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

Abstract The layered PrBaCo 2 O 5+ δ (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 BaCe 0.5 Zr 0.3 Y 0.16 Zn 0.04 O 3− δ (BCZYZ) as electrolyte. The fabricated single cell of NiO-BCZYZ/BCZYZ (∼20 μm)/PBCO was operated from 550 to 700 °C with humidified hydrogen (∼5% H 2 O) as fuel and the static air as oxidant. The BCZYZ perovskite electrolyte was completely dense after sintered at 1250 °C for 5 h, lower than that without zinc dopant about 150 °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 Ω cm 2 was achieved at 700 °C. The ratio of polarization resistance to total cell resistance decreased with the increase of operating temperature, from 54.2% at 550 °C to 17.9% at 700 °C, respectively. The experimental results indicated that PBCO is a promising cathode material for proton-conducting SOFCs.