Empowering polypropylene separator with enhanced polysulfide adsorption and reutilization ability for high-performance Li-S batteries

Abstract Originating from the severe polysulfide dissolution and notorious polysulfide shuttle, the practical applications of lithium-sulfur (Li-S) batteries confront huge challenges in low active material utilization, rapid capacity degradation, short cycling lifespan, and inferior rate capability. Herein, a rationally modified polypropylene (PP) separator with multi-functional nickel hydroxide@carbon nanotube (NiOOH@CNT) coating layer is proposed to overcome these critical obstacles. The conductive and porous CNT networks ensure the rapid electron/ion transport to achieve high reactivation and reutilization of active materials, as well as physically block the polysulfide migration. Meanwhile, the porous NiOOH nanowalls arrays layer with polar surface demonstrates superior chemical absorption ability for anchoring polysulfides, thereby significantly suppressing the shuttle effect. Such elaborately designed separator endows Li-S batteries with high specific capacity, superior capacity retention and remarkable rate capability. This work sheds new light on the multi-functional separators for high-performance Li-S batteries.