Conformation-Induced Ion Transport "Channels" in Artificial Polymer Solid Electrolyte Interphase for Aqueous Zn-Metal Batteries.

Artificial polymer solid electrolyte interphases (SEIs) are crucial for inhibiting side reactions and regulating Zn flux in aqueous Zn-metal batteries, where tuning the affinities and bond types between Zn and functional groups is considered the most effective strategy. However, the underlying determinant-polymer conformation control-is often overlooked. In this work, it is discovered that a high exposure degree of zincophilic sites is the prerequisite for establishing interaction. Due to the extraction effect of highly hydrophilic SO , the copolymer chain becomes more extended, and imidazole groups hidden within the conformation core are exposed and interact with Zn. Ion transport "channels" are thus constructed and characterized by dynamic light scattering, atomic force microscopy, and molecular dynamics simulation. The resultant copolymer (poly(1-vinylimidazole-co-sodium 4-styrenesulfonate, P(Im-SS)) SEI leverages the advantages of both functional groups, exhibiting fast charge transfer kinetics and regulated diffusion behavior. In situ and post-mortem characterizations reveal that side reactions, surface passivation, and dendrite formation are attenuated. Using P(Im-SS) SEI, long-term cycling of 2800 h for Zn/Zn cell and 3000 cycles with 99.7 % average coulombic efficiency for Zn/Cu cell are achieved. P(Im-SS)@Zn/NaVO·1.5HO full cells exhibited prolonged cycle lifetime and delivered a high areal capacity of ≈2 mAh cm at 5.7 mA cm.