Toward a Transferable Coarse-Grained Model for Glyme Electrolytes

Area of Science:

• Materials Science
• Computational Chemistry
• Electrochemistry

Background:

• Ether-based electrolytes are vital for energy storage, functioning as solvate ionic liquids and enabling cointercalation at graphite electrodes.
• While atomistic models exist for glyme ethers, coarse-grained models for these systems, especially concerning mesoscale structures for ion transport, are underexplored.

Purpose of the Study:

• To develop a simple and transferable coarse-grained modeling approach for ether-based electrolytes.
• To investigate the impact of long-range electrostatic interactions on electrolyte structure.
• To assess the transferability of the developed models across different glyme ethers.

Main Methods:

• A coarse-grained modeling strategy combining charge smearing for electrostatics and Boltzmann Inversion for short-ranged potentials.
• System selection for training the short-ranged interactions was emphasized.
• Model validation was performed on monoglyme, diglyme, and triglyme electrolytes.

Main Results:

• The developed coarse-grained model demonstrates good transferability for diglyme and monoglyme, accurately reflecting their ion-associated structures.
• The model successfully captures the influence of long-range interactions on electrolyte organization.
• The model fails to accurately represent the solvent-separated ionic structures observed in triglyme electrolytes.

Conclusions:

• A straightforward coarse-grained modeling approach has been established for glyme ether electrolytes.
• The model's success with ion-associated electrolytes highlights the importance of specific structural features in model development.
• Further refinement is needed to capture diverse ionic structures, such as those in triglyme, for broader applicability in energy storage research.