Supramolecular Anchoring of Charge-Asymmetric COF Interfaces to Regulate Ion Rectification for Monolithic Flexible Supercapacitors.

Zhang, Zhenni; Lu, Yanxu; Kang, Guida; Liu, Siyu; Wang, Shengdao; Ren, Dianfu; Wang, Guibin · Nano Lett · 2026

basic_science · Level V

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Abstract

Flexible supercapacitors (FSCs) often suffer from sluggish ion kinetics and mechanical vulnerability at mismatched electrode-electrolyte interfaces. Herein, we report an electric-field-driven nucleation strategy for the in situ supramolecular anchoring of ultrathin covalent organic framework (COF) films onto a conductive dual-network hydrogel, constructing a monolithic FSC. By pairing a cationic imidazole-COF with an electron-rich hydroxyl-COF, we engineer charge-asymmetric COF interfaces governed by synergistic hydrogen-bonding and electrostatic interactions. This architecture actively regulates ion rectification and dismantles solid-solid interfacial energy barriers, significantly accelerating electrochemical kinetics. Consequently, the device delivers an exceptional volumetric capacitance of 926.6 F cm<sup>-3</sup>, an ultrahigh energy density of 128.7 mWh cm<sup>-3</sup>, and a power density of 14.8 W cm<sup>-3</sup>. Benefiting from robust interfacial adhesion, it exhibits outstanding durability (97.6% retention over 20000 cycles) and operates stably under dynamic cyclic bending and stretching, enabling reliable self-powered sensing. This work establishes a molecular-level paradigm for integrated wearable electronics.