The electrochemical properties of Al2O3-coated LiCoO2 thin films with a partial coating coverage were investigated. The Al2O3-coated LiCoO2 films showed better cycle-Life performances with 100% coating coverage. In addition, the Al2O3-coating Layer with a partial coverage of 50% clearly enhanced the electrochemical properties of LiCoO2 cathodes even at 60°C. The Al2O3-coating Layer suppresses Co dissolution from LiCoO2, consequently enhancing the cycle-Life performance.