In order to assess the applicability of titanium as a bipolar plate for polymer electrolyte fuel cells (PEFCs), the electrochemical surface characteristics of commercially available pure titanium were examined in simulated PEFC conditions. The results of the electrochemical tests showed that the cathode operating potential of PEFC, 0.64 V (vs. Ag/AgCl(3.33 kmol·m-3 KCl)), lay in the anodic passivation region for titanium. The operating potential of the PEFC anode, -0.36 V, lay in the cathodic region or the cathodic to anodic transition region. Under the PEFC cathode condition, a barrier-type film with high charge transfer resistance and high contact resistance formed on the specimen. Under the PEFC anode condition, an oxide film with low charge transfer resistance and low contact resistance formed by a dissolution-precipitation mechanism.
- Bipolar plate
- Contact resistance
- Fuel cell
- Polymer electrolyte fuel cell (pefc)