Solvent effect on the adsorption of lithium polysulfides on single-atom Ni on N-doped graphene: a first-principles study

Abstract

We study the effect of solvent (dimethyl ether [DME] and 1,3-dioxolane [DOL]) on the adsorption of lithium polysulfides (Li2S4, Li2S6, and Li2S8) on single-atom Ni anchored on N-doped graphene by using density functional theory (DFT). All DFT calculations were carried out using Quantum ESPRESSO software. We found that lithium polysulfides (LiPSs) have relatively higher binding energy when they interact with DME solvent due to weaker overlapping between Li 2p and O 2p states. The binding energy difference of LiPSs ranges from 22-54 meV. In both solvents, the oxygen atom in the solvent interacts with the lithium atom in the LiPSs, thus weakening the bond between LiPSs and the catalysts. This research can better understand the sulfur reduction reaction for lithium-sulfur batteries applications.