Tuning of Molecular Water Organization in Water-in-Salt Electrolytes by Addition of Chaotropic Ionic Liquids

Water-in-salt electrolytes (WISEs) have expanded the useful electrochemical stability of water, making the development of functional aqueous lithium-ion batteries more accessible. The implementation of additives in the formulation of WISEs can further improve the electrochemical stability of water a...

Full description

Saved in:
Bibliographic Details
Published inJournal of physical chemistry. C Vol. 127; no. 50; pp. 24065 - 24076
Main Authors Tot, Aleksandar, Zhang, Leiting, Svensson, Per H., Kloo, Lars
Format Journal Article
LanguageEnglish
Published American Chemical Society 21.12.2023
Subjects
C: Energy Conversion and Storage
Additives
Battery performance
Electric discharges
Positive ions
Electrochemical stabilities
Tuning
Lithium-ion batteries
Molecular water
Solvation
Water activity
American Chemical Society
Salt solubility
Solvation shell
Ionic liquids
Electrolytes
Lithium ions
Li
Salt electrolytes
Online AccessGet full text

Cover

More Information
Summary:Water-in-salt electrolytes (WISEs) have expanded the useful electrochemical stability of water, making the development of functional aqueous lithium-ion batteries more accessible. The implementation of additives in the formulation of WISEs can further improve the electrochemical stability of water and avoid potential lithium-ion salt solubility issues. Here, we have used Gemini-type ionic liquids to suppress water activity by designing the structure of ionic-liquid cations. The different water-organizing effects of ionic-liquid cations have been investigated and correlated to battery performance in LTO/LMO full cells. The champion device, containing the most chaotropic ionic liquid, retained at least 99% of its Coulombic efficiency after 500 charging cycles, associated with a final specific discharge capacity of 85 mA h·g–1. These results indicated that water-rich Li+ solvation shells significantly contribute to the excellent device performance and long-term stability of the LTO/LMO-based full battery cells. This work shows that the fine-tuning of the Li+ solvation shell and water structure by the addition of chaotropic cations represents a promising strategy for generating more stable and effective lithium-ion-containing rechargeable aqueous batteries.
ISSN:1932-7447
1932-7455
1932-7455
DOI:10.1021/acs.jpcc.3c07164