Synergistic Interfacial Engineering for Stable Aqueous Zinc Batteries via Fluorine‐Oxygen Bridged Electrostatic Shielding and Hybrid SEI

ABSTRACT Despite having garnered significant attention for inherent safety and low‐cost advantages, the practical applications of aqueous zinc‐metal batteries are still limited due to uncontrolled zinc dendrite growth and complex interfacial side reactions. To address these challenges, this study pioneers eflornithine (EFL) as a multifunctional additive in ZnSO ₄ electrolytes. It is demonstrated that EFL plays a pivotal role in inhibiting interfacial side‐reactions by regulating the solvation structure of Zn ²⁺ via its amino and carboxyl groups and forming a fluorine‐oxygen bridged adsorption layer at the zinc anode surface. The modified solvation shell enhances ion migration kinetics, while the adsorption layer significantly suppresses the hydrogen evolution reaction through the electrostatic shielding of H ⁺ by amino cations. Furthermore, an organic‐inorganic solid electrolyte interphase (SEI) is formed owing to the reduction of EFL, enabling superior zinc stripping/plating reversibility. The Zn||Zn symmetric cell demonstrates an outstanding lifespan of 6000 h. The fabricated Zn||MnO ₂ pouch cell exhibits excellent cycling stability, sustaining high capacity and near‐unity Coulombic efficiency over 100 cycles, which highlights its practical viability. This study not only emphasizes the crucial role of fluorine in constructing robust SEI but also provides novel molecular engineering insights for designing high‐performance aqueous zinc electrolytes that integrate ionic regulation and interfacial stability.