Pulsed Controlled Operation Direct Methanol Fuel Cell Power System

The Direct Methanol Fuel Cell (DMFC) is a promising candidate for a high-energy, lightweight, compact power source for military applications, particularly as a replacement for the 20W primary LiSO2 batteries currently used to power the electronic equipment of individual soldiers. With further development DMFCs are expected to provide significantly higher specific energy and energy density than primary batteries, reducing the number of batteries the soldiers must carry. Performance of state-of-the-art DMFCs is primarily limited by the high overpotential for methanol oxidation due to formation of an adsorbed CO species on the Pt surface. These species act as a catalyst poison, blocking active sites required for methanol dehydrogenation. Laboratory half-cell studies have indicated that the adsorbed CO species are oxidatively removed by frequent short-duration pulses of the anode to high potentials, but there are a number of safety, lifetime and operational concerns in applying this to a practical DMFC stack and system. Giner, Inc. proposes to conduct single-cell and stack testing and system design studies to evaluate these concerns and tradeoffs. The feasibility of implementing anode pulsing in a practical 20W DMFC system that meets the Army requirements will be evaluated.