Nanostructured CuO/Co₂O₄@ nitrogen doped MWCNT hybrid composite electrode for high-performance supercapacitors

Nanosheet-like structures of copper cobaltite (CuO/Co₂O₄) decorated on N-MWCNT electrodes were synthesized through hydrothermal process in the presence of ammonia/urea. The structural and morphological properties were characterized by Raman, XRD, XPS, SEM, SEM-EDX and FE-TEM analysis. The electrochemical properties of the CuO/Co₂O₄@N-MWCNT hybrid electrodes were studied using cyclic voltammetry, galvanostatic charge−discharge, and electrochemical impedance analyses. The prepared CuO/Co₂O₄@N-MWCNT and CuO@N-MWCNT electrodes showed a specific capacitance of ∼246 F g⁻¹ and 100 F g⁻¹ at a current density of 0.5 A g⁻¹ for three electrode assembly. Further, the asymmetric cells also fabricated and it delivered the highest specific capacitance of 268 F g⁻¹ and 279 F g⁻¹ for CuO@N-MWCNT and CuO/Co₂O₄@N-MWCNT electrodes respectively. These electrodes possessed very good capacitance behavior with 89% retention even after 5000 cycles at 0.5 A g⁻¹ which overlay a way to use as promising candidates for the high-performance supercapacitors.