Elucidating Solvation Structures for Rational Design of Solvent-in-Salt Electrolytes for High Voltage Batteries Alkali-Metal Batteries

Northern Illinois University, Dekalb IL

Investigators

Abstract

High-voltage alkali-metal batteries have garnered significant attention due to their potential use in high-energy-density batteries for electric vehicles. It is crucial to understand the structure and dynamics of solvents and their effects on transport properties and stability to develop new electrolytes for these batteries. The success of this research will provide reliable methods to measure the structure and dynamics of concentrated battery electrolytes at both bulk and interface levels. Additionally, integrating research with education initiatives will have profound implications for universities, secondary education, and the public. The project will integrate research findings into teaching courses, fostering interdisciplinary research skills among the involved undergraduate and graduate students. An innovative educational outreach effort includes an annual workshop on Batteries for Energy Storage for local high school students and educators, aimed at expanding the impact of NSF programs and promoting STEM education. Through collaborative efforts between research and education, this project seeks to engage a broad audience, deepen understanding of energy technologies, and inspire interest in STEM subjects. While much research has focused on solvent-in-salt electrolytes, most studies have been limited to local and short-range solvation structures due to a lack of practical characterization tools. This project seeks to systematically study solvation structures and their dynamics from short to long-range at both bulk and interface levels. Understanding these structures is crucial to harnessing their unique transport properties and their impact on battery performance. This research targets the connection between molecular interactions and macroscopic and electrochemical properties of alkali metal electrolytes, employing advanced characterization techniques such as Raman spectroscopy, X-ray scattering, and neutron scattering. This project aims (1) to fully understand the solvation structures through multimodal characterization methods Raman, X-ray, or neutron scattering; (2) to investigate the dynamics of the electrolyte structure through advanced techniques, including X-ray Photon Correlation Spectroscopy (XPCS) and Quasi-Elastic Neutron Scattering (QENS); (3) to study interfacial solvation structures and early-stage solid-state interface formation employing Grazing Incidence Small Angle X-ray Scattering (GISAXS); and (4) to correlate the structure-property relationship by studying transport property and battery performance with their solvation structure and dynamics. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.