Fig. 4: The evolution mechanism of plated lithium morphology.

a Phase field modeling of different states during lithium plating and relaxation, the white bar in each subplot represents 1 μm length. In the Li metal morphology diagrams, the pure red areas represent the Li metal regions, the pure blue areas represent the electrolyte regions, and the intermediate zone is the transition zone of the phase field variable. The arrows represent the electric field direction and Li⁺ transport direction, respectively. b Schematic diagram of the morphology flattening due to the electric field relaxation during resting.