No abstract

Composites of polymer binders and conductive particles (e.g., graphite powder) are an interesting alternative bipolar plate material, since they are less expensive than pure graphite and less corrosion‐sensitive than metals. By appropriate choice of both components these composite materials can be tailored to meet the requirements of good high‐volume processability (e.g., by injection‐molding) and adequate behavior under fuel cell operation. Another graphite‐based bipolar plate material is graphite foil which is obtained by pressing expanded natural graphite. Both graphite based bipolar plate materials described in this chapter can be considered as “specialists” for different fuel cell applications. Graphite foil is especially attractive for lightweight fuel cell applications, e.g., in the portable and automotive field. For both kinds of bipolar plates, material issues are discussed and the processing technologies are described. Furthermore, techniques to reduce the contact resistance of molded graphite/polymer composite bipolar plates and to increase the gas‐tightness of graphite foil are indicated. The strong influence of the specifications of the starting materials and the processing conditions on the product quality is pointed out.