Class of Solid-like Electrolytes for Rechargeable Batteries Based on Metal–Organic Frameworks Infiltrated with Liquid Electrolytes

A new family of solid-like electrolytes was developed by infiltrating MIL-100(Al), an electrochemically stable metal–organic-framework (MOF) material, with liquid electrolytes that contain cations from the 3rd period (Na +, Mg 2+, and Al 3+ ) and the 1st group (Li +, Na +, K +, and Cs + ). The anions were immobilized within the MOF scaffolds upon complexing with the open metal sites, allowing effective transport of the cations in the nanoporous channels with high conductivity (up to 1 mS cm –1 ) and low activation energy (down to 0.2 eV). This general approach enables the fabrication of superior conductive solid-like electrolytes beyond lithium ions.