A Hydrophobic and Zincophilic Interfacial Nanofilm as a Protective Layer for Stable Zn Anodes

Abstract The Zn metal anode has emerged as a promising contender for aqueous batteries. However, challenges such as H₂ evolution and Zn dendrite formation have hindered the attainment of satisfactory cycling longevity. In this context, a hydrophobic and zincophilic interfacial nanofilm (HZF) is successfully developed and demonstrated as a protective layer for stabilizing Zn anodes. The HZF nanofilm, characterized by its uniformly distributed zincophilic groups, actively participates in the interfacial solvated structure of Zn²⁺ ions, thereby modulating the uniform deposition of Zn²⁺ flux onto Zn anodes and curtailing the deprotonation of solvated water molecules. Concurrently, the exposed hydrophobic surfactant within the nanofilm effectively acts as a barrier, preventing direct contact between water and the Zn anode. As a result, the Zn anode coated with the HZF nanofilm achieves stable and reversible Zn plating/stripping behavior. This is evidenced by the extended cycling lifespan of over 300 h at a discharge capacity of 10 mAh cm⁻², with a deep discharge of 67% Zn utilization.