Computational modeling of structure and OH-anion diffusion in quaternary ammonium polysulfone hydroxide – Polymer electrolyte for application in electrochemical devices

Using computational approaches we predict the microstructure of high-performance alkaline polymer, quaternary ammonium polysulfone hydroxide (QAPS-OH) membranes, dry and with ∼14 wt% water uptake. The microstructure can be described as a hydrophobic polymer backbone penetrated by a network of three-dimensional interlinked hydrophilic channels of different diameters. Mobile OH-anions are distributed inside the channels. OH diffusion coefficients and corresponding activation energy were calculated from our molecular dynamics simulations of the QAPS-OH membrane at different temperatures. The predicted values are consistent with available experimental data. Possible mechanisms of the OH-anion diffusion have been discussed.

► We model the microstructure and OH-diffusion in dry and hydrated QAPS-OH membranes. ► Our predicted OH-diffusion and activation energies are consistent with experiment. ► Structural characteristics of the QAPS-OH membranes are revealed and discussed. ► Mechanisms of the OH-anion diffusion in a QAPS-OH membrane are discussed.