A hybrid electrolyte comprises: (i) a first electrolyte having a first surface and an opposed second surface, wherein the first electrolyte comprises a solid state electrolyte material comprising an oxide, wherein the first surface is an acid-treated surface; and (ii) a second electrolyte comprising a liquid electrolyte, wherein the liquid electrolyte comprises an alkali metal salt and a solvent selected from the group consisting of electron pair donor solvents, and solvent mixtures including at least one electron pair donor solvent and at least one glyme solvent. The oxide can be a doped or undoped LLZO electrolyte material, and the acid can be selected from H3PO4 and HCl.