Hierarchical Octahedra Constructed by Cu S/MoS ⊂Carbon Framework with Enhanced Sodium Storage.

Metal sulfides have aroused considerable attention for efficient sodium storage because of their high capacity and decent redox reversibility. However, the poor rate capability and fast capacity decay greatly hinder their practical application in sodium-ion batteries. Herein, a self-template-based strategy is designed to controllably synthesize hierarchical microoctahedra assembled with Cu S/MoS heterojunction nanosheets in the porous carbon framework (Cu S/MoS ⊂PCF) via a facile coprecipitation method coupled with vulcanization treatment. The Cu S/MoS ⊂PCF microoctahedra with 2D hybrid nanosubunits reasonably integrate several merits including facilitating the diffusion of electrons and Na ions, enhancing the electric conductivity, accelerating the ion and charge transfer, and buffering the volume variation. Therefore, the Cu S/MoS ⊂PCF composite manifests efficient sodium storage performance with high capacity, long cycling life, and excellent rate capability.