Ion-Coordination-Active UiO-66-SO₃H Coating Stabilizes Zn Metal Anodes via Sulfonate-Directed Zn²⁺ Desolvation

Aqueous zinc batteries are limited by dendrite growth and parasitic interfacial reactions that accelerate polarization and trigger early failure of Zn metal anodes. Here, a chemically active artificial interphase is engineered by coating Zn foil with a sulfonated Zr-based metal-organic framework (UiO-66-SO₃H) using PVDF as a binder, converting a conventional surface coating into an ion-coordination-active interface in a 2 M ZnSO₄ electrolyte. In situ Raman spectroscopy indicates that the sulfonate-oxygen coordination sites transiently interact with Zn²⁺ and promote partial desolvation, while density functional theory (DFT) calculations show more favorable Zn²⁺ adsorption at sulfonate sites than on pristine UiO-66. These coupled effects reduce the nucleation overpotential to 31.1 mV and decrease charge-transfer resistance, enabling more uniform Zn plating/stripping as verified by operando optical microscopy and X-ray tomography. As a result, symmetric Zn||Zn cells cycle stably for >1000 h at 0.5 mA cm^-2 (0.5 mAh cm^-2) and >800 h at 3 mA cm^-2 (3 mAh cm^-2), and Zn||Cu cells deliver an average Coulombic efficiency of ∼99.6% over >500 cycles. Full cells paired with a NaVO cathode retain >1000 cycles at 6C with improved stability. This work establishes sulfonate-directed Zn²⁺ coordination and interfacial desolvation within robust UiO-66 scaffolds as a practical strategy to extend the lifetime of aqueous Zn metal anodes.