Solid-State Fabrication of SnS₂/C Nanospheres for High-Performance Sodium Ion Battery Anode

Abstract

Tin disulfide (SnS2) has emerged as a promising anode material for sodium ion batteries (NIBs) due to its unique layered structure, high theoretical capacity, and low cost. Conventional SnS2 nanomaterials are normally synthesized using hydrothermal method, which is time-consuming and difficult to scale up for mass production. In this study, we develop a simple solid-state reaction method, in which the carbon-coated SnS2 (SnS2/C) anode materials were synthesized by annealing metallic Sn, sulfur powder, and polyacrylonitrile in a sealed vacuum glass tube. The SnS2/C nanospheres with unique layered structure exhibit a high reversible capacity of 660 mAh g(-1) at a current density of 50 mA g(-1) and maintain at 570 mAh g(-1) for 100 cycles with a degradation rate of 0.14% per cycle, demonstrating one of the best cycling performances in all reported SnS2/C anodes for NIBs to date. The superior cycling stability of SnS2/C electrode is attributed to the stable nanosphere morphology and structural integrity during charge/discharge cycles as evidenced by ex situ characterization.