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.

Automated summary

NiCrCN coatings were deposited on SS316L substrates using CFUMSIP to improve the corrosion resistance and electrical conductivity of PEMFC bipolar plates. The results showed the existence of various phases in the coatings, and increasing the content of Cr7C3 can reduce the interfacial contact resistance. Additionally, the coating exhibited the most intensive cross-sectional growth pattern at a Cr target current of 4A, and the current density after prolonged polarization was significantly lower than that of SS316L.