Facile synthesis of hierarchical ZnMn2O4@ZnFe2O4 microspheres on nickel foam for high-performance supercapacitor applications

Abstract

Unique ZnMn₂O₄@ZnFe₂O₄ microspheres were fabricated on Ni foam using a facile and cost-effective hydrothermal method for high-performance supercapacitor applications. The resulting ZnMn₂O₄@ZnFe₂O₄ electrode was characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and electrochemical techniques. The ZnMn₂O₄@ZnFe₂O₄ electrode exhibited a microsphere-like morphology with a mean size of ∼50–115 nm. The electrochemical performance of the ZnMn₂O₄@ZnFe₂O₄ electrode was investigated and the results showed that the ZnMn₂O₄@ZnFe₂O₄ electrode exhibits a high specific capacitance of 1024.66 F g⁻¹ at 10 mA cm⁻², low internal resistance, and remarkable cycling stability with 95.8% capacitance retention after 3000 charge–discharge cycles, which was superior to those of the ZnMn₂O₄ and ZnFe₂O₄ electrodes. Such enhanced electrochemical performance and the facile synthetic method of ZnMn₂O₄@ZnFe₂O₄ electrode materials offer great promise in next generation supercapacitor applications.