Vapor-phase polymerized poly(3,4-ethylenedioxythiophene) (PEDOT)/TiO₂ composite fibers as electrode materials for supercapacitors

Vapor-phase polymerized poly(3,4-ethylenedioxythiophene) (PEDOT)/TiO₂ composite fibers were fabricated and applied as the supercapacitor electrode materials. TiO₂ fibers were prepared as substrates for the vapor-phase polymerization process, by electrospinning and calcination in air. The symmetric supercapacitor cells assembled with the resulting composites were studied by a series of electrical measurements including cyclic voltammetry, charge-discharge characterization and electrochemical impedance spectroscopy. To further understand the capacitive behavior, the band gap energy of the composite fibers and the specific surface area of TiO₂ fibers calcined at varied temperatures were measured. The highest specific capacitance of PEDOT on TiO₂ fibers to date, 87.9 F g⁻¹, was achieved with the composite fibers prepared by vapor-phase polymerization at 50 °C on the TiO₂ fibers calcined at 550 °C. The pseudocapacitance and the reversibility of PEDOT were improved in comparison to other PEDOT/TiO₂ binary composites.