Solvation of Lithium Ion in Dimethoxyethane and Propylene Carbonate

TL;DR

This study uses PM7-MD simulations to analyze how lithium ions are solvated in DME and PC mixtures, revealing preferential solvation by PC and the role of DME in solvation shells.

Contribution

First PM7-MD simulation study detailing lithium ion solvation shells in DME/PC mixtures, highlighting the dynamic substitution of solvent molecules.

Findings

Preferential solvation of Li+ by PC in equimolar mixtures

Presence of DME in the first solvation shell regardless of mixture composition

Complete solvation shell by DME in PC-poor mixtures

Abstract

Solvation of the lithium ion (Li+) in dimethoxyethane (DME) and propylene carbonate (PC) is of scientific significance and urgency in the context of lithium-ion batteries. I report PM7-MD simulations on the composition of Li+ solvation shells (SH) in a few DME/PC mixtures. The equimolar mixture features preferential solvation by PC, in agreement with classical MD studies. However, one DME molecule is always present in the first SH, supplementing the cage formed by five PC molecules. As PC molecules get removed, DME gradually substitutes vacant places. In the PC-poor mixtures, an entire SH is populated by five DME molecules.