Investigation on electrochemical behavior and surface conductivity of titanium carbide modified Ti bipolar plate of PEMFC

The titanium carbide (TiC) modified layer is prepared by plasma surface modification technology on the surface of Ti plate (TA1) to meet the performance requirements of bipolar plate of PEMFC. The microstructure characterization confirms that a compact and defectless TiC modified layer is formed on the surface of Ti bipolar plate. The corrosion current density of TiC modified plate in simulated PEMFC environment is reduced by approximately an order of magnitude and the self-corrosion potential is significantly improved compared with bare Ti plate. The interfacial contact resistance (ICR) of TiC modified plate (7.5 m Omega cm(2), under loading pressure of 140 N) is evidently lower than bare Ti plate (98.1 m Omega cm(2)). Even after potentiostatic polarization, the ICR of TiC modified plate still remains at satisfactory values. Furthermore, the contact angle of TiC modified plate reaches a higher value of 112 degrees, which is beneficial to the water discharge of PEMFC. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.