Communication—Characterization of LiAlCl₄·xSO₂Inorganic Liquid Li⁺Electrolyte

Abstract

The solvation of gaseous SO2 into LiAlCl4 was shown in 1988 to provide a liquid inorganic electrolyte with a remarkably high Li+ conductivity at 25°C that showed promise for a low-temperature rechargeable battery. We report a characterization of this inorganic liquid electrolyte that shows fast Li+ conductivity coexists with SO2 electric dipoles, but the SO2 solvate is reduced at voltages below 3.3 V and Cl2 gas is evolved from the LiAlCl4 conducting salt above 4.0 V. Nevertheless, the concept of synthesizing amorphous-ceramic or inorganic-liquid electrolytes that contain electronic dipoles and have a large electronic energy gap, appears to represent a potentially useful avenue of synthetic research.