Polymer Composites Bipolar Plates for PEMFCs

AbstractIn order to improve their commercial liability, many scientific and technological efforts are being performed on fuel cell systems. The bipolar plates represent a major part of the stack with about 80% of the total weight and 30 to 40% of cost. On the technical point of view, bipolar plates should fulfill functional challenges besides ensuring the mechanical strength of the stack. As a result an optimal material for bipolar plate application should present an unusual balance of properties, essentially high electrical conductivity and good mechanical strength. To date, many different materials for bipolar plates have been investigated and an alternative solution consists in polymer composite that com-bine the processability and mechanical properties of the polymeric phase and the conductivity of the carbon fillers. This communication provides a state-of-the-art review of the current development, manufacturing and structure-property re-lationship of polymer composites designed for bipolar plates applications. Both thermoset resins and thermoplastics were considered and combined to many different carbon fillers: graphite, carbon fibers, carbon black, carbon nanotubes. The interests and limitations of these formulations are presented in terms of processability and most relevant properties. A debate on the optimization of electrical and mechanical properties is presented