High corrosion resistance and through-plane electrical conductivity of C/Ti and C/Cr coated metal bipolar plates used in PEMFC

• Published in: Energy (Oxford) 2024-03, Vol.291, p.130366, Article 130366
• Main Authors: Fan, Hong-Qiang, Zhu, Xuan, Wang, Zhi-Long, He, Ze-kai, Hu, Jian-Feng, Behnamian, Yashar
• Format: Article
• Language: English
• Subjects: Buffer layer; Carbon film; Corrosion resistance; Interfacial contact resistance; Polymer electrolyte membrane fuel cell; Stainless-steel bipolar plate
• ISSN: 0360-5442
• DOI: 10.1016/j.energy.2024.130366

To improve the corrosion resistance and enhance the electrical conductivity in a simulated proton exchange membrane fuel cell, carbon bound SS316L stainless steel plates were modified with titanium (Ti) or chromium (Cr). The SS316L interfacial contact resistance of 312.38 mΩ·cm2 was reduced to 1.59 mΩ·cm2 when modified with Ti and to 1.32 mΩ·cm2 when modified with Cr. The increase in potential enhanced the shedding of C films and the oxidation and dissolution of Ti and Cr buffer layers. The corrosion current density in the C/Ti coating was lower than C/Cr coating under high voltage polarization. The oxidation of Ti and Cr buffer layers led to poor appetency between the C film and the SS316L and to degradation of the through-plane electrical conductivities in the C/Ti and C/Cr coated metal bipolar plates. •Ti or Cr were added to a carbon film to improve the corrosion resistance of SS316L.•Dissolutions of C/Ti and C/Cr film on SS316L after polarization were analyzed.•Pitting corrosion was the main cause of C/Ti/SS316L failure.•Intergranular and pitting corrosion were the main causes of C/Cr/SS316L failure.