Optimum design of the carbon composite bipolar plate (BP) for the open cathode of an air breathing PEMFC

Abstract

The proton exchange membrane fuel cells (PEMFCs) are a promising source of portable power due to its high energy density, low emissions and wide power range. However, PEMFCs have some limitations for portable applications because of the supplementary power consumption and the mass increase by balance of plants, such as the fuel pump, air compressor and humidifier. In this study, a light mass PEMFC system was developed using carbon composite bipolar plates (BPs) and an air breathing stack design with open cathode channel configurations to reduce the mass of the stack. However, under the high compaction pressure, the failure occurred in the carbon composite BPs for the open cathode. To enhance the durability of the BP against the compaction pressure, the finite element analysis, the compressive test and the fracture toughness test were performed. The maximum compaction pressure on the BP was calculated by applying the maximum strain failure criterion to the composite BP. Then, the optimum thickness and stacking sequence of the open cathode bipolar plate were determined by considering the mass and the maximum compaction pressure.