Metallic‐State SnS₂ Nanosheets with Expanded Lattice Spacing for High‐Performance Sodium‐Ion Batteries

Abstract

Metallic‐state 2D SnS2 nanosheets with expanded lattice spacing and a defect‐rich structure were synthesized by the intercalation of Ni into the van der Waals gap of SnS2. The expanded lattice spacing efficiently enhanced the electrochemical performance of the SnS2 for sodium‐ion batteries owing to the change electron state density and energy band structure. In operando synchrotron XRD and theoretical calculations were used to gain insight into the influence of foreign metal‐ion doping and its location. The optimized architecture obtained by in situ uniform growth of nanosheets on carbon fibers significantly enhanced the electrochemical performance. The inherent advantages of this architecture are shorter paths for ion insertion and extraction, larger contact area for more sodium diffusion pathways, and superior electrolyte penetration. Benefiting from the Ni intercalated SnS2 bilayer, the internal adjustment of the electronic state and the enlarged interlayer spacing significantly enhanced the electron transport kinetics, which can be explained by the metallic‐state properties. The integrated electrode exhibited an initial high reversible capacity of 795 mAh g−1 at 0.1 A g−1, with a stable capacity retention of 666 mAh g−1 after 100 cycles. Good rate capability was also exhibited with specific capacities of 691, 564, 437 mAh g−1 at current densities of 200, 500, and 1000 mA g−1, respectively.

Anchoring SnS2 on TiC/C Backbone to Promote Sodium Ion Storage by Phosphate Ion Doping

“…In addition, the sharp peak at around 0.45 V is corresponding to the conversion reaction of SnS 2 and alloying process of Sn as shown in Equations (2) and (3), which is consistent with the previous studies. [20,25,27] xNa SnS xe Na SnS Meanwhile, the decomposition of electrolyte and formation of solid electrolyte interface layer also happen in this process, leading to a low coulombic efficiency during the first CV scan, along with the irreversible reaction in Equation (1), and the peak below 0.1 V for SnS 2 @TiC/C is corresponding to the sodium insertion into the carbon layers of TiC/C sample. In the first charge process of SnS 2 @TiC/C, two peaks at around 0.27 and 1.16 V are detected due to the extraction reaction of sodium ion from Na x Sn and the oxidation of Sn to SnS 2 (Equations (2) and (3)), respectively.…”

“…Among these materials, SnS 2 featuring a typical CdI 2 ‐type crystal structure has been considered as a prospective candidate as anode for SIBs on account of its high specific capacity up to 1137 mAh g −1 , large interlamellar spacing of 0.59 nm, and low operation potential. [ 20,21 ] Nevertheless, pure SnS 2 anode is subjected to fast capacity fading and easy pulverization due to low intrinsic conductivity and large volume expansion in the sodium ion insertion/extraction process. To date, nanostructure design plus binder‐free composite with carbonaceous backbone have been demonstrated to be able to effectively address the above issues of SnS 2, [ 22,23 ] and it is generally accepted that the rational integration between nanostructured SnS 2 and carbonaceous material could achieve excellent electrochemical property owing to the synergetic effect of both shortened ion/electron path, improved electrical conductivity, and alleviated volume strain.…”

State-of-the-Art Electrode Materials for Sodium-Ion Batteries

“…The intercalation of Ni into the van der Waals gap of SnS 2 exhibited an initial high reversible capacity of 795 mA·h·g −1 at 0.1 A·g −1 , with a stable capacity retention of 666 mA·h·g −1 after 100 cycles. At a current density of 1 A·g −1 , the capacity was 437 mA·h·g −1 [ 337 ]. To improve the coulombic efficiency caused by the partial irreversible conversion reaction of SnS 2 , Ou et al fabricated heterostructured SnS 2 /Mn 2 SnS 4 /carbon nanoboxes by a facial wet-chemical method.…”

Sulfur-Deficient Porous SnS2−x Microflowers as Superior Anode for Alkaline Ion Batteries

“…As a typical layered metal dichalcogenide material, SnS 2 is a typical two-dimensional layered structure and the large interlayer spacing could not only store the intercalated Li + or Na + ions but also release the stress induced by volume change [13]. However, as a ceramic semiconductor, tin disulfide suffers from low electronic conductivities [14][15][16][17][18][19]. Different highly conductive materials have been added to composite with SnS 2 , such as grapheme [20][21][22][23][24][25], PPy [18], and so on [26,27].…”