Facile synthesis of ZnO–CoMoO4 nanocomposite using bio-organic fuel for energy storage application

Abstract

Supercapacitors are the highly investigated energy storage devices to solve the global energy storage problems. The metal oxide nanomaterials as electrode-active materials yield the desirable specific capacitance. However, the higher economic and environmental costs associated with the synthesis of nanomaterials limit their extensive implication in supercapacitors. In this work, the ternary metal oxides nanocomposite of zinc, cobalt, and molybdenum was synthesized by green, economic and simple sol–gel synthesis route using the extracted fuel of E. cognata and the precursors salts. The as-synthesized ZnO–CoMoO4 nanocomposite was investigated as supercapacitor electrode candidate. A notable capacitance of 294.7 F/g was obtained for ZnO–CoMoO4 electrode. The specific energy density of ~ 8 Wh/Kg was found from charge–discharge measurements. The ZnO–CoMoO4 nanocomposite displayed almost 100% Coulombic efficiency over 10,000 cycles of repeated charge–discharge testing indicating its excellent stability. The lower Ri of 0.8 Ω was observed in the current study demonstrating the lower resistance. Consequently, the nano-scaled and phyto-fueled ternary composites of ZnO–CoMoO4 exhibited enhanced electrochemical properties toward supercapacitor without stability.