Role of a Solid-Electrolyte Interphase in the Dendritic Electrodeposition of Lithium: A Brownian Dynamics Simulation Study

A robust, flexible, and uniform layer of solid-electrolyte interphase (SEI) is known to regulate the dendritic growth of a lithium metal anode during electrodeposition. The underlying mechanism and extent of such regulation are largely unknown. The present Brownian dynamics simulation elucidates the suppressive role of a SEI layer in the dendritic electrodeposition. By thinning out a SEI layer to a subnanometer scale, a dendrite with long arms becomes dense and mossy, and it grows much slower in time. The radial diffusion of lithium ions through a thin SEI layer gives an isotropic growth of a round tip, instead of a dendritic ramification along a particular direction.