Low temperature deposited (Ce,Gd)O2−x interlayer for La0.6Sr0.4Co0.2Fe0.8O3 cathode based solid oxide fuel cell

Abstract

Application of La0.6Sr0.4Co0.2Fe0.8O3 perovskites cathode in solid oxide fuel cell (SOFC) can benefit from its high electrocatalytic activity at 600–800°C. However, due to the chemical and mechanical incompatibility between the LSCF cathode and state-of-the-art yttria stabilized zirconia (YSZ) electrolyte, a ceria-based oxide barrier interlayer is usually introduced. In this work, gadolinia doped ceria (GDC) interlayers are prepared by screen printing (SP), electron beam evaporation (EB) and ion assisted deposition (IAD) methods. The microstructures of the GDC interlayers show great dependence on the deposition methods. The 1250°C-sintered SP interlayer exhibits a porous microstructure. The EB method generates a thin and compact interlayer at a low substrate temperature of 250°C. With the help of additional energetic argon and oxygen ions bombardment on the deposited species, the IAD method yields the densest GDC interlayer at the same substrate temperature, which leads to the best electrochemical performance of LSFC-based SOFC.