Polyoxometalate‐Cyclodextrin‐Based Cluster‐Organic Supramolecular Framework for Polysulfide Conversion and Guest–Host Recognition in Lithium‐sulfur Batteries

Abstract

Developing polyoxometalate-cyclodextrin cluster-organic supramolecular framework (POM-CD-COSF) still remains challenging due to an extremely difficult task in rationally interconnecting two dissimilar building blocks. Here we report an unprecedented POM-CD-COSF crystalline structure produced through the self-assembly process of a Krebs-type POM, [Zn₂ (WO₂ )₂ (SbW₉ O₃₃ )₂ ]^10- , and two β-CD units. The as-prepared POM-CD-COSF-based battery separator can be applied as a lightweight barrier (approximately 0.3 mg cm^-2 ) to mitigate the polysulfide shuttle effect in lithium-sulfur batteries. The designed Li-S batteries equipped with the POM-CD-COSF modified separator exhibit remarkable electrochemical performance, attributed to fast Li⁺ diffusion through the supramolecular channel of β-CD, efficient polysulfide-capture ability by the dynamic host-guest interaction of β-CD, and improved sulfur redox kinetics by the bidirectional catalysis of POM cluster. This research provides a broad perspective for the development of multifunctional supramolecular POM frameworks and their applications in Li-S batteries.