Compact Lightweight Monopolar Proton Exchange Membrane Fuel Cell

Fuel cells bring about the direct conversion of stored chemical energy to electrical energy having efficiencies much higher than those of Carnot engines. So far, the proton exchange membrane (PEM) fuel cell system is the leading candidate fuel cell power source for many military and commercial applications. In order to make PEM fuel cell power sources cost-competitive with competing technologies and more effective in meeting various mission requirements, the structure and configuration of fuel cell components need to be optimized with regard to weight, performance, cost and the ability to be mass produced. The objective of this project is to develop PEM hydrogen-air fuel cells using a simple monopolar structure and extremely lightweight components on a single piece of membrane to meet the specific requirements of the Army as future man-portable power supplies. Because of the strong dependence on expensive platinum metal as electrocatalysts and its easy susceptibility to contamination poisoning in conventional fuel cells, much effort will be devoted to incorporating novel Pt-free or low Pt-loading catalytic electrodes as an integral part of the fuel cell design. In particular, a new electroless deposition approach will be used to prepare contamination-tolerant anodes, containing composite electrocatalysts such as Pt-Sn and Pt-Pb, directly on the membrane in order for these soft metal electrocatalysts to be used in a strong acid environment, such as that of a PEM. Success in this effort will make the use of hydrogen derived from steam reformed methanol hydrocarbon fuels in PEM fuel cells possible and result in the production of long service life, high energy density, low cost, and more competitive fuel cell power source systems.