Hierarchically Structured Artificial SEI with Interlayer Electronic Coupling for High-Performance Aqueous Zinc...

Aqueous zinc-ion batteries (AZIBs) are considered promising candidates for large-scale energy storage owing to their intrinsic safety and low cost. However, challenges such as dendrite growth, parasitic reactions, and unstable interfaces severely limit their performance. Herein, we reported a multifunctional artificial SEI layer with an engineered armored petalosphere heterostructure (ZnO@MX-DE), constructed via a multi-step strategy involving ZIF-8 templating, MXene coating, ZnO converting, and dickite nanosheet compositing. This heterostructure induced significant interfacial electron reconstruction, wherein electrons migrated from Zn/Ti centers to oxygen-rich dickite nanosheet, effectively adsorbing Zn²⁺ and repelling SO₄ ^2-. The resultant SEI layer exhibited ultrahigh ionic conductivity (20.26 mS cm^-1) and Zn²⁺ transference number (0.89), enabling Zn//Zn cells to stably cycle over 4000 h. Remarkably, the Zn//MnO₂ full cell delivered 77.10% capacity retention after 700 cycles at 300 mA g^-1 and achieved 40 000 cycles at 30 A g^-1. This work offers a rational interfacial engineering strategy integrating morphological design and electronic tuning, promoting the development of high-performance AZIBs.