The electrical conductivity of a composite bipolar plate for fuel cell applications

A graphite/phenol formaldehyde resin composite bipolar plate was developed for fuel cell applications. The electrical conductivity of the composite was measured with the help of a four-probe technique. A basic model was modified to predict the electrical conductivity of the plate for a wide range of graphite content. The model was highly dependent on the shape factor and orientation factor of the conductive graphite filler in the composite. The concept of digital image processing was used to quantitatively determine the shape and orientation factors of the bipolar plate. The experimental values of the electrical conductivities were well predicted by the model. The most effective in-plane and through-plane electrical conductivities, at 75% graphite content, were found to be 165 and 103.3 S cm−1, respectively.