Synthesis and capability evaluation of quinone-enriched polymer with extended -conjugated and contorted structures for efficient energy storage

In this study, quinone-enriched polymers (PDQs) are uniquely combined with reduced graphene oxides (rGOs) for assembling organic molecular electrodes (OMEs). The PDQ polymers are synthesized via a Schiff-base reaction involving 1,5-Diaminoanthraquinone (DAAQ) and 2,4,6-Triformylphloroglucinol (Tp). PDQ's extended pi-conjugation system, substantial C--O groups, and contorted structures result in excellent electrochemical properties, while strong pi-pi interactions with rGO enhance the cycling stability. The as-prepared PDQ/rGO-0.3 delivers a specific capacitance as high as 483.6 F g-1 at 5 mV s-1, with remarkable capacitance retentions (80 % at 100 mV s-1) and an outstanding cycling stability, where 87.8 % capacity retains after 10,000 cycles at a high current density of 5 A g-1. To verify actual energy storage performance of PDQ/rGO-0.3, an aqueous asymmetric supercapacitor (ASC) is assembled by employing 2,5-dihydroxy-1,4-benzoquinone-modified reduced graphite oxide (DHBQ/rGO) as another electrode, of which redox reaction occurs in a positive potential range. The assembled ASC displays a high energy density of 28.8 Wh kg- 1 at a power density of 678 W kg- 1, maintaining 98 % after 10,000 cycles in 1 M H2SO4 aqueous electrolyte. To shed a light for practical use, a tandem configuration of two ASCs (PDQ/rGO-0.3//DHBQ/rGO) are demonstrated to power 46 LEDs effectively.