A novel high corrosion-resistant polytetrafluoroethylene/carbon cloth/Ag coating on magnesium alloys as bipolar plates for light-weight proton exchange membrane fuel cells

摘要

( )Magnesium alloy is a promising material for light-weight bipolar plates of proton exchange membrane fuel cell (PEMFC) owing to its low density, but high susceptibility to corrosion limits the application. In this paper, a novel hydrophobic Polytetrafluoroethylene (PTFE)/Carbon cloth/Ag multilayer coating is fabricated on Mg substrate. Potentiodynamic polarization results reveal that the multilayer coating decreases the corrosion current density of bare Mg dramatically from 17.24 mu A/cm(2) to 0.058 mu A/cm(2), meanwhile, the interfacial contact resistance (ICR) between carbon paper and coated magnesium drops from 100.6 m Omega(2) cm(2) to 27.28 m Omega(2) cm(2) at 1.4 MPa. The mechanism of the superior corrosion resistance and electrical property of coated Mg is discussed, which may shed light on the development of the novel light-weight magnesium bipolar plates of PEMFC.