Fig. 1. Importance of the surface state in controlling the morphology of Li deposit.

Schematic illustration of the nucleation and growth steps of a, the pristine and b, naked Li metal foils. The red and blue shading represents the existence of the native oxide film and electrolyte-based SEI, respectively. The green arrows signify the dominant direction for electrodeposition: out-of-plane and in-plane directional growth for the pristine and naked Li foils, respectively.