Phosphorus doping induced the co-construction of sulfur vacancies and heterojunctions in tin disulfide as a durable anode for lithium/sodium-ion batteries†
The reasonable design of electrode materials with heterojunctions and vacancies is a promising strategy to elevate their electrochemical performances. Herein, tin-based sulfide composites with heterojunctions and sulfur vacancies encapsulated by reduced graphene oxide (SnS2−xPx/RGO) were successfully designed and synthesized via a facile hydrothermal assisted phosphating method. The introduction of sulfur vacancies and construction of SnS–SnS2 heterojunctions were realized simultaneously by the phosphating process. The synergistic effect of the heterojunction, sulfur vacancy and phosphorus-doping could improve the conductivity, accelerate the ion transport dynamics, and enhance structural stability. Thus, high-rate, long-term cycling stability was observed for Li-half cells (337 mA h g−1 maintained after 3000 cycles at 10 A g−1) and Na-half cells (199 mA h g−1 maintained after 4000 cycles at 2 A g−1). The design strategy can effectively improve the energy storage performance of tin based sulfides and can be extended to other metal sulfides.