Enhanced Electrochemical Performance of Cobalt-Substituted Zinc Ferrite for High-Stability Supercapacitors

Cobalt-substituted zinc ferrite (CoxZn1-xFe2O4) nanoparticles were synthesized and studied for their structural, morphological and electrochemical properties. The XRD results confirmed that the prepared samples possess cubic spinel structure with crystallite size decreased from 31.45 nm to 26.13 nm upon cobalt substitution. FTIR and Raman spectroscopic studies validated spinel phase formation with metal-oxygen vibrations in tetrahedral and octahedral sites. The FESEM study showed agglomerated morphology and the EDX result confirmed stoichiometry. Electrochemical tests (CV, GCD, EIS, cyclic stability test) revealed improved charge storage and conductivity caused by cobalt content. Co0.5Zn0.5Fe2O4 achieved 306.2 F/g at 1 A/g and 96% capacitance retention after 4000 cycles at 10 A/g, indicating its potential as a high-performance supercapacitor electrode.