Understanding the Nanostructures in the Electrolytes By Small-Angle X-Ray Scattering

Abstract

The solution solvation structure of the liquid electrolyte directly affects transport properties, which ultimately determines the performance of batteries. It has been predicted that the nanoscale aggregates in the liquid electrolytes, especially as the salt concentrations increase. However, little is known about these structures due to the limitation of the traditional methods. Herein, we demonstrate that small-angle X-ray scattering-wide angle X-ray scattering (SAXS-WAXS), even ultra-small-angle X-ray scattering (USAXS) could be applied to capture these larger aggregates in the electrolytes, including conventional organic electrolytes, high concentration electrolytes, water-in-slat electrolytes, and redox-active electrolytes. Raman, neutron scattering, IR, and molecular dynamics (MD) simulations further support the proposed structures. This work highlights the fundamental structure analysis in nanoscale, which will prompt better electrolytes in the future.