Construction of a hollow octahedral NiCo2S4/carbon composite derived from a Cu-MOF template for high-performance supercapacitors

A hollow octahedral NiCo 2 S 4 /carbon composite was rationally constructed through precursor regulation, sulfidation, and subsequent carbonization using a Cu-MOF-derived template. Benefiting from the well-preserved hollow architecture, uniformly distributed NiCo 2 S 4 active shell, and conductive carbon framework, the optimized 3-NiCo 2 S 4 @HC sample exhibits enhanced electrochemical performance as a supercapacitor electrode. In a three-electrode system, 3-NiCo 2 S 4 @HC delivers a high specific capacity of 858.5 C·g −1 at 1 A·g −1 and retains 84.2% of its initial capacity at 30 A·g −1 . In addition, it shows excellent cycling stability with 94.27% capacity retention after 10,000 cycles at 10 A·g −1 . Kinetic analysis reveals that the charge-storage process involves both diffusion-controlled Faradaic reactions and capacitive contributions, while the hierarchical hollow porous structure facilitates electrolyte infiltration and ion/electron transport. Furthermore, an assembled 3-NiCo 2 S 4 @HC//AC hybrid supercapacitor operates stably up to 1.6 V, delivering an energy density of 54.9 Wh·kg −1 at a power density of 799.9 W·kg −1 , and retaining 84% of its initial capacitance after 10,000 cycles. This work demonstrates that the synergistic integration of hollow structural engineering and carbonization is an effective strategy for developing high-performance Ni Co sulfide-based supercapacitor electrodes.