- 5:15 PM

Performance of a First-Generation Biocarbon Fuel Cell

Teppei Nunoura, HNEI, University of Hawaii at Manoa, 1680 East-West Road, POST 109, Honolulu, HI 96822 and Michael J. Antal Jr., Hawaii Natural Energy Institute, University of Hawaii at Manoa, 1680 East-West Road, POST 109, Honolulu, HI 96822.

We studied the performance of an aqueous-alkaline fuel cell system that used biocarbon (i.e., carbonized charcoal) as a fuel. As a pretreatment, we carbonized Flash CarbonizationTM charcoal at 900 1050 C for 30 min, which caused a reduction of its electrical resistivity. Subsequently we compressed the charcoal at 38 MPa to form a carbon bed and used it as an anode electrode. The charcoal anode showed a low resistivity that was comparable to that of graphite electrodes. We used a Pt foil/Ag screen assembly as a cathode (oxygen reduction) and various aqueous-alkaline solutions as an electrolyte. To study the cell performance above 100C, the fuel cell apparatus was operated in a pressure vessel (up to 3.58 MPa).

In the last meeting, we reported the effect of the cathode configuration and the performance at low temperatures. In this meeting we will report the effect of cell temperature, electrolyte composition, anode size and composition, etc. upon the fuel cell performance (open circuit voltage, short circuit current density, and maximum power). We found that the presence of Li+ ion in the electrolyte enhances the cell performance. The performance improved as the cell temperature was increased, and at 245C using 6 M KOH/1 M LiOH mixture as the electrolyte, the cell showed the open circuit voltage of 0.57 V, short circuit current density of 44 mA/cm2, and maximum power of 19 mW.