Insights into morphology and ion transport from simulations of ionic polymers

Polymers that contain covalently bound charged groups display rich and interesting morphologies and dynamics, and are of current great research interest in part due to their possible use as electrolytes in solid-state batteries. As it is very difficult to resolve the nanoscale morphology from experiments, molecular simulations have played a crucial role in elucidating the morphologies. Similarly, experimental measures of ion dynamics are typically collective, such as measurements of ion diffusion coefficients or ionic conductivities. Simulations can reveal the ion transport mechanisms on the nanoscale. In this chapter, I review molecular dynamics (MD) simulations of two classes of charged polymers, melt ionomers and polymerized ionic liquids. I discuss some important details for simulating charged polymers and review methods for calculating properties of interest, including scattering intensities, ionic diffusivities, and ionic conductivity. I then describe insights regarding both morphology and dynamics obtained from MD simulations.