A novel organic molecule electrode based on organic polymer functionalized graphene for supercapacitor with high-performance

Abstract

Organic synthesis strategy can tune electrochemical behavior of organic molecules by molecular level design, which can offer more material choices for sustainable supercapacitors. Herein, an organic polymer (Poly-perylene-3,4,9,10-tetracarboxydiimide-anthraquinone, PPA) is designed and synthesized as an electrode material that can achieve Faraday reaction with 4 electron transfers in a structural unit. When the PPA is directly used as electrode material, the specific capacitance can be up to 245 F g−1 at 5 mV s−1 within a more negative potential. Furthermore, PPA is modified on reduced graphene oxide (rGO) to prepare an Organic Molecule Electrode (OME, PPA/rGO-1), which can reach higher specific capacitance (604 F g−1 at 5 mV s−1) with good cycle stability (capacitance retention of 69.9% at 5 A g−1, over 10,000 cycles). Besides, a 2,6-dihydroxynaphthalene (DN) modified graphene hydrogel (GH) is prepared as positive electrode to match with resultant OME for fabricating an asymmetrical supercapacitor (ASC). The device can deliver an energy density of ~20 Wh kg−1. Two ASCs (in series) light 40 Light Emitting Diodes (LEDs), suggesting a potential application.