For completeness, we also examined the local critical current density of LLZO with metallic Ag coating, obtained without thermal annealing. Although Ag 0 |LLZO shows comparable mean plating area to the Ag + -LLZO surface due to the high electronic conductivity of metallic Ag (effectively expanding the probe contact area), both the mean critical local current density and the total amount of plated Li are significantly decreased (Figure ). We note that the primary factor hindering the uniform plating of Li over the entire surface of Ag 0 |LLZO is the high sheet resistance of the thin 3-nm Ag coating.