Experimental investigation and assessment of direct ammonia fuel cells utilizing alkaline molten and solid electrolytes

In the present study, the solid anion exchange membrane and molten electrolyte entailing direct type ammonia fuel cells are uniquely developed, and their performances are investigated through energy and exergy efficiencies at varying operating conditions and state properties, based on the presently conducted experiments and datasets obtained. Both energy and exergy efficiencies are determined to be 12.1 +/- 0.4% and 13.8 +/- 0.4% respectively at the maximum power density value of 6.4 +/- 0.2 W m(-2) for the membrane based cell. Higher humidifier temperatures are observed to improve the performance of the fuel cell. The energy and exergy efficiencies of the molten alkaline electrolyte based cell are found to be 20.6 +/- 0.6% and 23.3 +/- 0.7% respectively at a temperature of 220 degrees C. The open circuit voltages are found as 278 8 mV and 520 +/- 16 mV for the anion exchange membrane and molten alkaline electrolyte based cells respectively. The open circuit voltage decreases and the short circuit current density increases with increasing electrolyte temperatures. (C) 2018 Elsevier Ltd. All rights reserved.