Silver implanted 316L stainless steel as bipolar plates in polymer electrolyte membrane fuel cells

Abstract

The major concerns of bipolar plates in polymer electrolyte membrane fuel cells (PEMFCs) are their corrosion resistance and interfacial contact resistance (ICR). Silver is well known for its excellent conductivity and good corrosion resistance. In this study, the performance of austenitic stainless steel 316L (SS316L) implanted with Ag is evaluated in the simulated polymer electrolyte membrane fuel cell (PEMFC) environment. The potentiodynamic test reveals that Ag implant improves the corrosion resistance of SS316L. The corrosion potential of SS316L shifts towards the positive direction from −0.30 V vs SCE to −0.04 V vs SCE in the anode environment and the passivation current density at 0.6 V is reduced from 11.26 μA cm −2 to 8.25 μA cm −2 in the cathode environment. The potentiostatic tests reveal a significant decrease from 10 μA cm −2 to 0.7 μA cm −2 after Ag implantation. Furthermore, the chemical stability in the simulated cathode environment and conductivity are improved after Ag implantation. The beneficial effects can be attributed to the addition of silver to the surface and reduction in the passive layer thickness caused by the ion implantation.