Hydrothermally synthesized three-dimensional hierarchical CuO nanomaterials for energy storage applications

Abstract

Copper oxide is a promising material for various applications because it exhibits excellent properties in different nanostructures. Highly porous nanomaterials are better suited to a variety of applications, including charge storage supercapacitors. In this research article, the binder-free, flower-like three-dimensional hierarchical copper oxide (3Dh-CuO) nanomaterials on stainless steel (SS) substrates via a hydrothermal technique for charge storage supercapacitor applications has been studied. The flower-like 3Dh-CuO monoclinic polycrystalline structures were confirmed by morphological and structural analysis. The quantum confinement effect was observed on a flower-like 3Dh-CuO nanomaterial. The Quantum Confinement Semiconductor (QCS) exhibits excellent charge storage electrochemical performance. The maximum specific capacitance of binder-free, flower-like 3Dh-CuO nanomaterials is 1312.8 Fg−1 at a 2 mVs−1 sweep rate and 1301.3 Fg−1 at a 1.0 mA cm−2 current density in 1 M KOH electrolyte. The maximum energy density (ED) is 152.73 Wh kg−1 and the power density (PD) is 4.33 kW kg−1. The Solid Asymmetric Hybrid Supercapacitor (SAsHSc)device of the flower-like 3Dh-CuO shows a capacitance of 172.8 Fg-1 at 10 mVs−1 in the 1.6 V potential, with the highest cycling stability up to 3000 cycles having 77.66% retention. The binder-free, flower-like 3Dh-CuO electrodes have been considered a potential candidate material for electrochemical supercapacitors.