Evaluation of Novel and Low-Cost Materials for Bipolar Plates in PEM Fuel Cells

Abstract

Bipolar plate material and fabrication costs make up a significant fraction of the total cost in a polymer electrolyte membrane fuel cell stack. In an attempt to reduce these costs, a novel manufacturing method was developed for use with composite materials. Conductive fillers were mixed with a polypropylene binder and molded into single cell monopolar plates. A fuel cell test stand, capable of testing six cells simultaneously, was used for long-term corrosion testing. In-situ tests took place in 5 cm2 active area fuel cells with cathode humidification. Using data from test cells containing graphite monopolar plates as a baseline, two composite formulations, were able to produce power at 66-79% of the baseline power. Power output from one cell remained in this range for over 200 hours, while the other sample experienced surface oxidation and eventually failed. With improvements in part conductivity coming from conductive polymers, this manufacturing technique holds the promise of producing monopolar and bipolar plates that could eventually be scaled up for use in fuel cell stacks.