Molecular Polarity Attenuation Tailors Weak Solvation Structure with Accelerated Kinetics and Robust SEI for High-Areal-Capacity Large-Format Pouch Zn-Based Batteries

Large-format, high-areal-capacity aqueous Zn-ion batteries are pivotal for practical energy storage but remain hindered by sluggish kinetics, heterogeneous local reactions, and drastic interfacial deformation. In this work, a molecular polarity-weakening strategy of electrolyte additive is proposed to customize a rapid-reaction-kinetics solvation structure and a hybrid solid-electrolyte interphase (SEI) for Zn metal pouch batteries. Leveraging this synergistic solvation-SEI regulation, a 25 cm² Zn||Zn pouch symmetric cell achieves unprecedent 352 h stable cycling at 40 mAh cm⁻² (DOD = 68%, 10 mA cm⁻²). More importantly, a 100 cm² Zn||I₂ pouch full battery delivers a high areal capacity of 9.8 mAh cm⁻² and sustains nearly 400 h of stable cycling.