Electrodeposition of Cobalt-Manganese Alloy Coatings onto Metallic SOFC Interconnects

Abstract

A pulse electrodeposition process is being developed and validated for coating ferritic stainless steel solid oxide fuel cell interconnects with a cobalt-manganese alloy. The electrodeposition process produces the alloy coatings from a single acidic sulfate based electrolyte containing cobalt and manganese ions, sodium gluconate, ammonium sulfate and boric acid. Subsequent to electrodeposition, the alloy coatings are oxidized at elevated temperatures to form spinel structures. Experiments demonstrate that the pulse waveform parameters influence the chemical composition of the alloy coating. Survival of long term exposure at elevated temperatures has shown that the coatings function as a barrier to chrome diffusion toward the surface with minimal increase in the area specific resistance.