Multidimensional Design of Backbones, Modulators, and Pore Spaces in Benzotrithiophene-Linked Metal-Organic...

Lithium-sulfur (Li-S) batteries are promising next-generation energy storage systems, yet critical challenges including severe sulfur volume expansion, uncontrolled lithium polysulfide (LiPS) shuttling, and sluggish sulfur redox kinetics impede their practical application. Herein, we develop a metal-organic framework (MOF) functionalization strategy across three distinct structural modules (MOF backbone, grafted modulators, and engineered pore space) to tackle these issues. Specifically, in the newly synthesized Zr-based spn topology FDM-221, its high surface area (1956 m² g^-1) and large pore volume (1.35 cm³ g^-1) provide ample pore space to accommodate sulfur volume expansion even after high sulfur encapsulation. Furthermore, sulfiphilic sites (coordinatively unsaturated Zr(IV) in the framework backbone) and lithiophilic moieties (S atoms from the benzotrithiophene-based linker and F atoms from the dangling modulators) work in tandem to furnish robust binding sites for LiPS adsorption while concurrently accelerating the redox catalysis of sulfur species. Li-S batteries based on this trinity structure deliver a high capacity of 1164 mAh g^-1 at 0.1C and excellent cycling stability over 1000 cycles at 2C, demonstrating the great potential of this MOF design strategy for next-generation batteries.