Modulating Li + and Polysulfide Solvation with Low‐Density Moderately Solvating Electrolytes for Lithium–Sulfur Batteries

Abstract Lithium–sulfur (Li–S) batteries show great promise as the next‐generation rechargeable batteries, yet they still suffer from polysulfide shuttling and interphasial instability. Electrolyte, as the medium for ion transport and sulfur conversion, plays a crucial role in overcoming these challenges. Here, we introduce a moderately solvating electrolyte (MSE) based on low‐density, low‐viscosity, and nonfluorinated ether co‐solvents that balances polysulfide suppression, Li metal stabilization, and redox kinetics. Through multiple solvent–solvent and solvent‐ion interactions, the optimized MSE weakens Li + ‐solvent pairing while strengthening cation–anion interactions, thereby lowering the desolvation…

• UD
  U.S. Department of Energy

  Award: DE-SC0005397
• WF
  Welch Foundation

  Award: H‐F‐0037
• UO
  University of Texas at Austin
• DO
  Department of Mechanical Engineering, University of Texas at Austin
• BE
  Basic Energy Sciences

  Award: DE-SC0005397