Evaluation of Cubic-Like Advanced ZnMn₂O₄ Electrode for High-Performance Supercapacitor Applications

In this work, a cubic-like ZnMn₂O₄ nanostructure was prepared by a cost-effective double-hydroxide-mediated hydrothermal route. As-synthesized material was characterized by powder X-ray diffraction and Fourier-transform infrared spectroscopy studies. The cubic-like surface morphology of the material was viewed using scanning electron microscopy and high-resolution transmission electron microscopy analyses. The electrochemical properties of the ZnMn₂O₄ electrode were examined by cyclic voltammetry, charge-discharge, and electrochemical impedance spectroscopy analyses. The electrochemical results revealed that the ZnMn₂O₄ electrode had battery-type Faradic behavior with the highest capacitance of 776 F g⁻¹ at a scan rate of 5 mV s⁻¹ in a 2 M KOH electrolyte and showed good cyclic stability, with an efficiency of 91.7% after 5000 continuous long cycles. The synthesis method entails that the ZnM₂O₄ electro-active material acts as a promising high-performance supercapacitor electrode.