Physics

Inert

Electrode

Organic chemistry

Separator (oil production)

Endocrinology

Engineering

Solubility

Faraday efficiency

Physical chemistry

Power (physics)

Inorganic chemistry

Chemistry

Materials science

Lithium (medication)

Ether

Cathode

Battery (electricity)

Quantum mechanics

Electrolyte

Chemical engineering

Electrochemistry

Medicine

Thermodynamics

Advanced Energy Materials

Rechargeable Li–S batteries are regarded as one of the most promising next‐generation energy‐storage systems. However, the inevitable formation of Li dendrites and the shuttle effect of lithium polysulfides significantly weakens electrochemical performance, preventing its practical application. Herein, a new class of localized high‐concentration electrolyte (LHCE) enabled by adding inert fluoroalkyl ether of 1H,1H,5H‐octafluoropentyl‐1,1,2,2‐tetrafluoroethyl ether into highly‐concentrated electrolytes (HCE) lithium bis(fluorosulfonyl) imide/dimethoxyether (DME) system is reported to suppress Li dendrite formation and minimize the solubility of the high‐order polysulfides in electrolytes, thus reducing the amount of electrolyte in cells. Such a unique LHCE can achieve a high coulombic efficiency of Li plating/stripping up to 99.3% and completely suppressing the shuttling effect, thus maintaining a S cathode capacity of 775 mAh g −1 for 150 cycles with a lean electrolyte of 4.56 g A −1 h −1 . The LHCE reduces the solubility of lithium polysulfides, allowing the Li/S cell to achieve super performance in a lean electrolyte. This conception of using inert diluents in a highly concentrated electrolyte can accelerate commercialization of Li–S battery technology.

High‐Fluorinated Electrolytes for Li–S Batteries