Boosting Extraordinary Capacitive Performance by Porous Structure Engineering of Binders in Activated Carbon‐Based Electrodes

Activated carbons (ACs) remain the dominant commercial active materials for supercapacitors. However, AC‐based electrodes typically exhibit limited specific capacitance and rapid performance degradation under ultrahigh‐rate conditions or at subzero temperatures. Here, a pore‐engineering‐in‐binder strategy is reported, which creates extra ion transport channels in thick electrodes and remarkably enhances ion accessibility to AC active materials especially at high charging rates. Thick electrodes fabricated from commercially available ACs achieve areal capacitances of up to 2.3 and 1.2 F cm ‒2 in aqueous and organic electrolytes, respectively, and retain 1.1 and 0.5 F cm ‒2 even at an ultrahigh scan rate of 1000 mV s ‒1 —representing 355% and 210% improvements over commercial electrodes. Notably, this extraordinary performance is maintained at subzero temperatures, enabling a high‐power output of 300 mW cm ‒2 at −40 °C, surpassing the best reported supercapacitors. These findings demonstrate a pathway to unlocking the extraordinary capacitive potential of ACs, thereby advancing the development of high‐performance supercapacitors based on nanoporous carbon‐binder systems.