Fabrication of high energy density symmetric polyaniline/functionalized multiwalled carbon nanotubes supercapacitor device with swift charge transport in different electrolytic mediums

Abstract

This work is conducted with aim of enhancing the energy density and cycling performance of PANI/fMWCNTs within a very low molar concentration of the mixed acidic/neutral electrolyte where not only the medium, but the structure too facilitates easy charge transfer because of increased ionic mobility. A promising optimized flower-like morphology of symmetric supercapacitor electrode of functionalized Multi-walled Carbon Nanotubes (f-MWCNTs) with Polyaniline (PANI) composites are prepared by in-situ chemical oxidative polymerization method with different doping concentrations of f-MWCNTs (5 wt% and 10 wt%). The synthesized PANI/f-MWCNTs (5 wt%) composite provides a large surface area (133.55 m2/g), high porosity (11.24 nm), low internal resistance (6.16 Ω) and charge transfer property (2.74 Ω) between the electrode within a mixed (0.1 M H2SO4 + 0.1 M Na2SO4) electrolyte interface. To overcome the cracking/swelling of PANI during electrochemical performance, the electrodes of PANI are incorporated with different doping concentration of f-MWCNT (5 wt% or 10 wt%). With a specific capacitance of 867 F g−1 at 10 mV/s, energy density ~77.0 Whkg−1 and power density ~801 Wkg−1, PFC1 nanocomposite indicates ~20 % more stability than pure PANI. Also, the nanocomposite electrode cell shows a columbic efficiency of 97 % and 98.5 % of its initial value of specific capacitance after 10,000 GCD cycles in a mixed acidic/neutral (0.1 M H2SO4 + 0.1 M Na2SO4) aqueous electrolytic solution.