Experimental and numerical investigations of the effects of PBI loading and operating temperature on a high-temperature PEMFC

In this paper, experimental and numerical investigations of the effects of polybenzimidazole (PBI) loading and operating temperature on a high-temperature proton exchange membrane fuel cell (PEMFC) performance are carried out. Experiments related to a PBI-based PEMFC are performed and a two-dimensional (2-D) simulation model is developed to numerically predict the cell characteristics. Variations of 5–30 wt% in PBI amount in the catalyst layer (CL) and 160–200 °C in cell temperature are considered. On the basis of the experimental and numerical results, the negative effect of PBI content and positive effect of operating temperature on the cell performance can be precisely captured. These effects can also be shown by measurements of the impedance spectrum and predictions of O₂ concentration and current density distributions. In addition, non-uniform distributions in the O₂ concentration and the current density in the cathode compartment are also shown in the model simulation results. Cell performance curves predicted by the present model correspond well with those obtained from experimental measurements, showing the applicability of this model in a PBI-based PEMFC.