Electrodeposited cobalt sulfide nanolayer fenced nickel-copper carbonate hydroxide nanowires as an electrode for hybrid supercapacitors: A wind turbine-driven energy storage system for portable applications

Abstract

Metal carbonate hydroxides/sulfides have attracted great interest from researchers in the energy storage-related fields due to their versatile electrochemical characteristics. Moreover, the synthesis of such a combination of materials is a challenging task. Herein, nickel-copper carbonate hydroxides with nanowire morphology (i.e., NiCu NWs) was in situ prepared over the carbon textile by a facile hydrothermal method. The synthesized NiCu-2 with equimolar salt concentrations (Ni-25 mM; Cu-25 mM) delivered a superior areal capacity of 65.5 µAh cm−2 at 1.5 mA cm−2 than the other two NiCu electrodes. To further improve the redox chemistry and electrochemical performance, cobalt sulfide (CS) nanolayer was electrodeposited on the NiCu NWs to make CS@NiCu-2 composite. The composite material with the combined redox features of both CS and NiCu materials as well as the hybrid morphology exhibited an improved areal capacity of 275.6 µAh cm−2 at the same current density. Furthermore, the hybrid supercapacitor (HSC) was fabricated using the CS@NiCu-2 as a positive electrode and the activated carbon as a negative electrode. For the fabricated device, a good areal capacitance of 410 mF cm−2 was achieved along with the maximum energy and power densities of 131.2 µWh cm−2 and 15000 µW cm−2, respectively. Besides, the practical applicability of HSC was tested by powering electronic gadgets.