Bottom-up dense zinc electrodeposition mediated by hydrophobic redox-active coating for ultralong-life aqueous Zn-metal batteries

Uncontrolled dendrite growth and severe interfacial side reactions continue to hinder the practical deployment of Zn metal anodes in aqueous batteries. Herein, we design a multifunctional hydrophobic interfacial coating composed of 2,4,5-trifluorophenylacetate and polyvinylidene fluoride to significantly improve the cycling stability and reversibility of Zn anodes. This redox-active coating promotes uniform Zn deposition by homogenizing the electron and Zn 2+ ions distribution through preferential and reversible redox reactions. Simultaneously, the coating releases Y 3+ ions via ion exchange, which electrostatically shield surface protrusions, guiding Zn 2+ transport for bottom-up deposition beneath the insulating film. The hydrophobic nature of the coating also accelerates Zn 2+ desolvation and mechanically suppresses dendrite growth, collectively enabling dense and stable Zn plating. As a result, the optimized PY150@Zn anode achieves over 4100 h of stable cycling at 1.0 mA cm −2 with a specific capacity of 1.0 mAh cm −2 . This coating also improves full-cell performance in Zn‖V 2 O 5 batteries by mitigating anode corrosion. The proposed “three-in-one” strategy—regulating ion flux, enhancing desolvation, and suppressing dendrite formation—offers a generalizable pathway toward high-performance aqueous metal batteries.