Develop of advanced bipolar plate using carbon fiber prepreg and graphite/polymer composite materials

In this study, we introduce an advanced composite bipolar plate (BP) to improve mechanical behaviors of BPs as compared to conventional composite BPs. The new BPs are fabricated by compression molding process in which the mixture of natural graphite particles as a major filler, synthetic graphite and carbon blacks (CBs) as the additive are compacted and integrated with epoxy-carbon fiber prepreg. The new BPs are evaluated and the test results clearly demonstrate that the proposed BP is superior to typical carbon composite BPs in terms of key BP properties including electrical conductivity with emphasis on its outstanding flexural strength. The unique feature of this new BP enables to further reduce the thickness of BPs, which directly contributes the reduction in fuel cell stack weight and volume.