Layered PrBaCo2O5+δ perovskite as a cathode for proton-conducting solid oxide fuel cells

The layered PrBaCo2O5+delta (PBCO) perovskite oxides were synthesized by modified Pechini method and investigated as a cathode material for solid oxide fuel cells (SOFCs) based on a stable and easily sintered perovskite oxide BaCe0.5Zr0.3Y0.16Zn0.04O3-delta (BCZYZ) as electrolyte. The fabricated single cell of NiO-BCZYZ/BCZYZ (similar to 20 mu m)/PBCO was operated from 550 to 700 degrees C with humidified hydrogen (similar to 5% H2O) as fuel and the static air as oxidant. The BCZYZ perovskite electrolyte was completely dense after sintered at 1250 degrees C for 5 h, lower than that without zinc dopant about 150 degrees C. A high open-circuit potential of 1.007 V, a peak power density of 361 mW cm(-2), and a low polarization resistance of the electrodes of 0.12 Omega cm(2) was achieved at 700 degrees C. The ratio of polarization resistance to total cell resistance decreased with the increase of operating temperature, from 54.2% at 550 degrees C to 17.9% at 700 degrees C, respectively. The experimental results indicated that PBCO is a promising cathode material for proton-conducting SOFCs. (C) 2010 Elsevier B.V. All rights reserved.