Electron-Induced Molecular Programming Drives Interfacial Chemistry for Ah-Level Zinc Batteries

Abstract

Solid–electrolyte interphases (SEIs) are essential for stabilizing metal anodes in aqueous zinc (Zn) batteries (AZBs), yet their formation remains intrinsically uncontrolled, leaving the interphase vulnerable to dissolution and water-driven parasitic reactions. Herein, we report an electron-induced molecular programming strategy that uses only 1 mM of 4-bromobenzenediazonium tetrafluoroborate (BDTF) to in situ construct a Zn2+-favored molecular lock on the ZnF2-rich SEI surface. Electrochemically generated p-bromoaniline becomes molecularly woven into the inorganic layer, forming an ultrathin molecular-lock shell (∼1 nm) atop a graded hybrid SEI. Through N–Zn coordination coupled with Br-induced interfacial polarization, the molecular lock reorganizes the local electrostatic environment, stabilizes ZnF2, limits water access, and promotes desolvation-facilitated Zn2+ transport. As a result, the programmed SEI enables highly reversible Zn plating/stripping with a 99.8% average Coulombic efficiency, and stable cycling under 80% depth of discharge at 10 mA cm−2. Moreover, it displays broad cathode compatibility, extending cycling stability in vanadium-, manganese-, and iodine-based full cells. In Ah-level pouch cells with ultrahigh vanadium-based cathode loading (21 mg cm−2), the system delivers 1.2 Ah with 81% retention after 100 cycles, surpassing state-of-the-art aqueous Zn batteries that typically fail at high mass loading.