Separator’s Contribution to the Ion Transport in Lithium Batteries

The performance and safety of lithium batteries are heavily dependent on the transport efficiency and deposition uniformity of lithium ions (Li⁺). As an essential component of lithium batteries, the separator’s physical structure and chemical characteristics significantly affect Li⁺ transport. Herein, the influence of separators on Li⁺ transport and design strategies for ion transport regulation are first elaborated at the mechanistic level along the Li⁺ transport path. Subsequently, the research progress of the current work on Li⁺ transport regulation is systematically reviewed by categorizing the improvement approaches, with comprehensive discussions on their respective advantages, limitations, and application scopes. Finally, it is concluded that future research should focus on the multifunctionalization with performance breakthroughs, as well as the cost, reliability and compatibility for industrial implementation, in order to transform laboratory innovations into industrial applications.