A thermal polymerization route was adopted to synthesize layered LiNi1/3Co1/3Mn1/3O2 materials. After annealing the polymer gel containing metal salts at different temperatures from 850 to 1000 degrees C for different time between 6 and 25 h, powders of pure alpha-NaFeO2 phase were obtained. The crystal structure, morphology and electrochemical properties of the products were investigated by XRD, SEM, electrochemical cell cycling and AC impedance spectroscopy. It is found that the powder annealed at 950 degrees C for 15 h shows the best electrochemical property with the first specific discharge capacity of 188 mAh/g at C/10 and 87% retention after 100 cycles. It exhibits good rate capability with the specific capacity of 169 mAh/g at 1 C and 110 mAh/g at 6 C. Adopting a slowly cooling procedure during the powder annealing can improve the electrochemical performance of the LiNi1/3Co1/3Mn1/3O2 powder. (C) 2008 Elsevier Ltd. All rights reserved.