Lithium titanate modified separators 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 diaphragm (LTO@PP). The characteristic properties such as morphology, EIS, and electrochemical performance of the LTO@PP diaphragm are systematically investigated. The results indicate that during the first discharge cycle, Li4Ti5O12 can undergo lithiation, facilitating the transfer of Li+ ions and thereby accelerating the migration kinetics of lithium ions within the LTO@PP diaphragm. The LTO@PP-based cell can stably cycle for more than 4800 h 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 1 mAh/cm2. Additionally, the LTO@PP diaphragm-based LFP cell displays a high capacity retention rate and excellent rate performance. Compared with current diaphragm modification methods, this work provides a promising prospect for the simple and rapid preparation of modified diaphragms.