Lithium-Ion Transport Properties in DMSO and TEGDME: Exploring the Influence of Solvation through Molecular Dynamics and Experiments

This study explores the properties of aprotic electrolytes via the application of experimental methods, including nuclear magnetic resonance spectroscopy and electrochemical techniques, along with molecular dynamic modeling. The aim is to provide a quantitative description of the physico-chemical properties of two well-established electrolytes (case studies), each exhibiting significantly distinct dielectric properties: a LiTFSI (Lithium bis(trifluoromethanesulfonyl)imide) solution in dimethyl sulfoxide (DMSO, dielectric constant & varepsilon; ${\varepsilon{} }$ =46.68) and a LiTFSI solution in tetraethylene glycol dimethyl ether (TEGDME, & varepsilon; ${\varepsilon{} }$ =7.71). We obtained a comprehensive insight into the properties of the electrolytes at both the macroscopic-collective and molecular levels with particular emphasis on the interactions between the Li ions and solvent molecules. We discovered remarkable disparities in the structural arrangements, solvation behaviors, and bulk-related properties of these electrolyte systems, particularly in response to temperature changes.A new set of experimental observables along with molecular dynamics has been used to characterize the conductive, electrochemical and structural properties of aprotic electrolytes based on LiTFSI in DMSO and TEGDME. The remarkable difference in their behavior, especially in response to temperature changes, was mapped onto their structural and solvation features. image