3D Adsorption‐Mediator Network Polymer Binders Improve Redox Kinetics and Flame Retardant Performance for High Loading Lithium–Sulfur Batteries

Abstract The commercial application of lithium–sulfur (Li–S) batteries is severely impeded by abominable shuttle effects, sluggish redox kinetics, and poor safety performance under high loading conditions. Herein, a novel adsorption‐mediator synergistic polymer binder (PAT) is reported to regulate the conversion of lithium polysulfides (LiPSs) through close intermolecular synergy. The abundant polar groups provide strong anchor ability for LiPSs to effectively inhibit the shuttle effect, and the anchored LiPSs are accelerated by adjacent mediator catalytic sites to facilitate their redox kinetics. Moreover, PAT itself features excellent flame retardant properties, which effectively enhance the safety performance of Li–S cells. Benefiting from these attributes, PAT‐based Li–S cells exhibit outstanding rate performance with an average capacity of 617.34 mAh g⁻¹ at 5 C and excellent cycling stability maintaining a capacity of 629.1 mAh g⁻¹ after 800 cycles at 2 C. Even under the harsh conditions of high loading (9.84 mg cm⁻²) and lean electrolyte (E/S = 3.56 µL mg⁻¹), PAT‐based cell delivers a high average areal capacity of 9.58 mAh cm⁻² and an ultralow overpotential of 3 mV, confirming the application potential of adsorption‐mediator synergistic polymer binder in high performance Li–S batteries.