Cone-shaped Sm-doped CeO2 (Ce0.8Sm0.2O1.9, SDC) electrolyte cylinders have been fabricated using the slip-casting technique. A single solid oxide fuel cell has been prepared by applying a Sm0.5Sr0.5CoO3 cathode on the outside of the cylinders and a NiO-SDC (7:3 wt%) anode on the inside. The open circuit voltage of the cell was 0.93 V at 400 degrees C, and a maximum power density of about 300 mW/cm(2) at 700 degrees C was obtained with humidified hydrogen (3% H2O) as the fuel and ambient air as the oxidant. Impedance results showed that the performance of the cell was mainly influenced by the ohmic resistance of the electrolyte.