Investigation on the corrosion resistance of carbon black–graphite-poly(vinylidene fluoride) composite bipolar plates for polymer electrolyte membrane fuel cells

• Published in: International journal of hydrogen energy 2011-09, Vol.36 (19), p.12474-12485
• Main Authors: Antunes, Renato Altobelli, Lopes de Oliveira, Mara Cristina, Ett, Gerhard
• Format: Article
• Language: English
• Subjects: Alternative fuels. Production and utilization; Applied sciences; Carbon black; Composite bipolar plates; Corrosion; Corrosion resistance; Electrical resistivity; Electrochemical impedance spectroscopy; Energy; Exact sciences and technology; Fluorides; Fuel cells; Fuels; Hydrogen; PEM fuel cells; Poly(vinylidene fluoride); Polyvinylidene fluorides; Resistivity
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2011.06.131

The goal of the present work was to evaluate the corrosion resistance of carbon black (CB)-synthetic graphite (SG)-poly(vinylidene fluoride) (PVDF) composites using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization curves. The tests were conducted in 0.5 M H 2SO 4 + 2 ppm HF solution at 70 °C to simulate the typical environment of polymer electrolyte membrane fuel cells. The fracture surface of the specimens was characterized by scanning electron microscopy. The through-plane electrical conductivity was also determined. The corrosion resistance decreased as the carbon black content increased up to 5 wt.%. The highest electrical conductivity was achieved for the composition CB = 5 wt.%, PVDF = 15 wt.%, SG = 80 wt.%. A detailed discussion of the EIS data is given. This approach is unprecedented in the current literature. EIS has proven to be a valuable tool to the design of electrically efficient bipolar plates. ► EIS results correlate with electrical conductivity measurements. ► Corrosion resistance depends on CB content and is inversely proportional to conductivity. ► The electrochemical behavior of the composites was explained by EIS modeling and SEM images.