An Efficient Strategy toward Multichambered Carbon Nanoboxes with Multiple Spatial Confinement for Advanced Sodium–Sulfur Batteries

Abstract

Intricate hollow carbon structures possess vital function for anchoring polysulfides and enhancing the utilization of sulfur in room-temperature sodium–sulfur batteries. However, their synthesis is extremely challenging due to the complex structure. Here, a facile and efficient strategy is developed for the controllable synthesis of N/O-doped multichambered carbon nanoboxes (MCCBs) by selective etching and stepwise carbonization of ZIF-8 nanocubes. The MCCBs consist of porous carbon shells on the outside and connected carbon grids with a hollow structure on the inside, bringing about a MCCBs structure. As a sulfur host, the multichambered structure has better spatial encapsulation and integrated conductivity via the inner interconnected carbon grids, which combines the characteristics of short charge transfer path and superb physicochemical adsorption along with mechanical strength. As expected, the S@MCCBs cathode realizes decent cycle stability (0.045% capacity decay per cycle over 800 cycles at 5 A g–1) and enhanced rate performance (328 mA h g–1 at 10 A g–1). Furthermore, in situ transmission electron microscopy (TEM) observation confirms the good structural stability of the S@MCCBs during the (de)­sodiation process. Our work demonstrates an effective strategy for the rational design and accurate construction of intricate hollow materials for high-performance energy storage systems.

Boosting Adsorption and Catalysis of Polysulfides by Multifunctional Separator for Lithium–Sulfur Batteries

“…Lithium–sulfur (Li–S) batteries are considered promising energy storage technologies because of their high theoretical capacity (1675 mAh g –1 ), environmental friendliness, and economic benefits. , However, several challenging issues of Li–S batteries associated with poor electronic conductivity of S, the shuttle effect of polysulfides (LiPS), and sluggish transformation process of LiPS result in unsatisfactory capacity and cycle life, severely hindering their practical application. − Encapsulating S into a porous carbon host can effectively improve the electronic conductivity of the S cathode, which is suitable for large-scale applications. − However, the weak interaction between nonpolar carbon and S or LiPS hardly restricts LiPS shuttling, leading to low sulfur utilization and poor electrochemical performance. Many strategies, such as introducing various polar transition metal compounds − and metal nanoparticles , into the S cathode, have been widely developed to anchor S and block the leaching of LiPS. Nevertheless, these methods involve a complicated, high temperature synthetic process or expensive reagents.…”

Hierarchical Nanocapsules of Cu-Doped MoS2@H-Substituted Graphdiyne for Magnesium Storage

“…In such a case, the HsGDY capsule could serve as the ion-buffer reservoirs to keep a steady flow of electrolyte, while the built-in skeletons facilitate ion diffusion across the whole bulks, both of which contribute to the improved Mg 2+ diffusion coefficient. 51 Besides, the fluffy feature of Cu-MoS 2 nanopetals with thinner layers compared with Cu-MoS 2 nanoboxes provides richer edge sites for Mg 2+ ions diffusion across the interlayer channels. 50 As a result, the Mg 2+ ions diffusion coefficient has been greatly improved in the order of MoS 2 , Cu-MoS 2 and Cu-MoS 2 @HsGDY.…”

“…When Cu-MoS 2 is further encapsulated in the HsGDY coating, the Mg 2+ diffusion coefficient is nearly doubled in the mode of Cu-MoS 2 @HsGDY over that of Cu-MoS 2 . In such a case, the HsGDY capsule could serve as the ion-buffer reservoirs to keep a steady flow of electrolyte, while the built-in skeletons facilitate ion diffusion across the whole bulks, both of which contribute to the improved Mg 2+ diffusion coefficient . Besides, the fluffy feature of Cu-MoS 2 nanopetals with thinner layers compared with Cu-MoS 2 nanoboxes provides richer edge sites for Mg 2+ ions diffusion across the interlayer channels .…”

Modulating Bond Interactions and Interface Microenvironments between Polysulfide and Catalysts toward Advanced Metal–Sulfur Batteries

“…A similar internal structure (multichambered carbon nanoboxes) is also designed by Yu and co-workers for high-performance room-temperature sodium-sulfur batteries (Figure 17c,d). [233] Moreover, a yolk-shell structure with the TiS x placed inside the hollow carbon sphere (TiS x @HCS) was designed to compensate for the imperfection of the original hollow one (Figure 17e). [234] Due to the anchoring and catalytic conversion ability of TiS x toward polysulfide, the TiS x @HCS/S cathode exhibited higher capacity retention (455.7 mAh g −1 was maintained after 400 cycles at 0.5 C) than the bare HCS/S cathode (only 229.1 mAh g −1 was maintained), indicating more efficient sulfur utilization.…”