Nano Cr–N/Ti–N multilayers coating is deposited on the SS304 surface by cathodic arc-PVD to enhance electrical conductivity and corrosion resistance of SS304 applied as a bipolar plate in PEMFCs. Afterward, the thickness, composition, corrosion rate, interfacial contact resistance and hydrophobicity of the samples are identified. According to the findings, the nano Cr–N/Ti–N multilayer can considerably increase the corrosion resistance due to the enhanced numbers of interfaces and preparing dense coating. The corrosion current density of the coating in the experimentally prepared cathodic solution of the fuel cell is 0.187 μA cm–2, which satisfies targets set by the DOE 2025 (i.e., <1 μA cm−2). The total porosity of coating is 0.0033% which illustrates the very dense nano multilayer PVD deposition. Moreover, the contact angle results indicate that Cr–N/Ti–N can enhance the hydrophobicity of electrode surface. The ICR measurements between the carbon paper and Cr–N/Ti–N coating before and after polarization shows very low value, which is in accordance with the U.S. DOE requirement (≤10 mΩ cm2 ).
