Engineering Robust Hydrophilic–Hydrophobic Interface via π‐electron Delocalization for Ultralong‐Lived Zinc–Ion Batteries

Abstract Aqueous zinc ion batteries (AZIBs) are hindered by the severe interfacial issues of Zn anode such as side reactions and dendrite growth. The in‐situ construction of robust interface to tackle above issues remains a grand challenge and lacks rational design principles, especially under high current density. Herein, a π‐electron delocalization strategy is proposed to in‐situ construct the self‐assembled hydrophilic–hydrophobic interface layer (HHIL) for ultralong‐lived AZIBs, where interface design principles are built based on the electronic structure and spatial configuration of additives. Encouragingly, HHIL derived by π‐π interactions and ion–dipole interactions is robust during long‐term cycling and facilitates the generation of an inorganic‐rich interface chemistry. The flexible HHIL and rigid inorganic‐rich interface afford the rapid interface kinetics, and effectively suppresses side reactions and dendrite growth. Notably, Zn//Zn cells deliver the cycling life over 900 h at 20 mA cm −2 and 10 mAh cm −2 , and Zn//NVO full cells stably perform over 25 000 cycles at 10 A g −1 . Furthermore, the practical pouch cell is also demonstrated.