α-MnO₂/RuO₂ Heterostructure-Modified Polypropylene Separator for High-Performance Lithium-Sulfur Battery

Lithium-sulfur (Li-S) battery is a promising next-generation energy storage system. However, the poor cyclability caused by the shuttle effect is still a key challenge for its practical application. Here, a polypropylene separator modified with alpha-MnO2/RuO2 heterostructure is presented to facilitate the transformation of lithium polysulfides (LiPSs) and optimize the rate-determining step in both the reduction and oxidation processes of the sulfur electrode. The unique separator effectively suppresses the dissolution and shuttling of soluble LiPSs in Li-S batteries. The alpha-MnO2/RuO2 heterostructure modified separator with a Ru content of approximate to 8 wt% enables a high areal capacity of over 5.0 mAh cm(-2) after 55 cycles at 0.2C in a Li-S coin cell, and the resultant pouch cell retains 78.2% of its initial capacity after 200 cycles at 0.1C, suggesting considerable potential for commercial applications. This work provides new insights into the regulation of electrochemical reactions in Li-S batteries.