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Updated: May 28, 2026
11:04
Synthesis of Ionic Liquid Based Electrolytes, Assembly of Li-ion Batteries, and Measurements of Performance at High Temperature
Published on: December 20, 2016
Polyhalide Ionic Liquid Phase-Separation Strategy Enables High-Performance Four-Electron Transfer Zinc-Iodine
Zhijie Xu1, Jiaxuan Wang1, Peng Sun2
1Shanghai Key Laboratory of Magnetic Resonance, School of Physics, Institute of Magnetic Resonance and Molecular Imaging in Medicine, East China Normal University, Shanghai 200241, China.
ACS Nano
|May 27, 2026
Summary
A novel ionic-liquid phase-separation strategy using 1-ethyl-3-methylimidazolium ([EMIm]+) enhances aqueous zinc-iodine batteries. This approach prevents capacity loss by stabilizing high-valent iodine and protecting the zinc anode for improved energy storage.
Area of Science:
- Electrochemistry and Materials Science
- Renewable Energy Storage Solutions
Background:
- Aqueous zinc-iodine batteries offer potential for grid-scale energy storage.
- Challenges include irreversible capacity loss due to high-valent iodine hydrolysis and zinc anode corrosion.
Purpose of the Study:
- To develop a strategy to overcome capacity fade in aqueous zinc-iodine batteries.
- To enable high-energy four-electron redox chemistry through improved stability and anode protection.
Main Methods:
- Introduction of a dual-functional additive, 1-ethyl-3-methylimidazolium ([EMIm]+), to induce polyhalide ionic-liquid phase separation.
- Coordination of [EMIm]+ with electrogenerated [IBr2]- to form a hydrophobic ionic liquid (EMImIBr2) that separates from the aqueous electrolyte.
- Investigation of the additive's role in suppressing hydrolysis, mitigating zinc corrosion, and guiding zinc deposition.
Main Results:
- Phase separation effectively isolates high-valent iodine species (I+), suppressing hydrolysis and enabling reversible I0/I+ conversion.
- [EMIm]+ mitigates Br- induced corrosion and promotes uniform Zn deposition on the (002) plane, enhancing plating/stripping reversibility.
- Zn||I2 cells demonstrate high specific capacity (391.0 mAh g-1 at 0.1 A g-1), excellent rate performance (302.4 mAh g-1 at 3 A g-1), and long-term cycling stability (70% retention over 2000 cycles).
Conclusions:
- The proposed polyhalide ionic-liquid phase-separation strategy significantly enhances the performance and stability of aqueous zinc-iodine batteries.
- This approach addresses key degradation mechanisms, paving the way for practical grid-scale energy storage applications.
- High-loading pouch cells demonstrated practical viability, powering electronic devices.
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