The LiMn2O4 thin film as a cathode material was prepared through solution deposition followed by rapid thermal annealing (RTA). The phase identification and the study of surface morphology were carried out by X-ray diffraction and scanning electron microscopy. Electrochemical properties were examined by cyclic voltammetry, galvanostatic charge-discharge experiments, and electrochemical impedance spectroscopy. The results show that the film prepared by this method is homogeneous, dense, and crack-free. The thin film has a capacity of 38 μAh/(cm2·μm) with the capacity loss of 0.037% per cycle after being cycled for 100 times. The average diffusion coefficient for lithium ions in the RTA-derived LiMn2O4 thin film is 1×l0-10 cm2·s-1.