From atomistic understanding of correlation and transport to electrolyte design

Electrolytes control battery recharge time and efficiency, anode/cathode stability, and ultimately safety, consequently electrolyte optimization is crucial for the design of modern energy storage devices. We adopt theoretical and molecular modeling techniques to shine light on transport properties and correlation effects in the electrolyte system. Here we focus on ionic liquid-based electrolytes.

Electrolytes containing ionic liquids (ILs) possess superior chemical stability, however, poor transport properties are hindering their applicability. Given the ionic nature, these systems possess high degrees of ion-ion correlation, therefore posing a non-trivial yet crucial and interesting challenge to understanding their transport properties. We show that, first, the strong ionic interactions result in significant correlations and deviations from ideal solution behavior. Second, we computationally confirm the recently measured negative Li transference number in Li-containing IL-based electrolytes, and extend this surprising result to a vast range of different chemistries, suggesting a universal behavior of this class of electrolytes. Third, we leverage our microscopic understanding to suggest and test modifications to increase the cation transference number.