Bipolar plate materials for PEMFCs: A conductivity and stability study

Commercial stainless steels, Ni-based alloys and physical vapor deposition (PVD) chromium nitride (CrN)-coated stainless steels were evaluated as possible metallic bipolar plate materials in conditions that resemble a typical PEMFC cathode environment with respect to their interfacial contact resistance (ICR) and corrosion resistance. Results show that stainless steels have a high ICR and undergo corrosion. Although Ni-based alloys showed an ICR value comparable as to that of graphite, their behaviour was not satisfactory in a corrosive acidic medium. Only CrN-coated stainless steels demonstrated to have low ICR values and a very good corrosion resistance.