A dynamic model of air-breathing polymer electrolyte fuel cell (PEFC): A parametric study

A dynamic model for an air-breathing PEFC has been built to investigate the transient response of the fuel cell to load changes. The sensitivities of the dynamic response, as well as the steady state performance, to: the ambient temperature and relative humidity; the thickness and the thermal conductivity of the cathode GDL; and the fuel utilisation, have been studied. A previously-developed steady-state model of the fuel cell was linked to the dynamic model to feed the latter with the data of the cell temperature as it changes with the current density. It was found that, when there are sudden changes to high loads, there exist optimum values for the ambient temperature and GDL thickness at which the overshoots are mitigated and the steady state performance is improved. Further, the transient and steady state performance were found to improve with increasing the ambient relative humidity and GDL thermal conductivity. Finally, the fuel utilisation was found to have no impact on the dynamic response of the fuel cell. All the above findings have been presented and discussed in the paper.