A cobalt-free layered perovskite oxide, GdBaFe2O5+x (GBF), was investigated as a novel cathode for intermediate temperature solid oxide fuel cells (IT-SOFCs). Area-specific resistance (ASR) of GBF was measured by impedance spectroscopy in a symmetrical cell. The observed ASR was as low as 0.15 Omega cm(2) at 700 degrees C and 0.39 Omega cm(2) at 650 degrees C, respectively. A laboratory sized Sm0.2Ce0.8O1.9 (SDC)-based tri-layer cell of NiO-SDC/SDC/GBF was tested under intermediate temperature conditions of 550-700 degrees C with humidified H-2 (similar to 3% H2O) as a fuel and the static ambient air as an oxidant. A maximal power density of 861 mW cm(-2) was achieved at 700 degrees C. The electrode polarization resistance was as low as 0.57, 0.22, 0.13 and 0.08 Omega cm(2) at 550, 600, 650 and 700 degrees C, respectively. The experimental results indicate that the layered perovskite GBF is a promising cathode candidate for IT-SOFCs. Published by Elsevier B.V.