Beyond Surface Confinement: Disorder‐to‐Local‐Order Regulated Carbon Cathodes Enabling Anion Intercalation for 5.1‐V Dual‐Ion Hybrid Capacitors

ABSTRACT Hybrid capacitors bridge the energy‐power gap between batteries and supercapacitors, yet their energy density remains fundamentally constrained by the surface‐confined charge storage of conventional activated carbon (AC) cathodes. Herein, we propose a crystal reconstruction strategy, through disorder‐to‐local‐order regulation within AC matrices, to unlock anion‐intercalation storage at elevated voltages and thus enable an unprecedented capacity. This approach realizes a transformative charge storage mechanism that synergistically integrates capacitive storage with bulk anion (de)intercalation. Consequently, the reconstructed carbon cathode (ACG‐750) in a 5.1‐V dual‐ion hybrid capacitor (DIHC) achieves a significantly improved specific capacity of 239 mAh g −1 at 0.2 A g −1 with tripled energy density versus pristine AC, while maintaining >1000‐cycle stability at 1 A g −1 . In a simulated pouch‐cell configuration paired with a 50‐µm Li anode, the device demonstrates >300 cycles of robust operation. This microstructure‐mediated dual‐ion charge storage paradigm provides novel insights for breakthroughs in carbon‐based cathodes.