Preparation of aqueous poly(3,4-ethylenedioxythiophene methanol)-poly(styrene sulfonate) dispersion and its capacitance performance as symmetric supercapacitors

Aqueous poly(3,4-ethylenedioxythiophene methanol)-poly(styrene sulfonate) dispersion (PEDTM-PSS) was prepared by chemical oxidation synthesis. As-formed PEDTM-PSS film was characterized by Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis, and scanning electron microscopy techniques. The results of Raman and FT-IR confirmed the formation of PEDTM-PSS. The electrochemical capacitance properties of PEDTM-PSS were firstly investigated in this paper by cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscope techniques. PEDTM-PSS electrode showed a specific capacitance of 62.3 F g−1 at a current density of 0.5 A g−1 in 0.1 M LiClO4/ACN solution, which was higher than the value of poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) (PEDOT-PSS) (50.5 F g−1). Furthermore, the energy density of assembled symmetric supercapacitor based on PEDTM-PSS was 2.4 Wh kg−1 at a power density of 325 W kg−1, which was also higher than that of PEDOT-PSS (1.6 Wh kg−1). Most importantly, the symmetric supercapacitor exhibited extraordinary stability up to 1000 cycles with a specific capacitance retention of 105 %. These results indicated that the PEDTM-PSS was a promising electrode material for the supercapacitors application.