High energy-density supercapacitor based on a novel conjugated poly (1, 5-diaminoanthraquinone)/intercalated graphene composite system

Abstract

In this work, we select a novel multi-redox poly (1, 5-diaminoanthraquinone) (PDAAQ) as electroactive material and Cetyltrimethylammonium bromide (CTAB) modified graphene oxide (CGO) as conductive substrate. Benefit from the excellent dispersion of CGO in organic polymerization medium and the abundant functional groups on the surface of CGO, 1, 5-diaminoanthraquinone (DAAQ) monomers may covalently graft on the conducting substrates and realize the directional growth of PDAAQ via the in-situ chemical oxidative polymerization. In three-electrode system, the optimization of PDAAQ/CGO electrode exhibits a high specific capacitance of 760 F g−1 at 1 A g−1 and superior electrochemical stability of 90.4% after 10 000 cycles. Most importantly, the electrochemical kinetic behavior of PDAAQ/CGO electrode is studied in detail. The result indicates that the energy storage process of PDAAQ/CGO is a synergistic result of diffusion-controlled process and capacitive effects, and the latter one is dominant. According to the simulation calculation of kinetic model, the capacitive contribution ratio of PDAAQ/CGO can be as high as 80.6% at a scan rate of 50 mV s−1. Finally, the as-fabricated asymmetric supercapacitor (ASC) can deliver an energy density up to 41.1 W h kg−1 at a power density of 1000 W kg−1, indicating a great potential application in high performance supercapacitors.