The introduction of high-entropy into Prussian blue analogues (PBAs) has yet to attract attention in the field of lithium-sulfur battery materials. Herein, we systematically synthesize a library of PBAs from binary to high-entropy by a facile coprecipitation method. The coordination environment in PBAs is explored by X-ray absorption fine structure spectroscopy, which together with elemental mapping confirm the successful introduction of all metals. Importantly, electrochemical tests demonstrate that high-entropy PBA can serve as polysulfide immobilizer to inhibit shuttle effect and as catalyst to promote polysulfides conversion, thereby boosting its outstanding performance. Additionally, a variety of nanocubic metal oxides from binary to senary are fabricated by using PBAs as sacrificial precursors. We believe that a wide range of new materials obtained from our coprecipitation and pyrolysis methodology can promote further developments in research on PBA systems and sulfur hosts.

The introduction of high-entropy into Prussian blue analogues (PBAs) has yet to attract attention in the field of lithium-sulfur battery materials. Herein, we systematically synthesize a library of PBAs from binary to high-entropy by a facile coprecipitation method. The coordination environment in PBAs is explored by X-ray absorption fine structure spectroscopy, which together with elemental mapping confirm the successful introduction of all metals. Importantly, electrochemical tests demonstrate that high-entropy PBA can serve as polysulfide immobilizer to inhibit shuttle effect and as catalyst to promote polysulfides conversion, thereby boosting its outstanding performance. Additionally, a variety of nanocubic metal oxides from binary to senary are fabricated by using PBAs as sacrificial precursors. We believe that a wide range of new materials obtained from our coprecipitation and pyrolysis methodology can promote further developments in research on PBA systems and sulfur hosts.

In lithium−sulfur batteries, a serious obstacle is the dissolution and diffusion of long-chain polysulfides, resulting in rapid capacity decay and low Coulombic efficiency. At present, a common practice is designing cathode materials to solve this problem, but this gives rise to reduced gravimetric and volumetric energy densities. Herein, we present a thiodimolybdate [Mo 2 S 12 ] 2− cluster as sulfur host material that can effectively confine the shuttling of polysulfides and contribute its own capacity in Li−S cells. Moreover, the [Mo 2 S 12 ] 2− cluster as a "bidirectional catalyst" can effectively catalyze polysulfide reduction and lithium sulfide oxidation. We further investigate the catalytic mechanism of [Mo 2 S 12 ] 2− clusters by theoretical calculations, in situ spectroscopic techniques, and electrochemical studies. The (NH 4 ) 2 Mo 2 S 12 /S cathodes show good electrochemical performance under a wide range of temperatures. In addition, a pouch cell fabricated with (NH 4 ) 2 Mo 2 S 12 /S cathodes maintains a stable output for more than 50 cycles.

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.

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