A novel PEM has been developed with internal channels that permit the direct access of water along the length of the membrane.
Control of liquid water within the regenerative fuel cell has been brought about by a second innovation. In a first innovation, electrodes function either as oxidation electrodes (hydrogen ionization or oxygen evolution) or as reduction electrodes (oxygen reduction or hydrogen evolution) in the fuel cell and electrolyzer modes, respectively. Drawbacks associated with existing regenerative fuel cells have been addressed. This difficulty is compounded in previous regenerative fuel cell designs by the fact that water, which is needed for proton conduction in the PEM during both modes of operation, is the reactant supplied to the anode in the electrolyzer mode of operation and the product formed at the cathode in the fuel cell mode. F.Ī difficulty encountered in designing a unitized regenerative proton exchange membrane ( PEM) fuel cell lies in the incompatibility of electrode structures and electrocatalyst materials optimized for either of the two functions ( fuel cell or electrolyzer) with the needs of the other function. Illustrated with explanatory graphics and figures, this report outlines the engineering motivations for the RFC as a solar energy storage device, the system requirements, layout and hardware detail of the RFC unit at NASA Glenn, the construction history, and test experience accumulated to date with this unit.Ī Novel Unitized Regenerative Proton Exchange Membrane Fuel Cell Garcia, Christopher P.Īn introduction to the closed cycle hydrogen-oxygen polymer electrolyte membrane ( PEM) regenerative fuel cell (RFC), recently constructed at NASA Glenn Research Center, is presented. Hydrogen-Oxygen PEM Regenerative Fuel Cell Energy Storage Systemīents, David J. Cycling data will be presented for Pt-Ir catalysts and limited bifunctional data will be presented for Pt, Ir, Ru, Rh, and Na(x)Pt3O4 catalysts as well as for electrode structure variations. In fuel cell mode, humidified hydrogen and oxygen were supplied at 207 kPa (30 psi) in electrolysis mode, water was pumped over the positive electrode and the gases were evolved at ambient pressure. The cells were operated alternately in fuel cell mode and electrolysis mode at 80 C. The work was done with DuPont Nafion 117 in complete fuel cells (40 sq cm electrodes).
#PEMNET RAM PRESSURE 1100 2200 UPDATE#
This paper will update the progress in developing electrocatalyst systems and electrode structures primarily for the positive electrode of single-unit solid polymer proton exchange membrane ( PEM) regenerative fuel cells.