Sonoelectrochemical deposition of graphen oxide-polypyrrole/cobalt oxide nanocomposite and investigation of their electrochemical properties in supercapacitors

As a type of electrochemical energy storage device supercapacitors have attracted considerable attention over the past decades. owing to the higher power density and longer cycle life than secondary batteries and higher energy density compared to conventional capacitors, they have application in some systems such as hybrid electric vehicles, portable electronics, mobile communications and etc. Generally, the charge storage mechanism of supercapacitors could be classified in to two types: electrochemical double layer capacitors (EDLCS) and faradaic pseudocapacitors. The aim of this project is the sonoelectrochemical deposition graphen oxide-polyppyrole/cobalt oxide nanocomposite and improvement of electrochemical properties in such as cycle stability, special capacity and etc. the morphology and structure of this materials were studied by using scanning electron microscopy and energy dispersive x-ray spectroscopy .electrochemical activity and capacitor behavior of prepared electrodes were studied using electrochemical techniques including cycle voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy.it was found the grapheme oxide-polypyrrole /cobalt oxide electrode has better capacitance and electrochemical properties thane graphen oxide -polypyrrole electrode and polypyrrole electrode ,the calculated specific capacities by cyclic voltammetry and charge-discharge confirmed this clam. The specific capacity value that obtained by cyclic voltammetry at the scan rate 10 𝑚𝑣.𝑠−1, consiste of 228 𝐹.𝑔−1 for the graphen oxide-polypyrrole/cobalt oxide electrode, 168 𝐹.𝑔−1 for graphen oxide -polypyrrole electrode and 22𝐹.𝑔−1 for polypyrrole electrode. The same a capacities amounts also obtained by charging – discharging technique.