Corrosion behavior of polyphenylene sulfide–carbon black–graphite composites for bipolar plates of polymer electrolyte membrane fuel cells

• The corrosion behavior of PPS–CB–graphite composites depends on the carbon black concentration.
• Oxidation of the composites at 0.6 V can significantly alter the corrosion behavior.
• The corrosion resistance tends to decrease for higher carbon black contents.
• Porosity and electrical conductivity are closely related to the corrosion behavior of the composites.

The aim of this work was to study the corrosion behavior of polyphenylene sulfide (PPS) – carbon black – graphite composites regarding their application as bipolar plates of polymer electrolyte membrane (PEM) fuel cells. Electrochemical impedance spectroscopy (EIS), potentiostatic and potentiodynamic polarization tests were used to characterize the electrochemical response of the composites in a simulated PEM fuel cell environment. Cross-sectional views of fractured specimens were observed by scanning electron microscopy (SEM). The results showed that the corrosion behavior depends on the carbon black content incorporated into the composite formulation. There was a trend of decreasing the corrosion resistance for higher carbon black contents. This behavior could be explained based on the porosity and electrical conductivity of the composites.