Study On Design And Fabrication Of Proton Exchange Membrane Fuel Cell Flexible Graphite Bipolar Plate

Proton Exchange Membrane fuel cell has attracted much attention for its efficiency,energy efficiency and environmental protection.Its key components are membrane electrode,bipolar plate,current collector,end plate and so on.As one of the key components of fuel cell,the bipolar plate occupies more than 60% of the stack volume and 30% of the total battery cost.Therefore,the development of bipolar plates with small size(ultra-thin),low cost and simple preparation method is the main direction of its further development.The flexible graphite bipolar plate was fabricated by molding and injection molding,using the flexible graphite plate as raw material,and the flexible graphite bipolar plate was fabricated by molding and pressing,thus low-cost and long-life bipolar plate for fuel cell could be produced in batch production,effectively promote the commercialization of hydrogen fuel cells.In this paper,the influence of porosity on the performance of flexible graphite bipolar plate was studied by introducing and analyzing the existing molding process of flexible graphite bipolar plate and resin impregnation,by directly reducing the thickness of the raw material,the local structure of the plate is improved and the thickness of the single plate is reduced.The results show that when the thickness of the plate is 6 mm,the thickness of the plate is 0.830 mm,the gas tightness and electrical conductivity of the prepared plate are up to the standard,and the bending strength is slightly lower than the target value.In this paper,the thinning technology of flexible graphite bipolar plate is studied by changing the material structure of flexible graphite plate and considering the material structure of flexible graphite plate with interlayer.From the point of view of strengthening the mechanical strength of the plate,taking into account the gas tightness and electrical conductivity of the plate,as well as the nature of the material itself,the modified materials include graphite powder,carbon fiber mesh,Metal Mesh and Polymer Mesh.The results show that the content of graphite powder can improve the bending strength of the bipolar plate,but reduce the gas tightness of the bipolar plate.The bipolar plate was made of flexible graphite plate with Carbon Fiber Mesh.The addition of Carbon Fiber Mesh can improve the bending strength of the bipolar plate,but reduce the conductivity.The results show that the graphite composite plate with Rhombic Copper Mesh and round Hole Copper Mesh has good mechanical and electrical properties.The results show that the graphite composite plate with Metal Mesh Sandwich has good electrical and mechanical properties.The results show that the graphite composite plate with polysulfone and Mesh Sandwich has good mechanical properties,and the graphite composite plate with Mesh Sandwich has good mechanical properties.