Formable chromium nitride coatings for proton exchange membrane fuel cell stainless steel bipolar plates. (29th May 2020)

• Record Type: Journal Article
• Authors: Haye, Emile; Deschamps, Fabien; Caldarella, Giuseppe; Piedboeuf, Marie-Laure; Lafort, Adeline; Cornil, Hugues; Colomer, Jean-François; Pireaux, Jean-Jacques; Job, Nathalie
• Is Part Of: International journal of hydrogen energy. Volume 45:Number 30(2020)
• Page Start: 15358
• Page End: 15365
• Publication Date: 2020-05-29
• Subjects: PEMFC -- Chromium nitride coating -- ICR -- DoE target; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2020.03.248
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Among the different coatings developed for proton exchange membrane fuel cell steel bipolar plate, nitride-based coatings present several advantages compared to gold or polymeric coating: high chemical stability, low interfacial contact resistance and reasonable cost. In this work, 50 nm thick chromium nitride coatings are deposited by reactive magnetron sputtering on 316L stainless steel foil. They are optimized to fulfill the Department of Energy targets in terms of interfacial contact resistance (ICR) and corrosion resistance, with values of 8.4 mΩ cm −2 (at 100 N cm −2 ) and 0.10 μA cm −2 (in 0.6 M H2 SO4 solution at 0.48 V vs. SCE potential) respectively. Moreover, they retain their excellent properties after high deformation (biaxial deformation of 20% in x-axis and 5% in y-axis), giving the possibility to achieve, in line, the stamping of a bipolar plate from a coated foil. The etching of the substrate, prior to the coating deposition, appears to be determinant to obtain low and stable corrosion current and ICR. The removing of interfacial oxyde leads to better coating adhesion and improves the corrosion resistance and electrical conductivity. The enhancement of the properties (low ICR and high corrosion resistance) is durable, with no signicant change of the ICR value up to 200 days after deposition. Highlights: 50 nm CrN coating on 316L stainless steel promotes corrosion resistance and low ICR. The etching improves coating adhesion, corrosion resistance and low ICR. The low ICR and high corrosion resistance is retained after biaxial deformation.