Chelating Anion-Mediated Solvation Structures for Rechargeable Magnesium Batteries
Ming Pan1, Yukun Sun1, Yazhen Zhao1
1School of Chemistry and Chemical Engineering, Shanghai Electrochemical Energy Devices Research Center, Shanghai Jiao Tong University, Shanghai, China.
Angewandte Chemie (International Ed. in English)
|April 1, 2026
Summary
This study introduces a novel magnesium salt with a chelating anion that improves rechargeable magnesium battery performance by optimizing ion solvation and forming a stable solid electrolyte interphase (SEI). This significantly lowers the voltage required for magnesium plating and stripping.
Area of Science:
- Electrochemistry
- Materials Science
- Battery Technology
Background:
- Regulating cation solvation structures in electrolytes is crucial for rechargeable metal batteries.
- Existing solvents and additives for magnesium metal batteries are limited.
- Developing new magnesium salts is essential for advancing battery performance.
Purpose of the Study:
- To propose a novel magnesium salt, MgEDTF, with a chelating anion to modulate Mg2+ solvation.
- To investigate the impact of this chelating anion on the solid electrolyte interphase (SEI) formation.
- To explore the synergistic effects of halide additives on Mg2+ solvation and SEI properties.
Main Methods:
- Synthesis and characterization of magnesium (1R,2R)-1,2-diphenylethane-1,2-diylbis(trifluoromethylsulfonylamide) (MgEDTF).
- Electrochemical studies including Mg plating/stripping overpotential measurements.
- Spectroscopic analysis to elucidate solvation structures and SEI composition.
Main Results:
- MgEDTF forms an unsaturated [Mg2+-(EDTF2-)-(DME)] complex, distinct from conventional structures.
- This complex facilitates anion-derived SEI formation, reducing Mg plating/stripping overpotential from 2.0 to 0.24 V.
- Trace halide additives further optimize solvation and SEI, reducing overpotential below 0.20 V.
Conclusions:
- Chelating anion-mediated solvation is a feasible strategy for rechargeable magnesium metal batteries.
- MgEDTF and synergistic halide additives offer a novel approach to enhance battery performance.
- This work provides a new pathway for solvation structure modulation in various metal-based battery systems.
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