Mathematical modeling of a direct urea fuel cell

Abstract

The performance of an anion exchange membrane-based direct urea/O2 fuel cell (AEM-DUFC) is analyzed via a mathematical model based on mass/charge transport and electrochemical reactions. The present model is verified using published experimental data, featuring a good accuracy with high R2 of 0.989 for polarization curve. The cell performances are evaluated in terms of voltage losses at anode/cathode, ohmic voltage loss in membrane, and urea crossover. The voltage losses in electrodes are dominant at a low current density; however, that in membrane is the highest at a high current density. The mathematical analysis results indicate that the structural design parameters (membrane thickness, porosity, and thickness of diffusion layers) and the operating parameters (urea fuel concentration and flow rate, O2/air, KOH feed concentration, and temperature) are important factors for high performance of AEM-DUFC. Urea and KOH concentrations exhibit optimum levels because of their composite effect. Overall, improve AEM-DUFC performance mainly depends on the structure and operating parameters of anode side. © 2022 Hydrogen Energy Publications LLC