Ceria Based Protective Coatings for Steel Interconnects Prepared by Spray Pyrolysis

Stainless steels can be used in solid oxide fuel/electrolysis stacks as interconnects. For successful long term operation they require protective coatings, that lower the corrosion rate and block chemical reactions between the interconnect and adjacent layers of the oxygen or the hydrogen electrode. One of the promising coating materials for the hydrogen side is ceria. Using standard sintering techniques, ceria sinters at around 1400 °C which even for a very short exposure would destroy the interconnect. Therefore in this paper a low temperature deposition method, i.e. spray pyrolysis, is used to deposit thin (∼400 nm), continuous CeO2 layers on Crofer 22 APU steel substrates. Influence of the deposition parameters on layer quality is elucidated in this work.