Development of Ti bipolar plates with carbon/PTFE/TiN composites coating for PEMFCs

A highly corrosion resistant and conductive carbon/PTFE/TiN composite coating on Ti bipolar plates is prepared by a two-step hydrothermal and impregnation process. The composite coating exhibits a full coverage with uniformly distributed PTFE and TiN particles when 0.1 mol/L of glucose is used as carbon source and 10 wt % PFTE + 3 g/L TiN suspension as impregnating solution. The as-prepared composite coating film shows 0.009 A cm(-2) of corrosion current density and 13 m Omega cm(2) of ICR in the simulated solution of proton exchange membrane fuel cells, respectively. Meanwhile, the potentiostatic polarization test shows that the corrosion current density of the composite coating is below 1 mu A cm(-2) under real PEMFC working conditions of the cathode (0.6 V) and anode (-0.1 V). Additionally, the composite coating enhances hydrophobic property with a static contact angle of 120.2 degrees and 115.5 degrees before and after polarization test, respectively. In summary, the Ti substrate with carbon/PTFE/TiN composite coating shows a great potential application as bipolar plates of PEMFCs. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.