Synthesis of graphene/polyaniline copolymer for solid-state supercapacitor

Abstract

Polyaniline attracts increasing attention in electrochemical devices, present works focus on improving its specific capacitance and electrochemical stability. In this paper, graphene grafted polyaniline copolymer (G-PC) with conjugated structure was prepared via in-situ chemical oxidation polymerization using p-phenylenediamine (PPDA) and triphenylamine (TPA) as comonomers. The large conjugated system facilitates the charge transfer of the G-PC composites, thereby enhances their electrical conductivity and electrochemical properties. The resultant G-PC electrode demonstrated an enhanced specific capacitance of 1701.1 F/g at a scan rate of 5 mV/s and a high retention after 4000 charge/discharge cycles in a three-electrode system. Finally, the assembled solid-state supercapacitor (SSC) with G-PC electrodes improved energy density up to 15.3 Wh/kg at a power density of 50 W/kg showing a capacitance retention of 94.9% after 5000 electrochemical cycles.