TNO Heterostructure as Multifunctional Regulating Interfacial Layers for Stable Zinc-Ion Batteries

Aqueous zinc-ion batteries (ZIBs) are promising candidates for large-scale energy storage. However, their practical application is severely hindered by Zn anode instability caused by water-induced side reactions and dendritic growth. Herein, a multifunctional TiN─TiO₂ (TNO) heterostructure is constructed on the Zn anode, effectively suppressing parasitic side reactions and regulating Zn deposition behavior to achieve dendrite-free anodes. Combined experimental characterizations and density functional theory (DFT) calculations reveal that the TNO layer modulates the local coordination environment of hydrated Zn²⁺ at the electrode-electrolyte interface, accelerating interfacial desolvation kinetics and inhibiting the hydrogen evolution reaction. Simultaneously, its strong chemical affinity toward the Zn (002) plane guides horizontal, dense, and highly textured Zn deposition. As a result, the TNO-coated Zn anode (TNO@Zn) exhibits outstanding electrochemical stability, enabling stable cycling for over 3000 h at 1 mA cm^-2 and 1.0 mAh cm^-2. Moreover, TNO@Zn//NH₄V₄O₁₀ cell retains a high specific capacity of 152 mAh g^-1 after 4000 cycles. The work provides mechanistic insights into interfacial heterostructure engineering and presents a viable strategy for the development of durable aqueous Zn metal batteries.