Enhanced electrochemical performance of mixed metal oxide (Bi2O3/ZnO) loaded multiwalled carbon nanotube for high-performance asymmetric supercapacitors

Abstract

Bismuth oxide/Zinc oxide (Bi2O3/ZnO-BZ) and Bismuth Oxide/Zinc Oxide loaded Multi-Walled Carbon Nanotube (Bi2O3/ZnO@MWCNT-BZM) nanocomposites (NCs) were successfully synthesized through the one-pot hydrothermal method. The prepared samples were analytically characterized to reveal their structural, morphological and functional group characteristics. The presence of Bi2O3 nanoparticles with mixed crystalline phases (Cubic and Monoclinic) and hexagonally structured ZnO nanoparticles in BZM NCs were confirmed by XRD analysis. The electrochemical performances of the prepared NCs were investigated using 1 M KOH electrolyte in an electrochemical workstation under two and three-electrode configurations. The asymmetric supercapacitor fabricated by using BZM NCs modified working electrode possessed the maximum of 204.92 Fg−1 specific capacitance, whereas BZ NCs modified working electrode showed only 145.90 Fg−1 at the scan rate of 5 mVs−1. BZ NCs retained their electrochemical behaviour of about 78.45 % after 5000 charge-discharge cycles and it was further extended up to 84.62 % by the incorporation of MWCNT. Through the fabrication of supercapacitors using BZM NCs, a maximum of 1800 Wkg−1 power density and 9.433 Whkg−1 energy density were achieved. The proposed BZM NCs-based electrodes with superior power and energy densities with high cyclic stability provided vital advantages for long-term commercial applications.