Effect of High Polarity on Ionic Transport in High Dielectric Constant Polyether-Based Electrolytes*

The ionic conductivities of polymer electrolytes are intrinsically related to the host material properties. In many polymer electrolytes, it has been shown that the host segmental dynamics is the primary controlling factor in lithium ion transport. However, prior studies of poly(glycidyl ether)-based polymer electrolytes have revealed that the host polymer polarity may also be a strongly influencing factor for ionic conductivity. This influence is mediated through competitive association of negatively charged polymer moieties and anions to lithium ions. As the polarity increases, the negatively charged moieties “win” this competition, thus leading to decreased ionic association. In this work, we seek to extend these findings to novel, highly polar polyethers. We hypothesize that increasing the host polymer polarity will indeed decrease ionic association. However, we anticipate increases in polymer-polymer and -ion interaction strength, which will considerably slow segmental dynamics. Using molecular dynamics, we seek to elucidate ionic transport mechanisms and the relative importance of host polarity and segmental dynamics to changes in ionic conductivity.