Advances in Nonwoven-Based Separators for Lithium-Ion Batteries

Lithium-ion batteries (LIBs) are energy-storage devices with a high-energy density in which the separator provides a physical barrier between the cathode and anode, to prevent electrical short circuits. To meet the demands of high-performance batteries, the separator must have excellent electrolyte wettability, thermotolerance, mechanical strength, highly porous structures, and ionic conductivity. Numerous nonwoven-based separators have been used in LIBs due to their high porosity and large surface-to-volume ratios. However, the fabrication of multi-functional fibers, the construction of nonwoven separators, and their integration into energy-storage devices present grand challenges in fundamental theory and practical implementation. Herein, we systematically review the up-to-date concerning the design and preparation of nonwoven-based separators for LIBs. Recent progress in monolayer, composite, and solid electrolyte nonwoven-based separators and their fabrication strategies is discussed. Future challenges and directions toward advancements in separator technologies are also discussed to obtain separators with remarkable performance for high-energy density batteries. Graphical abstract