Multifunctional Nano-Coatings for SOFC Interconnects

Abstract

Chromium evaporation from metallic interconnects in SOFCs is commonly poisoning the cathode of SOFCs. To reduce chromium evaporation, rather thick coatings have been deposited using various coating techniques. In this study a 22% Cr ferritic steel has been coated with multilayered nano coatings. The best coatings combine a Cr retention layer (800nm Co) with a 10nm layer of Ce that reduces the corrosion rate of the metallic interconnect. Such coatings might be a cost efficient way to meet the required lifetime targets for SOFC interconnects. The Cr evaporation measurements are carried out with a recently developed denuder technique which allows time resolved quantification of volatile chromium species. Downstream of the samples a denuder tube is placed which collects any CrO2(OH)2 evaporating from the samples.