Synergetic Molecular Engineering to Reconcile Self‐Assembled Monolayers for Dendrite‐Free Zinc‐Ion Batteries

ABSTRACT The deployment of aqueous zinc‐ion batteries remains severely hindered by the thermodynamic and kinetic instabilities at the zinc anode/electrolyte interface, fundamentally manifested as uncontrolled dendritic growth and chemical corrosion. Self‐assembled monolayers (SAMs) have emerged as a promising interfacial modification technique to mitigate these issues. However, a universal theory guiding the design of SAMs remains absent. In this study, we propose an exclusive molecular engineering strategy to construct a SAM for zinc electrodes, based on the interaction (zincophilicity) between the zinc ions and the functional groups of molecules. Optimal SAM molecules feature a strong‐zincophilicity head and a weak‐zincophilicity tail, helping capture and transfer Zn 2+ ions from the electrolyte to the substrate. A representative molecule of β‐mercaptoethanol has been designated to construct SAMs, reconstructing the double layer on the Zn surface and promoting the uniform nucleation of Zn 2+ . This monolayer enables uniform Zn deposition for over 3000 h at a current density of 4 mA cm −2 , and maintains an average Coulombic efficiency of ∼99.82% for 6200 cycles at 5 mA cm −2 , In addition, this monolayer also enables Zn||I 2 cells to retain 90.7% of the capacity over 6000 cycles at 0.5 A g −1 , thus highlighting its great potential in aqueous metal anodes.