MULTI-PHASE ELECTROLYTE FILM AND METHOD OF MAKING THE SAME

A multi-phase electrolyte film includes a first phase comprising a metal oxide, wherein the metal oxide is amorphous, crystalline, or a glass; and a second phase comprising a lithium salt having a decomposition temperature in air of greater than 200° C. or a lithium halide. The first phase is dispersed in the second phase and has an average particle size of 5 to 200 nanometers. Methods for the manufacture of the electrolyte film are also disclosed.