Heterostructure Interface Construction of Zinc/Cobalt Sulfides Derived From Binary Metal–Organic Framework Toward Ultrastable Sodium-Ion Half/Full Batteries

Developing stable material structures and modulating electronic structures is a good strategy for improving metal-sulfide electrode conductivity, reducing volume change, and enhancing the reaction kinetics of Na⁺ electrodes to achieve stable electrochemical performance. However, it continues to be challenging to create hybrid structures with precisely defined architectures and desired compositions. Thus, the carbon-coated Zinc/Cobalt sulfide heterostructure nanorods (ZnS/CoS@C) are prepared by sulfidation treatment of the Zinc/Cobalt binary metal–organic framework in one step. As expected, ZnS/CoS@C heterostructure displayed an ultra-long lifespan (403 mAh g⁻¹ at 10 A g⁻¹ over 1700 cycles) and superior rate performance (653.1/333.3 mAh g⁻¹ at 0.5/30 A g⁻¹). The kinetic analysis and Density functional theory calculations show that the excellent electrochemical performance is attributed to the high pseudocapacitive and fast kinetic behavior. The Na-ion storage mechanism of ZnS/CoS@C is revealed by in X-ray diffraction, ex situ X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy. Furthermore, the full cells of ZnS/CoS@C//Na₃V₂(PO₄)₃@rGO are successfully assembled and demonstrated impressive performance (186.3 mAh g⁻¹ at 0.5 A g⁻¹ for 600 cycles). This study offers an easy way to design heterostructured anode materials for superior sodium-ion batteries.