Research progress on TiO₂-modified lithium and lithium-sulfur battery separator materials

With the increasing promotion of new energy vehicles and the rapid popularization of digital electronic products, there is a growing demand for lithium-ion and lithium-sulfur batteries. These batteries have gained widespread attention due to their excellent electrochemical performance. However, with the continued demand for high-power applications in new energy vehicles and digital electronics, the safety and stability of the batteries have become critical. TiO₂ is commonly utilized in battery separators owing to its capacity to enhance the thermal stability, mechanical properties, and electrochemical stability. It can inhibit the “shuttle effect” of polysulphides in lithium-sulfur batteries through physical and chemical methods to improve the cycling performance of lithium-sulfur batteries. This review will outline three methods for modifying TiO₂ separators: blending (utilizing electrostatic spinning and phase conversion), coating (involving the coating method, immersion fabrication method, and vacuum filtration method), and grafting. Finally, the prospective evolution of battery separators and the concomitant challenges they confront will be contemplated.