and it is found that the cathode material consisted of highly ordered single crystalline particles with layered-hexagonal Structure. Test cells were assembled and cycled in the voltage range of 2.0-4.9 V with a current density of 7.947 mA/g. Electrode with (x = 0.2) delivered a high reversible capacity of around 280 mA h/g in cycling. (c) 2006 Elsevier Ltd. All rights reserved.