An analogous periodic law for strong anchoring of polysulfides on polar hosts in lithium sulfur batteries: S- or Li-binding on first-row transition-metal sulfides?

Lithium-sulfur (Li-S) batteries are strongly considered for next-generation energy storage devices. However, severe issues such as the shuttle of polysulfides restrict their practical applications. Exploring the design principle of anchoring polysulfides physically and chemically through the polar substrate is therefore highly necessary. In this Letter, first-row transition-metal sulfides (TMSs) are selected as the model system to obtain a general principle for the rational design of a sulfur cathode. The strong Sbinding that is induced by charge transfer between transition-metal atoms in TMS slabs and S atoms in Li₂S is confirmed to be of great significance in TMS composite cathodes. An analogous periodic law is proposed, which is also extended to first-row TM oxides. VS has the strongest anchoring effects on Li₂S immobilization and a relatively low lithium ion diffusion barrier. The binding energies and Li diffusion properties are considered as the key descriptors for the rational design of sulfur cathodes.