Properties of graphite-composite bipolar plate prepared by compression molding technique for PEM fuel cell

Abstract

Bipolar plate is an important key component of fuel cell on the basis of its manifold function. In this direction a lot of effort is going on worldwide to make light-weight and cost-effective bipolar plate for fuel cell application. In the present investigation effort was made to develop graphite-composites bipolar plate by compression molding technique to achieve the requisite goal. The composites plates were prepared by using different reinforcing fillers such as natural graphite, synthetic graphite, carbon black, carbon fibers with phenolic resin as polymer matrix precursor in its liquid and powder form. The composition of different filler constituent adjusted in between 5 and 40 vol%. The composite plates prepared with appropriate proportion of filler components were characterized for physical and mechanical properties. It is found that no single reinforcing filler constituent composites plate gives the requisite properties for being used as bipolar plate in the PEM fuel cell. The judicious combination of reinforcing constituents gives the properties which are required for bipolar plate to use in fuel cell. By controlling the ratio of reinforcing constituents, one can able to achieve properties such as bulk density ∼ 1.85 g cm - 3 , electrical conductivity > 150 S cm - 1 , shore hardness > 65 , bending strength > 60 MPa , modulus > 10 GPa and compressive > 70 MPa by applying the pressure ( 100 kg cm - 2 ) during compression molding. I – V characteristic of the composite bipolar plate, with optimum combination of reinforcing constituent, is found to be adequate as per the US-DOE target for composite bipolar plate.