Electrochemical and mechanical behavior of carbon composite bipolar plate for fuel cell

Composite bipolar plates for fuel cells were prepared by a compression molding technique using novolac type phenol formaldehyde resin as a binder and natural graphite, carbon black and carbon fiber as reinforcements. The plates were characterized for electrical conductivity, mechanical strength and corrosion resistance. The flexural strength of the bipolar plate for optimum composition (PF:30%; NG:60%; CB:5%; CF:5%) was 55.28 MPa, with a deflection of 5.2% at mid-span, while the in-plane and through-plane electrical conductivities were 286 and 92 S cm−1, respectively. Corrosion analyses were conducted in normal and rigorous simulated polymer electrolyte membrane fuel cell and alkaline fuel cell environments. The corrosion current density was close to the limit set by the USA Department of Energy. The corrosion current density at the optimum composition was found to be 0.99 μA cm−2 for polymer electrolyte membrane fuel cell and 17.62 μA cm−2 for alkaline fuel cell environments.