Non-covalently self-assembled organic molecules graphene aerogels to enhance supercapacitive performance

Abstract

Organic molecules electrodes with high electrochemical reversibility has enormous potential in energy storage. Here, benz[a]anthracene-7, 12-quinone (BAQ) and 2, 5-dihydroxy-p-benzoquinone (DHBQ) are anchored on reduced graphene oxide (rGO) [BAQ (DHBQ)/rGO] by non-convent method to form the porous 3D dry aerogels. The optimal BAQ (DHBQ)/rGO electrode materials display capacitance all in excess of 400 F g−1 at current density of 1 A g−1 and an excellent rate capability in 1 M H2SO4 electrolyte. And BAQ/rGO and DHBQ/rGO are used respectively as the negative and positive electrode to fabricate the asymmetric supercapacitor (ASC), which achieves high energy density of 30.33 Wh kg−1 with power density of 802.9 W kg−1. Finally, 47 light-emitting diode (LED) bulbs aligned in a ‘NWNU’ shape are lit by two ASCs device in series, demonstrating its outstanding energy storage performance. Moreover, density functional theory (DFT) calculations are employed to understand the adsorption orientations, binding interactions and charge storage mechanism of BAQ on rGO surface, elucidating the superior electrochemical performance of the tested organic molecule electrode. In short, quinones non-covalently modified graphene is a promising and effective strategy for energy storage devices in future.