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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(SbW9O33)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. [ABSTRACT FROM AUTHOR]

Abstract: A series of rod‐shaped polyoxometalates (POMs) [Bu4N]7[Mo6O18NC(CH2O)3MnMo6O18(OCH2)3CNMo6O18] and [Bu4N]7[ArNMo6O17NC(CH2O)3MnMo6O18(OCH2)3CNMo6O17NAr] (Ar=2,6‐dimethylphenyl, naphthyl and 1‐methylnaphthyl) were chosen to study the effects of cation–π interaction on macroionic self‐assembly. Diffusion ordered spectroscopy (DOSY) and isothermal titration calorimetry (ITC) techniques show that the binding affinity between the POMs and Zn2+ ions is enhanced significantly after grafting aromatic groups onto the clusters, leading to the effective replacement of tetrabutylammonium counterions (TBAs) upon the addition of ZnCl2. The incorporation of aromatic groups results in the significant contribution of cation–π interaction to the self‐assembly, as confirmed by the opposite trend of assembly size vs. ionic strength when compared with those without aromatic groups. The small difference between two aromatic groups toward the Zn2+ ions is amplified after combining with the clusters, which consequently triggers the self‐recognition behavior between two highly similar macroanions. [ABSTRACT FROM AUTHOR]