Oxide Nanoclusters on Ti<sub>3</sub>C<sub>2</sub> MXenes to Deactivate Defects for Enhanced Lithium Ion Storage Performance
Xiaobin Hui, Danyang Zhao, Peng Wang, Haoxiang Di, Xiaoli Ge, Peng Zhang, Longwei Yin
Abstract
Abstract The commercialization of MXenes as anodes for lithium‐ion batteries is largely impeded by low initial coulombic efficiency (ICE) and unfavorable cycling stability, which are closely associated with defects such as Ti vacancies ( V Ti ) in Ti 3 C 2 MXenes. Herein, an effective strategy is developed to deactivate V Ti defects by in situ growing Al 2 O 3 nanoclusters on MXenes to alleviate the irreversible electrolyte decomposition and Li dendrites formation trend induced by defects, improving ICE and cycling stability. Furthermore, it is revealed that excessively lithiophilic V Ti defects would impede Li ions diffusion due to their strong adsorption, leading to a locally nonuniform Li flux to these “hot spots,” setting scene for the formation of Li dendrites. The Al 2 O 3 nanoclusters anchored on V Ti sites can not only improve Li diffusion kinetics but also promote the homogeneous solid electrolyte interphase formation with small charge transfer resistance, achieving uniform Li deposition in a smaller overpotential without formation of Li dendrites. As expected, Ti 3 C 2 @Al 2 O 3 ‐11 electrode delivers a high ICE of 76.6% and an outstanding specific capacity of 285.5 mAh g −1 after 500 cycles, which is much higher than that of pristine Ti 3 C 2 sample. This work sheds light on modulating defects for high‐performance energy storage materials.