Multilayer coating for a corrosion-resistant metal bipolar plate for a proton exchange membrane fuel cell (PEMFC)

摘要

The present disclosure includes a fuel cell bipolar plate having a coating and methods of forming the coating. The bipolar plate may comprise a steel substrate and a coating in contact with the steel substrate. The coating may comprise a plurality of alternating oxide-forming layers and elution-resistant layers. The oxide-forming layers may comprise pure titanium, doped titanium or a titanium alloy (eg doped / alloyed with niobium, zirconium, vanadium, silver, tantalum, yttrium, scandium or nitrogen) and the elution resistant layers may be a noble metal or tantalum (e.g. B. gold, iridium, ruthenium or tantalum). There may be 2 to 20 layers each of the oxide-forming layers and the elution-resistant layers. The coating can prevent elution of iron ions from the steel substrate, for example, by forming oxide plugs in defects or pinholes in the oxide-forming and / or elution-resistant layers. The coating can also reduce the overall consumption of precious metals, such as gold.