Transfunctionalization of graphite fluoride engineered polyaniline grafting to graphene for High-Performance flexible supercapacitors.

Low energy density is the major obstacle for the practical all-solid-state supercapacitors, which may be raised by the combination of the pseudocapacitance with the electrochemical double-layer capacitance. Although graphene and polyaniline have been demonstrated two effective materials, the synthetic route of graphene and their hybrid mode largely dictated the capacitive performances and cyclability of graphene/polyaniline nanocomposites. Herein, we employed commercial graphite fluoride as the precursor to obtain graphene with a well-preserved carbon lattice. After graphite fluoride functionalization by p-phenylenediamine (pPDA) and in situ oxidative polymerization of anilines, polyaniline (PANI) chains were covalently attached to graphene framework through pPDA bridges. Multiple characterizations were performed to confirm the covalent binding mode between graphene scaffolds and PANI partners, and electrochemical tests unraveled the as-prepared G-pPDA-PANI triads delivered a gravimetric capacitance as high as 638F g and a further amplified volumetric capacitance (up to 759F cm). The bendable all-solid-state supercapacitors yielded an encouraging energy density of over 18 W   h L at a power density high to 5,950 W L, while exhibiting an exceptional rate capability, cycling stability and mechanical flexibility.