An MXene/CNTs@P nanohybrid with stable Ti-O-P bonds for enhanced lithium ion storage --- J. Mater. Chem. A, 2019, 7, 21766-21773.

Shixue Zhang, ^# Huan Liu, ^# Bin Cao, Qizhen Zhu, Peng Zhang, Xin Zhang, Renjie Chen*, Feng Wu, Bin Xu*

Two-dimensional transition metal carbides (MXenes) have a unique structure, excellent electronic conductivity and a low Li⁺ diffusion barrier, and show potential for application in energy storage. Especially, MXenes can act as a conductive matrix to achieve excellent lithium storage performance. Herein, a Ti₃C₂T_x MXene/carbon nanotubes@red phosphorus (Ti₃C₂T_x/CNTs@P) nanohybrid with stable Ti–O–P bonds is fabricated. The CNTs are introduced into Ti3C2Tx to construct a conductive network, and then the Ti₃C₂T_x /CNTs are combined with P by a ball-milling method. In this process, the surface oxygen-containing functional groups of Ti₃C₂T_x interact with P, forming Ti–O–P bonds. Owing to the large capacity contribution of P, the conductive network and buffering role of Ti₃C₂T_x /CNTs, and the effect of the Ti–O–P bond, the Ti₃C₂T_x /CNTs@P nanohybrid exhibits a superior reversible capacity of 2598 mA h g^-1 at 0.05C (1C=2600 mA g^-1, based on the active material P), excellent cycling stability (2078 mA h g^-1 after 500 cycles) and superior rate capability (454 mA h g^-1 at 30C). These results demonstrate that the Ti₃C₂T_x/CNTs@P nanohybrid offers fascinating potential for high-performance lithium-ion batteries.