Interlayer Expanded SnS 2 Anchored on Nitrogen‐Doped Graphene Nanosheets with Enhanced Potassium Storage

Potassium‐ion batteries (PIBs) are promising candidates to substitute lithium‐ion batteries (LIBs) as large‐scale energy storage devices. However, developing suitable anode materials is still a great challenge that has limited the anticipated application of PIBs. Herein, the interlayer expanded SnS 2 nanocrystals anchored on nitrogen‐doped graphene nanosheets (SnS 2 @NC) are synthesized following a facile one‐step hydrothermal strategy. Relying on the exquisite nanostructure with larger interlayer spacing, the K + ions diffusion and charge transfer will be accelerated. In addition, the intense coupling interaction between nitrogen‐doped graphene nanosheets and SnS 2 can endow a sturdy nanostructure, avoiding the collapse and aggregation of SnS 2 nanocrystals upon cycling. Based on the above merits, the as‐prepared SnS 2 @NC anode exhibits improved electrochemical performanc (desirable rate capability of 206.7 mAh g −1 at 1000 mA g −1 and advanced cyclic property of 262.5 mAh g −1 , while after 100 cycles at 500 mA g −1 ). More importantly, multistep reactions of K + storage mechanism combining with intercalation, conversion and alloying reactions are clearly illustrated by combined in‐situ XRD measurement and ex‐situ TEM detection. This strategy of enhancing K + storage performances has a great potential for other electrode materials.