A Dusty Fluid Model for Predicting Hydroxyl Anion Conductivity in Alkaline Anion Exchange Membranes

Advances in metal-cation-free, quaternary ammonium, polymer alkaline anion exchange membranes (AAEMs) have provided a recent resurgence of interest in the alkaline fuel cell (AFC). The alkaline environment supported by the AAEM offers several potential advantages, including opportunities for the use of non-noble metal catalysts with high energy density and logistically favorable fuels and oxidants, such as methanol and air. However, recent experimental literature has shown that the AAEM derived AFCs have considerable resistive losses that can be attributed to the AAEM. This work describes a dusty fluid model used to predict AAEM conductivities as a function of relative humidity and membrane properties in an initial attempt at forming a framework for understanding the processes at work. A percolation model is used to account for the membrane structure. The model is validated using Nafion 115 conductivity data.