Chiral Supramolecular Electrolyte Engineering Enables Ultra‐Long‐Cycling Aqueous Zinc‐Ion Batteries

The practical application of aqueous zinc‐ion batteries (AZIBs) is severely hampered by unregulated dendrite growth and parasitic hydrogen evolution reaction at Zn anodes. Electrolyte additive engineering affords a promising strategy. Herein, a bio‐derived composite additive is fabricated via intermolecular proton transfer between chitosan and L‐ascorbic acid, yielding chiral supramolecular associations supported by a rigid macromolecular backbone. Simulations and experiments verify a dual‐regulation mechanism: the chiral configuration enables stereoselective adsorption on Zn anodes, forming a protective interphase with ultralow lattice mismatch ( δ < 20%) with the Zn (101) facet, which thermodynamically favors selective nucleation and simultaneously suppresses interfacial side reactions. Meanwhile, the chiral supramolecular associations form continuous polar channels, facilitating Zn 2+ desolvation by partially displacing coordinated water and reconstructing the hydrogen‐bonding network of the electrolyte, thereby inhibiting dendrite growth. Furthermore, the strong binding affinity between Zn 2+ and chiral polar groups further facilitates uniform Zn deposition kinetics. Consequently, Zn//Zn symmetric cells achieve an ultralong cycling lifespan exceeding 4900 h at 1.0 mA cm −2 , along with the Zn//Cu asymmetric cells showing exceptional reversibility, and both Zn//NH 4 V 4 O 10 and Zn//I 2 full cells deliver exceptional cycling stability. This chirality‐driven crystal facet engineering strategy provides valuable insights for constructing advanced AZIBs.