Improved electrochemical performances of CuCo2O4/CuO nanocomposites for asymmetric supercapacitors

The impact of reaction time on the electrochemical capacitive properties of CuCo₂O₄/CuO is reported. The CuCo₂O₄/CuO nanocomposites are synthesized by microwave assisted reflux method at different reaction times (1, 5, 10 and 15min) and are subjected to necessary characterization techniques to find its physico-chemical properties. The compound formation temperature is identified through TG/DSC analysis. Subsequently the phase formation is envisaged from XRD analysis. The characteristic functional groups and valency state of the elements are revealed from FT-IR and XPS analysis, respectively. The spherical and rod-like shape CuCo₂O₄/CuO particles are visualized from FESEM and TEM analysis. The CuCo₂O₄/CuO prepared at 5min reaction time provides the enhanced capacitance of 781Fg⁻¹ at 2mVs⁻¹ in 1M KOH electrolyte. Further the asymmetric supercapacitor (ASC) is fabricated with activated carbon (AC) as negative electrode, which rendered the specific capacitance of 141Fg⁻¹ at 1mVs⁻¹ with an energy density of 18Whkg⁻¹ and power density of 259Wkg⁻¹ at 1mAcm⁻² in 1M KOH electrolyte. In addition, this ASC retains nearly 100% of its initial capacitance over 5000 cycles.