Hydrogen Peroxide Based Fuel Cell for High Energy Density Space Application

The objective of this Phase II project is to demonstrate the engineering feasibility of a high power, unitized, regenerative fuel cell that uses sodium borohydride (NaBH4) and hydrogen peroxide (H2O2) directly at the fuel cell (FC) electrodes. Such a Regenerative Fuel Cell (RFC) is ideally suited for the demanding Unconventional Space Power requirements set forth by DARPA. The engineering prototype proposed would be a kW-class unit, based on the scale-up of the highly successful NaBH4/ H2O2 fuel cell demonstrated by NPL Associates in Phase I. This cell, termed I-CHARGERTM, uses aqueous solutions of NaBH4 and H2O2 directly at the anode and cathode, respectively. This direct process, as shown in experiment, results in >30% higher voltage output compared to ordinary H2/O2 fuel cell, and consequently a 30% higher efficiency. Also the unique combination of the fuel and oxidizer, both being in aqueous form, paves the way for a unique unitized design which is inherently compact compared cells that use gas phase reactants, such as the conventional H2 and O2 fuel cell. Thus I-CHARGERTM is uniquely suited for space power applications, and that is the primary focus of the Phase II development.