Utilization of the van der Waals Gap of 2D Materials

Abstract

Since their discovery, two-dimensional (2D) materials have attracted significant research attention owing to their excellent and controllable physical and chemical properties. These materials have emerged rapidly as important material system owing to their unique properties such as electricity, optics, quantum properties, and catalytic properties. 2D materials are mostly bonded by strong ionic or covalent bonds within the layers, and the layers are stacked together by van der Waals forces, thereby making it possible to peel off 2D materials with few or single layers. The weak interaction between the layers of 2D materials also enables the use of van der Waals gaps for regulating the electronic structure of the system and further optimizing the material properties. The introduction of guest atoms can significantly change the interlayer spacing of the original material and coupling strength between the layers. Also, interaction between the guest and host atom also has the potential to change the electronic structure of the original material, thereby affecting the material properties. For example, the electron structure of a host can be modified by interlayer guest atoms, and characteristics such as carrier concentration, optical transmittance, conductivity, and band gap can be tuned. Organic cations intercalated between the layers of 2D materials can produce stable superlattices, which have great potential for developing new electronic and optoelectronic devices. This method enables the modulation of the electrical, magnetic, and optical properties of the original materials, thereby establishing a family of 2D materials with widely adjustable electrical and optical properties. It is also possible to introduce some new properties to the 2D materials, such as magnetic properties and catalytic properties, by the intercalation of guest atoms. Interlayer storage, represented by lithium-ion batteries, is also an important application of 2D van der Waals gap utilization in energy storage, which has also attracted significant research attention. Herein, we review the studies conducted in recent years from the following aspects: (1) changing the layer spacing to change the interlayer coupling; (2) introducing the interaction between guest and host atoms to change the physico-chemical properties of raw materials; (3) introducing the guest substances to obtain new properties; and (4) interlayer energy storage. We systematically describe various interlayer optimization methods of 2D van der Waals gaps and their effects on the physical and chemical properties of synthetic materials, and suggest the direction of further development and utilization of 2D van der Waals gaps.

Constructing Artificial SEI Layer on Lithiophilic MXene Surface for High‐Performance Lithium Metal Anodes

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Core–Shell Structured C@SiO2 Hollow Spheres Decorated with Nickel Nanoparticles as Anode Materials for Lithium‐Ion Batteries

“…Lithium-ion batteries (LIBs) with high energy density have been regarded as one of the prominent devices to meet the demand of portable electronic devices and electric vehicles. [1][2][3][4][5][6][7] the tensile hoop stress arising from the volume variation. And carbon not only greatly enhances electron transport but also boosts mechanical robustness.…”

Applications and Challenges of 2D Materials in Lithium Metal Batteries

“…Thanks to the unique chemical, physical, and mechanical properties, 2D materials, with sheet-like structure and atomic thickness, provide a great opportunity for the research and development of clean energy devices to meet the challenges of global energy demand [12][13][14] . In the field of LMBs, 2D materials not only exhibit abundant lithiophilic sites, but also can participate in the construction of artificial SEI layers, which are of great help to improve the performance of LMBs.…”