Extremely Lighweight Hydrogen Fuel Cells

The proton exchange membrane (PEM) fuel cell is being considered as power source for a variety of applications (1-4). Gravimetric and volumetric energy density, life cycle costs, ease and safety of operation are major considerations which may favor a PEM fuel cell power source over batteries. The proposed PEM fuel cell power source relies on an assembly of series connected cells arranged on board. For this purpose, ionically conductive areas of the ionexchange membrane are separated by zones in which the sulfonic acid group has been neutralized to render it ionically non conductive. The conductive areas of the ionexchange membrane are laminated with circular electrodes to form a multi cell MEA. The electrodes are contacted by porous carbon structures with hydrophilic and hydrophobic zones. They are electrically isolated and facilitate reactant distribution and product water transport. These circular multipurpose collectors are positioned by a locating board followed by another board with electrical feed throughs which facilitate external, series cell-to-cell connection while providing a manifold cover for reactant distribution. A 4 cell PEM fuel cell board will be constructed. In an optional phase of the proposed effort, it will be combined with a hydrogen generator relying on product water for reaction with alkali metal hydrides.