Conductive particles embedded carbon composite bipolar plates for proton exchange membrane fuel cells

Proton exchange membrane (PEM) fuel cell systems are environmentally friendly power sources that have many potential applications. Although carbon fiber composite bipolar plates have high strength and stiffness with good corrosion resistance in an acid environment, they exhibit only a marginal electrical conductivity, which compromises the efficiency of PEM fuel cells. In this work, electrically conductive particles (graphite powder and carbon black) are sprayed onto carbon-epoxy composite prepregs of a bipolar plate to decrease the electrical resistivity of the bipolar plate. The electrical resistance and mechanical properties are measured using conventional test methods. In addition, a unit cell performance assessment is conducted with the developed carbon composite bipolar plates and compared with that of the conventional bipolar plate.