Low‐cost graphite coated copper as bipolar plates of proton exchange membrane fuel cells for corrosion protection

Abstract The aim of this essay is to explore a new method to prepare a graphite coating on the surface of copper foil. In our study, we find that when the treated copper foil is buried in natural flake graphite powder and heated to 900°C for 1 h, the surface of copper foil grows a graphite coating. The graphite coating on the surface of copper foil increases the corrosion resistance under the simulated proton exchange membrane fuel cell environment. At the same time, graphite coating also increases corrosion potential and is higher than the anode working potential. This keeps the anode in a cathodic protection state and avoids the generation of metal ions. Compared to the substrate, the coated potentiostatic polarization for 4 h shows that it is not only corrosion current density can get reduced by an order of magnitude but also can quickly reach a steady state. The value of the copper with graphite coating in interfacial contact resistance is ∼18.4 mΩ cm 2 under 1.4 MPa, which is also reaching the Department of Energy targets.