Electrochemical Impedance Spectroscopy Effects of Vanadium doped - Cobalt Ferrite Nanomaterials for Supercapacitor Applications

Abstract

Vanadium-assisted cobalt ferrite nanoparticles generated using the co-precipitation process have better structural, morphological, and electrochemical properties than pure cobalt ferrite. The remarkable crystallinity of the cubic crystal structure was confirmed by X-ray diffraction (XRD) investigation. The use of field emission scanning electron microscopy (FESEM) demonstrated the presence of vanadium and consistent elemental composition with cobalt ferrite, while energy dispersive X-ray analysis (EDAX) verified the spherical nanoparticles with an average size of around 20 nm. Electrochemical impedance spectroscopy (EIS) indicated significant improvements in electrochemical performance, with a reduction in equivalent series resistance (ESR) from 1.54 Ω to 1.22 Ω and charge transfer resistance from 1.68 x 10⁻³ Ω to 1.5 x 10⁻³ Ω for V-doped CoFe₂O₄. Additionally, lower internal and Warburg resistance values were observed for V-doped CoFe₂O₄, suggesting efficient ion transport and storage capabilities. These findings highlight the potential of vanadium-doped cobalt ferrite nanostructures as promising materials for next-generation supercapacitors, addressing critical challenges in energy storage for renewable energy systems and portable electronics. Future studies should concentrate on refining the synthesis procedure and investigating other dopants in order to significantly improve the efficiency of supercapacitors based on cobalt ferrite.