Polypyrrole nanostructures//activated carbon based electrode for energy storage applications

Abstract

In this study, a self-assembled polypyrrole nanostructure with the high electrochemical performance was synthesized via a chemical polymerization method. The structure, morphology and compositional analysis were investigated using Fourier transmission infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FESEM) and X-ray photoelectron spectroscopy (XPS). The FTIR analysis of the synthesized samples confirmed the presence of pyrrole chain located at 1313\xa0cm−1. The XPS spectrum showed the presence of C1s and N1s binding energy peaks. The FESEM images confirmed the presence of self-assembled nanostructures with a size range of ~\u2009200\xa0nm. The effect of various aqueous electrolytes on the electrochemical performance of polypyrrole was studied. Because of its smaller hydration sphere radius, increased molar conductivity and higher ionic mobility, self-assembled polypyrrole nanostructure (P1) delivered a high specific capacitance of 623\xa0F g−1 in 0.5\xa0M H2SO4 electrolyte. Finally, we have fabricated a solid-state symmetric (SSC) and asymmetric supercapacitor (ASC) based on polypyrrole electrode. Among them, the as-assembled P1//activated carbon-based ASC delivered a maximum energy density (25.3 Wh kg−1) and power density (2400\xa0W\xa0kg−1) with excellent cycling stability after 40,000 charge/discharge cycles.