Embedding WS2 sheets parallel to SnS sheets for high performance in K-ion batteries

Abstract

Tin sulfide (SnS) exhibits the potential to be used as a superior-performance electrode material for potassium ion batteries. However, serious volume expansion and poor ion transport capacity hinder the applications of SnS. In order to solve the above problems, this work designed a structure that parallel WS2 sheets were embedded in SnS sheets (SnS/WS2@C). SnS/WS2@C displayed excellent kinetic properties and stability when applied to anode materials for potassium ion batteries, as well as a high reversible capacity. SnS/WS2@C maintains a superior specific capacity of 619 mAh g−1 after 100 cycles at 0.2 A g−1 and 210 mAh g−1 at 10 A g−1. Such excellent performance is attributed to the fact that parallelly oriented WS2 sheets provide fast channels for the transportation of potassium ions, which significantly improves the kinetic performance of the electrode, and can play an anchoring role for products in the process of charging and discharging by virtue of its excellent stability to effectively prevent structural fragmentation. This work provides new ideas for improving ion diffusion and enhancing the structural stability of transition metal layered compounds while maintaining the capacity advantage.