A solid electrolyte for a negative electrode of a secondary battery includes a first solid electrolyte having a first surface and a second solid electrolyte on the first solid electrolyte and having a second surface. The first solid electrolyte and the second solid electrolyte each have an ionic conductivity effective for a deposition metal, and the first surface and the second surface are different in composition, structure, or both. An electrode assembly and an electrochemical cell including the solid electrolyte and method for the manufacture thereof are also described.