Deposition of Vulcan XC-72/Polypyrrole Coatings on Stainless Steel Bipolar Plates by Reverse Pulsed DC Voltage Electrophoretic Deposition (EPD) for Fuel Cell Applications

摘要

In this study, surface coatings of a mixture of Vulcan XC-72 and polypyrrole (PPy), labeled as PPy-C, were deposited on stainless steel (SS) substrates by EPD under reverse pulsed DC voltage in order to study the corrosion protection. The effect of applied voltages (50, 70, 90 and 120 V) and deposition time (2, 6, 10 and 15 min) on the film characteristics was evaluated. The coatings were analyzed by SEM, and the result showed that the amount of PPy electrodeposited and the morphology of the film depended on the deposition conditions. Polarization curves were conducted in order to evaluate the corrosion resistance of the bipolar plates in 0.1 M H_2SO_4 at room temperature. The experimental results indicated that the PPy-C composites increased the corrosion potential of the SS and decreased the corrosion current density by one order of magnitude. The structure properties of the coatings were characterized by Fourier Transform Infrared Spectroscopy (FTIR), and the spectra shows the presence of characteristics absorption bands of PPy. These results indicated that EPD is a suitable technique to deposit polymer/carbon corrosion protection films for applications in fuel cell bipolar plates.