Enhanced Reversible Sodium‐Ion Intercalation by Synergistic Coupling of Few‐Layered MoS2 and S‐Doped Graphene

Abstract Sodium‐ion batteries (SIBs) are regarded as the best alternative to lithium‐ion batteries due to their low cost and similar Na + insertion chemistry. It is still challenging but greatly desired to design and develop novel electrode materials with high reversible capacity, long cycling life, and good rate capability toward high‐performance SIBs. This work demonstrates an innovative design strategy and a development of few‐layered molybdenum disulfide/sulfur‐doped graphene nanosheets (MoS 2 /SG) composites as the SIB anode material providing a high specific capacity of 587 mA h g −1 calculated based on the total composite mass and an extremely long cycling stability over 1000 cycles at a current density of 1.0 A g −1 with a high capacity retention of ≈85%. Systematic characterizations reveal that the outstanding performance is mainly attributed to the unique and robust composite architecture where few‐layered MoS 2 and S‐doped graphene are intimately bridged at the hetero‐interface through a synergistic coupling effect via the covalently doped S atoms. The design strategy and mechanism understanding at the molecular level outlined here can be readily applied to other layered transition metal oxides for SIBs anode and play a key role in contributing to the development of high‐performance SIBs.