Mixed-reactant fuel cells are unconventional electrochemical power sources which use a thermodynamically unstable mixture of fuel and oxidant. In the work described here a 2-phase mixture of alkaline potassium formate (liquid)/oxygen(gas) is the fuel/oxidant combination used in the “flow-by” mode with mixed-reactant fuel cells, developed in the laboratory from a 10E-4 m 2 single cell to a bipolar stack of nineteen 35E-4 m 2 cells. With Pd/Ag anode/cathode catalysts, operating at 500 kPa(abs), 80 °C the single cell with a Pd load of 0.054 kg m −2 reaches a superficial power density of 4,000 W m −2 at 10,000 A m −2 . Tests of the 19 cell stack with a Pd load of 0.036 kg m −2 at 300 kPa(abs), 60 °C give power output up to 120 W, with a corresponding volumetric power density about 400 kW m −3 . To demonstrate the fuel cell performance three nominally 100 W 19 cell stacks are wired in parallel to a 250 W electric motor to drive a modified electric scooter, with on-board fuel, oxidant and an adult passenger, for about 15 minutes at 10 km h −1 . To our knowledge this is the first time mixed-reactant fuel cells have been used alone to power a vehicle.
Forysinski, P., Oloman, C., Kazemi, S., Nickchi, T., & Usgaocar, A. (2019). Development and use of a mixed-reactant fuel cell. Journal of Power Sources, 366–376. https://doi.org/10.1016/j.jpowsour.2018.12.081