Localized Water?In?Salt Electrolyte for Aqueous Lithium?Ion Batteries

Water-in-salt (WIS) electrolytes using super-concentrated organic lithium (Li) salts are of interest for aqueous Li-ion batteries. However, the high salt cost, viscosity, poor wettability, and environmental hazards remain a great challenge. Herein, we present localized water-in-salt (LWIS) electrolyte based on low-cost nitrate (LiNO3) 1,5-pentanediol (PD) as inert diluent. The addition PD maintains solvation structure WIS electrolyte, improves stability via hydrogen-bonding interactions with water NO3? molecules, reduces total concentration. By in situ gelling LWIS tetraethylene glycol diacrylate (TEGDA) monomer, window can be further expanded to 3.0 V. as-developed Mo6S8|LWIS gel electrolyte|LiMn2O4 (LMO) batteries delivered outstanding cycling performance an average Coulombic efficiency 98.53 % after 250 cycles at 1 C.