Effect of Composition and Morphology on Ion Transport in Ternary Polymer-Polymer-Salt Blend Electrolytes*

Conventional battery electrolytes typically employ a blend of high polarity and low viscosity liquid organic hosts, each of which have some intrinsic ionic conductivity at a given salt concentration. Naively, one may assume that the conductivities of the blend electrolytes will be an average of the intrinsic conductivities weighted by each parent host’s volume fraction. However, experiments have shown that the ionic conductivities of these blend electrolytes display a positive deviation relative to this simple mixing rule. We hypothesize that similar physics, in which there will be marked positive departure from this simple mixing rule, may manifest in blend polymer electrolytes. The strength of these deviations may depend on various factors, such as the phase stability of the blend. Using fully atomistic molecular dynamics, we explore ion transport in poly(glycidyl ether)-based, ternary polymer-polymer-salt blend electrolytes and seek to correlate underlying micro-/nanoscopic blend morphology to observed changes in ionic transport.