The single phase of LiCo0.3Ni0.7O2 was prepared by oxidation-ion exchange Of beta-Co0.3Ni0.7(OH)(2) and LiOH at low temperature. The optimal synthetic conditions were determined as that the reaction was carried out at 120 degrees C for 12 h with a eight-fold LiOH added before the addition of oxidant (the molar ratio of K2S2O8:beta-Co0.3Ni0.7(OH)(2) is 1) and the obtained sample was washed to pH 11. The synthesized sample exhibits an initial discharge capacity of 130.0 mAh g(-1) with 70.0% coulombic efficiency due to lower crystallinity. After heat treatment at 750 degrees C for 5 h, the initial discharge capacity is increased to 165.1 mAh g(-1) and with a better capacity retention of 95.7% after 50 cycles, which is attributed to the improvement of the structural integrity. It suggests that the oxidation-ion exchange method together with heat treatment process is a very promising route to prepare the cathode material with good electrochemical performance for lithium ion batteries. (c) 2007 Elsevier B.V. All rights reserved.