Effects of nickel content on the electrochemical performance of nanosized ternary nickel–zinc–cobalt oxide supercapacitors

To improve the electrochemical performance and structural durability of supercapacitors, herein, well-ordered, porous Ni-Zn-Co ternary oxide nanostructures were synthesized by doping Ni to Zn-Co oxide using ultrasonic electrodeposition. Our investigations revealed that Ni-Zn-Co ternary oxide exhibited superior capacity and rate performance when compared to Zn-Co oxide. In particular, the incorporation of 1 mol/L of Ni markedly improved the electrochemical capabilities of the cathode materials. Remarkably, under the influence of ultrasonic power at 500 W, Ni-Zn-Co oxide exhibited a superior mass loading of 6.2 mg/cm2, coupled with exceptional electron transfer efficiency. The growth mechanism and valence composition of Ni-Zn-Co oxides were studied by SEM and XPS analysis. Moreover, electrodes fabricated from Ni-Zn-Co oxide, synthesized via ultrasonic electrodeposition, demonstrated remarkable area capacitance and rate capabilities, achieving an impressive 1.779 F/cm2 at a current density of 3 mA/cm2. Additionally, the supercapacitor incorporating the Ni-Zn-Co oxide electrode exhibited exceptional long-term stability, maintaining a capacity retention rate of 125.2 % over 24,000 cycles in a mild alkaline electrolyte. This study not only contributes to advancing highperformance cathode materials but also offers valuable perspectives on novel techniques for their fabrication.