The effect of Pt additive on the microstructure and electrochemical properties of synthesized LiCoO2-based material was investigated. Besides incorporating into LiCoO2 lattice in small amounts, Pt additive induces dispersed Li2PtO3 and Pt in the LiCoO2 matrix to form multi-phase composites. In comparison with the single phase of LiCoO2, the multi-phase composite shows improved rate performance and cycleability at high rates. This improved rate behaviors can be attributed to the enhanced diffusion of Li+, which are caused by the enlarged c axis of LiCoO2 lattice due to Pt incorporating and fast diffusion paths of Li+ provided by the interfaces among in LiCoO2, Li2PtO3 and Pt. The dispersed Li2PtO3 and Pt are also beneficial to the cycleability.