Properties Of The Different Morphology Carbon Reinforced EG/PF Composite Bipolar Plate

The proton exchange membrane fuel cell (PEMFC) is a kind of clean energy,which convertes chemical energy directly into electrical energy. With thecharacteristics of high energy conversion rate, low pollution degree and operationtemperature, PEMFC has been widely used in household electricity, electric car andoutdoor power equipment. The bipolar plate is one of the main components ofPEMFC and affects the development of the fuel cell.The bipolar plate for PEMFC was studied from two aspects. First of all, theadsorption compound method and the melt mixing method were used to prepareexpanded graphite/phenolic resin (EG/PF) composite bipolar plate. The adsorptioncompound method toke full advantage of the porous structure of expanded graphiteand the physical characteristics of thermoplastic phenolic resin. The compositescomplexed very completely. Melt mixing method used phenolic resin powder as rawmaterials mixing with expanded graphite directly and the preparation process wassimple. The results showed that the preparation process would impact the productperformance greatly. When the content of phenolic resin was in a certain range, thebipolar plate could meet the requirements of the composite performance of the U.S.Department of Energy (DOE).In the second part, the solution blending method and melt mixing method weresynthesized to prepare different morphologies carbon materials reinforced EG/PFcomposite bipolar plate. The content of phenolic resin is fixed at45wt%. Theoptional carbon fillers were carbon nanotubes, graphene and carbon black. Thecharacteristic of composite materials was measured by scanning electron microscope,infrared spectroscopic analysis, X-ray diffraction spectroscopy and thermalgravimetric. The electrical conductivity, mechanical properties, bulk density, porosity,corrosion current density and the contact angle of the bipolar plate were determined.The results show that the morphology, size and content of reinforced materialseffected the comprehensive performance of the composite bipolar plate greatly.Because of its large aspect ratio and anisotropy in the composite, one-dimensionaltubular carbon nanotubes have a great influence on the mechanical and electricalproperties of the bipolar plate. Because of the excellent hardness and electricalconductivity properties of graphene, which has two-dimensional lamellar structure,the hardness and electrical properties of bipolar plates have an outstandingperformance. Because of its small particle size and high specific surface area, thethree-dimensional spherical carbon black plays an significant role in reducing the density and cost of the composites. The composite materials with carbon nanotubes,graphene, carbon black content of2wt.%,1wt%,5wt.%, respectivily, performancethe most outstanding performance.