Electrochemical deposition of uniform and porous Co–Ni layered double hydroxide nanosheets on nickel foam for supercapacitor electrode with improved electrochemical efficiency

In this study, Co–Ni layered double hydroxide (LDH) nanosheets are synthesized on nickel foam (NF) using a simple, facile, and cost effective electrochemical deposition method. We present a comparative study of Co–Ni LDH nanosheets on NF for use in supercapacitor electrodes. The method is based on electrochemical deposition using cyclic voltammetry (CV) with different cycles (4, 6, 8, and 10 cycles). Compared to other cycles, the Co–Ni LDH nanosheets on NF as electrode materials obtained higher specific capacitance at eight cycles. In 1 M potassium hydroxide (KOH), a significant specific capacitance of 3130.8 F/g was obtained at a scan rate of 5 mV/s, with good cyclic stability of 72.4% capacitance retention after 3000 cycles. The uniform and porous structure of Co–Ni LDH nanosheets on NF and the fast ion transfer between the electrolyte–electrode interface and reduced resistance contribute to this superior electrochemical efficiency, confirmed by CV and electrochemical impedance (EIS) studies. Co–Ni LDH nanosheets on NF are promising candidates for low-cost high-efficiency energy storage electrode materials for supercapacitor applications because of their superior performance and ease of preparation.