Structural Engineering of SnS₂ Encapsulated in Carbon Nanoboxes for High‐Performance Sodium/Potassium‐Ion Batteries Anodes

Abstract

Conversion-alloying type anode materials like metal sulfides draw great attention due to their considerable theoretical capacity for sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs). However, poor conductivity, severe volume change, and harmful aggregation of the material during charge/discharge lead to unsatisfying electrochemical performance. Herein, a facile and green strategy for yolk-shell structure based on the principle of metal evaporation is proposed. SnS 2 nanoparticle is encapsulated in nitrogen-doped hollow carbon nanobox (SnS 2 @C). The carbon nanoboxes accommodate the volume change and aggregation of SnS 2 during cycling, and form 3D continuous conductive carbon matrix by close contact. The well-designed structure benefits greatly in conductivity and structural stability of the material. As expected, SnS 2 @C exhibits considerable capacity, superior cycling stability, and excellent rate capability in both SIBs and PIBs. Additionally, in situ Raman technology is unprecedentedly conducted to investigate the phase evolution of polysulfides. This work provides an avenue for facilely constructing stable and high-capacity metal dichalcogenide based anodes materials with optimized structure engineering. The proposed in-depth electrochemical measurements coupled with in situ and ex situ characterizations will provide fundamental understandings for the storage mechanism of metal dichalcogenides.

Carbon‐based anode materials for potassium‐ion batteries: From material, mechanism to performance

“…Particularly, when the transition metals of the transition metal compounds could be alloyed with K metal, such as Sb and Sn whose alloying mechanisms were discussed in the previous section, a following alloying process of transition metal and K metal would occur after the intercalation‐conversion process to provide extra capacity. However, the problem is that they often suffer from severer transformation, leading to much poorer cycle ability 121,124‐127 . One typical example is that bare Sb 2 S 3 nanowires showed a high capacity of near 500 mA h/g based on the intercalation‐conversion and alloying mechanism, but poor rate capacity and cycle stability due to the severe structural deformation during the charge/discharge process, revealed by in situ TEM at the atomic scale 121 .…”

Synthesis and Applications of Nanostructured Hollow Transition Metal Chalcogenides

“…MIBs [192] Fe 7 S 8 /C@d-MoS 2 Hollow nanocages 505 mAh g −1 at 0.5 A g −1 , 318 mAh g −1 at 5 A g −1 286 mAh g −1 at 4 A g −1 , 500 cycles PIBs [127] SnS 2 @C Hollow nanobox 508 mAh g −1 at 0.1 A g −1 , 222 mAh g −1 at 2 A g −1 347 mAh g −1 at 1 A g −1 , 300 cycles 72% capacity retention PIBs [134] N-CoS 2 Yolk-shell nanospheres 744 mAh gZn −1 at 5 mA cm −2 165 h at 10 mA cm −2 ZABs [193] NiCo 2 S 4 Hollow spheres 1387.4 F g −1 at 1 A g −1 , 755 F g −1 at 10 A g −1 1387.5 F g −1 at 1 A g −1 , 4500 cycles 92.2% capacity retention SCs [194] For example, a semiconductor photocatalyst condenses electrons on the catalyst surface, thereby improving the photocatalytic CO 2 reduction ability. [69] Therefore, the preparation of some new-type, good-effect, and environment friendly photocatalysts has aroused great interest from many researchers.…”

“…Sun et al designed a simple and versatile single-shell structure based on the principle of metal evaporation. [134] The nitrogen-doped carbon is encapsulated on the surface of the SnS 2 nanoparticles forming a spherical structure to further form a SnS 2 @C nanobox (Figure 5a). Where a reasonable internal space between the SnS 2 nanoparticles and the shell carbon layer can be clearly seen (Figure 5b-d), providing a good contact area as well as a high electrical conductivity.…”

“…In terms of electrochemical energy storage system, in addition to LIBs [190] and SIBs, [191] rechargeable batteries also include magnesium ion batteries (MIBs), [192] potassium ion batteries (PIBs), [127,134] and Zn-air batteries (ZABs), [193] etc. Among them, supercapacitors (SCs) and batteries are used as energy storage components and are part of the energy storage system.…”

“…b,c) SEM and TEM images of SnS 2 @C. d) Elemental mapping of SnS 2 @C (C, S, and Sn). Reproduced with permission [134]. Copyright 2020, Wiley-VCH GmbH & Co. KGaA, Weinheim.…”