Highly Reversible Sodiation/Desodiation from a Carbon-Sandwiched SnS₂ Nanosheet Anode for Sodium Ion Batteries

Abstract

The further improvement of sodium ion batteries requires the elucidation of the mechanisms pertaining to reversibility, which allows the novel design of the electrode structure. Here, through a hydrogel-embedding method, we are able to confine the growth of few-layer SnS2 nanosheets between a nitrogen- and sulfur-doped carbon nanotube (NS-CNT) and amorphous carbon. The obtained carbon-sandwiched SnS2 nanosheets demonstrate excellent sodium storage properties. In operando small-angle X-ray scattering combined with the ex situ X-ray absorption near edge spectra reveal that the redox reactions between SnS2/NS-CNT and the sodium ion are highly reversible. On the contrary, the nanostructure evolution is found to be irreversible, in which the SnS2 nanosheets collapse, followed by the regeneration of SnS2 nanoparticles. This work provides operando insights into the chemical environment evolution and structure change of SnS2-based anodes, elucidating its reversible reaction mechanism, and illustrates the significance of engineered carbon support in ensuring the electrode structure stability.

Nanostructured MoS2‐, SnS2‐, and WS2‐Based Anode Materials for High‐Performance Sodium‐Ion Batteries via Chemical Methods: A Review Article

“…They showed that the prepared material exhibits high reversible capacity of 370 mAh g −1 at current density of 1 A g −1 up to 200 cycles and long stability of 240 mAh g −1 at the same current density after 2000 cycles, as shown in Figure 7c. Recently, Liu et al [ 84 ] received success in confining few layers of SnS 2 nanosheets between the nitrogen‐ and sulfur‐doped carbon nanotube (NS‐CNT) and amorphous carbon by the hydrogel‐embedding technique (Figure 7d). This structure (Figure 7e) was named carbon‐sandwiched SnS 2 nanosheets.…”

“…Reproduced with permission. [ 84 ] Copyright 2020, American Chemical Society. h) TEM image and i,j) electrochemical performance of K‐SnS 2 @SG.…”

Electrolyte/Structure-Dependent Cocktail Mediation Enabling High-Rate/Low-Plateau Metal Sulfide Anodes for Sodium Storage

“…By contrast, another series of metal (Sn, Sb, Bi, etc.) sulfides (AMSs) with conversion/alloying-reaction mechanisms can show acceptable voltage hysteresis and relatively lower voltage plateau [23][24][25][26][27][28][29][30]. However, these AMSs always suffer from severe volume change during discharge/charge processes, resulting in poor rate capability and cyclability in ester-based electrolytes (Scheme 1b).…”

Ultra-small Fe3O4 nanodots encapsulated in layered carbon nanosheets with fast kinetics for lithium/potassium-ion battery anodes

“…These exceptional electrochemical behaviors are highly ascribed to the elaborately designed material features on shortening Li/K ion's diffusion length, fast reaction kinetics, high electronic conductivity, and robust structure stability. 29,45 Experimental Chemicals Catechol (C 6 H 4 (OH) 2 , >98%), iron(III) nitrate hexahydrate (Fe(NO 3 ) 3 $9H 2 O, >98.5%), N,N-dimethylformamide (C 3 H 7 NO, DMF, >99.5%), ethanol (ET, >95%) were purchased from Sinopharm Chemical Reagent Co. Ltd. All the chemicals were used without further purication. Deionized water (DI) was obtained from a Milli-Q System (Millipore).…”