Synergistic interplay of quinones and dopants in 3D graphene architecture for next-gen supercapacitors

The pursuit of high-performance, sustainable energy storage systems has catalyzed the convergence of two powerful chemistries including redox-active organic molecules and heteroatom-doped carbon architectures. In this work, we explore the synergistic interaction between quinone-functionalization and dual heteroatom doping strategies on three-dimensional graphene (3DG) architecture to engineer high-performance hybrid super-capacitors. Nitrogen-doped and nitrogen-sulfur co-doped quinone-anchored 3D graphene (NQ_N-3DG and NQ_N, S-3DG) were synthesized via a facile self-assembly process induced by chemical reduction. The resulting materials exhibit enhanced porosity, increased defect density, and abundant electroactive sites. The NQ_N,S-3DG and nitrogen-doped graphene aerogel (N-GA) electrodes were assembled into an asymmetric coin-cell super-capacitor (NQ_N,S-3DG//N-GA) using a PVA/Na2SO4 gel polymer electrolyte membrane as both the separator and electrolyte. The resulting hybrid cell achieved a specific capacitance of 329.5 F.g-1 at 0.25 A.g-1, an energy density of 183.1 Wh.g-1 at 500 W.kg-1, and outstanding cycling stability over 90 % for 20,000 cycles at 10 A. g-1. Even at a high current density of 10.0 A.g-1, the device still delivers 207.4 F.g-1 specific capacitance. This synergistic interplay between organic redox-active moieties and heteroatom-doped 3D carbon frameworks highlights a powerful dual-chemistry strategy for unlocking advanced charge storage capabilities in next-generation supercapacitors.