A cathode-supported SOFC with thin Ce0.8Sm0.2O1.9 electrolyte prepared by a suspension spray

Abstract

In order to develop a cost-effective route to fabricate solid oxide fuel cells (SOFCs), a dense Ce0.8Sm0.2O1.9 (SDC) electrolyte was fabricated on a porous cathode based on a mixed conducting La0.8Sr0.2FeO3-δ (LSF) via a suspension spray/co-firing process. For the purpose of shrinkage matching between the cathode support and the electrolyte membrane, nano-SDC1 powder for the easily sinterable electrolyte was synthesized with ammonia as the precipitant from the nitrates, whereas SDC2 powder prepared by modified glycine-nitrate method (GNP) was added into cathode to favor the shrinkage of La0.8Sr0.2FeO3-δ(LSF). Sm-doped ceria solid solution was directly formed during precipitation at 50 °C, and this is ascribed to the role of OH-. The powders calcined at 800 °C for 2 h were still uniform and exhibited an average particle size of 20 nm. The bi-layer with 10 μm dense SDC electrolyte was obtained by co-sintering at 1250 °C for 5 h. A thin and well-adherent anode was formed by depositing ultra-fine NiO-SDC powders, followed by sintering at 1000 °C. The obtained single cells were tested with humidified (3% H2O) hydrogen as fuel and the static air as oxidant. The maximum power density reached 67.2 mW/cm2 at 600 °C. © 2007 Elsevier B.V. All rights reserved.