Ion and solvent dynamics in ‘solvent-in-salt’ electrolytes

ORAL

Abstract

Recently, the solvent-in-salt (SIS) systems have attracted significant attention as a perspective electrolytes for the next generation of high voltage batteries and supercapacitors. In this study we analyzed ion and solvent dynamics in highly concentrated solutions in water and acetonitrile of two similar salts Li- TFSI and Li-FSI. We performed comprehensive study of bulk properties using Broadband dielectric spectroscopy (BDS), quasielastic neutron scattering (QENS), NMR, FTIR, and MD simulations. The results revealed that even small amount of solvent leads to high ionic conductivity. Moreover, the conductivity of FSI systems is always greater than the TFSI systems. Analysis reveals that the high conductivity is provided by high solvent mobility even in these very concentrated salt solutions, and higher mobility in the FSI systems is caused by weaker anion-solvent interactions. Presented results suggest that FSI based systems are more promising for use in electrical energy storage systems.

*Work was supported by the Fluid Interface Reactions, Structures and Transport (FIRST) Center, an Energy Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences.

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Presenters

  • Ivan Popov

    • Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
    • Oak Ridge National Lab

Authors

  • Ivan Popov

    • Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
    • Oak Ridge National Lab

  • Robert Sacci

    • Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA

  • Nicolette Sanders

    • Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA

  • Naresh C Osti

    • Neutron Scattering Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
    • Neutron Scattering Division, Oak Ridge National Laboratory

  • Eugene Mamontov

    • Neutron Scattering Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
    • Oak Ridge National Laboratory
    • Neutron Scattering Division, Oak Ridge National Laboratory
    • Neutron Scattering Division, Neutron Sciences Directorate, Oak Ridge National Laboratory

  • Takeshi Kobayashi

    • U.S. DOE Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA

  • Marek Pruski

    • U.S. DOE Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA

  • Ray Matsumoto

    • Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee 37235, USA
    • Chemical and Biomolecular Engineering, Vanderbilt University
    • Vanderbilt University

  • Matt Thompson

    • Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee 37235, USA

  • Peter Thomas Cummings

    • Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee 37235, USA
    • Chemical and Biomolecular Engineering, Vanderbilt University
    • Vanderbilt University

  • Alexei Sokolov

    • Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
    • University of Tennessee, Knoxville