Influence of anode pore forming additives on the densification of supported BaCe0.7Ta0.1Y0.2O3-δ electrolyte membranes based on a solid state reaction

We describe a solid state reaction for the preparation of both NiO-BaCe0.7Ta0.1Y0.2O3-delta anode substrates and BaCe0.7Ta0.1Y0.2O3-delta (BCTY10) electrolyte membranes on porous NiO-BCTY10 anode substrates. The amounts of the pore forming additive in the substrates showed a significant influence on the densification of the BCTY10 membranes. After sintering at 1450 degrees C for 5 h, the BCTY10 membrane on a NiO-BCTY10 anode containing 30 wt.% starch achieved a high density and showed adequate chemical stability against H2O and CO2. The chemical stability of BCTY10 was even better than that of BaCe0.7Zr0.1Y0.2O3-delta. With a mixture of BaCe0.7Zr0.1Y0.2O3-delta (BZCY7) and La0.7Sr0.3FeO3-delta (LSF) as a cathode, a single fuel cell with 12 mu m thick BCTY10 electrolyte generated maximum power densities of 142, 93, 29 mW/cm(2) at 700, 600 and 500 degrees C, respectively. The electrolyte resistance and interfacial polarization resistance of the cell under open circuit conditions were also investigated. (C) 2009 Elsevier Ltd. All rights reserved.