Expanded Graphite Epoxy Composite Bipolar Plates for PEM Fuel Cells

Abstract

Light weight, flexible and thin single layer epoxy impregnated expanded graphite bipolar plates were manufactured and evaluated as a PEM fuel cell bipolar plate material. Mechanical strength values up to 17.41 MPa, in-plane electrical conductivity values up to 136.6 S/cm, through-plane electrical resistance of 0.027 Ohm-cm and flexibility (deflection at mid-span) values up to % 4.38 were obtained with epoxy impregnation in expanded graphite foams. The low thickness (~0.5 mm) and density (~1.2 g/cm3) values of the prepared composite plates put them one step ahead for mobile applications which require high mass and volumetric power density (W/kg, W/L). On the other hand, corrosion current and contact angle values of these composite plates couldn't achieve desired values.