Work

Protective TiOxNy -based multilayer coatings for 316L stainless steel bipolar plates in a PEM water electrolyzer

Year: 2025

Type: article

Abstract: The present work reports the optimization of magnetron-sputtered titanium/titanium oxynitride thin-film coatings for application on 316L stainless steel bipolar plates (BPP) in proton exchange membrane water electrolyzers (PEMWE). As it will be shown, these coatings display tunable electrical conductivity and mechanical hardness to optimize the interfacial contact resistance (ICR). By controlling the elemental composition and thickness of the coating, and by using multilayers instead of single TiON layers, the ICR can be reduced to 1.5 mΩ cm 2 , a value lower than the targeted ICR (10 mΩ cm 2 ) for BPP in PEMWE. Moreover, due to its stable oxide nature, in contrast to uncoated steel, the coated steel was undamaged after 168 h at 60 °C under the experimental conditions found in PEMWE, in which the BPP surface potential is decoupled from the cell voltage. This proposed low-cost coating should therefore be considered as a promising material to enhance the competitiveness of the PEMWE technology. • Novel thin titanium oxynitride (TiO x N y )-based coatings were deposited on 316L stainless steel substrates. • TiO x N y /Ti/TiO x N y multilayer coatings improve the interfacial contact resistance with respect to single TiO x N y layers. • Coated SS316L exhibits stability and no sign of metal leaching after 168 h under BPP-like conditions.

Source: International Journal of Hydrogen Energy

DOI: 10.1016/j.ijhydene.2025.151650