Application of ultrasonic dispersion in the preparation of composite bipolar plates for PEMFC

Natural graphite,carbon black,and epoxy modified phenolic resin were chosen to make graphite/polymer composite bipolar plates by compression molding.The influences of preparing methods on the structure and properties of the composite bipolar plates were investigated,and single cells were assembled with the composite bipolar plate and non-porous graphite plate respectively to investigate the electrochemical property of the composite bipolar plates.The results showed that properties of the composite bipolar plates prepared by ultrasonic dispersion were obviously better than that prepared with a kneader.The battery voltage and power density of the proton exchange membrane fuel cells(PEMFCs) assembled with composite bipolar plate and non-porous graphite plate respectively are similar at low current density.While at high current density,both battery voltage and power density of the PEMFC assemble with composite bipolar plate are lower than that assembled with non-porous graphite bipolar plate,which is the result of the relatively lower electric conductivity of the composite bipolar plate.