CuO@NiO/Polyaniline/MWCNT Nanocomposite as High-Performance Electrode for Supercapacitor

This work reports facile and well-controlled synthesis of a number of binary, ternary, and quaternary nanocomposites using combinations of metal oxides (CuO, NiO), multiwalled carbon nanotubes (MWCNTs), and conducting polymer polyaniline (PANI) for application as electrode in supercapacitor. X-ray diffraction and electron microscopic analyses confirmed the formation of different composites made of binary CuO@NiO, ternary CuO@PANI/MWCNT, NiO@PANI/MWCNT, and quaternary CuO@NiO/PANI/MWCNT nanocomposites. Such combination of materials has not been reported previously, and with specific capacitance of 1372 F g–1 and good cyclic stability (83% capacity retention after 1500 cycles), the quaternary nanohybrid electrode shows the best performance compared to all other binary and ternary electrodes tested and promises to be a very good electrode material for supercapacitor application. The improved performance of the quaternary nanocomposite is attributed to the well-designed structural advantages and the synergistic effects of the components that lead to significant reduction in the charge transfer resistance as revealed by electrochemical impedance spectroscopy. Thus, we show a simple method to control the charge storage capacity of CuO- and/or NiO-based electrodes by suitable selection of their surface morphology and combining with MWCNT and PANI. The results may have large potential in the development of novel electrode materials for a supercapacitor using CuO and/or NiO and may be further extended to other transition-metal-oxide-based electrodes.