Lattice Boltzmann modeling of phosphoric acid leaching process in high‐temperature proton exchange membrane fuel cells

Abstract

As the primary proton‐conducting carrier in high‐temperature proton exchange membrane fuel cells (HT‐PEMFCs), the leaching process of phosphoric acid (PA) substantially accelerates performance decay and reduces the lifespan of PEMFCs. A three‐dimensional Lattice Boltzmann Method model is presented to simulate the PA leaching process in HT‐PEMFCs by coupling the catalytic layer structures generated by the improved quartet structure generation set method. The model demonstrates high efficiency, accuracy, and realism. Based on this model, the process of PA droplets invading the catalytic layer is described in detail, and the influence of factors such as porosity on fluid dynamics is analyzed. The results indicate that in the catalytic layers with different porosities, ε = 54% is associated with reduced droplet invasion and an acceptable pressure increase; smaller droplets, lower gas velocity conditions, thicker catalytic layers, and larger contact angles have been shown to be more conducive to mitigating the impact of PA invasion.