Development of composite proton exchange membrane from polystyrene butadiene rubber and carbon nanoballs for fuel cell application

Sulphonated polystyrene butadiene rubber/carbon nanoballs (SPSBR/CNBs) composites proton exchange membrane was developed by sulphonation of polystyrene butadiene rubber using chlorosulphonic acid as the sulphonating agent. The sulphonated rubber was then blended with non-catalytic carbon nanoballs (CNBs) produced by swirled floating catalytic chemical fluid deposition (SFCCVD) method. The SPSBR/CNBs composites proton exchange membrane was characterized to determine the thermal stability, water uptake, porosity and proton conductivity. The results obtained revealed that blending of the membrane with CNBs improved the thermal stability, water uptake retention and proton conductivity of the membrane with about 50% increase in proton conductivity. The synthesized and composite membranes were sandwiched between two electrodes to produce a membrane electrode assembly (MEA). The performance of the fabricated MEA was tested in a single PEM fuel cell using hydrogen as the fuel gas and oxygen as oxidant. The results obtained revealed that the utilization of SPSBR-CNBs composite proton exchange membrane resulted in higher performance compared to Nafion 112. Nafion 112 produced a maximum power density of 66.9 mW/cm2, while the developed membrane gave a maximum power density in the range of 73.7-97.1 mW/cm2 depending on the mass of CNBs.