Enhanced electrochemical performance of CuCo2O4 and CuCo2O4/activated carbon composites for supercapacitor applications

This study presents the synthesis and evaluation of CuCo 2 O 4 and CuCo 2 O 4 /activated carbon (AC) composites as electrode materials for supercapacitors. X-ray diffraction confirmed the cubic spinel phase, with crystallite size reduced from 43.89 nm in pristine CuCo 2 O 4 to 33.79 nm in the composite. Incorporation of AC significantly enhanced the surface area from 20 m 2 /g to 562 m 2 /g and reduced pore size to 1.9 nm, enabling efficient ion transport. Electrochemical studies revealed a specific capacitance of 643.75 F g −1 for CuCo 2 O 4 /AC, notably higher than 389.06 F g −1 for pristine CuCo 2 O 4 at 1 A g −1 . Dunn analysis showed capacitive charge storage contributions of 55–82% for the composite compared to 11–33% in pristine CuCo 2 O 4 . Electrochemical impedance spectroscopy confirmed reduced internal resistance and improved charge transfer, with R s and R ct values decreasing to 4.66 Ω and 627.87 Ω, respectively. These findings demonstrate that CuCo 2 O 4 /AC composites deliver enhanced charge storage, excellent rate capability, and durable cycling, establishing them as promising electrodes for advanced supercapacitors.