1T–2H MoS2/Ti3C2 MXene Heterostructure with High-Rate and High-Capacity Performance for Sodium-Ion Batteries

Despite the outstanding theoretical capacities of two-dimensional (2D) molybdenum sulfide (MoS2) with low costs, its low conductivity and easy agglomeration greatly impede the business application as anode materials. The heterostructures between 2D MoS2 and Ti3C2 MXene are able to combine the collective superiorities of MoS2 and Ti3C2, thus greatly ameliorating the electrical conductivity and rate capacity through synergistic effects. Herein, we design a simple intercalation–sulfidation strategy for the construction of the TH MoS2/Ti3C2 heterostructures with a compact stacking lamellar structure and investigate the electrochemical sodium storage properties of the composite. In the architecture, fallen leaf-like MoS2 nanosheets with a mixed-phase crystal containing 1T and 2H phases grow tightly on the surface and interlayer of Ti3C2 matrixes. The expanded layer spacing of Ti3C2 as a result of MoS2 insertion can greatly accelerate electronic/sodium ion transport. Meanwhile, 2D Ti3C2 can serve as a strong mechanical support for the composite electrode to provide a buffer space for volume expansion and avoid structural collapse during cycles. Benefiting from these structural advantages, the TH MoS2/Ti3C2 anode reveals higher sodium storage capacity of 743.6 mAh g–1 than bare MoS2 (579.4 mAh g–1) at 0.2 A g–1. Furthermore, the anode exhibits significantly improved battery rate performance with a high sodium storage capacity of 653.3, 539.1, 512.1, 488.7, 439.3, and 586.7 mAh g–1 at 0.2, 0.5, 1, 2, 5, and 0.2 A g–1. Our study provides a unique synthesis route to construct layered heterostructure composites by artificial stacking of different types of 2D materials, which are considered as highly promising electrode materials for sodium-ion batteries (SIBs).