An anode-supported solid oxide fuel cell (SOFC), consisting of a dense 10 mu m Gd0.1Ce0.9O1.95 (GDC) electrolyte, a porous Ba0.5Sr0.5Co0.8Fe0.2O3-delta (BSCF) cathode and a porous Ni-GDC cermet anode, is successfully assembled and electrochemically characterized. With humidified (3% water vapour) hydrogen as the fuel and air as the oxidant, the cell exhibits open-circuit voltages of 0.903 and 0.984 V when operating at 600 and 500 degrees C, respectively. The cell produces peak power densities of 1329, 863, 454, 208 and 83 mW cm(-2) at 600, 550, 500, 450 and 400 degrees C, respectively. These results are impressive and demonstrate the potential of BSCF for use as the cathode material in new-generation SOFCs with GDC as the electrolyte. In addition, the sustained performance at temperatures below 600 degrees C warrants commercial exploitation of this SOFC in stationary and mobile applications. (c) 2006 Elsevier B.V. All rights reserved.