The fuel cell arrangement air, La0.4Sr0.6Co0.2Fe0.8O3 parallel to Ce(0.9)Gd(0.1)O(1.95)parallel to Ni/YSZ, fuel, incorporating either thick film (5-10 mu m) or self supported (similar to 300 mu m) Ce0.9Gd0.1O1.95 electrolyte, was investigated at 650 degrees C. Scanning electron microscopy (SEM) analysis showed that a dense electrolyte layer in good contact with highly porous electrodes was achieved using either the thick him or self supported electrolyte. Measurements of the current-voltage characteristics, using H-2/CO2/H2O fuel to simulate reformed methanol, showed that a higher terminal voltage was obtainable with the self supported electrolyte, but that the voltage dropped off quickly with increasing currents. Hence the thick film based arrangement was more suitable for the fuel cell and power outputs exceeding 100 mW/cm(2) were obtained.