Lithium–sulfur (Li–S) batteries have attracted much attention in the field of electrochemical energy storage due to their high energy density and low cost. However, the “shuttle effect” of the sulfur cathode, resulting in poor cyclic performance, is a big barrier for the development of Li–S batteries. Herein, a novel sulfur cathode integrating sulfur, flexible carbon cloth, and metal–organic framework (MOF)‐derived N‐doped carbon nanoarrays with embedded CoP (CC@CoP/C) is designed. These unique flexible nanoarrays with embedded polar CoP nanoparticles not only offer enough voids for volume expansion to maintain the structural stability during the electrochemical process, but also promote the physical encapsulation and chemical entrapment of all sulfur species. Such designed CC@CoP/C cathodes with synergistic confinement (physical adsorption and chemical interactions) for soluble intermediate lithium polysulfides possess high sulfur loadings (as high as 4.17 mg cm–2) and exhibit large specific capacities at different C‐rates. Specially, an outstanding long‐term cycling performance can be reached. For example, an ultralow decay of 0.016% per cycle during the whole 600 cycles at a high current density of 2C is displayed. The current work provides a promising design strategy for high‐energy‐density Li–S batteries.

On account of increasing demand for energy storage devices, sodium‐ion batteries (SIBs) with abundant reserve, low cost, and similar electrochemical properties have the potential to partly replace the commercial lithium‐ion batteries. In this study, a facile metal‐organic framework (MOF)‐derived selenidation strategy to synthesize in situ carbon‐encapsulated selenides as superior anode for SIBs is rationally designed. These selenides with particular micro‐ and nanostructured features deliver ultrastable cycling performance at high charge–discharge rate and demonstrate ultraexcellent rate capability. For example, the uniform peapod‐like Fe7Se8@C nanorods represent a high specific capacity of 218 mAh g−1 after 500 cycles at 3 A g−1 and the porous NiSe@C spheres display a high specific capacity of 160 mAh g−1 after 2000 cycles at 3 A g−1. The current simple MOF‐derived method could be a promising strategy for boosting the development of new functional inorganic materials for energy storage, catalysis, and sensors.

To solve the serious problems (the agglomeration of nano-Fe, dissolution of polysulfide, and low electronic conductivity of LiS) of earth-abundant pyrite (FeS) cathodes for lithium batteries, a simple in situ encapsulation and transformation route has been successfully developed to synthesis pitaya-structured porous carbon embedded with FeS nanoparticles. Due to such a hierarchical architecture design, this cathode of pitaya-structured FeS@C can effectively avoid the serious agglomeration and coarsening of small Fe nanoparticles, reduce the dissolution of polysulfide, and provide superior kinetics toward lithium storage, resulting in enhanced reversibility and rate capability. Cycling in the voltage region of 1.0-3.0 V at 0.3 A g, the current conversion-based FeS@C cathode displays a high and stable energy density (about 1100 Wh kg), ultrahigh rate capability (a reversible capability of 660, 609, 554, 499, 449, and 400 mA h g at 0.2, 0.5, 1.0, 2.0, 5.0, and 10 A g, respectively), and stable cycling performance.

For solving the drawbacks of low conductivity and the shuttle effect in a sulfur cathode, various nonpolar carbon and polar metal compounds with strong chemical absorption ability are applied as sulfur host materials for lithium–sulfur (Li–S) batteries. Nevertheless, previous research simply attributed the performance improvement of sulfur cathodes to the chemical adsorption ability of polar metal compounds toward lithium polysulfides (LPS), while a deep understanding of the enhanced electrochemical performance in these various sulfur hosts, especially at the molecular levels, is still unclear. Herein, for a mechanistic understanding of superior metal phosphide host in Li–S battery chemistry, an integrated phosphide-based host of CF/FeP@C (carbon cloth with grown FeP@C nanotube arrays) is chosen as the model, and this binder-free cathode can exclude interference from the binder and conductive additives. With a systematic electrochemical investigation of the loading sulfur in such oxide- and phosphide-based hosts (CF/Fe3O4@C and CF/FeP@C), it is found that CF/FeP@C@S shows much superior Li–S performances. The greatly enhanced performance of CF/FeP@C@S suggests that FeP can well suppress the shuttle effect of LPS and accelerate their transformation during the charge–discharge process. The first-principles calculations reveal the performance variations of Fe3O4 and FeP in Li–S batteries mainly because the shifts of the p band of the FeP could accelerate the interfacial electronics transfer dynamics by increasing the electronic concentration in the Fermi level of adsorbed Li2S4. The current work sheds light on the promising design of superior Li–S batteries from both theoretical and experimental aspects.

Although lithium-sulfur (Li-S) batteries are promising next-generation energy-storage systems, their practical applications are limited by the growth of Li dendrites and lithium polysulfide shuttling. These problems can be mitigated through the use of single-atom catalysts (SACs), which exhibit the advantages of maximal atom utilization efficiency (≈100%) and unique catalytic properties, thus effectively enhancing the performance of electrode materials in energy-storage devices. This review systematically summarizes the recent progress in SACs intended for use in Li-metal anodes, S cathodes, and separators, briefly introducing the operating principles of Li-S batteries, the action mechanisms of the corresponding SACs, and the fundamentals of SACs activity, and then comprehensively describes the main strategies for SACs synthesis. Subsequently, the applications of SACs and the principles of SACs operation in reinforced Li-S batteries as well as other metal-S batteries are individually illustrated, and the major challenges of SACs usage in Li-S batteries as well as future development directions are presented.

Uniform MnS hollow microspheres in situ crystallized on reduced graphene oxide (RGO) nanosheets via a facile hydrothermal method. The MnS/RGO composite material was used as the anode for Na-ion batteries for the first time and exhibited excellent cycling performance, superior specific capacity, and great cycle stability and rate capability for both Li- and Na-ion batteries. Compared with nonencapsulated pure MnS hollow microspheres, these MnS/RGO nanocomposites demonstrated excellent charge-discharge stability and long cycle life. Li-ion storage testing revealed that these MnS/RGO nanocomposites deliver high discharge-charge capacities of 640 mAh g(-1) at 1.0 A g(-1) after 400 cycles and 830 mAh g(-1) at 0.5 A g(-1) after 100 cycles. The MnS/RGO nanocomposites even retained a specific capacity of 308 mAh g(-1) at a current density of 0.1 A g(-1) after 125 cycles as the anode for Na-ion batteries. The outstanding electrochemical performance of the MnS/RGO composite attributed to the RGO nanosheets greatly improved the electronic conductivity and efficiently mitigated the stupendous volume expansion during the progress of charge and discharge.

Conventional lithium-ion batteries, with flammable organic liquid electrolytes, have seriouss afety problems, which greatly limit their application.A ll-solid-state batteries (ASSBs) have received extensive attention from large-scale energy-storage fields,s uch as electric vehicles (EVs) and intelligent powerg rids, due to their benefits in safety,e nergy density,a nd thermostability.A st he key component of ASSBs, solid electrolytes determine the properties of ASSBs. In past decades, various kinds of solid electrolytes, such as polymers and inorganic electrolytes, have been explored.Amongt hese candidates, organic-inorganic composite solid electrolytes (CSEs) that integrate the advantages of these two differente lectrolytes have been regarded as promising electrolytes for high-performanceA SSBs, and extensive studies have been carried out. Herein,r ecent progress in organic-inorganic CSEs is summarized in terms of the inorganic component, electrochemical performance, effects of the inorganicc eramic nanostructure, and ionic conducting mechanism. Finally,t he main challenges and perspectiveso fo rganic-inorganic CSEs are highlighted for future development.

Hierarchical Fe3O4@polypyrrole nanocages constructed with thin nanosheets are synthesized via a reduction and in situ polymerization route. They exhibit a stable cycling performance (650 mA h g−1 capacity at 2000 mA g−1 after 500 cycles) and superior rate capability (reversible capabilities of 1120, 950, 796, 657, and 490 mA h g−1 at 100, 300, 1000, 2500, and 5000 mA g−1, respectively).