Sulfur-Mediated Interface Engineering Enables Fast SnS Nanosheet Anodes for Advanced Lithium/Sodium-Ion Batteries

Interface design is generally helpful to ameliorate the electrochemical properties of electrode materials but challenging as well. Herein, in situ sulfur-mediated interface engineering is developed to effectively raise the kinetics properties of the SnS nanosheet anodes, which is realized by a synchronous reduction and carbon deposition/doping process. The sulfur in the raw SnS₂ directly induces the sulfur-doped amorphous carbon layer onto the in situ reduced SnS nanosheet. In situ and ex situ electrochemical characterizations suggest that the sulfur-mediated interface layer can enhance the reversibility and kinetics properties, promote the ion/electron swift delivery, and maintain the configurational wholeness of the SnS nanosheet anodes. Consequently, a relatively high Li-storage capacity of 922 mAh g^-1 and Na-storage capacity of 349 mAh g^-1 at 1.0 A g^-1 even after 1000 and 300 long-term cycles are achieved, respectively. The facile method and excellent performance suggest the effective interface tuning for developing the SnS-based anodes for batteries and beyond.