Electrochemical energy storage properties of solvothermally driven ZnFe2O4 microspheres

Abstract

Herein, a facile solvothermal technique was employed to produce ZnFe2O4 microspheres. The physico-chemical properties of these microspheres were probed by various techniques such as XRD, SEM and TEM. Furthermore, these microspheres were utilized to design a cost-effective, binder-free supercapacitor electrode. The obtained noticeable specific capacitance (175 F g-1 at a current density of 5 A g-1) and rate performance with good cycling stability were assigned to the large surface area and unique porosity of ZnFe2O4 microspheres, which allows faster ion-diffusion across the electrode and buffer volume changes during rapid charging-discharging. Electrochemical impedance spectroscopy analysis further verifies the observed phenomena as noted in voltammetric and charge-discharge studies. The work opens up an avenue to consider crystalline, porous and high surface area enabled hetero-metallic oxides to be promising candidates for high-performing supercapacitors. © 2019 IOP Publishing Ltd.