A high-performance solid oxide fuel cell (SOFC) single cell with La0.9Sr0.1Ga0.8Mg0.2O3-delta (LSGM) thin film (5 mu m thick) as electrolyte, working at 400-700 degrees C, was demonstrated. A Ce0.8Sm0.2O2-delta (SDC) interlayer (400 nm thick) was introduced between the anode substrate of NiO-Fe2O3-SDC and the LSGM thin film to prohibit the reaction between LSGM and NiO and also to promote the electrode processes. Both SDC and LSGM films were deposited by pulsed laser deposition. The peak power density reached 3270, 1951, 612, and 80 mW/cm(2) at 700, 600, 500, and 400 degrees C, respectively, which may broaden the SOFC application to the mobile field. (c) 2005 The Electrochemical Society.