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Controlling the Size, Shape and Stability of Supramolecular Polymers in Water
Published on: August 2, 2012
Unlocking High-Rate Sodium Storage in Hard Carbon via Interfacial Conformation Entropy Modulation in Localized
Bin Qiu1,2, Ning Sun1,3, Xue Li1
1State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, China.
Angewandte Chemie (International Ed. in English)
|July 29, 2026
Summary
Introducing interfacial conformation entropy (SICE) to sodium-ion batteries (SIBs) improves performance. A new electrolyte enhances SICE, boosting Na+ desolvation and enabling ultrafast charging with excellent durability for hard carbon anodes.
Area of Science:
- Electrochemistry
- Materials Science
- Energy Storage
Background:
- Ether-based electrolytes are common in sodium-ion batteries (SIBs) with hard carbon (HC) anodes due to good wetting and low solvation energy.
- However, traditional sodium hexafluorophosphate (NaPF6) electrolytes suffer from poor initial Coulombic efficiency, rate capability, and low-temperature performance.
Purpose of the Study:
- To introduce interfacial conformation entropy (SICE) as a descriptor for Na+ desolvation and interfacial migration.
- To develop a high-performance electrolyte for SIBs by enhancing SICE.
Main Methods:
- Formulated a locally high-concentration electrolyte (LHCE) by adding 10 vol% 1,4-dioxane (14DX) to 1 M NaPF6 in diethylene glycol dimethyl ether (DEGDME).
- Investigated the effect of the tailored solvation microenvironment on SICE, Na+ desolvation, and interphase formation.
- Tested the performance of HC|Na cells and NVP|HC pouch cells.
Main Results:
- The LHCE formulation effectively enhanced SICE, promoting solvent conformational flexibility.
- This led to accelerated Na+ desolvation and the formation of a conductive, robust interphase.
- HC|Na cells achieved ultrafast-charging durability, retaining 89.46% capacity after 9000 cycles at 10C (154.28 mAh g-1).
- An Ah-level NVP|HC pouch cell demonstrated practical viability.
Conclusions:
- Interfacial conformation entropy (SICE) is a valuable descriptor for understanding and optimizing SIB electrolyte performance.
- The developed LHCE strategy offers a promising approach for designing high-rate and durable SIB electrolytes.
- This work paves the way for advanced sodium-ion battery technologies.
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