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

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.