A comprehensive performance study of NiCrCN coated 316L stainless steel as bipolar plates for proton exchange membrane fuel cell

NiCrCN coatings are deposited on the surfaces of 316 L stainless steel (SS316L) substrates via closed field unbalanced magnetron sputtering ion plating (CFUMSIP) to improve the corrosion resistance and electrical conductivity of proton exchange membrane fuel cell (PEMFC) bipolar plates. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) results show that CrN, Cr2N, Ni, and Cr7C3 phases exist in NiCrCN coatings. As the Cr target current grows from 2 A to 6 A, the Cr7C3 content in the carbon compounds increases from 3.39% to 11.46%, and the interfacial contact resistance (ICR) value is reduced from 18.0 mU cm2 to 11.2 mU cm2. When the Cr target current reaches 4 A, the NiCrCN coating shows the most intensive cross-sectional growth pattern by cold-field scanning electron microscopy (CFSEM) results, and the current density after prolonged polarization (0.11 mA cm-2) is much lower than that of SS316L (1.86 mA cm-2).(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.