Asymmetric Supercapacitors Based on Co₃S₄–ZnCo-Layered Double Hydroxide Nanocomposite Electrodes

In this study, Co3S4–ZnCo-layered double hydroxide nanocomposites (Co3S4–ZnCo-LDH) were successfully prepared on nickel foam by a simple and economical three-step hydrothermal method. The combination of Co3S4 nanowires and petal-shaped ZnCo-LDH provides abundant active sites, which enhance the ion and electron transfer through synergy, showing remarkable electrochemical performance. The supercapacitor with Co3S4–ZnCo-LDH as the electrode material shows a high specific capacitance of 1910.8 F/g at a current density of 1 A/g. The assembled Co3S4–ZnCo-LDH//active carbon all-solid-state asymmetric supercapacitor can provide a working voltage of 1.6 V. The device provides a specific capacitance of 128.56 F/g at a current density of 0.5 A/g and an energy density of 58.45 W h/kg at a power density of 200 W/kg. Especially, the series connected supercapacitors are integrated and driven by the commercial solar cell, which indicates that they can be used for solar energy collection and storage equipment. Therefore, the study provides a simple strategy for optimizing and integrating electrode materials to develop high-performance supercapacitors for energy storage.