A two-dimensional MXene/BN van der Waals heterostructure as an anode material for lithium-ion batteries

Abstract

Titanium carbide (Ti₃C₂T_x) is highly regarded as a promising anode material for lithium-ion batteries but suffers from sluggish kinetics with low storage capacity. In this work, a BN/Ti₃C₂T_x heterostructure is effectively fabricated by high energy ball-milling, which plays a series of roles in enlarging the interlayer spacing, reducing the size of the nanosheets and maintaining the structural integrity. Benefiting from the synergistic effect between the BN and Ti₃C₂T_x monolayers, it delivers a high reversible capacity of 521.6 mA h g^-1 at 0.1 A g^-1, excellent rate capabilities (344.9 mA h g^-1 at 1 A g^-1 and 251.3 mA h g^-1 at 2.5 A g^-1) and a robust long-term cycling stability with 84.4% capacity retention after 1400 cycles. In particular, the theoretical calculations further confirm that the BN/Ti₃C₂T_x heterostructure manifests improved adsorption energies, an ultralow diffusion barrier and a high charge-discharge rate. These findings provide an important new strategy for further design and rational fabrication of MXenes for energy storage applications.