Fulleroid‐Containing Carbon‐Only Composite for High‐Performance Hybrid Supercapacitors

As the global pursuit of efficient and sustainable energy storage solutions intensifies alongside the transition to renewable energy sources and the evolution of electrified transportation systems, hybrid supercapacitors have emerged as promising candidates. Supercapacitors address the requirements of high power density and enhanced energy density storage. This study describes polyacrylonitrile (PAN), poly(methyl methacrylate) (PMMA), and [6,6]‐phenyl‐C61‐butyric acid methyl ester (PCBM) composites for hybrid supercapacitor electrodes. Synthesized via electrospinning, stabilization, carbonization, and CO ₂ activation, the freestanding electrodes were characterized by cyclic voltammetry, galvanostatic charge–discharge (GCD), electrochemical impedance spectroscopy, and cycling stability tests, as well as physical and chemical characterizations. The results show promising performance, with the PAN/PMMA/PCBM electrodes achieving an energy density of up to 89.2 Wh/kg and a specific capacitance of up to 209 F/g at a current density of 1 A/g in GCD experiments. These findings highlight the potential of PCBM for efficient energy storage and offer valuable insights into advancing sustainable energy storage systems to meet the evolving demands of modern energy applications.