Use of oil in the polymerization of aniline to polyaniline salt containing dual dopants, sulfuric acid, and castor oil: material for high-performance supercapacitor

Supercapacitor is an important energy storage device. In this work, for the first time, oil (castor oil) is used instead of hazardous acids in the polymerization of aniline. This process yields polyaniline salt containing dual dopants, sulfuric acid, and castor oil. This castor oil is expected to interact with electrolyte in supercapacitor and thereby increases the electrochemical performance of supercapacitor. Polyaniline salt was synthesized by the oxidation of aniline in presence of castor oil instead of strong acid using ammonium peroxydisulfate oxidant via interfacial polymerization pathway. Formation of polyaniline salt was confirmed from IR, XRD analyses, and morphology studies from FE-SEM analyses. The results of this study showed the formation of nano-oblate/rod morphologies of semi-crystalline polyaniline salts, which show a specific capacitance value of 410 F g⁻¹. Higher specific capacitance, cycle life, low charge transfer resistance, and high phase angle of polyaniline supercapacitor cell indicate a higher performance supercapacitor system.