Abstract
Single-ion conducting polymer electrolytes such as the polymerized Ionic Liquids (polyILs) are of great interest with potential applications in lithium-ion batteries, supercapacitors, fuel cells, and other similar products. However, currently available single-ion conducting polymer electrolytes have ionic conductivity significantly lower than required for use in these applications. Ion-ion correlations quantified in terms of inverse Haven ratio have been shown to be responsible for the reduced conductivity of single-ion conducting polymer electrolytes. However, a microscopic understanding of the inverse Haven ratio has been lacking and is needed to design single-ion conducting polymer electrolytes with superior ionic conductivity. In this talk, we present the results of a coarse-grained molecular dynamics study investigating the effects of local polarization on the inverse Haven ratio and ionic conductivity of single ion conducting polymer electrolytes. In particular, we simulate single-ion conducting polymer electrolytes with a spatially uniform dielectric constant and compare it with the simulations containing polarizable ions. The polarizability is introduced using Drude oscillators and encodes non-uniform polarization in these polymer electrolytes. Effects of cation size, dielectric constant, and polarizability of the ions on the inverse Haven ratio and the ionic conductivity of single ion conducting polymer electrolytes will be presented.
* This work was supported by Center for Nanophase Materials Sciences (CNMS), which is a US Department of Energy, Office of Science User Facility at Oak Ridge National Laboratory. Also, this work was supported as part of the Fast and Cooperative Ion Transport in Polymer-Based Materials (FaCT), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences at Oak Ridge National Laboratory under contract DE-AC05-00OR22725.
