Facile Synthesis of Pre-Lithiated LiTiO 2 Nanoparticles for Quick Charge and Long Lifespan Anode in Lithium-Ion Batteries.

Titanium dioxide (TiO 2 ) has been widely used as an alternative anodic material for lithium-ion batteries (LIBs) due to its ultrahigh capacity retention and long cycle lifespan. However, the restriction of lithium insertion, intrinsically poor electronic conductivity, and sluggish lithium ionic kinetics of bulk TiO 2 hinder their specific capacity and rate performance. Herein, LiTiO 2 nanoparticles (NPs) are synthesized via a facile ball milling method by the reaction of anatase TiO 2 with LiH. The as-prepared LiTiO 2 NPs have strong structural stability and a "zero strain" effect during the repeated intercalation/deintercalation, even at low potential. As anodic materials for LIBs, LiTiO 2 NPs exhibit a superior rate performance of ∼100 mA h g -1 at 10C (3350 mA g -1 ) with a capacity retention of 100% after 1000 cycles, which is 5 times higher than that of the original commercial anatase TiO 2 powder. The higher specific capacity of LiTiO 2 NPs is attributed to the increased conversion of Ti 3+ to Ti 2+ on the porous surface of LiTiO 2 NPs, which provides a more capacitive contribution. This study not only provides a new fabrication approach toward Ti-based anodes for ultrafast LIBs but also underscores the potential importance of embedding lithium into transition metal oxides as a strategy for boosting their electrochemical performance.