Surface/Interface Structure and Chemistry of Lithium–Sulfur Batteries: From Density Functional Theory Calculations’ Perspective

Abstract

Nowadays, the rapid development of portable electronic products and low‐emission electric vehicles is putting forward higher requirements for energy‐storage systems. Lithium–sulfur (Li–S) batteries with an ultrahigh energy density (2500 Wh kg−1) are considered the most promising candidates for next‐generation rechargeable batteries. However, the low conductivity of sulfur, the shuttle effect of lithium polysulfide (LPS), and inadequate safety caused by lithium dendrite formation limit their practical applications. In the research of Li–S batteries, it is observed that the surface/interface structure and chemistry of sulfur host materials play significant roles in the performance of Li–S batteries. The reason is that the adsorption/conversion of LPS mainly occurs on the surface/interface of host materials. The functional hosts are used to prevent the polysulfide shuttle or catalyze Li–S conversion reactions (enhance the reaction kinetics), and density functional theory (DFT) is used to understand the mechanism of the interaction between host and polysulfides. Herein, the surface/interface structure and chemistry of sulfur host materials involving structural factors and adsorption/conversion mechanisms of LPS (based on DFT calculation) on the interface are demonstrated. Finally, the remaining challenges, such as the fundamental studies and commercialized applications, as well as the future research directions are discussed.