Effects of graphite/polypropylene on the electrical conductivity of manufactured bipolar plate

Abstract

Conductive polymer composite (CPC) has been used on bipolar plates by compression and injection molding methods. The CPC material comprises 25% polypropylene and 75%graphite with size variation (40, 100, 150, and 200 µm) according to particle size dispersion test. The composite is mixed using an internal mixer to obtain a homogeneous mixture at a process temperature of 200 °C. Electrical conductivity tests are performed on each particle size composition. The highest electrical conductivity produced by compression and injection molding methods is 17 and 12 S/cm, respectively. These values are both obtained on a 40 µm graphite filler. Results show that the type of manufacturing process affects the value of electrical conductivity using the same material.