Electrodeposition of CoMn onto stainless steels interconnects for increased lifetimes in SOFCs

A pulse and pulse reverse electrochemical deposition process is being developed for cost effective coating of solid oxide fuel cell (SOFC) interconnects. Faraday Technology and WVU demonstrated that the developed process could produce uniform dense, crack-free, well-adhered CoMn alloy coatings of various compositions on a 5 cm x 5 cm 441 stainless steel interconnect surface. The post-deposition thermal treatment converted the CoMn alloy coatings to (Mn,Co) ₃O ₄ spinels in which a coating thickness of ∼3 μm was shown to be sufficient to mitigate chromia diffusion and oxidation. Various electrochemical deposition-processing parameters are examined to determine their affect on the coatings performance, while the coatings thickness and composition are also varied in order to obtain preliminary coating performance limits. Additionally, a preliminary economic analysis based on using batch manufacturing for the pulse reverse electrodeposition process demonstrated that the innovative coating technology can meet DOE's high volume target of 1,600,000 plates per annum for 250 MW of fuel cell stacks at a cost of ∼$1.23 per 25 cm x 25 cm coated interconnect.