Graphite-epoxy composites for bipolar plates: The gas permeability issue

To sustain Hydrogen Economy, proton exchange membrane (PEM) devices are expected to play a central role in both the generation of clean hydrogen and its efficient employment. Bipolar plates are an essential part of PEM devices, therefore investigations directed to technical improvement and cost reduction of these components deserve considerable attention. This work represents an extension of our previous study on graphite-epoxy composites suitable for manufacturing bipolar plates and based on the use of cheap and commercially available materials. Through appropriate changes in the formulation of the composites and in the processing conditions, we succeeded in obtaining materials with full technical compliance, in terms of electrical conductivity and gas permeability. The processability and productivity of the method were improved as well, through the reduction of molding times. The variation of the properties of the samples with the molding pressure was analyzed.