Optimizing the interfacial potential distribution to mitigate high transient potential induced dissolution on C/Ti coated metal bipolar plates used in PEMFCs

Developing a conductive and corrosion-resistant coating on metal bipolar plates is essential to mitigate the degradation induced by the high cathodic transient potentials of proton exchange membrane fuel cells. In this work, a multilayer nanoscale C/Ti coating is prepared on SS316L (C/Ti/SS). The C/Ti/SS achieves a highly prominent ICR of 1.59 mΩ cm² and corrosion rate of 2 × 10^–8 A/cm², remarkably better than the targets. Analysis of coating microstructure and composition suggests that the significantly enhanced corrosion resistance is attributed to the diffusional interfaces which optimize the potential distribution across the coating and improve the transpassive potential of C/Ti/SS.