As mentioned, both the local critical current density and plating diameter depend strongly on the annealing temperature. Among the annealing conditions, Ag + -LLZO annealed at 300 °C exhibit the largest plating diameter at failure (Figure ). For example, Ag + -LLZO annealed at 400 °C shows a substantial decrease in both plating diameter and critical current density compared to those annealed at 300 ºC. This is likely due to surface lithium loss at elevated temperatures which could induce tensile stress to the LLZO surface. Alternatively, the higher temperature may facilitate deeper silver diffusion, resulting in a lower concentration of Ag + near the surface.