HIGH POWER DENSITY FUEL CELL.

This report describes the results of an analytical and experimental program to investigate fuel cells for short duration high energy density applications. An optimized system concept was defined based on the results of previous work and analysis under this contract. The concept includes a low temperature-trapped electrolyte fuel cell stack gaseous hydrogen and oxygen reactants and open cycle heat and product water removal. A heat removal concept utilizing the evaporation of water from wicks adjacent to the fuel cells was demonstrated. Results of system studies indicated that energy densities of fuel cell systems exceeded those of AgO-Zn primary batteries and was comparable to the goals for Li-Cl2 batteries. Fuel cell system energy densities of up to 100 watt-hours per pound were estimated for a 30 minute discharge. For a 5 minute discharge the energy density is approximately 35 watt-hours per pound. Optimum design power densities were between 800 and 1500 wattssq. ft. depending primarily on mission duration. Author