One-step hydrothermal synthesis of flaky attached hollow-sphere structure NiCo₂S₄ for electrochemical capacitor application

In this work, the flaky attached hollow-sphere structure NiCo₂S₄ electrode materials have been synthesized via one-step hydrothermal method. The metallographic phase structures, morphologies and pore distribution are characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and nitrogen adsorption-desorption. In view of the influence of reaction time, different compared tests and corresponding electrochemical performances (the measurements of CV, GCD, EIS, cycle life) are performed. As a result, the NCS-10 electrode shows an excellent specific capacitance (Csp) of 1366 F g⁻¹ at the current density of 1 A g⁻¹, high rate capability (51.25% even at 20 A g⁻¹) and good cycle property (89.8% of the initial specific capacitance even after 2000 cycles). The NCS-10 electrode demonstrates great potential as a power source for electrochemical energy storage devices.