Metallic 1T MoS2 overlapped nitrogen-doped carbon superstructures for enhanced sodium-ion storage

The rational design and development of robust anode materials are important to realize high-performance sodium-ion batteries (SIBs). Herein, intrinsically conductive MoS2 supported nitrogen-doped carbon superstructures (MoS2/NC) are reported as a highly active and conductive Na-ion battery anode. The in-situ formation of nitrogen-doped carbon matrices during hydrothermal treatment significantly favours the formation and coexistence of the 2H (semiconducting) and 1T (metallic) phases of MoS2 due to the confinement effect of nitrogen and carbon. In addition, the restacking and intrinsic conductivity of MoS2 nanosheets are diminished through the generation of layered carbon structures. As an anode material for Na-ion battery, the as-prepared MoS2/NC material exhibited improved Na-ion storage with a reversible capacity of 394 mAh g(-1) at a current rate of 0.1 C, and a good rate capability. The improved electrochemical performances of the MoS2/NC superstructures might be due to the coexistence of the 2H and 1T phases of MoS2. The layers of carbon in these structures act as spacers to prevent the agglomeration of MoS2 sheets, thus enhancing the conductivity by mitigating volume changes.