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

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Despite the outstanding theoretical capacities of two-dimensional (2D) molybdenum sulfide (MoS 2 ) with low costs, its low conductivity and easy agglomeration greatly impede the business application as anode materials. The heterostructures between 2D MoS 2 and Ti 3 C 2 MXene are able to combine the collective superiorities of MoS 2 and Ti 3 C 2, 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 MoS 2 /Ti 3 C 2 heterostructures with a compact stacking lamellar structure and investigate the electrochemical sodium storage properties of the composite. In the architecture, fallen leaf-like MoS 2 nanosheets with a mixed-phase crystal containing 1T and 2H phases grow tightly on the surface and interlayer of Ti 3 C 2 matrixes. The expanded layer spacing of Ti 3 C 2 as a result of MoS 2 insertion can greatly accelerate electronic/sodium ion transport. Meanwhile, 2D Ti 3 C 2 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 MoS 2 /Ti 3 C 2 anode reveals higher sodium storage capacity of 743.6 mAh g –1 than bare MoS 2 (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).