Presenting highest supercapacitance for TiO₂/MWNTs nanocomposites: Novel method

Abstract

A facile two step, binder-free method is successfully developed for the synthesis of TiO2 nanodots on the walls of multi-walled carbon nanotubes (MWNTs). TiO2/MWNTs nanocomposite exhibited excellent specific capacitance and stability as supercapacitor electrode materials due to the synergistic effect of both components as well as the nanodots-like structure of TiO2, which increases the specific surface area of the nanocomposite. The TiO2/MWNTs prepared by this binder-free approach yields the largest specific and interfacial capacitances of 329 F g(-1) and 52 mF cm(-2) at a scan rate of 0.005 V s(-1), which is the utmost value of capacitance obtained till date. Importantly, TiO2/MWNTs showed remarkable rate capability with 6 mF cm(-2) capacitance at higher scan rate (0.4 V s(-1)) with good long-term cycling stability. The Ragone plot of TiO2/MWNTs nanocomposite discovers better power and energy density values. Lastly, the method used here is promising for producing high performance supercapacitors which can be scalable for large area application for industrial route. (C) 2014 Elsevier S.V. All rights reserved.