Design of High-Capacity MoS₃ Decorated Nitrogen Doped Carbon Coated Cu₂S Electrode Structures with Dual Heterogenous Interfaces for Outstanding Sodium-Ion Storage

The hierarchical Cu₂S@NC@MoS₃ heterostructures have been firstly constructed by the high-capacity MoS₃ and high-conductive N-doped carbon to co-decorate the Cu₂S hollow nanospheres. During the heterostructure, the middle N-doped carbon layer as the linker facilitates the uniform deposition of MoS₃ and enhances the structural stability and electronic conductivity. The popular hollow/porous structures largely restrain the big volume changes of active materials. Due to the cooperative effect of three components, the new Cu₂S@NC@MoS₃ heterostructures with dual heterogenous interfaces and small voltage hysteresis for sodium ion storage display a high charge capacity (545 mAh g⁻¹ for 200 cycles at 0.5 A g⁻¹), excellent rate capability (424 mAh g⁻¹ at 15 A g⁻¹) and ultra-long cyclic life (491 mAh g⁻¹ for 2000 cycles at 3 A g⁻¹). Except for the performance test, the reaction mechanism, kinetics analysis, and theoretical calculation have been performed to explain the reason of excellent electrochemical performance of Cu₂S@NC@MoS₃. The rich active sites and rapid Na⁺ diffusion kinetics of this ternary heterostructure is beneficial to the high efficient sodium storage. The assembled full cell matched with Na₃V₂(PO₄)₃@rGO cathode likewise displays remarkable electrochemical properties. The outstanding sodium storage performances of Cu₂S@NC@MoS₃ heterostructures indicate the potential applications in energy storage fields.