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

Abstract

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).

Petroleum-Pitch-Based Carbon Nanocages Encapsulated Few-Layer MoS2 with S Vacancies for a High-Performance Sodium-Ion Battery

“…Obviously, the batter cycling stability of 305 mAh g –1 is presented for MoS 2 /C-1-700, while MoS 2 /AC-1-700 declines gradually in the first 200 cycles. Moreover, the increasing specific capacity is due to the gradual activation process and increased number of active sites in the MoS 2 nanosheets that are more beneficial for sodium storage. − Meanwhile, at a high current density of 1 A g –1 , MoS 2 /C-1-700 displays a higher capacity retention of 84.2% after long-term cycles and maintains a relatively stable state with the capacity of 252 mAh g –1 in the first 300 cycles, as shown in Figure h. In contrast, MoS 2 /AC-1-700 decays dramatically after 300 cycles, only with a lower capacity retention of 52.3%.…”

Titanium Carbide MXenes Cocatalyst with Graphitic Carbon Nitride for Photocatalytic H2 Production, CO2 Reduction, and Reforming Applications: A Review on Fundamentals and Recent Advances

“…Aside from that, MXenes, like Ti 3 C 2 , can reverse metal ion introduction to gain proper characteristics for use as an electrode in non-lithium-ion batteries. 109,110 2.5. General Reaction Mechanism Over Ti 3 C 2 /g-C 3 N 4 Based Composites.…”

“…In addition, a functional group as an O termination has been cited as a source of capacitance improvement. Aside from that, MXenes, like Ti 3 C 2 , can reverse metal ion introduction to gain proper characteristics for use as an electrode in non-lithium-ion batteries. , …”

A Review of Nb2CTx MXene as an Emerging 2D Material: Synthesis, Applications in Rechargeable Batteries and Supercapacitors, Progress, and Outlook

“…Selection of a particular MXene for a specific application depends mainly on the method by which the MXene is synthesized and its stoichiometry, layer thickness, elemental composition, and lateral flake size. Among the family of MXenes, Ti-based MXenes (for example, Ti 2 CT x ) are widely explored − and others are in their infancy.…”