Abstract
This work reports the synthesis of CuFe2O4 (CFO) nanoparticles via the co-precipitation method for supercapacitor applications, emphasizing the effect of annealing temperature. High-resolution X-ray diffraction (HR-XRD) confirms a tetragonal spinel phase, with grain size increasing due to Ostwald ripening. Raman spectra further validate CFO’s tetragonal phase, while FE-SEM confirms nanoparticle agglomeration. HR-TEM analysis reveals an average particle size of ∼71.66 nm. FTIR identifies functional groups, and EDS confirms the presence of Cu, Fe, and O, with XPS verifying Cu2+, Fe2+, Fe3+, and O2− oxidation states. Magnetic measurements indicate ferromagnetic behaviour. BET analysis shows that CFO annealed at 800 °C has the highest specific surface area, improving electrochemical performance. Electrochemical tests (CV, GCD, and EIS) reveal optimal redox activity and ion diffusion at 800 °C, achieving a specific capacitance of 911.1 F/g at 1 A/g. An asymmetric supercapacitor with CFO-800 used as positive electrode while negative electrode made of activated carbon delivers 44.42 F/g capacitance, 12.97 Wh/kg energy density, and 3.92 kW/kg power density, with 77.26 % cycling retention and 101.8 % Coulombic efficiency over 5000 cycles. These results highlight CFO’s potential for next-generation energy storage applications.
