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

Abstract

A method to create a garnet-based solid electrolyte separator for a battery cell is provided. The method includes 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. The method further includes 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. The solid-state reaction creates a fluoride-treated and solid-state reacted garnet-based material powder including the aluminum oxide and the lithium fluoride. The method further includes sintering the fluoride-treated and solid-state reacted garnet-based material powder including the aluminum oxide and the lithium fluoride. The sintering includes applying pressure upon the fluoride-treated and solid-state reacted garnet-based material powder to densify the powder and create the separator.