Experimental and numerical investigations of high-temperature PEM fuel cells under different anode dilution levels and varying temperatures
Mengfan Zhou, Johann Cyprian Feistner, Na Li, Samuel Simon Araya, Giovanni Cinti, Vincenzo Liso
Abstract
This work investigates the effect of nitrogen in the anode gas mixture on the performance of HT-PEMFCs using experiments and simulations. It explores four H2/N2 ratios (100/0, 80/20, 60/40 and 50/50) at three temperatures (140 °C, 160 °C, 180 °C), and four current densities (0.1 A cm−2 to 0.4 A cm−2). The results demonstrate that N2 dilution negatively impacts fuel cells performance, but higher temperatures can mitigate this effect. Temperature influences electrochemical impedance spectroscopy, with initial ohmic resistance increase followed by a slight decrease. N2 dilution effects charge and mass transfer resistances. Current density has minimal impact on ohmic resistance but improves charge transfer resistance, especially at high frequencies. This understanding can optimize fuel cell performance, especially in ammonia-fueled systems with hydrogen and nitrogen mixtures or during anode gas recycling with significant nitrogen crossover.