Dynamic Protective Multi‐Layers for MnO2 Cathodes: Ion Sorting and Structural Protection for Superior Zinc‐Ion Battery Cycling Performance

Abstract Aqueous zinc metal batteries (AZMBs) are characterized by high safety, low cost, and eco‐friendliness, among which manganese‐based cathodes stand out due to their abundance and high theoretical capacity. However, failure behaviors such as lattice collapse, Mn dissolution, and sluggish kinetics hinder their application. Herein, a dynamic multi‐protective interface has been designed through a simple one‐step manufacturing process, emulating the structural and functional attributes of biological membranes and cell walls. It comprises three distinct layers: an outer high‐valent oxide layer that enhances chemical stability and selectively facilitates proton intercalation while governing the intercalation of Zn 2+ ; a middle low‐valent oxide and metal composite layer, which functions as a buffer to selectively adsorb Mn 2+ , thereby inhibiting Mn dissolution and augmenting the chemical stability of the cathode; and an inner heterojunction layer, which boosts conductivity and alleviates Jahn–Teller distortion through lattice distortion and entropy‐mediated electronic delocalization. The surface modified cathode exhibits outstanding stability, with nearly zero capacity decay observed over 300 cycles at a low current density of 0.4 A g −1 , and 15 000 cycles under a high current of 10 A g −1 . With significantly enhanced cycling stability, rate capability, and electrochemical reversibility, this strategy presents a promising solution for high‐performance MnO 2 ‐based cathodes in AZMBs.