Electrochemical Supercapacitor Studies of GO – MWCNTs

over the past few years, considerable effort has been devoted to the development of alternative energy storage/conversion devices with high power and energy densities because of the everincreasingenvironmental problems and the up-coming depletion of fossil fuels. Supercapacitors have attracted a great deal of attention owing to their higher power densities relative to secondary batteries and traditional electric double-layer capacitors[1-3]. Graphene and multiwalled carbonnanotubes (MWCNTs) have enjoyed significant recent attention. [2]. Herein we report physical mixing/dispersion method for preparing the electroactive material forsupercapacitor electrode. GO was prepared by Hummer’s method[4] and dispersed in distilledwater and then MWCNTs were added to it by ultrasonication for 0.5h. The specific capacitance of GO-MWCNTs from the cyclic voltammetry (CV) curves of figure (1) was found to be 256mF. cm-2 at scan rate of 10 mV.s-1 that was greater than of 12 mF.cm-2 obtained for MWCNT byHonda, et al [5]. MWCNTs tend to agglomerate while suspended in water, and surfactants are needed for uniform dispersion. The high dispersibility of graphene oxide (GO) in water and its π-π interaction with MWCNTs facilitates the dispersion of MWCNTs without use of surfactant [6]. High specific surface area of GO and MWCNTs and surface functionalization can cause an improvement in the specific capacitance of carbon materials.

کلیدواژه ها:

Supercapacitor ، Graphene Oxide ، MWCNTs ، Capacitance