The Hydrotropic Effect of Ionic Liquids in Water-in-Salt Electrolytes*.
Angew Chem Int Ed Engl
; 60(25): 14100-14108, 2021 Jun 14.
Article
em En
| MEDLINE
| ID: mdl-33786945
ABSTRACT
Water-in-salt electrolytes have successfully expanded the electrochemical stability window of aqueous electrolytes beyond 2â
V. Further improvements in stability can be achieved by partially substituting water with either classical organic solvents or ionic liquids. Here, we study ternary electrolytes composed of LiTFSI, water, and imidazolium ionic liquids. We find that the LiTFSI solubility strongly increases from 21â
mol kg-1 in water to up to 60â
mol kg-1 in the presence of ionic liquid. The solution structure is investigated with Raman and NMR spectroscopy and the enhanced LiTFSI solubility is found to originate from a hydrotropic effect of the ionic liquids. The increased reductive stability of the ternary electrolytes enables stable cycling of an aqueous lithium-ion battery with an energy density of 150â
Wh kg-1 on the active material level based on commercially relevant Li4 Ti5 O12 and LiNi0.8 Mn0.1 Co0.1 O2 electrode materials.
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MEDLINE
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En
Ano de publicação:
2021
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Article