In Situ Constructed Zn 3 N 2 ‐Enriched Hybrid Solid Electrolyte Interphase Enables Highly Efficient Zinc Deposition Kinetics for Ultra‐Stable Zinc‐Iodine Batteries

Rechargeable aqueous zinc-iodine (Zn-I₂) batteries face severe challenges, primarily stemming from the interfacial incompatibility between the Zn anode and electrolyte, complex side reactions, and the aggravated polyiodide shuttle effect induced by sluggish charge-transfer kinetics. To mitigate these issues, this work introduces copper hexadecafluorophthalocyanine (FCP) as a novel electrolyte additive to in situ construct a mechanically robust, Zn₃N₂-rich inorganic-organic hybrid solid electrolyte interphase (SEI). This unique SEI, featuring highly ion-conductive Zn₃N₂, not only accelerates Zn²⁺ migration but also leverages the macrocyclic conjugated structure of FCP to generate a delocalized electric field, facilitating the desolvation of hydrated Zn²⁺. Additionally, the planar π-conjugated backbone promotes in-plane electron transport, further optimizing interfacial kinetics. Furthermore, FCP molecules preferentially adsorb onto the Zn surface, guiding uniform Zn deposition and improving interfacial stability. As a result, the assembled symmetric cells achieve ultrastable cycling for over 6000 cycles at ultrahigh current densities (20 and 50 mA cm^-2), while the Zn anode exhibits an ultrahigh Coulombic efficiency of 98.7% and exceptional reversibility in plating/stripping. A Zn-I₂ full battery also delivers outstanding long-term cycling stability, retaining 80.9% capacity after 65000 cycles at an ultrahigh rate of 50 C.