Lithium metal batteries are widely recognized as a pivotal technology for overcoming the limitations of current battery energy density. Their ultra-high theoretical specific capacity and low electrode potential endow them with immense potential, particularly in the realm of electric vehicles. Nevertheless, lithium metal batteries encounter a multitude of challenges in real-world applications. These include uneven interfacial ion transport kinetics, concentration polarization, the formation of lithium dendrites, and a short cycle life. These issues become even more prominent during rapid charging and under high-load conditions. As a fundamental component of lithium metal batteries, the separator not only serves to prevent short circuits between the cathode and anode but also exerts a direct impact on lithium-ion transport, anion migration, interfacial concentration distribution, and lithium deposition behavior. Traditional polyolefin separators, such as polypropylene (PP), mainly function as inert porous membranes and lack the capability to chemically and selectively regulate ion transport.