Fully organic polyaniline nanotubes as electrode material for durable supercapacitor

Herein, we have reported fully organic acid doped polyaniline nanotube as a metal free electrode material for supercapacitor device fabrication. The energy storage behavior of this polymer greatly depends with morphology of nanostructure that has been optimized by using different number of carboxylic groups functionalized organic acid like benzene dicarboxylic acids (OA2), benzene tricarboxylic acids (OA3) and benzene tetracarboxylic acids (OA4). Prepared nanostructures were characterized by UV-Vis, XRD, FTIR, FESEM and HRTEM. Importantly, the charge storage properties of nanostructure were studied by Cyclic voltammetry (CV), galvanic charge discharge (GCD) and electrochemical impedance spectroscopy (EIS). It has been noticed that benzene tetracarboxylic acids (OA4) doped polyaniline (OA4PAN) is the optimum nanostructure having specific capacitance - 400 F/g at 0.5 A/g in the three-electrode system. A symmetrical solid-state device with excellent mechanical flexibility has been fabricated with optimized nanostructure revealed the specific capacitance of 107 F/g at a 0.2 A/g in wide potential window with high cyclic stability up to 5000 cycle at 2 A/g (similar to 91% retention of specific capacitance). This nanostructure could be eligible to use for various energy storage system in near future.

Automated summary

This study reported fully organic acid doped polyaniline nanotube as a metal-free electrode material for supercapacitor device fabrication. The optimized nanostructure with benzene tetracarboxylic acids (OA4) doping exhibited high specific capacitance and cyclic stability, making it a promising candidate for future energy storage systems.