MnS nanoparticles embedded in N,S co-doped carbon nanosheets for superior lithium ion storage

Manganese sulfide has been explored as anode for LIBs owing to its impressive theoretical capacity. However, inferior electronic/ionic conductivity and severe volume expansion occurring during the electrochemical cycle usually result in poor electrochemical performance. In this report, a novel composite, MnS nanoparticles integrating N,S co-doped carbon nanosheets (N,S-C) grown on flexible carbon fiber cloth (MnS@N,S-C/CFC), is fabricated as anode material for LIBs. The N,S co-doped carbon nanosheets protect MnS particles from aggregation so as to facilitate nanosized structure formation, significantly accelerating Li⁺ diffusivity and accommodating stress/strain caused by volume changes. Nanosheets are also connected by CFC substrate to provide the transmission pathway of the electrons and promote fast electron transfer. Morever, compared to the MnS/CFC particles, the remarkably boosted integration between MnS@N,S-C and CFC substrate ensures superior conductivity and improved mechanical stability. Consequently, the MnS@N,S-C/CFC electrode delivers superior specific capacity of 800 mAh g⁻¹ at 0.05 A g⁻¹ as well as excellent rate-capability (535 mAh g⁻¹ up to 2 A g⁻¹), and improved durability (maintaining 52.7% after 500 cycles at 2 A g⁻¹), presenting a simple strategy to boost the electrochemical performance of LIBs anodes by encapsulation of conductive carbon and heteroatom doping.