Molecular Insight into Microstructural and Dynamical Heterogeneities in Magnesium Ionic Liquid Electrolytes.

Area of Science:

• Electrochemistry
• Materials Science
• Physical Chemistry

Background:

• Ionic liquids (ILs) are advanced solvents for multivalent electrolytes.
• Understanding ion clustering in electrolytes is critical for battery performance.
• Multivalent ion behavior is less studied than ion pairs.

Purpose of the Study:

• Investigate the impact of ion clusters on IL-based electrolytes for Mg batteries.
• Explore how ion cluster formation affects electrolyte transport and electrochemical properties.
• Determine the role of IL denticity in mitigating ion agglomeration.

Main Methods:

• Computational simulations were employed to study ion behavior.
• Small-angle X-ray scattering (SAXS) was used to analyze electrolyte structure.
• Electrochemical techniques assessed Mg deposition/stripping and Coulombic efficiency.

Main Results:

• Higher denticity ILs reduce ion agglomeration and parasitic reactions in Mg electrolytes.
• Ion clustering decreases Mg2+ diffusivity.
• Despite reduced diffusivity, Coulombic efficiency for Mg deposition/stripping is enhanced.

Conclusions:

• Microstructural and dynamical heterogeneities are key for designing better multivalent electrolytes.
• Controlling ion clustering in ILs is a promising strategy for improving Mg battery performance.
• ILs offer tunable properties for advanced electrolyte development.