Development and performance evaluation of a passive direct ammonia fuel cell

In this work, a new passive ammonia fuel cell prototype is designed and tested. The developed ammonia fuel cell features a passive supply of ammonia to the anode, eliminating the need for a complex fuel delivery system, while the cathode is designed as an open cathode to directly use oxygen from the ambient air as oxidant. To demonstrate the working principle of the passive ammonia fuel cell, its general performance is first investigated and results show that the developed passive ammonia fuel cell can provide a peak power density of 31.9 mW cm⁻² and an open-circuit voltage of 0.63 V. To gain insights into the physical and chemical processes involved in the cell and as well enhance the understanding of the mass/charge transport mechanism within the cell, the developed passive ammonia fuel cell prototype was tested under different operating conditions, such as various operating temperature and reactant concentrations. In addition, the structural parameters of the membrane electrode assembly, such as the thickness of the membrane, catalyst loading, and hydrophobicity of the diffusion layer are investigated and analyzed to examine their influence on the mass transport behavior and performance of the passive ammonia fuel cell.