Advancements in Glass Fiber Separator Technology for Lithium-Sulfur Batteries: The Role of Transport, Material Properties, and Modifications.

Lithium-sulfur batteries (LSBs) are widely regarded as a promising next-generation energy storage technology due to their exceptional theoretical capacity and energy density. However, their commercialization has been hindered by challenges such as the polysulfide shuttle effect and poor reaction kinetics, which limit efficiency and cycle life. This review delves into the critical aspects of LSB technology, beginning with an overview of the fundamental mechanisms and challenges. The role of transport in porous media is analyzed, particularly in relation to its impact on ion mobility, sulfur utilization, and overall battery performance. Key criteria for separator design are then explored, emphasizing the importance of multifunctional separators in mitigating polysulfide diffusion, enhancing electrochemical stability, and prolonging cycle life. Glass fiber (GF) separators are highlighted for their intrinsic properties, including thermal stability and electrolyte wettability, which make them ideal candidates for modification. Various modification techniques are reviewed, demonstrating how functional coatings and advanced materials can transform GF separators into highly efficient components of Li-S batteries. By integrating novel approaches to separator modification, significant improvements in performance and cycling stability are achieved. The outlook and future directions in this research field are also given.