Regulated Li₂S Deposition toward Rapid Kinetics Li‐S Batteries by a Separator Modified by CeO₂‐Decorated Porous Carbon Nanostructure

Abstract Although the high‐energy‐density lithium sulfur (Li‐S) battery has been considered one of the most promising next‐generation energy storage technology, the practical applications have been plagued by the sluggish reaction kinetics and the shuttle effect of lithium polysulfides intermediates. Here, to address the above issues, the authors report a novel separator modified by CeO₂‐decorated porous carbon nanostructure (CeO₂/KB/PP). Benefiting from the strong polar surface and large specific surface area, (CeO₂‐doped Ketjen Black) delivers efficient chemical adsorption toward lithium polysulfides. Moreover, rich oxygen vacancies of CeO₂ provide abundant active sites to expedite lithium polysulfides conversion and regulate deposition and nucleation of Li₂S. Taking advantage of these merits, the battery with the CeO₂/KB/PP separator exhibits remarkable electrochemical performance, including low‐capacity decay of only 0.06% per cycle over 1000 cycles at 2 C and superior rate capability of 627 mAh g^‐1 at 3 C. Even with a high sulfur loading of 6.6 mg cm^‐2, the battery can achieve a high areal capacity of 3.6 mAh cm^‐2 after 100 cycles. This work provides a new application of rare‐earth‐based materials to facilitate Li‐S batteries.