Mesoporous spinel manganese zinc ferrite for high-performance supercapacitors

We report on the synthesis of manganese zinc ferrite (MnZnFe2O4) nanoneedles via a simple one-pot coprecipitation method and their characterization using energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), high-resolution transmission electron microscope (HRTEM) and N-2 adsorption/desorption techniques. The electrochemical performance of MnZnFe2O4 nanoneedles-based supercapacitors was investigated, showing superior specific capacitance of 783 F g(-1), which is significantly higher than that reported for any ferrite material. Also, the spinel MnZnFe2O4 exhibits very high columbic efficiency and an excellent long-term stability. The fabricated asymmetric supercapacitor based on MnZnFe2O4 nanoneedles/activated carbon electrodes can deliver 15.8 Wh kg(-1) energy density at a power density of 899.7 W kg(-1). The contribution of the double layer capacitance was found to be only 3.14% of the total specific capacitance and mainly based on psuedocapacitance faradaic mechanism. Therefore, the fabricated MnZnFe2O4 electrode is a promising candidate for supercapacitor applications.