A Facile In Situ Sulfurization Strategy for Heterostructured SnS₂@Graphene Scrolls Anode with Enhanced Initial Coulombic Efficiency for High‐Energy Lithium Storage

Abstract

The initial Coulombic efficiency (ICE) for anode materials is usually one of important parameters for the energy density improvement of batteries. However, due to the lack of effective regulatory methods, the excellent ICE is usually difficult to achieve for SnS2 systems based on alloying/conversion mechanisms in Li‐storage process. Herein, a heterostructure constructed from SnS2 nanoflakes in situ anchored on graphene scroll (SnS2@GS) is engineered and fabricated involving a facile in situ sulfurization strategy. The SnS2@GS anode benefiting from 1D open and organized ion diffusion pathways, along with rapid charge transfer in the heterogeneous interfaces, achieves improved reversibility and kinetics. This material exhibits a remarkable specific capacity coupled with a high ICE (≈88%) while yielding robust rate properties. These exceptional lithium storage properties derive from improved conductivity and reduced energy barriers for Li‐ion migration in the heterostructures, as indicated by the density functional theory calculations. Besides, the full‐cell (LiFePO4//SnS2@GS) and the lithium‐ion capacitor based on SnS2@GS anode are assembled and deliver superior energy densities of 330 and 349 W h kg−1, respectively. This proposed approach is also popularized for the fabrication about other metal sulfide wrapped in graphene scroll to construct the anodes with remarkable properties.