Nanocomposites of polypyrrole/graphene nanoplatelets/single walled carbon nanotubes for flexible solid-state symmetric supercapacitor

Abstract

With the rapid depletion of fossil fuels and rising energy consumption, the development of renewable as well as sustainable energy source has become one of the foremost challenges in energy storage. Herein, a low-cost and easy preparation procedure has been employed for the fabrication of nanocomposites based on graphene nanoplatelets (GP), single-walled carbon nanotubes (SWNTs) and polypyrrole (PPy) [GP/SWNTs/PPy] for the superior supercapacitor electrode materials by taking advantage of electrochemical double layer capacitance of carbonaceous moieties and pseduocapacitance of conducting polymer. Spectroscopic techniques have suggested the interactions of both GP and SWNTs with PPy. GPs are homogeneously covered by PPy and the covered GPs are wrapped by PPy coated SWNTs to have a unique morphology, observed from morphological analysis. Highest specific capacitance of 1224 F/g at current density 0.5 A/g, better energy and power density have been achieved for the nanocomposite. Further, GP/SWNTs/PPy based all-solid state flexible supercapacitor device has been fabricated and it has showed the specific capacitance of 324 F/g at current density 0.5 A/g, energy density of 28.8 Wh/kg and power density of 1975.22 W/kg. Apart from these electrochemical characteristics, these nanocomposites have exhibited nonlinear current–voltage characteristic, indicating the semiconducting behavior. Considering the excellent electrochemical properties, these nanocomposites should be used for the superior electrode materials for the fabrication of coin-type supercapacitor.