Growth of Cr-Nitrides on Commercial Ni-Cr and Fe-Cr Base Alloys to Protect PEMFC Bipolar Plates

Journal Article · Mon Jan 01 00:00:00 EST 2007 · International Journal of Hydrogen Energy

DOI:https://doi.org/10.1016/j.ijhydene.2006.08.044· OSTI ID:978213

Brady, Michael P ^[1]; Wang, Heli ^[2]; Yang, Bing ^[1]; Turner, John ^[2]; Bordignon, Melanie ^[3]; Molins, Regine ^[3]; Abdelhamid, Mahmoud ^[4]; Lipp, Ludwig ^[5]; Walker, Larry R ^[1]

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1. ORNL
2. National Renewable Energy Laboratory (NREL)
3. Ecole des Mines de Paris
4. General Motors Technical Center
5. FuelCell Energy Inc

Nitridation of Cr-bearing alloys can yield low interfacial contact resistance (ICR), electrically- conductive and corrosion-resistant CrN or Cr2N base surfaces of interest for a range of electrochemical devices, including fuel cells, batteries, and sensors. This paper presents results of exploratory studies of the nitridation of two high Cr (30-35 wt%) commercially available Ni-Cr alloys and a ferritic high Cr (29 wt.%) stainless steel for proton exchange membrane fuel cell (PEMFC) bipolar plates. A high degree of corrosion resistance in sulfuric acid solutions designed to simulate bipolar plate conditions and low ICR values were achieved via nitridation. Oxygen impurities in the nitriding environment were observed to play a significant role in the nitrided surface structures that formed, with detrimental effects for the Ni-Cr base alloys, but beneficial effects for the stainless steel alloy. Results of single-cell fuel cell testing are also presented.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). High Temperature Materials Lab. (HTML)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 978213
• Journal Information: International Journal of Hydrogen Energy, Vol. 174, Issue 1
• Country of Publication: United States
• Language: English