One-step electrodeposition of polypyrrole/Ti3C2Tx MXene composite coating for 304SS bipolar plates in PEMFC

Polypyrrole (PPY) coating is promising for the anticorrosion of stainless steel (SS) bipolar plates (BPs) in virtue of its good conductivity and corrosion resistance. However, the poor adhesion and pore defects of pure PPY coating limit its application. In this work, a PPY/Ti3C2Tx MXene composite coating was synthesized on 304SS BPs by one-step electrodeposition, which is a facile method to realize the polymerization of PPY and the doping of MXene at the same time. The PPY/MXene coating exhibits better long-term immersion stability in simulated proton exchange membrane fuel cell (PEMFC) environment than pure PPY. The enhanced corrosion resistance is mainly benefited from the enhanced barrier effect, anodic protection effect and adhesion by the introduction of MXene. Meanwhile, the introduction of MXene significantly improves the conductivity of the coating and decreases the interfacial contact resistance at 1.4 MPa from 108.16 mΩ·cm2 to 55.24 mΩ·cm2.