Gadolinia-doped ceria and yttria stabilized zirconia interfaces: Regarding their application for SOFC technology

For solid oxide fuel cells (SOFCs) operating at intermediate temperatures the adjacency of the state-of-the-art yttria-stabilized zirconia (YSZ) electrolyte with ceria-based materials to both anodic and cathodic sides is regarded as crucial Tor the effectiveness of the cell. Solid-state reaction, however, and interdiffusion phenomena between YSZ and ceria-based materials can cause degradation of the electrolyte. When a gadolinia-doped-ceria (GDC) layer is used to protect YSZ against interaction with Go-containing cathodes, an unfavorable solid stair reaction at the YSZ-GDC interface can be efficiently suppressed when a thin (less than or equal to1 mum thick) interlayer with nominal composition of Ce0.43Zr0.43Gd0.10Y0.04O1.93 is incorporated at the interface. When ceria is to be employed at the electrolyte-anode interface to reduce polarization losses, use of a ceria-40% vol Ni cermet is recommended, since suppression of the reactivity between YSZ and ceria can also be achieved in the presence of Ni. (C) 2000 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved.