Solid–Liquid Synergy Enables a Trisulfur‐Radical‐Rich Microenvironment for Accelerated Li–S Conversion Kinetics

ABSTRACT Understanding and regulating the rate‐determining steps (RDSs) of lithium–sulfur batteries (LSBs) is crucial for enhancing their electrochemical performance. Herein, we propose a synergistic strategy that integrates a template sulfur host containing oxygen vacancies with a high‐donor‐number (high‐DN) solvent as an additive of the traditional ether‐based electrolyte. The strategy establishes a localized high‐DN microenvironment with a significant concentration of trisulfur radicals on the cathode side. Both experiments and calculations confirm that trisulfur radicals serve as key mediators in accelerating the RDS from the intrinsically sluggish quasi‐liquid–solid reaction to the more kinetically favorable trisulfur radicals‐mediated conversion. Benefiting from the RDS enhancement mediated by trisulfur radicals, the LSB maintains an 85.4% capacity after 500 cycles at 1 C, with an average decay rate of only 0.03% per cycle. In addition, an initial capacity of 659.6 mAh g −1 is achieved at 5 C or 1126.9 mAh g −1 at a high sulfur loading of 4.6 mg cm −2 . This work presents a novel trisulfur radicals mediated‐catalytic mechanism and breaks the limitations of the intrinsic RDS through integration of interface engineering and electrolyte modulation.