Hierarchical MoS2@CNTs Hybrid as a Long-Life and High-Rate Cathode for Aqueous Rechargeable Zn-Ion Batteries

As a cathode material of aqueous rechargeable zinc-ion batteries (ARZIBs), molybdenum disulfide (MoS2) still suffers sluggish intercalation kinetics, poor electronic conductivity and insufficient active surface. Here, a hierarchical hybrid composing of ultrathin MoS2 nanosheets with expanded interlayer spacing that grow directly on the surface of carbon nanotubes (MoS2@CNTs) is firstly proposed as the cathode material of ARZIBs. Its zinc storage performance and corresponding enhanced mechanism are investigated via electrochemical characterizations and density functional theory calculations. The results reveal that the enlarged spacing of MoS2 interlayer decreases the energy barrier of Zn2+ intercalation and the CNTs backbone improves the electron transfer. What's more, the hierarchical structure provides a great number of active sites for electrochemical reactions. As a result, the hierarchical MoS2@CNTs hybrid delivers a high reversible capacity with good cycling stability and rate capability.