LiCoO2 thin films have received attention as cathodes of thin-film microbatteries in these days. In the present work, LiCoO2 thin films were prepared by sol–gel spin-coating method with a polymer additive (PVP) and a post annealing process which was very effective for preparing crack-free thin film. We have deposited LiCoO2 thin films on silicon wafers coated with Pt and annealed at 750 °C. The crystallinity, microstructure, and composition of final films were studied by XRD, SEM, and AFM. These results show that the films formed at low temperature shows cubic phase while at high temperature the structure changes to hexagonal. Films heat-treated under appropriate conditions exhibit high capacity and good crystallinity so these films are considered to be candidates as cathodes for thin-film microbatteries.