Organic Molecule-Functionalized Reduced Graphene Oxide for All-Carbon Asymmetric Supercapacitor Applications

An organic molecular electrode (OME) is obtained, in which the polyhydric organic molecules (3,4,5-trihydroxybenzamide, THBA) act as a guest molecule to decorate graphene hydrogel (rGO(1)). The THBA acts as a spacer to prevent the rGO sheet from aggregation and provides an active center for OME. In the three-electrode configuration, the prepared OME (rGO(1)-THBA) presents a capacitance of 390.6 F g(-1) and has a capacitance retention of 73.7% even when the scanning rate increases from 5 to 100 mV s(-1). Furthermore, we synthesize an organic molecule 1,4,5,8-naphthalenetetracarboxylic diimide (NDP) and immobilize it onto the rGO surface to form another OME (rGO-NDP) as the counter electrode. An all-carbon asymmetric supercapacitor (rGO(1)-THBA//rGO-NDP: ASC) is constructed by using rGO(1)-THBA and rGO-NDP as the positive and negative electrodes, respectively. The resultant device achieves a capacitance of 70.8 F g(-1) and delivers an energy density of 14 W h kg(-1), supplying the power of 590 W kg(-1). More importantly, the two asymmetric devices in series connection are able to light up 24 LED lights for 100 s.

Automated summary

The study successfully prepared organic molecular electrodes by using polyhydric organic molecules and decorating them with graphene hydrogel, enhancing capacitance and energy density. By utilizing two different organic molecules as positive and negative electrodes, an all-carbon asymmetric supercapacitor was constructed, achieving high energy density and power output, capable of lighting up LED lights.