Method to improve ionic conductivity of a solid electrolyte in a battery cell

A method to create a solid electrolyte separator for a battery cell, the method comprising:

• creating the solid electrolyte separator, including:
• coating an LLZO powder, initially including a lithium carbonate layer upon an outer surface of the LLZO powder, with aluminum fluoride to create a fluoride-treated LLZO powder;
• operating a solid-state reaction upon the fluoride-treated LLZO powder, such that the aluminum fluoride reacts with the lithium carbonate layer to create aluminum oxide, carbon dioxide, and lithium fluoride, wherein the solid-state reaction creates a fluoride-treated and solid-state reacted LLZO powder including the aluminum oxide and the lithium fluoride;
• and
• sintering the fluoride-treated and solid-state reacted LLZO powder including the aluminum oxide and the lithium fluoride, wherein the sintering includes applying pressure upon the fluoride-treated and solid-state reacted LLZO powder to densify the fluoride-treated and solid-state reacted LLZO powder and create the solid electrolyte separator;
• and
• creating the battery cell including:
• disposing an anode and a cathode within an external case;
• and
• disposing the solid electrolyte separator between and in contact with the anode and the cathode;
• and
• wherein the aluminum oxide acts as a dopant to stabilize the LLZO powder in a cubic phase.

A solid electrolyte separator for use in a battery cell, comprising:

• the solid electrolyte separator created by:
• coating a garnet-based material powder, initially including a lithium carbonate layer upon an outer surface of the garnet-based material powder, with aluminum fluoride to create a fluoride-treated garnet-based material powder;
• operating a solid-state reaction upon the fluoride-treated garnet-based material powder, such that the aluminum fluoride reacts with the lithium carbonate layer to create aluminum oxide, carbon dioxide, and lithium fluoride, wherein the solid-state reaction creates a fluoride-treated and solid-state reacted garnet-based material powder including the aluminum oxide and the lithium fluoride;
• and
• sintering the fluoride-treated and solid-state reacted garnet-based material powder including the aluminum oxide and the lithium fluoride, wherein the sintering includes applying pressure upon the fluoride-treated and solid-state reacted garnet-based material powder to densify the fluoride-treated and solid-state reacted garnet-based material powder and create the solid electrolyte separator.