Transient analysis of alkaline anion exchange membrane fuel cell anode

摘要

Alkaline anion exchange membrane (AAEM) fuel cell has attracted increasing attention in recent years due to its several outstanding advantages over proton exchange membrane (PEM) fuel cell such as fast electrochemical kinetics and friendly alkaline environment for catalysts. In this study, a three-dimensional (3D) half-cell transient model is developed to study the dynamic characteristics of AAEM fuel cell under different step changes of operating conditions. It is found that the current density has significant effects on the distribution of liquid water, while the anode stoichiometric ratio effect is insignificant. More time is needed to reach a steady state when the current density decreases rather than increases, and the similar phenomenon also occurs when the operating temperature de-creases rather than increases, however, this effect within a low temperature range be-comes insignificant. Moreover, the overshoot and undershoot of water diffusion through membrane can also be observed with the step change of the anode stoichiometric ratio and anode inlet relative humidity. The model prediction also has reasonable agreement with published experimental data. The dynamic behaviors observed in this study are of sig-nificant importance to the development of AAEM fuel cells for portable and automotive applications.