An interlayer spacing design approach for efficient sodium ion storage in N-doped MoS2

MoS2 in a graphene-like structure that possesses a large interlayer spacing is a promising anode material for sodium ion batteries (SIBs). However, its poor cycling stability and bad rate performance limit its wide application. In this work, we synthesized an N-doped rGO/MoS2 (ISE, interlayer spacing enlarged) composite based on an innovative strategy to serve as an anode material for SIBs. By inserting NH4+ into the interlayer of MoS2, the interlayer spacing of MoS2 was successfully expanded to 0.98 nm. Further use of N plasma treatment achieved the doping of N element. The results show that N-rGO/MoS2(ISE) exhibits a high specific capacity of 542 mA h g(-1) after 300 cycles at 200 mA g(-1). It is worth mentioning that the capacity retention rate reaches an ultra-large percentage of 97.13%, and the average decline percentage per cycle is close to 0.01%. Moreover, it also presents an excellent rate performance (477, 432, 377, 334 mA h g(-1) at 200, 500, 1000, 2000 m A g(-1) respectively). This work reveals a unique approach to fabricating promising anode materials and the electrochemical reaction mechanism for SIBs.

Automated summary

An N-doped rGO/MoS2 composite with an enlarged interlayer spacing was synthesized as an anode material for sodium ion batteries. After 300 cycles, N-rGO/MoS2(ISE) exhibited a specific capacity of 542 mA h g(-1), a capacity retention rate of 97.13%, and an average decline percentage per cycle close to 0.01%. It also showed excellent rate performance. This work reveals a unique approach to fabricating promising anode materials and the electrochemical reaction mechanism for SIBs.