Advancements in functionalized high-performance separators for lithium-sulfur batteries

Lithium-sulfur batteries as a promising candidate for the next generation of battery systems face major challenges in their commercialization process, primarily due to the irreversible loss of active sulfur substances during the operation of the battery and the instability of the lithium anode. As a critical component of lithium-sulfur batteries, the separator not only separates the cathodes and anodes to prevent battery short circuits but also provides a pathway for ion transport. Constructing functionalized high-performance separators can effectively suppress the 'shuttle effect' and stabilize the lithium anodes, thereby enhancing the performance of lithium-sulfur batteries and accelerating their practical application process. In recent years, research on separators for lithium-sulfur batteries has been increasing. However, existing reviews on lithium-sulfur battery separators seem to be inadequate, making it difficult to provide effective guidance for researchers. To address this, this review comprehensively elaborates on the research work of functionalized separators from three perspectives: modified separators, electrospun separators, and polymer electrolyte separators. In addition, we have conducted a preliminary evaluation of the staged applications of these three types of separators. This review not only provides directions for subsequent scientific research work but also offers effective guidance for enterprises in the production of functionalized high-performance separators.