Solvation Dynamics in Dual-Solvent Systems for Enhanced Electrochemical Performance at Ultra-Low Temperatures

About This Grant

This project addresses one of the most pressing limitations in energy storage — how to ensure lithium-ion batteries (LiBs) operate effectively in extreme cold environments. At sub-zero temperatures, traditional batteries suffer from dramatic losses in performance and lifespan due to the sluggish movement of lithium ions and unstable internal interfaces. These shortcomings hinder the deployment of battery-powered systems in electric vehicles, aerospace, national defense, and renewable energy storage. The research team will explore new liquid electrolyte systems that enable LiBs to charge and discharge efficiently at temperatures as low as -80°C. The project will uncover how certain solvent molecules interact with lithium ions under low-temperature conditions. The project's findings are expected to establish new scientific principles that guide the next generation of high-performance batteries for use in harsh climates on Earth and in space. Beyond advancing electrochemical science, the project will contribute to national priorities in clean energy, climate resilience, and STEM education. The project will integrate educational initiatives such as K–12 outreach, curriculum development, and hands-on research opportunities to broaden participation in battery science and strengthen the U.S. energy workforce. This project aims to advance the fundamental understanding and molecular design of electrolyte systems that enable LiBs to operate reliably at ultra-low temperatures (ULTs). The primary objective is to develop and characterize a new class of dual-solvent electrolytes, modified with a non-solvating fluoroether solvent. These systems are designed to overcome the critical lithiation limitations of conventional carbonate-based electrolytes at ULTs, which suffer from high viscosity, low ionic conductivity, and unstable electrode interfaces at low temperatures. The research will focus on three central objectives: (1) To understand dual-solvent electrolyte systems and engineer primary solvation shells to enhance lithium-ion transport, lithiation, and stability under ULT conditions. (2) To investigate anion-induced solvation structures in dual-solvent electrolytes incorporating weakly coordinating fluoroether co-solvents. (3) To understand how the composition of pre-reduced SEI-forming additives influences the reductive stability of dual-solvent electrolytes on graphite electrodes and affects ion transport efficiency at low temperatures. The project will combine molecular modeling (DFT, MD) with advanced characterization tools, including in-operando Raman, in-operando SAXS/WAXS, XPS, EIS and GITT, to probe solvation dynamics, SEI formation, and ion transport across a wide temperature range. These efforts will establish molecular design principles for cryogenic electrolytes compatible with graphite/NMC full cells. 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.