Facile synthesis of ultrathin MoS2/C nanosheets for use in sodium-ion batteries

We present a clean and simple method for the synthesis of MoS2/C hybrids. Commercial ion-exchange resins are used to absorb aqueous molybdate, followed by annealing with sulfur powder in an inert atmosphere. Even ultrathin MoS2 nanosheets with enlarged interlayers (0.63 nm) are homogeneously wrapped by mesoporous graphitic carbon. When evaluated as anodes for sodium-ion batteries, the MoS2/C nanocomposite exhibits good electrochemical performance. The first discharge/charge capacities at current density 50 mA g(-1) are 784.3 and 590.0 mA h g(-1), respectively, with initial coulombic efficiency of approximately 75%. It exhibits superior rate capabilities, with specific discharge capacities of 513.1, 467.3, 437.1, 399.2, 361.8, and 302.7 mA h g(-1) at current densities of 50, 100, 200, 500, 1000, and 2000 mA g(-1), respectively. This superior electrochemical performance is mainly due to the synergistic effect between the uniformly-distributed, ultrathin MoS2 nanosheets and the highly graphitized carbon. This not only mitigates mechanical stress during repeated cycling, but also provides good conductivity.