Promotive Effect of MWCNT on ZnCo2O4 Hexagonal Plates and Their Application in Aqueous Asymmetric Supercapacitor

Abstract

ZnCo2O4 (ZCO) hexagonal nanoplates were synthesized by a facile, robust and cost-effective co-precipitation method. The as-synthesized nanoplates were utilized as an electrode material and their electrochemical properties were investigated in three-electrode and two-electrode configurations with aqueous electrolyte of 1 M KOH. The fabricated ZCO electrode materials exhibited a specific capacity of 37 mAh g−1 at 1 A g−1. The capacity of the pristine ZCO nanoplates was further improved by incorporating multiwall carbon nanotubes (MWCNTs). The MWCNT@ZCO showed a specific capacity of 64 mAh g−1 at 1 A g−1. To examine practical performances, asymmetric supercapacitor (ASC) was also fabricated using MWCNT@ZCO as a positive electrode and activated carbon as a negative electrode. The specific capacity of the ASC was found to be 17 mAh g−1 at 0.38 A g−1. ASC could store sufficient energy to power a parallel combination of two red color light-emitting diodes. These findings may open new opportunities for the design of effective, stable, and easily recyclable ZCO electrode material for energy storage devices.