Amorphous Carbon Surface Coating of Titanium Plates Toward Corrosion Protection of Bipolar Plates in Proton Exchange Membrane Fuel Cell

ABSTRACT Bipolar titanium plates in proton exchange membrane fuel cells (PEMFC) undergo corrosion due to aggressive chemicals produced during fuel cell performance. Anti‐corrosion coating of bipolar plates is a prospective strategy for improving the efficiency, safety, and durability of PEMFC. However, traditional coatings still face difficulties associated with complex preparation, low production rate, and uniform distribution of nanofillers. In this study, amorphous carbon coating (∼600 nm) for protection of titanium plates from corrosion in PEMFC environments by electrochemical deposition of polypyrrole followed by annealing is described. The resulting coating demonstrates a reduced corrosion current density of 0.168 µA/cm 2 and a positive shift of the corrosion potential of 101 mV compared to the Ag/AgCl electrode. Surface morphology, wettability, electrochemical tests, potentiostatic polarization, and immersion tests confirm stable corrosion resistance durability in accordance with accepted standards for fuel cells. Even with a thin layer nanosized coating demonstrated efficient contribution to corrosion inhibition due to it's hydrophobic nature. It is shown that the contact resistance and corrosion stability of the resulting coating not only meet the standards for fuel cells, but also exceed commercial samples (Toyota Mirai). This study advances the understanding of mechanisms of protection of bipolar plates in the PEMFCs environment.