High Stability Hypha-Like Core–Shell Nanostructure by In Situ Induced Phase Inversion for Zinc Metal Batteries

Nanomaterials are widely used in many fields for their unique physical and chemical properties and especially demonstrate irreplaceability in energy storage systems. In this paper, a novel composite of copper sulfide with hypha-like core-shell nano-structure is synthesized by in situ phase inversion method, which serves as high stability negative electrode materials of zinc-ion batteries (ZIBs). The unique structure facilitates efficient electron and ion transport, enhances the kinetics of electrochemical reactions, and effectively suppresses the undesired expansion and decomposition of transition metal compounds. As a result, the half battery exhibits high specific capacity (250.2 mAh g⁻¹ at 0.1 A g⁻¹), reliable rate performance, and cycle stability (98.3 mAh g⁻¹ at 1 A g⁻¹ after 500 cycles). Additionally, when assembled with Zn_xMnO₂ positive to form a full battery, it demonstrates good cycling capacity at an intermediate current density of 2 A g⁻¹, while maintaining excellent structural stability over 5,000 cycles (61% retention).