Polymer electrolyte membrane (PEM) fuel cells have the potential for use in automotive propulsion system because of their low operating temperatures (<100oC) which allows quick start-up times. They have higher power density than other fuel cells and can sustain large load cycles. They are also less harmful to our environment. Stainless foils appear to be a promising candidate for future use as bipolar plates in PEM fuel cells. However, their main drawback is the corrosive products produced in a low pH environment of a fuel cell and the contact resistance due to the formation of surface passivation film. Nb-cladding and polymer coating are investigated as the protective layer on stainless steel foils. Failure mechanisms of void nucleation and growth from the intermetallic interface for Nb-SS foils are under investigation. Also, failure mechanisms of delamination and cracking of polymer coating of SS foils are under investigation.
Cross sectional micrograph after flattening tests of a Nb-clad stainless sheet.
Cross sectional micrograph after flattening tests of a polymer coated sheet.