Investigation of SmBaCuCoO5+δ double-perovskite as cathode for proton-conducting solid oxide fuel cells

SmBaCuCoO5+delta, a double-perovskite oxide, was synthesized by the modified Pechini method and developed as cathode material for proton-conducting solid oxide fuel cells. The SmBaCuCoO5+delta powders calcined at 800 degrees C, show the double-perovskite structure in powder XRD pattern. SmBaCuCoO5+delta has a more suitable thermal expansion coefficient than SmBaCo2O5+delta for BaCe0.7Zr0.1Y0.2O3-delta electrolyte-based solid oxide fuel cells. The single cell was tested with humidified hydrogen (similar to 3% H2O) as the fuel and static air as the oxidant. The performance of the cell was characterized by DC Electronic Load and AC impedance spectroscopy. The peak power densities reached 355-86 mW cm(-2) in the range of 700-550 degrees C and the interfacial polarization resistance decreased with increasing operation temperature, from 3.1 Omega cm(2) at 550 degrees C to 0.22 Omega cm(2) at 700 degrees C. The high power density and low polarization demonstrate that SmBaCuCoO5+delta is a potential candidate for proton-conducting solid oxide fuel cells. (C) 2010 Elsevier Ltd. All rights reserved.