Membrane Electrolyte Assembly (MEA) Model

Fuel cell's core component is a membrane-electrode-assembly(MEA) consisting of porous electrodes(cathode and anode) and an electrolyte in between electrodes. Hydrocarbon fuel is fed into the anode and thermochemically reformed to hydrogen-CO-rich composition, and mainly H2 and CO are electrochemically oxidized producing electrons. These electrons are utilized to produce oxygen ion from oxygen gas coming through the cathode. To complete the whole circuit, the oxygen ion is transported from cathode side to anode side. In order to understand and improve the physical mechanism, we have developed a model using the state-of-the-art approaches. In tandem with our lab expertise, the chemically reacting flow through the porous electrode is modeled using Dusty Gas Model with a detailed elementary heterogeneous chemistry and in the process of adding homogeneous chemistry. With regard to electrochemistry, we have applied detailed elementary steps for each half-cell reaction and derived a relationship between current and activation overpotential, rather than using a Butler-Volmer equation for a whole half cell reaction. This approach enables us to explain a limiting current density without using any physically questionable model suggested before.