LiMn2O4 thin film (1μm thick) was prepared on a gold substrate by the PVP sol–gel method. The electrochemical properties of the thin-film electrode were studied in an electrolyte 1moldm−3 LiClO4/(ethylene carbonate+diethyl carbonate). The prepared LiMn2O4 showed a good charge–discharge performance, and the capacity fade was ca. 20% during 200 cycles. The Li+ ion diffusion in the LiMn2O4 thin film was investigated by means of potentiostatic intermittent titration technique and electrochemical impedance spectroscopy. The chemical diffusion coefficients were estimated to be 10−8 to 10−10 cm2 s−1.