Lithium titanate modified separator for long cycling life lithium metal anode

Lithium dendrites produced during the process of lithium metal cycling lead to poor cycle stability and safety problems, seriously hindering the practical application and commercialization of lithium metal. In this work, a facile method is used to coat lithium titanate (LTO) onto polypropylene (PP), resulting in the formation of a lithium titanate separator (LTO@PP). The characteristic properties such as morphology, EIS, and electrochemical performance of the LTO@PP separator are systematically investigated. The results prove that the transformation from Li 4 Ti 5 O 12 into Li 7 Ti 5 O 12 during the first cycle of discharge promotes the transfer of Li + , thus accelerating the migration dynamics of lithium ions in the LTO@PP separator. The LTO@PP-based cell can stably cycle for more than 4800 hours in a Li symmetrical battery at a high current density of 3 mA cm − 2 , with an overvoltage as low as 6 mV. The Li | Cu battery can stably cycle for more than 380 cycles under a deposition rate of 1mAh/cm 2 . Additionally, the LTO@PP separator-based LFP cell displays a high capacity retention rate and excellent rate performance. Compared with current separator modification methods, this work provides a promising prospect for the simple and rapid preparation of modified separators.