Ti 3 Si 0.75 Al 0.25 C 2 Nanosheets as Promising Anode Material for Li-Ion Batteries.

Herein we report that novel two-dimensional (2D) Ti 3 Si 0.75 Al 0.25 C 2 (TSAC) nanosheets, obtained by sonically exfoliating their bulk counterpart in alcohol, performs promising electrochemical activities in a reversible lithiation and delithiation procedure. The as-exfoliated 2D TSAC nanosheets show significantly enhanced lithium-ion uptake capability in comparison with their bulk counterpart, with a high capacity of ≈350 mAh g -1 at 200 mA g -1 , high cycling stability and excellent rate performance (150 mAh g -1 after 200 cycles at 8000 mA g -1 ). The enhanced electrochemical performance of TSAC nanosheets is mainly a result of their fast Li-ion transport, large surface area and small charge transfer resistance. The discovery in this work highlights the uniqueness of a family of 2D layered MAX materials, such as Ti 3 GeC 2 , Ti 3 SnC 2 and Ti 2 SC, which will likely be the promising choices as anode materials for lithium-ion batteries (LIBs).