Coating developments for Metal-supported Solid Oxide Fuel Cells

Metal supported cells (MSC) are considered the next generation Solid Oxide Fuel Cells due to higher robustness and cost-efficiency. However, improvement of the low temperature performance ( 700°C), increased durability and the use of manufacturing routes compatible to the metal substrate are key parameters for success. Within the EU-FCH JU project RAMSES, HÖGANÄS AB has developed a metallic powder appropriate for the manufacturing of the porous metallic substrates for MSCs, while SINTEF has developed protective coatings in order to improve the oxidation resistance of the metal under operating conditions, reduce the chromium evaporation and poisoning, and increase the conductivity of the protective oxide scale. In this project, both anode-side and cathode-side options are considered, i.e., the anode or the cathode is deposited onto the metallic substrate. The oxidation of the coated and non-coated pre-sintered porous metallic substrates under conditions relevant for anode- or cathode side metal supported SOFC has been compared by CEA. The oxidation tests and post-characterization confirm extensive formation of iron oxides for uncoated metal substrates at 600 °C in wet hydrogen, while the oxidation resistance is improved by a factor of more than 1000 by coating the pre-sintered porous metallic substrate. Examples on coatings applied to the metal support both before and after sintering of the cell components, will be given. Results of the coating developments, including coating composition, coating procedure (application and sintering) and temperature stability will be presented.