Electrochemical Synthesis of PANI on 316L Stainless Steel Bipolar Plates of PEMFC and its Corrosion Performance

Abstract

PANI conducting polymer coating was electrochemically deposited on 316L stainless steel bipolar plates of PEMFC in the bath of 0.5M H2SO4 and 0.5M aniline. PANI coating could be synthesized with optimal conditions presenting in smooth and dense feature when the voltage was from 0.75V to 0.85V(Vs.SCE). The anti-corrosion performance of the coating was evaluated by electrochemical technique in the medium of 1M H2SO4 and 2ppM NaF at 70°C to simulate the working environment of PEMFC. It was found that the anodic branch of polarization curves presented in passivation character. EIS results indicated that the radius of the capacity impedance for PANI coating increased distinctly, which validated the excellent corrosion resistance of the coating. The surface morphology of the coating was observed by SEM, and the results showed that the surface of 316L stainless steel bipolar plates was covered by claviform shape coating. The chemical composition of the coating was investigated by FTIR and the results illustrated that the coating were composed of PANI.