In this paper, the effect of RF power on LiCoO₂ thin films was investigated using X-ray diffractometer (XRD), atomic force microscopy, UV–Vis spectrophotometer, and potentiostat. The microstructural, surface, optical and electrochemical impedance measurements were performed to LiCoO₂ thin films, are used to for the fully solid-state battery cathode material. According to obtained results, the relative intensities of the Li (002) crystal phase in XRD patterns of deposited LiCoO₂ thin films were increased by increasing applied RF power, for the first time. The intensity of the LiCoO₂ (104) plane is nearly invariant. The relative intensities of the LiCoO₂ (113) plane were decreased by increasing RF power. The peak locations of the Li (002) and LiCoO₂ (104) were not changed. It was found that Li (002) relative intensities affect the all investigated parameters for the LiCoO₂ thin films. Especially, transmittance value increased about 20%. The band gap of the deposited film was changed 100–300 meV drastically. Deposited samples are shown high transparency in the visible region. Randles circuit was used for the equivalent circuit model. Nyquist plots, fitting parameters values and value of the circuit elements were estimated by ZSim software.