Molybdenum disulfide nanosheets embedded in hollow nitrogen-doped carbon spheres for efficient lithium/sodium storage with enhanced electrochemical kinetics

Molybdenum disulfide nanosheets@hollow nitrogen-doped carbon (MoS₂@NC) spheres were prepared via a facile synthesis and investigated as a host material for ion storages. When used in lithium ion batteries (LIBs) or sodium ion batteries (SIBs), the MoS₂@NC spheres electrodes exhibited excellent electrochemical performances. A high capacity of 1386 mAh g⁻¹ after 100 cycles was obtained at a current density of 200 mA g⁻¹ for LIBs. As for SIBs, a capacity of 330 mAh g⁻¹ was retained after 400 cycles at 1000 mA g⁻¹. The remarkable ion storage performances can be attributed to the hierarchical architecture of the MoS₂@NC spheres, which not only supply abundant active sites and efficient electron and ion pathways, but also alleviate the volume change of the active MoS₂ material. Meanwhile, synergistic effect of the heterogeneous components, interfacial ion storages, nitrogen doping and induced defects are responsible for high capacities of the MoS₂@NC electrodes. And the electrodes exhibited enhanced electrochemical kinetics due to the significantly improved electrical conductivity and the large specific area of the MoS₂@NC spheres.