Numerical and experimental investigations of bipolar membrane fuel cells: 3D model development and effect of gas channel width

Bipolar membrane fuel cells, which features a hybrid acid-alkaline membrane architecture, show great potential for practical applications because of their ability for self-humidification during operation. The principle of self-humidification behavior and associated transport mechanisms are reported in previous studies with reduced-dimension models. This paper reports on a three-dimensional model and new experimental data that further elucidate the mechanism of self-humidification, provide detailed characterization of the effects of design parameters on flow field and cell performance. The multidimensional-multiphysics model accounts for interface reaction kinetics, as well as transport of gas species, charged species and momentum. Simulations and quantitative analysis are performed for the cathode catalyst layer where water transport is critical for the electrochemical reaction therein. Three-dimensional model fully captures geometric features and gradients, and offers more comprehensive resolution of mass transport inside the cell. Based on the three-dimensional model, effects of channel width on cell performance are investigated both numerically and experimentally.