This study aimed at developing highly conductive, lightweight, and low-cost bipolar plates for use in proton exchange membranes (PEM) fuel cells. Injection and compression molding of highly filled polypropylene, PP, and polyphenylene sulfide, PPS, based blends were used as a mean for mass production of bipolar plates. Loadings up to 60-wt% in the form of graphite, conductive carbon black and carbon fibers were investigated. The developed formulations have a combination of properties and processability suitable for bipolar plate manufacturing, such as good chemical resistance, sufficient fluidity, and good electrical and thermal conductivity. Electrical resistivities around 0.15 and 0.09 Ohm-cm were respectively achieved for the PP and PPS-based blends, respectively. Two bipolar plate designs were successfully fabricated by molding the gas flow channels over aluminum plates to form a metallic/polymer composite plate, or simply by direct injection molding of the conductive polymer composite. For the first design, overall plate resistivities of 0.2 and 0.1 Ohm-cm were respectively attained using PP and PPS based blends as conductive skin. A lower volume resistivity of around 0.06 Ohm-cm was attained for the second injected plate design with PPS based blend.
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