Interconnect materials for next-generation solid oxide fuel cells

Highly-efficient solid oxide fuel cell (SOFC) systems are gaining increased attention for future energy conversion applications. Many planar SOFC stack designs utilise ferritic stainless steel (FSS) interconnect components. During operation, surface corrosion of FSS interconnects degrades stack operation by increasing electrical resistance and introducing other deleterious material interactions. To minimise these effects, various surface modifications and coatings are currently under investigation. Two of these methods under development for this application are: metal organic chemical vapour deposition (MO-CVD); and, large area filtered arc deposition (LAFAD). SOFC interconnect-relevant corrosion behaviour of an MO-CVD coating on Crofer 22 APU, AL453, Fe30Cr and Haynes230, and complex, amorphous LAFAD AlCrCoMnTiYO coatings on FSS 430 were investigated. Both of these surface modifications and coatings exhibit significantly improved corrosion protection as compared with uncoated FSS samples.