Indanthrene dye enhanced graphene electrodes for high-performance supercapacitors

Enhancing the energy density of supercapacitors while maintaining their excellent cycling stability remains a major challenge in the field of energy storage. Herein, we report a novel non-covalently modified reduced graphene oxide (rGO) electrode using Indanthrene Black BBN (BBN), a commercially available industrial dye with a planar conjugated structure and high redox activity. Through strong π-π stacking interactions, BBN was uniformly anchored onto rGO sheets, forming a hybrid architecture that integrates electric double-layer capacitance and Faradaic pseudocapacitance. The resulting BBN-rGO-0.8 composite, obtained via a one-step hydrothermal process, exhibited superior electrochemical performance, including a high specific capacitance of 457 F g −1 at 1 A g −1 and remarkable rate capability with 91.6 % capacitance retention at 20 A g −1 in a three-electrode configuration. When assembled into a flexible symmetric aqueous supercapacitor using a PVA/H₂SO₄ gel electrolyte, the device achieved a high energy density of 19.8 Wh kg −1 at a power density of 800 W kg −1 , while maintaining 85.8 % capacitance retention over 10,000 charge-discharge cycles. This study not only demonstrats the potential of BBN as a cost-effective redox-active additive for graphene-based electrodes, but also provids a new strategy for designing high-performance energy storage devices through structure-function-cost integration.