Orchestrating Penta‐Element Interplay in Gradient‐Porous Carbons for Advanced Sodium‐Ion Hybrid Capacitors

Abstract

Abstract Sodium‐ion hybrid capacitors (SIHCs) offer a cutting‐edge synergy between battery‐level energy density and supercapacitor‐like power density, yet face critical challenges in balancing the kinetic and capacity mismatch between Faradaic anodes and capacitive cathodes. Herein, we present a penta‐element doped gradient‐porous carbon (PE‐GPC) with a nanosphere architecture, engineered with high‐entropy principles and a gradual pore density variation to enhance mass transport and charge storage. Operando spectroscopy and machine learning potentials unveil a concerted penta‐element interplay: thiophene‐like S configurations mediate dynamic redox processes, enabling pseudocapacitive Na⁺ and anion storage, while fluorine functionalities foster a self‐rejuvenating NaF‐rich solid electrolyte interphase (SEI), stabilizing long‐term cycling. Meanwhile, the synergistic N/B/P triad engineers a hierarchical defect network that enhances electronic conductivity and fine‐tunes ion adsorption energetics. This orchestrated interplay empowers the SIHC full cell with a high energy density of 196 Wh kg −1 , a formidable power density (10.4 kW kg −1 ), and an impressive 88.2% capacity retention after 9000 cycles. By establishing a high‐entropy stabilization paradigm, this work paves the way for multi‐ion storage architectures, offering a universal strategy to bridge the charge‐transfer imbalance in advanced energy devices.