ABSTRACT Ideal separators for rechargeable lithium–sulfur (Li–S) batteries should facilitate Faradaic reactions near the electrode surface while mitigating the shuttle effect. However, conventional separator materials often exhibit sluggish Li + migration rates and reaction kinetics due to their high Li + desolvation energy and diffusion resistance. Investigating the Li + transport mechanism within separators and elucidating Li + desolvation process remains a significant challenge. Herein, we systematically elucidated the desolvation capability of Metal–organic frameworks (MOF) channels in Li + diffusion process by MOF pore engineering. It is concluded that negative charge sites weaken the interaction between Li + and solvent molecules, and smaller pore sizes reduce the distance between Li‐solvent complexes and negatively charged sites, which further improve the desolvation of Li + . The desolvated Li + subsequently participates rapidly in the polysulfide conversion process, thereby enhancing sulfur redox kinetics and keeping the concentration of polysulfides in the electrolyte remains at a lower level. This enables Li–S batteries to exhibit excellent electrochemical performance under high current densities and high sulfur contents. This work provides valuable new insights into controlling the Li + solvation structure, highlight the significant potential of MOF‐based separators in Li–S batteries.
Lian et al. (2026) studied this question.