Ultra high speed curing bipolar plates made of carbon fabric/phenolic composite using acid catalyst for proton exchange membrane fuel cell

Abstract

The proton exchange membrane fuel cell (PEMFC) is composed of bipolar plates, end plates, membrane electrode assemblies (MEAs) and gas diffusion layers (GDLs), from which the bipolar plate is a major component to determine the cost, volume and performance of the PEMFC stack. In this study, the bipolar plate has been developed using carbon fabric/phenolic composite because phenolic resin has much faster cure reaction than epoxy resin, which enables the carbon/phenolic resin based bipolar plate to be mass-produced. The p-toluene sulfonic acid catalyst is used to accelerate the curing reaction of carbon fabric/phenolic, and the electrical conductivity and tensile strength of the composites are measured with respect to catalyst content because these two characteristics of composite determine the performance of composite bipolar plate. The experimental results show that the curing time of the carbon fabric/phenolic decreased much as the amount of catalyst is increased. However both the tensile strength and interfacial contact resistance of the composite also decrease as the amount of catalyst is increased because the excess catalyst works as impurities in the composite. Therefore, an optimum content of the catalyst is investigated considering the electrical conductivity with little compromise of mechanical properties.