Two-dimensional host materials for lithium-sulfur batteries: A review and perspective

Rechargeable lithium-sulfur (Li–S) batteries are considered as promising candidates for next-generation energy storage devices due to their high capacity and high energy density. However, their large-scale practical applications suffer from a series of challenges, such as the insulating nature of sulfur, the shuttle effect of soluble lithium polysulfides (LiPSs), and the volume expansion upon lithiation. Numerous research work proved that modification of the cathodes with host materials is efficient for alleviating these issues. Two-dimensional (2D) materials have recently emerged as a candidate of choice for the sulfur host materials. Herein, a comprehensive review of the recent advances in 2D sulfur host materials is presented, including the mechanism of Li–S batteries and the basic requirement for hosts. Furthermore, different types of 2D hosts are summarized and discussed in detail. Finally, an outlook of possible research directions, challenges, and perspectives are presented. This review paves the way for the rational design of 2D host materials for Li-S battery applications.