Preparation of (Vx, Ti1−x)2C MXenes and their performance as anode materials for LIBs

MXenes as anode materials for Li-ion batteries (LIBs) have shown excellent electrochemical performance, and they still have great potential. To explore the effect of chemical composition on their electrochemical performance, herein we report an approach for preparation of (Vx, Ti1−x)2C MXenes (x = 1, 0.7, 0.5, 0.3, 0) via etching their precursor solid solutions of (Vx, Ti1−x)2AlC. The exfoliated (Vx, Ti1−x)2C MXenes with good multilayered morphology exhibit good electrochemical properties when used as anodes of LIBs, and the electrochemical performance is optimized for the solid solution of (V0.5, Ti0.5)2C which possesses the highest reversible capacity of 204.9 mAh g−1 and a coulombic efficiency of nearly 100% at 1 A g−1. The heteroatoms in M site of MXene are responsible for the enhanced lithium storage performance.