Balanced Polysulfide Containment and Lithium Ion Transport in Lithium-Sulfur Batteries via Nitrogen-doped Carbon Hollow Multi-shelled Structures on Modified Separators

Representing the next-generation technology in lithium-ion batteries,lithium-sulfur(Li-S)batteries offer increased specific energy without relying on scarce metals like nickel and cobalt,but suffer from a low practical specific energy due to poor conductivity and a short lifespan due to the shuttle effect of polysulfides.Balancing the confinement of polysulfides and the transport of lithium ions requires highly elaborate modifiers for separators.Hollow multi-shelled structures(HoMSs)show promise as hierarchical mesostructures for separators,offering multiple shell layers and internal cavities that effectively inhibit polysulfide shuttle.Thoughtful design of these structures is crucial to address these challenges effectively.In this study,nitrogen-doped carbon HoMS(NC HoMS)was created using polymer templates through a precisely controlled polymerization process.Batteries featuring NC HoMS-modified separators exhibit improved capacity and cycling stability in comparison to those utilizing commercial separators.Especially,triple-shelled NC HoMS strikes a balance in polysulfide containment and lithium ion transport.Featuring a sulfur loading of 6.34 mg/cm^(2),the Li-S battery can consistently complete 100 charge-discharge cycles,starting with a discharge capacity of 966.4 mA·h/g with a 75.8%capacity retention rate.NC HoMS holds potential as the separator modifier in addressing the polysulfide shuttle problem and facilitating the Li-ion transportation for advanced Li-S batteries.