Research Of Graphite Composite Bipolar Plates Of PEM Fuel Cells

The polymer electrolyte membrane fuel cells (PEMFC) are the most promising power sources in the near future. It is important to research the bipolar plates for industrialization of PEMFC. Graphite, metals, graphite composite materials and structural mulriple materials are used to make bipolar plate, but they all have different advantages and disadvantages.Composite bipolar plates for polymer electrolyte fuel cell have been prepared by vacuum compression moulding in which PF, ZD002 PI, ZD002 PI, GCPI and MF as bulking agent and graphite as bulk material. Firstly, influence of compaction pressure, different material, content of polymer and metal particles to contact resistance were studied. It was found that conductivity of the composite was increased with the graphite content increased. With increasing compaction pressure, the contact resistance of the materials decreased rapidly at low compaction pressures and then arrived gradually a constant value at high compaction pressure;There were less distinction of contact resistances among materials made of different polymers;Contact resistance decreased with increasing polymer's degree of scatter and content of graphite. It was increased if metal particle put in the composite material. Secondly, electrochemical analysis showed that composite material's corrosive behaviors was comparable with those of pure graphite had. The corrupt current of materials containing metal particle was large than that of no metal particles. Flexural strength, thermo-gravimetric analysis, dynamic mechanical thermal analysis and microphotograph of the material were examined for composite materials. All showed that ZD002 PI was one of good candidate material forbipolar plates.