PNNL

Abstract

We demonstrate crown ether (CE)-based type II porous liquid (PL) electrolytes in which CEs provide internal porosity and are capable of coordinating with Li+ and Mg2+ ions. We investigated the physicochemical properties of the PL electro-lytes with different functional groups and cavity sizes. Among the electrolytes studied, the 12-crown-4 (12C4)-based PL electrolyte exhibited the most enhanced ionic conductivity due to size match between the CE cavity and the Li+ ion. Nu-clear magnetic resonance and Fourier transform infrared analyses revealed that addition of CEs reduces the Li+ ion–solvent interaction, resulting in the formation of Li-CE complexes. The simulation study clearly showed that the solvated Li+ and Mg2+ ions form complexes with 12C4. The strategy described here using CE-based PLs should be applicable to the design versatile electrolytes for various metal-ion batteries.