The electrochemical activity of polyaniline: An important issue on its use in electrochemical energy storage devices

The efficiency of an energy storage device is closely related to the reversibility and electrochemical activity of the electrode materials. Although polyaniline (PANI) has been used to fabricate various electrochemical devices, its electrochemical activity has not received enough attention. Here, high reversible electrochemical active PANI nanofibers are prepared and mixed with hydroxyethyl cellulose (HEC). Their supercapacitive performance is investigated by cyclic voltammetry (CV), galvanostatic charge/discharge and electrochemical impedance spectroscopy (EIS) techniques on Pt electrodes. The results show that the obtained PANI has reversible electrochemical activity on Pt electrode. But the electrochemical activity decreases gradually with the increase of HEC content and even disappears when the HEC content reaches 30%. It suggests that the content of the inactive materials should be controlled strictly to guarantee the electrochemical activity of the electrode materials in fabricating high performance electrochemical energy storage devices.