Effect of Magnetic Field on Corrosion Behaviors of Gold-Coated Titanium as Cathode Plates for Proton Exchange Membrane Fuel Cells

Abstract

Effects of the self-induced magnetic fields (MFs) generated by the operating current of proton exchange membrane fuel cells (PEMFCs) on metal bipolar plates have hardly been noticed but cannot be ignored. Therefore, corrosion behaviors and conductivity of gold-coated titanium (Ti/Au) and bare titanium (grade TA2) in simulated PEMFC cathode environment under MF were evaluated by electrochemical tests and interfacial contact resistance (ICR) measurements. The results indicated a considerable decrease in corrosion current and ICR of as-received Ti/Au, reaching 1/16 and 1/10 of those of bare TA2, respectively. The applied MF also led to a sharp decline in corrosion current of TA2 but slight increase for Ti/Au. Electrochemical impedance spectroscopy and scanning electron microscopy results suggested that MF significantly facilitated the corrosion durability of TA2 and ameliorated the induced pitting due to coating defects on Ti/Au. Compared to results obtained without MF, ICR of TA2 after 24 h potentiostatic polarization under MF further increased by 24%, while a decrease by 8% was recorded for Ti/Au. In sum, effects of self-induced MFs on the corrosion of metal bipolar plates is significant and these results revised for taking MF effects in account could be more accurate and realistic.

Review on Magnetism in Catalysis: From Theory to PEMFC Applications of 3d Metal Pt-Based Alloys

“…Some authors also investigated the effect of these self-induced magnetic fields on the corrosion of the metal bipolar plates in PEMFCs. S. Feng and co-workers investigated such effects on Ti- and Au-coated Ti (Ti/Au) cathode plates [ 437 ]. The self-induced magnetic field was simulated by inserting a Nd-Fe-B permanent magnet into the electrodes.…”