Single-step hydrothermal synthesis of ZnO/NiO hexagonal nanorods for high-performance supercapacitor application

The single-step hydrothermal technique was used to synthesize nickel (II) oxide-zinc nitrate hexahydrate (NZ), hexagonal-shaped nanorods for high-performance supercapacitors applications (SC). The structural morphology and physical properties of the NZ nanocomposite were investigated via XRD, FESEM, HRTEM, XPS, and Raman spectroscopy. Among the prepared nanocomposite, NZ-10 shows the most significant properties, which were used for the fabrication of all-solid-state symmetric supercapacitors (SSC). Electrochemical analysis of the Galvano charging-discharging (GCD) curves achieved a high specific capacitance (Csp) of 665.4 Fg(-1) at a current density (CD) of 1 Ag-1. The cyclic Voltammetry (CV) curve for the electrode shows a high Csp of 514.4 Fg(-1) at a scan rate of 10 mV/s. Even after 5000 repeated cycles, it maintains strong cyclic stability, with capacitance retention of 73.43% and a coulombic efficiency of 96.12%. In addition, the NZ-10 composite has a high energy density (ED) of 26.73 Whkg(-1) and a power density (PD) of 641.5 Wkg(-1). In addition, the SSC device is connected in series to switch on a commercial blue LED that lasts 2-3 min and has a voltage drop of 2.71 V. As a result, these electrochemical performances are the highest in these materials, and they may be a good aspirant to fabricate advanced active materials for high-performance SC applications.