Porous poly(3,4-ethylenedioxythiophene) nanoarray used for flexible supercapacitor

Abstract Porous poly(3,4-ethylenedioxythiophene) (PEDOT) nanoarray used for flexible supercapacitor has been prepared to investigate its electrochemical capacitance performance. Well-aligned titania (TiO 2 ) and titanium nitride (TiN) nanotube array was fabricated by an anodization, crystallization, nitridation processes. PEDOT-TiO 2 and PEDOT-TiN nanoarray hybrid was fabricated by coating PEDOT on nanotube walls of TiO 2 and TiN through a pulse voltammetry electrodeposition process. PEDOT nanopore array was fabricated through HF corrosion of TiN from PEDOT-TiN. The morphology and microstructure of PEDOT-TiO 2 , PEDOT-TiN and PEDOT were characterized by scanning electron microscopy and Raman spectroscopy. The electrochemical capacitance was investigated by cyclic voltammetry and galvanostatic charge–discharge measurements. PEDOT-TiO 2 and PEDOT-TiN showed heterogeneous coaxial nanotube structure. PEDOT exhibited free-standing nanopore array structure. The specific capacitance of PEDOT-TiN nanoarray hybrid was determined to be 393.1 F g −1 at a current density of 1.0 mA cm −2 , presenting much higher capacitance than PEDOT-TiO 2 nanoarray hybrid (128.7 F g −1 ) and PEDOT nanopore array (109.3 F g −1 ). All-solid-state flexible supercapacitor was constructed using supple electrode of PEDOT-TiN nanoarray hybrid and polyvinyl alcohol gel electrolyte of sulphuric acid. The volume specific capacitance, energy and power density were determined to be 4.08 F cm −3 , 2.26 mW h cm −3 and 250 mW cm −3 at a high output voltage of 2.0 V and a current density of 10 mA cm −2 . PEDOT-TiN nanoarray hybrid exhibited the effective energy storage in flexible supercapacitor application.