Exploring the potential of exfoliated graphene nanoplatelets as the conductive filler in polymeric nanocomposites for bipolar plates

This research explored the potential of using exfoliated graphene nanoplatelets, GNP, as the conductive filler to construct highly conductive polymeric nanocomposites to substitute for conventional metallic and graphite bipolar plates in the polymer electrolyte membrane (PEM) fuel cells. Polyphenylene sulfide (PPS) was selected as the polymer matrix because of its high thermal and chemical tolerance. Solid state ball milling (SSBM) followed by compression molding was then applied to fabricate PPS/GNP nanocomposites. Results showed that PPS/GNP nanocomposites made by this method exhibit excellent mechanical and gas barrier properties but unsatisfied electrical conductivity. However, it was found that the electrical conductivity of these nanocomposites could be substantially enhanced if we combine GNP with second minor conductive filler for a positive synergistic effect and also optimize the processing time of SSBM. Meanwhile, PPS impregnated GNP papers were embedded into these PPS/GNP nanocomposites in order to further improve various properties of the resulting bipolar plates. It is believed that the bipolar plates made from PPS/GNP nanocomposites will allow lighter weight of PEM fuel cells with enhanced performance which is particularly suited for automotive applications. (C) 2012 Elsevier B.V. All rights reserved.