Cushion‐Maskant‐Regulated Interfacial Chemistry Enables Durable Zinc Metal Anodes

Aqueous electrolytes, while conferring inherent safety advantages, inevitably induce hydrogen‐evolution corrosion, resulting in nonuniform Zn deposition and shortened cycle life. Herein, a novel electrolyte with buffering function is designed to modulate ion behavior and stabilize interface pH. The introduced additive acts as a cushion maskant (CM) that spontaneously adsorbs onto the Zn metal surface, displacing interfacial water molecules and thereby suppressing corrosion. Simultaneously, its coordination with Zn 2+ homogenizes the Zn 2+ flux to promote uniform deposition. Moreover, the protonation/deprotonation equilibria of CM within the electrolyte buffer local pH fluctuations, stabilizing the interfacial microenvironment. Consequently, a beneficial solid electrolyte interphase (SEI) is established, which further shields the Zn anode, enhances interfacial stability, and markedly improves cycling durability. Accordingly, Zn//Zn symmetrical cells in CM‐containing electrolyte can realize exceptional lifespan for 2800 h at 2 mA cm −2 and 970 h even at 10 mA cm −2 . In addition, CM demonstrates the superior practical applicability in Zn//I 2 full cells for long‐term and rate tests. Zn//I 2 pouch full cell can operate for 150 mAh with CM. This study offers a distinctive and comprehensive strategy for stabilizing the Zn anode.