Polysulfide Immobilization and Sulfur Conversion Kinetics Promotion via a Tetrathiafulvalene–Crown Ether COF@Graphene Layer for High‐Rate Lithium–Sulfur Batteries

ABSTRACT The rational design of conversion‐kinetics‐promoting framework architectures offers a powerful strategy to overcome the polysulfide shuttling and sluggish conversion kinetics that limit lithium–sulfur (Li–S) batteries. Here, we report a new covalent organic framework, TUS‐44, constructed from tetrathiafulvalene‐based 4,4',4'',4'''‐([2,2'‐bi(1,3‐dithiolylidene)]‐4,4',5,5'‐tetrayl)tetraaniline and benzo[18]crown‐6‐derived 4,4′,4′′,4′′′‐(6,7,9,10,17,18,20,21‐octahydrodibenzo[ b , k ][1,4,7,10,13,16]hexaoxacyclooctadecine‐2,3,13,14‐tetrayl) tetrabenzaldehyde linkers. The resulting imine‐linked, π‐conjugated framework integrates heteroatom‐rich coordination sites within an electron‐delocalized π‐conjugated backbone, establishing a hierarchical, site‐specific interaction network (N > O > S) that governs Li ⁺ coordination, polysulfide anchoring, and dynamic charge redistribution. When coupled with conductive graphene to form an interfacial TUS‐44@G architecture, the hybrid layer functions as a chemisorptive, conversion‐kinetics‐promoting interface that regulates soluble polysulfides, facilitates interfacial charge‐transfer, and stabilizes intermediate species throughout cycling. This synergistic chemical–electronic coupling yields remarkable electrochemical performance: a high reversible capacity of 1455.7 mA h g ⁻¹ at 0.2 A g ⁻¹ , excellent rate capability of 773 mA h g ⁻¹ at 10 A g ⁻¹ , and outstanding durability with 0.034% capacity fading per cycle over 1000 cycles at 5 A g ⁻¹ . A Li–S pouch cell incorporating TUS‐44@G further delivers an outstanding initial energy density of ∼674 Wh kg ⁻¹ at 0.05 A g ⁻¹ (sulfur loading 44.558 mg), underscoring the practical potential of architecting conversion‐catalytic framework interfaces for high‐energy, durable Li–S batteries.