Dopant-Modulating Mechanism of Lithium Adsorption and Diffusion at the Graphene/Li2S Interface

Abstract

Modifying graphene is important for exploiting sulfides as excellent electrode materials in high-capacity Li-ion and Li-S batteries, but a physical, mechanistic picture is needed to interpret the enhancement of electrochemical properties induced by different dopants. The authors find Li storage with intercalation character in the Li${}_{2}$S---doped graphene system, and reveal two mechanisms to enhance interfacial lithium adsorption and diffusion, plus the synergistic effect of codoping. These calculations give a theoretical basis for materials engineering using doped graphene for advanced energy storage.