Molecular Dynamics-Based Optimization of Glyme Electrolytes

As the demand for high-energy-density lithium-ion batteries has increased, lithium metal batteries have emerged as promising alternative. Glyme-based electrolytes are attractive candidates for lithium metal systems due to their high ionic conductivity and improved electrochemical stability compared to conventional carbonate-based electrolytes. In this study, we employed atomistic molecular dynamics simulations to optimize glyme electrolytes with the goal of enhancing the ionic conductivity and cation transference number while preserving mechanical integrity. By systematically varying the chain length (N = 5-10) and end-group chemistry, we investigate their impact on the transport properties and elucidate the molecular mechanisms that govern Li⁺ mobility. The total ionic diffusivity is decomposed into intrachain, segmental, and interchain contributions to identify the dominant transport mechanism. In addition, we determine the conditions under which the correlated ionic motion is minimized, providing insight into optimizing the ion transport efficiency. Viscosity is also evaluated for each system to establish design criteria for balancing mechanical robustness with ion transport performance. This study provides molecular-level insights into the ion transport, transference number, and viscosity of glyme electrolytes, thereby offering design guidelines for glyme electrolytes.