How does hydrofluoroether affect the liquid structure, transport properties, and electrochemistry of localized high-concentration electrolytes?
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| Název: | How does hydrofluoroether affect the liquid structure, transport properties, and electrochemistry of localized high-concentration electrolytes? |
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| Autoři: | Takeshita, Kousuke1, Tatara, Ryoichi1,2 tatara-ryoichi-nx@ynu.ac.jp, Tsuzuki, Seiji2, Ishikawa, Masashi3, Dokko, Kaoru1,2 tatara-ryoichi-nx@ynu.ac.jp |
| Zdroj: | Journal of Chemical Physics. 11/7/2025, Vol. 163 Issue 17, p1-13. 13p. |
| Témata: | *HYDROFLUOROETHERS, *ELECTROCHEMISTRY, *ELECTROLYTES, *MOLECULAR dynamics, *SOLVATION |
| Abstrakt: | Understanding the effects of non-coordinating diluents on the physicochemical properties of localized high-concentration electrolytes (LHCEs) is essential for the rational design of battery electrolytes. In this study, we examined the effect of a hydrofluoroether (HFE), 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether, on the liquid structure, transport properties, and electrochemical reaction kinetics of a model LHCE containing lithium bis(fluorosulfonyl)amide (LiFSA), 1,2-dimethoxyethane (DME), and HFE. Raman spectroscopy revealed that the Li+ solvation structure in the model LHCE remained largely unchanged upon dilution with HFE. The ion-pairing environment involving FSA− was also preserved, consistent with the weak coordinating ability of HFE. Although HFE did not coordinate with Li+, molecular dynamics simulations indicated strong interactions between HFE protons and FSA−, supporting its miscibility with the concentrated [LiFSA]/[DME] = 1/2 electrolyte. With increasing HFE content, viscosity decreased, while ionic conductivity reached a maximum at an intermediate LiFSA concentration owing to the trade-off between ion concentration and mobility. The diffusion coefficients increased with dilution; however, the decreasing molar conductivity/diffusivity ratio indicated a dynamic domain structure and prolonged ion-pair lifetime in the LHCEs. Electrochemical impedance analysis revealed that the charge-transfer reaction resistance at the LiMn2O4 electrode reached a minimum at an intermediate concentration ([LiFSA]/[DME]/[HFE] = 1/2/1), while the activation energy remained nearly constant. This finding indicates that HFE lowers viscosity without affecting the energy barrier for Li+ desolvation at the electrode–electrolyte interface. These findings demonstrate that non-coordinating diluents modulate the liquid structure, ion transport, and interfacial properties of LHCEs. [ABSTRACT FROM AUTHOR] |
| Databáze: | Academic Search Index |
Nájsť tento článok vo Web of Science | Abstrakt: | Understanding the effects of non-coordinating diluents on the physicochemical properties of localized high-concentration electrolytes (LHCEs) is essential for the rational design of battery electrolytes. In this study, we examined the effect of a hydrofluoroether (HFE), 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether, on the liquid structure, transport properties, and electrochemical reaction kinetics of a model LHCE containing lithium bis(fluorosulfonyl)amide (LiFSA), 1,2-dimethoxyethane (DME), and HFE. Raman spectroscopy revealed that the Li+ solvation structure in the model LHCE remained largely unchanged upon dilution with HFE. The ion-pairing environment involving FSA− was also preserved, consistent with the weak coordinating ability of HFE. Although HFE did not coordinate with Li+, molecular dynamics simulations indicated strong interactions between HFE protons and FSA−, supporting its miscibility with the concentrated [LiFSA]/[DME] = 1/2 electrolyte. With increasing HFE content, viscosity decreased, while ionic conductivity reached a maximum at an intermediate LiFSA concentration owing to the trade-off between ion concentration and mobility. The diffusion coefficients increased with dilution; however, the decreasing molar conductivity/diffusivity ratio indicated a dynamic domain structure and prolonged ion-pair lifetime in the LHCEs. Electrochemical impedance analysis revealed that the charge-transfer reaction resistance at the LiMn2O4 electrode reached a minimum at an intermediate concentration ([LiFSA]/[DME]/[HFE] = 1/2/1), while the activation energy remained nearly constant. This finding indicates that HFE lowers viscosity without affecting the energy barrier for Li+ desolvation at the electrode–electrolyte interface. These findings demonstrate that non-coordinating diluents modulate the liquid structure, ion transport, and interfacial properties of LHCEs. [ABSTRACT FROM AUTHOR] |
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| ISSN: | 00219606 |
| DOI: | 10.1063/5.0293467 |