Enriched Doping Level and Tuned Fiber Fractal Dimensions in Nonwoven Carbon‐Doped Polyaniline for Efficient Solid‐State Supercapacitors

Nonwoven fibrous mats of polyaniline/carbon black on conducting substrates are synthesized through a two‐step oxidative process. Adsorbed and catalyzed aniline monomers in the synthesis process improved the doping degree (0.381) in the hybrid fibers. The formation of a porous mat on substrates was confirmed by using electron microscopy and small‐angle X‐ray scattering. The fractal dimensions of the fibers are correlated with Porod's law and suggest the presence of a nonfractal structure in the PCN1 mat. The hybrid mat exhibited a high porosity and effective surface area, even interfaces, and conductive pathways for the electrode/electrolyte to improve the kinetic process. Electrochemical measurements have been conducted on developed fibers, which showed a high specific capacitance of around 1526 F g −1 , excellent cyclic stability, and elevated energy density (212 Wh kg −1 ) after doping carbon into polyaniline (PANI). Additionally, a symmetric solid‐state supercapacitor device was fabricated, a capacitance around 270 F g −1 was measured, and it was able to light a commercial light‐emitting diode (LED).