Energy Storage Science and Technology

   

Simulation Study of the Solvation Structure and Ion Migration Behavior in Localized High-Concentration Electrolytes

Chao PANG1,2(), Shuang DING2, Xiaokun ZHANG1(), Yong XIANG1   

  1. 1.School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu Sichuan 611731, China
    2.CETC Lantian Technology Co. , Ltd. , Tianjin 300384, China
  • Received:2025-02-12 Revised:2025-02-28
  • Contact: Xiaokun ZHANG E-mail:pc11qdu@163.com;zxk@uestc.edu.cn

Abstract:

The impact of intermolecular interactions on Li+ transport in electrolytes remains poorly understood. In this study, molecular dynamics (MD) simulations were employed to explore the heterogeneous structure of localized high-concentration electrolytes (LHCEs). 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropylether (D2) was used as diluent to construct the LHCE model. The interactions between solvent molecules and the diluent were analyzed in detail to investigate how these interactions affect the Li+ coordination structure and migration behavior. The results demonstrate that Li+ moves via a repeated ion dissociation/association hopping manner, and accelerate migration through the D2-CIP interface. The D2 molecules act as carriers for the fast transport pathway. In addition, it was found that the electrolyte comprising LiFSI: DME: D2 = 1:1.2:2 (molar ratio) exhibits an ion migration rate extremum (turnover) effect, significantly enhancing both the reduction resistance of the lithium salt and the ionic migration rate. This study provides important theoretical insights for developing novel dilution strategies for high-concentration electrolytes (HCEs).

Key words: Localized high-concentration electrolytes, Molecular dynamics, Solvation structure, Ion migration behavior

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