Functionalized polymers in general are claiming more and more novel applications; for example, they can function as a metal replacement. Especially the E&E- market or the green technologies re-quire highly engineered polymers with a high level of thermal or electrical conductivity. To functional-ize an intrinsically isolating polymer high loadings of conductive fillers, like graphite, carbon blacks, CNTs, metals and/or others, are necessary. For fuel cell applications contents of more than 80 wt% of graphite in a thermoplastic polymer are needed to function as bipolar plate material.
Since the fuel cell is a very demanding environment for materials, only very corrosion resistant materials can be applied. Typically, petrochemical polypropylene is used as a matrix material in graphite composite bipolar plates. And furthermore, since the catalyst of the fuel cell is very sensitive to pollutants, synthetic graphite is used, which is very energy intensive in production.
In an ongoing research project, the goal is to find more climate friendly alternatives to these two materials, while still maintaining performance of the bipolar plate. For this purpose, drop-in polymers and bio-polymers are evaluated as matrix material, while synthetic graphite is replaced by natural graphite.
To proof performance bipolar plates are used in a stack test and compared to conventional materials.