Stability of the solid electrolyte Li3OBr to common battery solvents

Recently a new class of solid lithium ion conductors was reported based on the anti-perovskite structure, notably Li3OCl and Li3OBr. For many beyond lithium-ion battery uses, the solid electrolyte is envisioned to be in direct contact with liquid electrolytes and lithium metal. In this study we evaluated the stability of the Li3OBr phase against common battery solvents electrolytes, including diethylcarbonate (DEC) and dimethylcarbonate (DMC), as well as a LiPF6 containing commercial electrolyte. In contact with battery-grade organic solvents, Li3OBr was typically found to be insoluble but lost its crystallinity and reacted with available protons and in some cases with the solvent. A low temperature heat treatment was able to restore crystallinity of the samples; however evidence of proton ion exchange was conserved.