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Synthesis of Ionic Liquid Based Electrolytes, Assembly of Li-ion Batteries, and Measurements of Performance at High Temperature
Published on: December 20, 2016
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Two phosphonium ionic liquids with high Li(+) transport number
Vitor L Martins1, Nédher Sanchez-Ramirez, Mauro C C Ribeiro
1Instituto de Química, Universidade de São Paulo - C.P. 26077, CEP 05513-970, São Paulo, SP, Brazil. martinsv@iq.usp.br rtorresi@iq.usp.br.
Physical Chemistry Chemical Physics : PCCP
|August 15, 2015
Summary
This study characterizes ionic liquids with phosphonium cations and Li(+) mixtures, revealing a high Li(+) transport number of 0.54. These findings suggest potential applications for these electrolytes in advanced battery technologies.
Area of Science:
- Electrochemistry
- Materials Science
- Physical Chemistry
Background:
- Ionic liquids (ILs) are promising electrolytes for energy storage.
- Phosphonium-based ILs offer unique physicochemical properties.
- Understanding Li(+) ion behavior in ILs is crucial for battery development.
Purpose of the Study:
- To characterize two phosphonium-based ionic liquids and their Li(+) mixtures.
- To evaluate their potential as electrolytes for lithium-ion batteries.
- To investigate the influence of cation structure on Li(+) transport.
Main Methods:
- Physicochemical characterization (density, viscosity, conductivity, electrochemical window).
- Diffusion coefficient measurement (PGSE-NMR, Li electrodeposition).
- Li(+) transport number calculation (PGSE-NMR, electrochemical methods).
- Structural analysis (Raman spectroscopy, molecular dynamics simulations).
Main Results:
- High Li(+) transport number (up to 0.54) was determined.
- PGSE-NMR underestimated diffusion coefficients for charged species.
- Li(+) interactions with the anion were similar across ILs, but cation structure influenced Li(+) solvation.
- Electrochemical window, density, viscosity, and ionic conductivity were systematically measured.
Conclusions:
- The studied ILs and Li(+) mixtures exhibit favorable properties for battery electrolytes.
- Cation structure, particularly ether chains, impacts Li(+) ion solvation and mobility.
- Further research into these ILs could lead to enhanced battery performance.
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