A Separator Coated by Cerium-Zirconium Oxide/Carbon Nanotube Promotes Li₂S Precipitation for Advanced Li-S Batteries

Although lithium-sulfur (Li-S) batteries exhibit extensive potential application as a novel type of rechargeable battery, their practical implementation is hindered by the shuttle effect of soluble polysulfides and the sluggish redox kinetics involved in converting polysulfides to Li₂S₂/Li₂S. Herein, we synthesized cerium-zirconium oxide/carbon nanotube (CZO/CNT) composite via a facile hydrothermal-calcination method for use as a separator coating. In this material, the highly conductive network structure of CNTs optimizes charge transport pathways, ensuring rapid lithium-ion migration. Meanwhile, the strong polarity of CZO exhibits strong adsorption-catalytic capacity toward Lewis-basic polysulfides, thereby accelerating the reaction kinetics and improving the deposition efficiency of Li₂S. Based on these merits, the Li-S battery utilizing CZO/CNT separator delivered a high discharge capacity of 1339 mAh g^-1 at 0.1 C. In particular, the battery exhibited exceptional cycling stability, retaining a reversible capacity of 490 mAh g^-1 for 800 cycles at 2 C, with a 0.059% capacity fade per cycle. This research demonstrates the potential of CZO/CNT composite in enhancing Li-S battery performance, offering a promising approach for developing advanced separator materials.