A super high performance asymmetric supercapacitor based on Co3S4/NiS nanoplates electrodes

Abstract

In this paper, we successfully designed and synthesized Co₃S₄/NiS nanoplates by both ion-exchange action and Ostwald ripening reactions during the sulfurization process. As asymmetric supercapacitor electrode material, Co₃S₄/NiS exhibited an ultra-high specific capacitance of 1810 mF cm⁻² at a current density of 4 mA cm⁻², 12 times larger than the pristine Co₃O₄ electrode, as well as good rate capability and excellent cycling stability. The asymmetric supercapacitor based on Co₃S₄/NiS can work steadily at a voltage of 1.6 V and deliver a high energy density of 6.44 W h m⁻² at a high power density of 32 W m⁻². Moreover, we applied this device to successfully light light-emitting-diodes in a simulated solar illumination system. The perfect integration of two types of capacitor materials into Co₃S₄/NiS satisfies the requirements of high energy density supercapacitor. Co₃S₄/NiS nanoplates may have practical applications in the field of energy storage.