Two‐Dimensional SnS2 Nanoplates with Extraordinary High Discharge Capacity for Lithium Ion Batteries

Two-dimensional (2D) layered nanostructures have received increasing interest due to their unique nanoscale phenomena and their potential applications ranging from electronics and energy to catalysis. Recent investigation has revealed that laterally confined layered nanocrystals (LCLN) have remarkably enhanced electrochemical properties compared to their bulk counterparts owing to nanoscale characteristics that include large surface areas, finite lateral sizes, and enhanced open-edge morphologies. Among the variety of layered materials that have been described, tin sulfides are of particular interest because of their unique structural properties. SnS2 has a layered CdI2-type structure, composed of tin atoms sandwiched between two layers of hexagonally disposed closepacked sulfur atoms. The 2D layered characteristics of this substance are revealed in alkali metal intercalation phenomena, and by investigating anisotropy of properties such as electric and photoelectric conductivity. Owing to their large theoretical capacities for battery applications, bulk or micron sized tin-based materials have been extensively studied as possible alternatives for commercially available carbon electrodes. However, the main drawback of this system has been stemming from the large volume changes and accompanying sharp decrease in capacity that occur during electrochemical cycles. Aifantis et al. have reported that active sites with spherical and smaller volume fraction could improve electrochemical properties of anode materials from the view point of fracture mechanics. Other researchers also have reported that nanoscale tin sulfide-based materials would lead to an improvement in the cycling stability of these systems. Especially, layered SnS2 nanoplates with swelling tolerant hosting spaces and enhanced guest accessibility would provide enhanced diffusion for Li ion, and lead to the formation of Li-Sn alloy during the cycle, and improve the