We report an alternative hydrothermal process for the preparation of pure phase LiCoO(2) cathode material for potential application under high rates. By adjusting the hydrothermal conditions, nanoplate-like LiCoO(2) crystals were obtained, with grain size about 200 nm. It was found in the experiment that the H(2)O(2) concentration and hydrothermal temperature were the two key factors that influence the phase purity and crystal shape, while LiOH concentration has only a slight effect on the crystal size of the product. The electrochemical test revealed a good rate behavior of the synthesized pure phase LiCoO(2) nanoplates, demonstrating a potential of the hydrothermal process for mass production.