Synergistic chaotropic effect and defect engineering promoting ultrahigh ionic conductivity in MOFs

Abstract

The development of aqueous electrolytes exhibiting high ionic conductivities through solvent-free methods is of great significance for the progress of aqueous battery technology. This study presents a high-performance ionic conductor engineered through a synergistic chaotropic effect and defective structure using a solvent-free approach. The combination of localized acidification at vacancy sites and doping chaotropic LiI enhances ionic diffusion in D-UiO-66-LiI. The generated cationic substructure promotes ion confinement effects within the D-UiO-66-LiI pores, establishing efficient conduction pathways. Furthermore, temperature-dependent analysis reveals that thermal energy increases ion movement and weakens the hydration of Li⁺ ions, not only increasing ion mobility but also maintaining the water networks through dynamic hydrogen bonding reconstruction. These coordinated effects enable D-UiO-66-LiI to achieve ultrahigh ionic conductivities across wide temperature and humidity ranges.