Facile synthesis of polypyrrole/graphene composite aerogel with Alizarin Red S as reactive dopant for high-performance flexible supercapacitor

Polypyrrole (PPy)/graphene composite aerogel with three-dimensional porous network structure is prepared by a facile one-step hydrothermal method using Alizarin Red S (ARS) as crosslinker, oxidant and dopant. Analysis of infrared spectroscopy, ultraviolet spectroscopy, Raman spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy confirm the elimination of oxygen functional groups of graphene oxide, the successful polymerization of PPy and the efficient doping effect of ARS. The optimized aerogel electrode (PGA-10) provides outstanding specific capacitance of 461 F/g at a current density of 0.5A/g. The assembled symmetrical flexible solid supercapacitor constructed from two identical PGA-10 electrodes exhibits excellent electrochemical performance, 134 F/g (316.67 mF/cm 2 ) within a wide potential window up to 1.8V, 60.3 W h kg −1 (142.5 μW h cm −2 ) at power density of 900.7 W kg −1 (900.7 μW cm −2 ), while maintaining good cycle stability (capacitance retention rate of 84.4% after 10,000 cycles) and excellent flexibility. This work demonstrates that the feature of high flexibility, light-weight and outstanding supercapacitive performances for PGA-10 composite aerogel can provide promising applications in wearable and portable electronics. • Facile preparation of graphene/PPy aerogel is achieved with ARS as reactive dopant. • PGA-10 with 3D network delivered an energy density of 60.3 W h kg −1 at 900.7 W kg −1 . • The flexible, light weight aerogel provides outstanding energy storage properties.