Synergistic regulation of de-solvation effect and planar deposition via in-situ interface engineering for ultra-stable dendrite-free Zn-ion batteries

Advanced interfacial engineering is essential to address key challenges such as dendrite formation, parasitic reactions, and sluggish electrochemical kinetics, in aqueous zinc-ion batteries. In this study, by using a facile self-assembly method, we developed an armor-like interfacial layer (ZSL) on the Zn surface, serving as both an ion re-distributor and a protective barrier. This compact interfacial layer exhibits suitable hydrophilic and zincophilic features, enabling consistent and uniform Zn 2+ flux and reducing voltage polarization. The ZSL also enhances the de-solvation process, speeds up zinc deposition kinetics, and suppresses parasitic reactions induced by water decomposition. Furthermore, it decreases the surface energy, promoting planar deposition of Zn 2+ . As a result, the modified zinc anodes demonstrate exceptional cycling stability, maintaining a dendrite-free surface for more than 8000 h with minimal byproduct formation. The asymmetric cell utilizing ZSL@Zn anodes exhibits highly stable reversibility over 6000 cycles with an average Coulombic efficiency (CE) of 99.89%. In full cells paired with Na 2 V 6 O 16 ·3H 2 O (NVO) cathodes, the Zn-ion batteries exhibit excellent rate performance and long-term cycling durability. This work highlights the significant role of in-situ interfacial layers in achieving highly stable and reversible zinc anodes for large-scale zinc-ion battery applications.