Introducing of leached supercapacitor coin-devices with excellent performance based on tungsten oxide-carbon nanotubes-graphite nanocomposite

Abstract

In this study, leached graphite coin decorated with tungsten oxide nanoparticles and carbon nanotubes (leached tungsten oxide/carbon nanotubes-graphite coin) with high surface area and excellent mechanical strength is introduced as a novel and low-cost electrode in the supercapacitor application. The leached tungsten oxide/carbon nanotubes-graphite coin was easily fabricated via uniform addition of commercial Zinc-metal powder into the matrix of commercial graphite powder and carbon nanotubes powder, pressing under optimized pressure followed by treatment in H2SO4 solution for leaching out of Zinc from carbon nanotubes-graphite matrix and finally electrodeposition of tungsten oxide nanoparticles onto the previously leached coin. The surface chemistry and structure features of the leached coin were investigated by FTIR, RAMAN, XRD, SEM, TEM, AFM and BET analysis. The leached tungsten oxide/carbon nanotubes-graphite coin had acceptable capacitive characteristic such as negligible ohmic drop and favorite specific capacitance of 3519 mF cm−2 at 2 mA cm−2 in aqueous 1.0 M H2SO4 media. After assembling a symmetric supercapacitor coin-device including leached tungsten oxide/carbon nanotubes-graphite coin in a PVA/H2SO4 gel, the coin-device shows a high specific capacitance of 283 mF cm−2 at the current density of 2.5 mA cm−2.