Increased adoption of portable electronic devices, electric vehicles, and large-scale energy storage systems in our daily activities has led to an increased demand for high-performance lithium-ion batteries (LIBs). Among the critical components of LIBs, the separator plays a pivotal role in ensuring battery safety and high performance by preventing direct contact between the anode and cathode, while also facilitating ion transport during the charge–discharge cycles. Traditionally, separators are fabricated from polyolefin materials with high mechanical strength and chemical stability. However, these materials suffer from poor thermal stability, which can lead to safety hazards like thermal runaway under high-temperature conditions. Various modifications to separator materials have been explored to address these limitations, including the incorporation of inorganic fillers and surface coatings, and the development of composite separators.

One promising strategy for improving battery performance involves the integration of metal–organic frameworks (MOFs) into separators. MOFs, renowned for their high surface areas, tunable pore structures, and outstanding thermal stabilities, have demonstrated significant potential in lithium–sulfur (Li–S) batteries. Specifically, MOF-coated separators act as both physical and chemical barriers, effectively mitigating polysulfide migration and enhancing cycling stability. In addition to their application in Li–S systems, MOFs have also been investigated for their ability to enhance the thermal and electrochemical performance of lithium-metal anodes.