Achieving superior performance in aqueous supercapatteries and Ni-Zn batteries by employing 3D-NiO flowers/NF electrode

Abstract

Supercapacitors and batteries, two extremely capable and competent energy storage technologies, were able to satisfactorily supply the energy requirement in industrial-scale electronic equipment. In this approach, developing unique and morphology-dependable electrodes with good capacity performance plays a moral role in energy storage technologies. In this present work, nickel oxide (NiO) microflowers were hydrothermally bestowed on the Ni-foam current collector via binder-free process in energy storage applications. The NiO/NF cathode material delivered an admirable capacitance (capacity) of ∼ 1381.8 F g^-1 (∼ 212.49 mA h g^-1) under the current density of 2 A g^-1 with better stability retention of 84.59 % over 5000 cycles. By coupling with a BiVO₄/NF anode, the assembled NiO||BiVO₄ supercapattery device achieved peak energy and power densities of ∼ 38 Wh kg^-1 and ∼ 9600 W kg^-1, respectively. A researchable full-cell Ni-Zn battery was employed with NiO/NF as a cathode and a Zn plate as anode, which were assessed in an aqueous electrolyte medium. As a result, the aqueous Ni-Zn cell reached peak energy and power densities of ∼ 157.14 Wh kg^-1 and ∼ 13.4 k W kg^-1 along with 86 % of cycling retention after 5000 cycles. The arisen capacity and exceptional stability performance of the device may provide sufficient NiO electroactive sites during the Zn⁺ ions insertion/desertion process. This electrochemical investigation provides good redox performance, further, we conclude that NiO/NF microflower cathode material is as promised as an electrochemical energy storage system.