Vitreous solid electrolyte sheets of Li ion conducting sulfur-based glass and associated structures, cells and methods

A standalone positive electrode assembly, comprising:

• a positive electroactive component layer and a first solid electrolyte sheet,
• wherein the positive electroactive component layer is encapsulated on a first major surface by the solid electrolyte sheet;
• and,
• further wherein the solid electrolyte sheet comprises freestanding substantially amorphous solid electrolyte wall structures that are dense, inorganic and conductive of Li ions, the wall structures comprising:
• i) a continuous Li ion conducting inorganic amorphous material phase with room temperature Li ion conductivity ≥10−5 S/cm;
• ii) first and second opposing principal sides and associated surfaces;
• and
• ii) a microstructure devoid of contiguous crystalline grain boundaries and powder particle boundaries extending between the opposing principal side surfaces.