Weakly Coordinated Solvent Network-Induced Ternary Water-Deficient Eutectic Electrolytes for Low-Polarization Zn Anodes.

Eutectic electrolytes are attractive for zinc-based energy storage owing to their green chemistry attributes and intrinsic stability; however, their practical deployment is limited by severe polarization stemming from sluggish ion transport and strong solvation. Here, we propose a ternary water-deficient eutectic electrolyte without water solvent whose polarization approaches that of aqueous systems by engineering a weakly coordinated solvent network via solvation-structure restructuring. A strongly coordinated solvent network enables salt dissolution, whereas the introduction of a weakly coordinating co-solvent disrupts the constrained coordination environment and drives a transition to a dynamic, weakly coordinated solvation structure. This restructuring enhances anion participation while suppressing ion bridging, yielding abundant yet size-confined aggregates, thereby accelerating ion-transport kinetics and lowering desolvation barriers. Furthermore, the formation of a robust solid-electrolyte interphase effectively stabilizes the Zn anode. As a result, the ternary water-deficient electrolyte enables highly reversible Zn plating/stripping with low polarization under ambient conditions, while also delivering excellent low-temperature performance. Enhanced kinetics in Zn||PANI cells and consistent performance across both coin cells and printed energy devices highlight the strong potential of this water-deficient eutectic electrolyte for scalable zinc-ion energy storage.