The study of polythiophene, poly(3-methylthiophene) and poly(3,4-ethylenedioxythiophene) on pencil graphite electrode as an electrode active material for supercapacitor applications

•The polymer films were synthesized on pencil graphite electrode.•The polymer films have been characterized by electrochemical methods.•Electrochemical storage properties of electrodes were investigated.•Electrodes can be suggested using for low voltage applications.

Films of polythiophene (PTh), poly(3-methylthiophene) (PMeT) and poly(3,4-ethylenedioxythiophene) (PEDOT) have been grown using cyclic voltammetry (CV) in acetonitrile (ACN) solution containing lithium perchlorate (LiClO4) and perchloric acid (HClO4) on pencil graphite electrode (PGE). The morphologies of the electrodeposited films have been monitored using scanning electron microscopy (SEM). The utilities of the polymer coated electrodes (PGE/PTh, PGE/PMeT and PGE/PEDOT) as an electrode active material for supercapacitor applications have been investigated in ACN solution which contains 0.1 M LiClO4. The values of specific capacitance of the electrodes have been evaluated by CV and electrochemical impedance spectroscopy (EIS) methods. Measured specific capacitances of PGE/PTh, PGE/PMeT and PGE/PEDOT are 1503.20, 2621.76 and 8668.58 mF g−1 at a scan rate of 10 mV s−1 according to CV measurements, respectively. Cycling stabilities of the electrodes have been examined by 1000 consecutive cycles using repeating chronopotentiometry (RCP) method.