Multidentate Coordination Enables Coupled Bulk Solvation and Interfacial Regulation for Stable Zinc Metal Anodes

ABSTRACT

Aqueous Zn metal batteries are fundamentally constrained by the coupled instability of Zn ²⁺ solvation chemistry and interfacial reactions, which induces parasitic side reactions and non‐uniform Zn deposition. Here, we report a multidentate‐coordination electrolyte strategy using N‐acetylneuraminic acid (NANA) as a multifunctional additive to regulate bulk solvation and interfacial deposition behavior in ZnSO ₄ electrolyte. In the bulk electrolyte, NANA participates in the Zn ²⁺ solvation sheath through cooperative interactions among carboxyl, hydroxyl, and acetamide groups, weakens sulfate‐involved contact ion pairing, and reconstructs a more relaxed mixed‐solvation environment. At the interface, NANA shows strong affinity to Zn and promotes the formation of an organic‐rich interfacial layer, which suppresses parasitic reactions and homogenizes Zn ²⁺ flux during deposition. As a result, Zn deposition evolves toward denser and more Zn(002)‐textured growth with reduced surface roughening and by‐product accumulation. Consequently, Zn||Zn symmetric cells operate stably for 7700 h at 0.5 mA cm ⁻² /0.5 mAh cm ⁻² and 1250 h at 10 mA cm ⁻² /10 mAh cm ⁻² , while Zn||Cu cells deliver 8700 cycles with an average coulombic efficiency of 99.88%. The concept is further validated in Zn||MnO ₂ full cells and pouch‐type devices. This work provides an effective coordination‐based electrolyte strategy for durable aqueous metal batteries.