Development of planar, air-breathing, proton exchange membrane fuel cell systems using stabilized sodium borohydride solution

In this study, the rate of hydrogen generation is varied from 0 to 18 cm3 min−1 by controlling the mass transport of stabilized NaBH4 solution. The open-circuit voltage (OCV) and maximum power density are, respectively, 0.9 V and 128 mW cm−2 at ambient temperature and pressure. Assuming a fuel conversion efficiency of 100%, the Faradic efficiency and energy efficiency of this system estimated to be 75% and 46%, respectively. In a planar 8-cell series-connected format, the maximum power density and cathode temperature are 3.1 W (103 mW cm−2) at 103 mW cm−2 and 46 °C, respectively.