Understanding the Relationship between Separator Parameters and Characteristics of Practical Lithium Metal Batteries

The demand for low-cost, high-energy-density lithium-ion batteries (LIBs) has risen due to the entry of grid-level energy storage systems (ESSs) and electric vehicles (EVs) into the market. Lithium metal batteries (LMBs) promise improved energy density, but safety issues related to Li dendrite growth and reactivity persist. The separator, which prevents short circuits, plays a vital role in the performance and safety of LIBs.<br/>Selecting an appropriate separator thickness is crucial because reducing the separator thickness significantly enhances the volumetric energy density and electrochemical performance of LMBs. In addition, the results of the study identify pore closure within the separator as a critical issue affecting cell failure. Effective prevention of pore closure involves maintaining robust mechanical properties, achieving the appropriate solid electrolyte interface composition, and suppressing lithium dendrite growth during cycling. Balancing mechanical strength and low resistance in the separator, along with developing materials to inhibit pore closure, advances the commercialization of high-energy-density LMBs with improved performance and longevity.<br/>This study investigates the relationship between separator parameters and practical lithium metal batteries (LMBs) characteristics to achieve stable and long-term cycling performance for successful commercialization.