Electrochemical synthesis and capacitance properties of a novel poly(3,4-ethylenedioxythiophene bis-substituted bithiophene) electrode material

• A novel 3,4-ethylenedioxythiophene bis-substituted bithiophene (BEDOT-BT) was synthesized.
• BEDOT-BT was further electropolymerized into PEDOT-BT polymer.
• PEDOT-BT had high thermal stability and electrochemical cycling stability.
• The specific capacitance of PBEDOT-BT electrode reached 171 F g−1 at 1 A g−1.

A novel EDOT-bithiophene-EDOT based comonomer, 5,5′-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-2,2′-bithiophene (BEDOT-BT), was synthesized, and further, it was electrodeposited into PBEDOT-BT on platinum electrode as an active electrode material for supercapacitor. As-formed PBEDOT-BT film was characterized by FTIR, SEM and thermal analysis. The electrochemical performances of the PEDOT-BT electrode with good thermal stability were also investigated by cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy techniques. The electrochemical results showed that PBEDOT-BT electrode afforded a specific capacitance of 171 F g−1 at a current density of 1 A g−1 and good cycling stability in ACN-Bu4NPF6 electrolyte solution. The specific energy of the PEDOT-BT electrode reached 23.76 Wh/kg at a specific power of 0.49 kW/kg. These results indicated that the PBEDOT-BT is a promising electrode material for supercapacitor applications.