ZnO/carbon nanotube nanocomposite for high energy density supercapacitors

• Published in: Electrochimica acta Vol. 95; pp. 119 - 124
• Main Authors: Aravinda, L.S., Nagaraja, K.K., Nagaraja, H.S., Bhat, K. Udaya, Bhat, Badekai Ramachandra
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.04.2013
• Subjects: Capacitors; Carbon nanotubes; Electrodes; Energy density; Magnetron sputtering; Nanocomposites; Nanomaterials; Nanostructure; Scanning electron microscopy; Supercapacitor; Supercapacitors; Zinc oxide; Supercapacitor; Carbon nanotubes; Zinc oxide; Magnetron sputtering
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2013.02.027

► ZnO/multiwalled carbon nanotube composite was synthesized via reactive magnetron sputtering in Ar/O2 environment. ► The electrochemical tests were carried out with a wide potential range from −2V to 1V using non aqueous electrolyte. ► ZnO/multiwalled carbon nanotube composite exhibits high energy density of 13.1Whkg−1 with good cycle stability. A facile, green and highly efficient method for the decoration of carbon nanotubes with ZnO was developed for the fabrication of binder-free composite electrode for supercapacitor applications. The nano composite was prepared by using reactive magnetron sputtering in Ar/O2 environment. This approach leads to more uniform coating with tuneable thickness, which alters the electrochemical performance of the nano composite electrodes. The structure and surface morphology of the composite film have been studied by means of X-ray diffraction (XRD) analysis, scanning electron microscopy and field emission scanning electron microscopy (FESEM). The XRD study reveals the formation of Wurtzite ZnO structure. The electrochemical performance of nano composite electrode was investigated using cyclic voltammetry, chronopotentiometry and electrochemical impedance measurements in non-aqueous electrolyte. The nano composite electrode shows significant increase in the specific capacitance up to 48Fg−1 with an energy density 13.1Whkg−1 in the potential range −2V to 1V.