A Goldilocks‐Inspired Amphiphilic Additive Orchestrates Interfacial Microenvironment Homeostasis for Stable 1.2 Ah Zinc Pouch Cells

ABSTRACT Multifunctional additives addressing zinc anode interfac ial instability face inherent trade‐offs among surface adsorption, solvation control, and pH buffering. Inspired by the “Goldilocks effect” of the clinical antihypertensive drug lisinopril (LNPL), we propose a biomimetic amphiphilic electrolyte additive strategy to achieve interfacial microenvironment homeostasis. Systematic investigations reveal that long‐term zinc stability is governed by a homeostatic balance among multiple competing interfacial regulatory processes, rather than maximizing each individual function independently. At the homeostatic equilibrium achieved with 1 mM, LNPL preferentially adsorbs on the zinc surface to suppress contact with H 2 O and SO 4 2− , adaptively buffers local pH fluctuations through reversible proton exchange, and simultaneously modulates the Zn 2+ solvation environment by reducing coordinated water. Furthermore, LNPL induces a ZnO/ZnS/organic‐rich hybrid SEI that suppresses side reactions, homogenizes Zn 2+ flux, and inhibits dendrite growth. Consequently, the Zn||Zn cell exhibits stable cycling for over 6600 h, and the Zn||Cu cell achieves an average coulombic efficiency of 99.85% over 3000 cycles. Meanwhile, the Zn||I 2 full cell achieves over 20 000 cycles with 98.3% capacity retention, while the pouch cell delivers 1.2 Ah with 84.6% retention after 200 cycles. This work establishes a Goldilocks‐inspired design principle for multifunctional electrolyte additives in aqueous metal batteries.