Solvation\nSheath Reorganization by Alkyl Chain Tuning\nPromises Lean-Electrolyte Li–S Batteries

Sparsely solvating electrolyte (SSE), which can achieve\na quasi-solid-phase\nsulfur reaction path, stands out as a promising strategy to alleviate\nthe dependence on electrolyte usage and construct lean-electrolyte\nlithium–sulfur (Li–S) batteries. Nonetheless, its formation\nrelies upon a high dosage of salt and diluent, thereby leading to\nincreased electrolyte cost. To this end, we herein customize a localized\nSSE (LSSE) featuring a low ratio of salt-to-solvent and diluent-to-solvent\nthrough alkyl chain tuning. A multimodal 2D nuclear magnetic resonance\ntechnique is developed to unveil the Li-ion solvation sheath reorganization,\nwhich is crucial for studying the coordination and dynamics in liquid\nelectrolytes. LSSE affords an anion-derived solid electrolyte interface\nand effective restriction of the shuttling effect; hence, our Li–S\nbatteries can sustain a steady operation under 4 μL mg<sub>S</sub><sup>–1</sup> and 3 mg cm<sup>–2</sup>. Our work opens\na new avenue for advancing SSE design in the pursuit of pragmatic\nlean-electrolyte Li–S batteries.