Metal-organic frameworks as solid magnesium electrolytesElectronic supplementary information (ESI) available: detailed synthesis or all materials discussed, description of experimental techniques including Langmuir surface area determination, 1H-NMR, elemental analysis, impedance analysis, variable temperature conductivity measurements, powder diffraction and thermogravimetric analysis. See DOI: 10.1039/c3ee43143f

A series of solid magnesium electrolytes were synthesized via the transmetallation of magnesium phenolates to coordinatively unsaturated metal sites lining the pores of the metal-organic frameworks Mg 2 (2,5-dioxidobenzene-1,4-dicarboxylate) and Mg 2 (4,4′-dioxidobiphenyl-3,3′-dicarboxylate). The resulting materials represent a new class of solid magnesium electrolytes that are both crystalline, and exhibit room-temperature ionic conductivities up to 0.25 mS cm −1 . The materials reported herein are one-hundred times more conductive at room temperature than any other solid magnesium electrolyte and represent the only class of materials sufficiently conductive for practical consideration in magnesium batteries. By post-synthetic modification of a metal-organic framework, solid magnesium electrolytes have been prepared with room temperature ionic conductivities over one-hundred times greater than any previously reported rigid material.