GdBaCO2O5+x (GBCO) was evaluated as a cathode for intermediate-temperature solid oxide fuel cells. A porous layer of GBCO was deposited on an anode-supported fuel cell consisting of a 15 mu m thick electrolyte of yttria-stabilized zirconia (YSZ) prepared by dense screen-printing and a Ni-YSZ cermet as an anode (Ni-YSZ/YSZ/GBCO). Values of power density of 150 mW cm(-2) at 700 degrees C and ca. 250 mW cm(-2) at 800 degrees C are reported for this standard configuration using 5% of H-2 in nitrogen as fuel. An intermediate porous layer of YSZ was introduced between the electrolyte and the cathode improving the performance of the cell. Values for power density of 300 mW cm(-2) at 700 degrees C and ca. 500 mW cm-2 at 800 degrees C in this configuration were achieved. (C) 2007 Elsevier B.V. All rights reserved.