A comparative study of solid electrolyte interphase evolution in ether and ester-based electrolytes for Na-ion batteries
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Type
Journal Article
Abstract
The solid electrolyte interphase (SEI) largely determines the electrochemical performance of negative
electrodes in sodium-ion batteries (SIBs). Ether-based electrolytes, such as diglyme, have been shown
to form a more stable and thinner SEI on sodium anodes than traditional commercial ester-based elec trolytes. Nonetheless, variations in the detailed evolution of the chemical composition and mechanical
strength of the SEIs formed in these two electrolytic solutions during the electrochemical process have
rarely been investigated. In this work, we conduct a comparative study of the SEI formed in diglyme-based
and carbonate-based electrolytes with Na2Ti3O7 (NTO) as a proof-of-concept material, using energy-tuned
photoelectron spectroscopy, operando electrochemical atomic force microscopy, and electrochemical tech niques. The results show that diglyme forms a thin, homogeneous, and stable SEI with a well-defined
inorganic-organic bilayer structure, as opposed to ester-based electrolytes, which form a thicker, nonuni form, and dynamically changing SEI with randomly distributed inorganic-organic structure. Moreover,
the less resistive and higher capacitive interfacial processes induced by the diglyme-based electrolyte
decrease the overall battery impedance. These advantages enable the NTO anode to exhibit superior spe cific capacity, cycle stability, and rate capability. This study provides an in-depth view of the factors
behind the electrolyte-dependent performance of SIB anodes, which could inform the design and pairing
of electrolytes with electrode materials in rechargeable batteries.
electrodes in sodium-ion batteries (SIBs). Ether-based electrolytes, such as diglyme, have been shown
to form a more stable and thinner SEI on sodium anodes than traditional commercial ester-based elec trolytes. Nonetheless, variations in the detailed evolution of the chemical composition and mechanical
strength of the SEIs formed in these two electrolytic solutions during the electrochemical process have
rarely been investigated. In this work, we conduct a comparative study of the SEI formed in diglyme-based
and carbonate-based electrolytes with Na2Ti3O7 (NTO) as a proof-of-concept material, using energy-tuned
photoelectron spectroscopy, operando electrochemical atomic force microscopy, and electrochemical tech niques. The results show that diglyme forms a thin, homogeneous, and stable SEI with a well-defined
inorganic-organic bilayer structure, as opposed to ester-based electrolytes, which form a thicker, nonuni form, and dynamically changing SEI with randomly distributed inorganic-organic structure. Moreover,
the less resistive and higher capacitive interfacial processes induced by the diglyme-based electrolyte
decrease the overall battery impedance. These advantages enable the NTO anode to exhibit superior spe cific capacity, cycle stability, and rate capability. This study provides an in-depth view of the factors
behind the electrolyte-dependent performance of SIB anodes, which could inform the design and pairing
of electrolytes with electrode materials in rechargeable batteries.
Date Issued
2025-07-01
Date Acceptance
2025-05-12
Citation
PRX Energy, 2025, 4 (3)
ISSN
2768-5608
Publisher
American Physical Society
Journal / Book Title
PRX Energy
Volume
4
Issue
3
Copyright Statement
Published by the American Physical Society Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.
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Publication Status
Published
Article Number
033002
Date Publish Online
2025-07-15