Controlled construction of hollow nanocubic crystalline-amorphous CoS₂/NC@MoS₂ heterointerface anodes for enhanced...

Cobalt disulfide (CoS₂), noted for its high theoretical specific capacity, is considered a promising anode material for sodium-ion batteries. However, the cycling and rate capabilities are limited by sluggish charge transfer kinetics and poor structural stability. To address these challenges, heterojunction engineering has been identified as a viable solution. In this study, hollow nanocubic crystalline-amorphous CoS₂/NC@MoS₂ heterostructures have been fabricated using template-guided strategy and stepwise sulfidation approach. This design effectively establishes an interfacial built-in electric field activated by crystalline CoS₂ and amorphous MoS₂. Furthermore, the unique hollow heterostructure combines the benefits of highly conductive crystalline frameworks and amorphous phases rich in active sites, thereby synergistically enhancing electrochemical kinetics and structural integrity. As anticipated, the CoS₂/NC@MoS₂ anode achieves a reversible capacity of 427 mAh g^-1 at 0.5 A g^-1, demonstrates superior rate performance with 299.5 mAh g^-1 at 10 A g^-1, and exhibits exceptional cycling stability, retaining 301.9 mAh g^-1 after 2000 cycles at 2 A g^-1. This work establishes an effective paradigm for designing high-performance heterostructured anodes through precise control of crystallinity and interface engineering, offering new insights into the development of advanced SIBs materials.