Low-nickel austenitic stainless steel as an alternative to 316L bipolar plate for proton exchange membrane fuel cells

Suitability of low Ni austenitic stainless steel (201 SS) as an effective alternative to 316L stainless steel bipolar plates for proton exchange membrane fuel cells (PEMFC) was investigated. Polarization studies showed 201 SS behaved similar to 316L in the cathodic environment of fuel cell, but performed poorly in the anodic environment. Electrochemical impedance spectroscopy (EIS) studies revealed that in the anodic environment the oxide thickness and resistance of 201 SS is lower than 316L, whereas in the cathodic environment both steels showed similar behavior. Mott-Schottky analysis revealed that the defect concentration in oxide layer is higher for 201 SS at the anodic environment, whereas the oxide stability is better than 316L at the cathodic environment. The interfacial contact resistance (ICR) for both the steels was similar.