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

Abstract The hierarchical Cu 2 S@NC@MoS 3 heterostructures have been firstly constructed by the high‐capacity MoS 3 and high‐conductive N‐doped carbon to co‐decorate the Cu 2 S hollow nanospheres. During the heterostructure, the middle N‐doped carbon layer as the linker facilitates the uniform deposition of MoS 3 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 Cu 2 S@NC@MoS 3 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 Cu 2 S@NC@MoS 3 . 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 Na 3 V 2 (PO 4 ) 3 @rGO cathode likewise displays remarkable electrochemical properties. The outstanding sodium storage performances of Cu 2 S@NC@MoS 3 heterostructures indicate the potential applications in energy storage fields.