1. Nickel–cobalt oxide nanosheets asymmetric supercapacitor for energy storage applications.
- Author
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Alrousan, S., Albiss, B., Aljawrneh, B., Alshanableh, A., Al-Othman, Amani, and Megdadi, H.
- Abstract
Supercapacitors are a promising candidate in applications that necessitate high electrochemical stability and storage energy. In this study, NiCo 2 O 4 nanosheets were prepared hydrothermally on an ITO substrate and investigated to be utilized as supercapacitor electrodes. The morphology of NiCo 2 O 4 nanosheets was examined by scanning electron microscopy (SEM ) and atomic force microscopy (AFM ). The SEM results showed a 3D-flower-like nanostructure with interconnected nanosheets which was confirmed by the AFM results. However, X-ray fluorescence (XRF) results showed that the as-prepared sample has stoichiometry of Nickle (1) : Cobalt (2) . The electrochemical measurements of the as-prepared NiCo 2 O 4 supercapacitor electrode such as cyclic voltammetry (CV ) and galvanostatic charge/discharge (GCD ) studies were done in a two-electrode system with 1.0 M KOH and 1.0 M H 2 SO 4 . CV curves showed quasi-rectangular shape and high electrochemical stability in KOH and H
2 SO4 electrolyte solutions. In addition, the integral areas of CV curves for both electrolytes are almost identical, indicating efficient charge transfer and ion transport at the electrode/electrolyte interface. Electrochemical impedance spectroscopy (EIS ) curves of KOH and H 2 SO 4 electrolyte revealed a significant difference. This difference indicates that, the charge transfer in H 2 SO 4 electrolyte is faster than charge transfer in KOH , resulting in a linear behavior of the EIS curve. A fabricated hybrid asymmetric supercapacitor (SC ) composed of NiCo 2 O 4 / ITO anode and graphite/ITO cathode delivered a specific capacity of around 235 F / g in KOH solution and 723 F / g in H 2 SO 4 electrolyte at 10 mV/s scan rate. The superior electrochemical performances could be attributed to the large surface area that facilitates charge transfer at the electrode/electrolyte interface. [ABSTRACT FROM AUTHOR]- Published
- 2023
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