CeO2/MnO2 Composite material for asymmetric supercapacitor applications

Abstract

Supercapacitors have attracted significant attention to play prominent roles in resolving the energy crisis, global warming, and environmental pollution. MnO₂ is the most abundant material on earth, with high theoretical capacitance. It has multiple oxidation states that contribute to redox reactions. CeO₂ is a good redox stability, which can help to improve the conductivity of MnO₂. CeO₂ helps to improve the cyclic stability of the composite material. In the present study, the composite material consisting of CeO₂ nanoparticles decorated with MnO2 nanowires was synthesized using the low-cost, wet chemical hydrothermal technique. The synthesized materials were characterized and analyzed by Raman spectroscopy, XRD, SEM, and XPS. XRD pattern and Raman spectroscopy analysis of CeO₂ nanoparticles decorated MnO₂ nanowires revealed the presence of tetragonal α- MnO₂ phase. The electrochemical supercapacitor performance of pristine MnO₂, CeO₂, and CeO₂ nanoparticles decorated MnO₂ nanowires are analyzed by cyclic voltammetry, galvanostatic charge- discharge, and electrochemical impedance spectroscopy. The specific capacitance of the composite material was approximately 145.19 F/g. The combination of these two materials in a composite can lead to synergistic effects, resulting in improved electrochemical performance, and it can be an outstanding active electrode material for supercapacitor applications.