MODIFIED SOLID-STATE ELECTROLYTE FOR LI METAL SOLID-STATE BATTERIES

According to one or more embodiments, a solid-state battery includes a cathode; an anode including lithium metal; and an inorganic ceramic polycrystalline separator between the cathode and anode. The separator includes grains of an ionically conductive bulk phase and grain boundaries defined between the grains, with the grain boundaries including an oxidizing agent. The oxidizing agent is configured to oxidize the lithium metal, brought into contact with the oxidizing agent via lithium metal nucleation at or dendritic growth along the grain boundaries that results from plating of the lithium metal on the anode, to form an electronically insulating phase to prevent formation of electronic conduction pathways along the grain boundaries. The oxidizing agent is further configured to partially reduce, upon oxidation of the lithium metal, to form an ionically conductive phase to facilitate ionic conduction along the grain boundaries.