Fabrication of Sm0.5Sr0.5CoO3-δ-Sm0.1Ce0.9O2-δ cathodes for solid oxide fuel cells using combustion CVD

This study aims at optimization of major processing parameters of combustion CVD for solid oxide fuel cell (SOFC) electrode fabrication. A series of depositions were performed to reveal the correlation between process parameters and the microstructures observed as well as the interfacial resistances between electrodes and electrolytes. It is found that deposition temperature has a significant impact on electrode morphology as well as interfacial resistance. Deposition temperatures lower than 1000 degreesC resulted in cathodes with very high interfacial resistances while temperatures higher than 1400 degreesC led to over-densification. Thus for deposition of Sm0.5Sr0.5CoO3-delta (SSC) - Sm0.1Ce0.90O2-delta (SDC) composite cathodes on Gd0.1Ce0.9O2-delta (GDC) electrolyte, the performance is optimized at deposition temperatures between 1200 and 1300 degreesC. Cathodes of 25-40 mum thick can be deposited onto GDC pellets in 5 - 10 min using a 0.05 M precursor solution. The interfacial polarization resistances between SSC-SDC electrode and YSZ electrolyte were two orders of magnitude higher than those between the electrode and GDC electrolyte. (C) 2004 Elsevier B.V. All rights reserved.