Electrochemical Performance of 2D-Hierarchical Sheet-Like ZnCo₂O₄ Microstructures for Supercapacitor Applications

Abstract

With the rapid improvement of the global economy, the role of energy has become even more vital in the 21st century. In this regard, energy storage/conversion devices have become a major, worldwide research focus. In response to this, we have prepared two-dimensional (2D)-hierarchical sheet-like ZnCo2O4 microstructures for supercapacitor applications using a simple hydrothermal method. The 2D-hierarchical sheet-like morphologies with large surface area and smaller thickness enhanced the contact area of active material with the electrolyte, which increased the utilization rate. We investigated the electrochemical performance of sheet-like ZnCo2O4 microstructures while using Cyclic voltammetry (CV), Galvanostatic charge-discharge (GCD), and Electrochemical impedance spectroscopy (EIS) analysis. The electrochemical results demonstrated that the ZnCo2O4 electrode possesses 16.13 mF cm−2 of areal capacitance at 10 µA cm−2 of current density and outstanding cycling performance (170% of capacitance is retained after 1000 cycles at 500 µA cm−2). The high areal capacitance and outstanding cycling performance due to the unique sheet-like morphology of the ZnCo2O4 electrode makes it an excellent candidate for supercapacitor applications.

Keywords

• supercapacitors
• hydrothermal method
• areal capacitance
• sheet-like ZnCo₂O₄