ZnONR Microstructure Modification and their Potential for High Reversibillity Performance of AC-Mn<sub>2</sub>O<sub>3</sub> Supercapacitor

Abstract

One of Indonesia's most significant issues with technological growth is the lack of electrical energy storage devices. Active materials have low electrical conductivity, accessibility, and ion diffusion. Therefore, it is urgently required to study the combination of higher electrical conductivity ZnO and high surface area of AC-Mn2O3. However, ZnO nanorods (ZnONR) can be modified from ZnO nanoparticles (ZnONP). The structure modification may increase energy density due to having a higher surface area than ZnONP. Three different electrodes with AC-Mn2O3 addition various spin coated of 1000 rpm (MZnONR1), 2500 rpm (MZnONR2), and 3000 rpm (MZnONR3). The electrodes were then packaged in a sandwich flat symmetric supercapacitor. The characterization was carried out using X-RD, SEM-EDX cross-section, FTIR, and Cyclic Voltammetric. It is obtained that the highest specific capacitance showed by symmetric supercapacitor MZnONR1 with low speed of spin coating. We also found that the greater the deposited ZnNR content, the lowest thickness until 43.76 μm, the crystallinity until 62% and the highest porosity until 79%. This shows that the MZnONR1 sample exhibits the best electrochemical performance, which is supported by its morphological properties. It is shown that the higher the Zn content, the stability performance AC-Mn2O3 supercapacitor higher. ZnONR1 sandwich flat symmetric supercapacitor have a specific capacitance 0.0086 Fg-1 with an 0.00433 Whg-1 energy density. Furthermore, it was found that the addition of the AC-Mn2O3 increased 2800x compared to the ZnONR1, which reached 28.04 Fg-1 and an 14.09 Whg-1 of capacitance specific and energy density, respectively.