Preparation of NiCo₂S₄ nanomaterials and their electrochemical properties

The Co-MOF precursor was prepared by solvothermal method, and the hollow NiCo-layered double hydroxides (LDH) material was obtained by hydrolyzing and etching the precursor with Ni²⁺, and then NiCo₂S₄ material was obtained by high temperature calcination and sulfurization. The properties of the metal-organic framework make the NiCo₂S₄ material have more excellent performance. The electrochemical data show that the NiCo₂S₄ material has a high specific capacity of 204.8 mA·h·g⁻¹ (1843.6 F·g⁻¹) at a current density of 1 A·g⁻¹, and when the current density is increased to 10 A·g⁻¹, its capacity is still 50.9% of the initial capacity. Finally, a hybrid supercapacitor was assembled using activated carbon as the negative electrode and NiCo₂S₄ material as the positive electrode, and the hybrid supercapacitor (HSC) device had an energy density of 38 W·h·kg⁻¹ at a power density of 800 W·kg⁻¹ and a capacity retention rate of 71.4% after 5000 cycles at a current density of 10 A·g⁻¹.