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 (TiO2) and titanium nitride (TiN) nanotube array was fabricated by an anodization, crystallization, nitridation processes. PEDOT-TiO2 and PEDOT-TiN nanoarray hybrid was fabricated by coating PEDOT on nanotube walls of TiO2 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-TiO2, 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-TiO2 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 393.1Fg−1 at a current density of 1.0mAcm−2, presenting much higher capacitance than PEDOT-TiO2 nanoarray hybrid (128.7Fg−1) and PEDOT nanopore array (109.3Fg−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 4.08Fcm−3, 2.26mWhcm−3 and 250mWcm−3 at a high output voltage of 2.0V and a current density of 10mAcm−2. PEDOT-TiN nanoarray hybrid exhibited the effective energy storage in flexible supercapacitor application.