The impact of Fe3+ doping on the flexible polythiophene electrodes for supercapacitors

Fe3+ doping is used to enhance the capacity of polythiophene as supercapacitor electrode and the flexible Fe3+ doped PTh electrode on carbon cloth is prepared with an electrochemical deposition method. The successful doping of Fe3+ is confirmed by IR, XPS, and EDS measurements. The electrochemical performance of the PTh electrode is evaluated using cyclic voltammetry, galvanostatic charge-discharge technique, and electrochemical impedance spectroscopy in acidic aqueous electrolyte. The pristine PTh exhibits specific capacitance of 77.2 F g−1 at a current density of 0.5 A g−1. After Fe3+ doping, the specific capacitance is improved to 108.1 F g−1 and the retention rate also improved from 7.8% to 21.2% after 1000 charge-discharge circles.