Interface induced degradation of amorphous carbon films/stainless steel bipolar plates in proton exchange membrane fuel cells

In the field of proton exchange membrane fuel cells (PEMFCs), amorphous carbon (aC) films have attracted considerable attention as a surface functional coating for metallic bipolar plates (BPPs), given that they can endow metallic BPPs with both high corrosion resistance and electrical conductivity under harsh PEMFC environments. In this study, to determine the role of aC/metallic substrate interfaces on the performance of PEMFCs, and clarify the associated degradation mechanism, a series of aC films are deposited on 316L stainless steel (316Lss) samples at different sputtering powers. The composition, microstructure, interfacial contact resistance (ICR), and corrosion resistance of the aC films are then systemically investigated, before and after electrochemical corrosion tests. The results obtained reveal that all the aC films can greatly improve the performance of 316Lss under simulated PEMFC operational …