Function‐Oriented Modular Molecular Design of a Chitin‐Derived Self‐Healable Binder for Promising Zinc Powder Anodes

ABSTRACT Replacing zinc foil with Zn micropowders (ZnMPs) enhances manufacturing compatibility for Zn‐metal batteries but imposes challenges like uncontrolled Zn deposition and accelerated structural degradation, typically resulting in a short cycle life of < 50 cycles. Herein, we synthesize a multifunctional bottle‐brush polycationic binder based on naturally abundant and mechanically robust chitin, which enables exceptional long‐term Zn plating/stripping reversibility, averaging 99.5% Coulombic efficiency over 300 cycles. The design rationales are experimentally validated as follows: diverse functional groups integrated onto the chitin backbone provide multiple supramolecular interactions ensuring ZnMP electrodes’ spatial uniformity and structural robustness; Zn 2+ ‐carboxylate coordination simultaneously enhances the binder's mechanical strength (~1.2 MPa), toughness (~8.6 MJ m −3 ) and ionic conductivity (an 87% increase, reaching 1.72 × 10 −5 S cm − 1 ) upon swelling; while synergistic dynamic electrostatic interactions and hydrogen bonding permit rapid self‐recovery of the electrodes during cycling. This work underscores the promise of supramolecular engineering for binders targeting aggressive electrode chemistries.