Amorphous LiCoO2 thin films were deposited on the NASICON-type glass ceramics, Li1+x+y Al x Ti2−x Si y P3−y O12 (LATSP), by radio frequency (RF) magnetron sputtering below 180°C. The as-deposited LiCoO2 thin films were characterized by X-ray diffraction, scanning electron microscopy and atomic force microscope. All-solid-state Li/PEO18–Li (CF3SO2)2N/LATSP/LiCoO2/Au cells were fabricated using the amorphous film. The electrochemical performance of the cells was investigated by galvanostatic cycling, cyclic voltammetry, potentiostatic intermittent titration technique and electrochemical impedance spectroscopy. It was found that the amorphous LiCoO2 thin film shows a promising electrochemical performance, making it a potential application in microbatteries for microelectronic devices.