Facile preparation NiS/NiCo-LDH via electrodeposition for hybrid supercapacitors

Abstract

Transition metal sulfides are widely recognized for their low cost, low toxicity, high safety, and potential as a positive electrode material for supercapacitors. However, due to its own volume effect, it usually has poor capacitance retention as positive electrode materials. Herein, the NiS/NiCo-LDH (Layered double hydroxide, LDH) electrodes with considerable practical application potential is designed and prepared. The composite electrodes are prepared by a simple two-step electrodeposition process. The NiS/NiCo-LDH electrode, with its rational design, exhibits more superior electrochemical performance compared to a single NiS electrode. The NiS/NiCo-LDH electrode shows a mass specific capacitance of 2620 F/g at a current density of 1 A/g, which is 1.88 times that of the single NiS electrode. Furthermore, the assembled NiS/NiCo-LDH//AC hybrid supercapacitor (HSC) device achieves an energy density of 93.3 Wh kg⁻¹ at a power density of 800 W kg⁻¹. Therefore, this work provides a new strategy for preparing supercapacitor electrode materials with excellent electrochemical performance.