Explicit Polarization in Coarse-Grained Simulations of Ionomer Melts

Christopher Balzer, California Institute of Technology

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Ion-containing polymers show promise as safer and cheaper alternatives to conventional battery electrolytes. Strong electrostatic interactions between ionomers and diffusing ions lead to ionic aggregation and slow ion dynamics. Understanding the formation of ion aggregates and dynamics at the molecular level is essential to guide design of ionomer materials. Previous coarse-grained simulations of these systems have not included explicit polarization, which likely plays a role in the formation and resulting local structure of the ionic aggregates. However, the computational cost of explicit polarization can be prohibitive. In this work, we incorporate explicit polarization into the coarse-grained model of ionomer melts via Drude oscillators. We compare the structure in the ionic aggregates, dynamics of free ions, and overall aggregate morphologies to that of non-polarizable simulations. Most notably, unlike the non-polarizable system, we find that find that the single ion transport does not have to be linked to the morphology of the ion aggregates.

Abstract Author(s): Christopher Balzer, Amalie Frischknecht