Potential Application of Graphene/Antimonene Herterostructure as an Anode for Li-Ion Batteries: A First-Principles Study

Exploring the effect of the covalent functionalization in graphene-antimonene heterostructures

The growing field of two-dimensional (2D) materials has recently witnessed the emergence of heterostructures, however those combining monoelemental layered materials remain relatively unexplored. In this study, we present the chemical fabrication and characterization of a heterostructure formed by graphene and hexagonal antimonene. The interaction between these 2D materials is thoroughly examined through Raman spectroscopy and first-principles calculations, revealing that this can be considered as a van der Waals heterostructure. Furthermore, we have explored the influence of the antimonene 2D material on the reactivity of graphene by studying the laser-induced covalent functionalization of the graphene surface. Our findings indicate distinct degrees of functionalization based on the underlying material, SiO2 being more reactive than antimonene, opening the door for the development of controlled patterning in devices based on these heterostructures. This covalent functionalization implies a high control over the chemical information that can be stored but also removed on graphene surfaces, and its use as a patterned heterostructure based on antimonene and graphene. This research provides valuable insights into the antimonene-graphene interactions and their impact on the chemical reactivity during graphene covalent functionalization.

Graphyne-based 3D porous structure and its sandwich-type graphene structure for alkali metal ion battery anode materials

In order to develop candidate materials for more metal ion battery anodes, a three-dimensional (3D) porous structure 3D-PGY was designed based on graphyne, and a sandwich structure graphene/PGY/graphene (G/PGY/G) was constructed by adjusting the distance between two layers of graphene with 3D-PGY as the middle layer. Systematic calculations have shown that 3D-PGY is thermally and mechanically stable even at temperatures up to 1000 K. Li can migrate in multiple diffusion directions in two structures because of its smaller radius while Na and K ions can only migrate through the larger pores. The energy barriers of Li, Na and K ions in 3D-PGY are 0.18, 0.43 and 0.27 eV respectively. After forming the sandwich structure with graphene, the minimum energy barriers of Li, Na and K ions are decreased to 0.12, 0.37 and 0.24 eV, respectively. As the anode for Li, Na, and K ion batteries, the theoretical specific capacities of 3D-PGY are about 558 mA h g-1, and the average open circuit voltages of 3D-PGY and G/PGY/G are about 0.48/0.52/0.29 and 1.08/1.04/1.39 V, respectively. Finally, using ab initio molecular dynamics simulations, the diffusion coefficients for 3D-PGY at different temperatures, as well as for G/PGY/G at 400 K were obtained. The Li, Na and K ions in both structures can diffuse rapidly and have good rate capabilities. These excellent performances show that the graphyne-based 3D porous structure and its sandwich-type graphene structure are very promising for the development of new battery materials.

Black phosphorene/SnSe van der Waals heterostructure as a promising anchoring anode material for metal-ion batteries

Black phosphorene (BP) is a glowing two-dimensional semiconducting layer material for cutting-edge microelectronics, with high carrier mobility and thickness-dependent band gap. Here, based on van der Waals (vdW)-corrected first-principles approaches, we investigated stacked BP/tin selenide (BP/SnSe) vdW heterostructure as an anode material for metal ion batteries, which exhibits a significant theoretical capacity, along with relatively durable binding strength compared to the constituent BP and SnSe monolayers. Our calculations demonstrated that the Li/Na adatom favors insertion into the interlayer region of BP/SnSe vdW heterostructure owing to synergistic interfacial effect, resulting in comparable diffusivity to the BP and SnSe monolayers. Subsequently, the theoretical specific capacities for Li/Na are found to be as high as 956.30 mAhg-1and 828.79 mAhg-1, respectively, which could be attributed to the much higher storage capacity of Li/Na adatoms in the BP/SnSe vdW heterostructure. Moreover, the electronic structure calculations reveal that a large amount of charge transfer assists in semiconductor-to-metallic transition upon lithiation/sodiation, ensuring good electrical conductivity. These simulations verify that the BP/SnSe vdW heterostructure has immense potential for application in the design of metal-ion battery technologies.

Interfacial effects on lithium-ion diffusion in two-dimensional lateral black phosphorus-graphene heterostructures

Lateral heterostructures constructed from different two-dimensional (2D) materials can be potentially used in lithium-ion batteries (LIBs). The interface between two different components strongly affects LIB charge and discharge processes. Herein, the atomic structures, electronic properties, and Li-ion diffusion characteristics of lateral black phosphorus-graphene (BP-G) heterostructures are studied via first-principles calculations. The obtained results reveal that BP-G heterostructures with either zigzag (ZZ) or misoriented interfaces constructed according to Clar's rule possess a small number of interfacial states and are electronically stable. Furthermore, compared with the perfect ZZ interface of BP-G, Clar's interfaces provide a larger number of diffusion paths with much lower energy barriers. The findings of this study suggest that lateral BP-G heterostructures can provide insights for rapid charge and discharge processes in LIBs.

High-Capacity Ion Batteries Based on Ti2C MXene and Borophene First Principles Calculations

In this paper, we report an ab initio study of a composite material based on Ti2C and borophene B12 as an anode material for magnesium-ion batteries. The adsorption energy of Mg, specific capacitance, electrical conductivity, diffusion barriers, and open-circuit voltage for composite materials are calculated as functions of Mg concentration. It is found that the use of Ti2C as a substrate for borophene B12 is energetically favorable; the binding energy of Ti2C with borophene is −1.87 eV/atom. The translation vectors of Ti2C and borophene B12 differ by no more than 4% for in the X direction, and no more than 0.5% in the Y direction. The adsorption energy of Mg significantly exceeds the cohesive energy for bulk Mg. The energy barrier for the diffusion of Mg on the surface of borophene B12 is ~262 meV. When the composite surface is completely covered with Mg ions, the specific capacity is 662.6 mAh g−1 at an average open-circuit voltage of 0.55 V (relative to Mg/Mg+). The effect of reducing the resistance of borophene B12 upon its binding to Ti2C is established. The resulting electrical conductivity of the composite Ti16C8B40 is 3.7 × 105 S/m, which is three times higher than the electrical conductivity of graphite. Thus, a composite material based on Ti2C and borophene B12 is a promising anode material for magnesium-ion batteries.

Surface plasmon biosensor based on Bi2Te3 antimonene heterostructure for the detection of cancer cells

This theoretical investigation proposes the preliminary stage detection of cancer cells using a prism-based surface plasmon resonance biosensor. The surface plasmon resonance (SPR) biosensor is label-free and rapid; it supports real-time investigations, including greater sensitivity, and it has an enormous possibility for detecting different forms of cancer. The refractive index alteration of cancer cells is 1.360-1.401. The performance of the SPR sensor has been analyzed. The different types of cancer cells for skin, cervical, blood, adrenal, and breast (type I and II) have been analyzed, and sensitivities of 292, 384, 229, 242, 254, and 261 (degree/RIU) have been achieved, respectively. A high figure of merit of 115.2RIU^-1 has been achieved for HeLa cells and achieved detection accuracy of 0.32deg^-1 for basal cells.

Metallic VS2/graphene heterostructure as an ultra-high rate and high-specific capacity anode material for Li/Na-ion batteries

Graphene has been used as a conductive substrate to improve the electrochemical performance of layered VS₂ as an anode material for lithium-ion batteries. However, there is still a lack of in-depth understanding of the synergistic effect between the layered VS₂ and graphene, which contributes to the enhanced performance of Li/Na-ion batteries. In this work, using first-principles calculations, we have systematically studied the VS₂/graphene heterostructure as an anode material for Li/Na-ion batteries. Our results show that the VS₂/graphene heterostructure is a promising anode material with good structural stability, high adsorption strength, high stiffness, intrinsic metallic characteristic after Li/Na adsorption, high theoretical specific capacity, shallow averaged open-circuit voltage and ultra-low ion diffusion barriers. The diffusion barriers are found to be 0.03 eV (Li) and 0.08 eV (Na), superior to that of the widely studied heterostructure materials, which guarantees an extremely fast Li/Na diffusion rate during charge/discharge cycling. The anode overall open-circuit voltages for the Li/Na-ion batteries are calculated to be as low as 0.65 and 0.46 V, and the maximum theoretical storage capacity is 771 and 578 mA h g^-1, respectively. The above results provide valuable insights into the experimental set-up of the VS₂/graphene nanocomposite anode material for ultra-high rate and high-specific capacity Li/Na-ion batteries.

Black phosphorene/blue phosphorene van der Waals heterostructure: a potential anode material for lithium-ion batteries

Van der Waals (vdW) heterostructure-based electrodes have invoked tremendous research interest due to their intriguing properties and their capability to break the limitations of the restricted properties of single-material systems. Herein, based on first-principles approaches, we propose that the black phosphorene/blue phosphorene (BLK-P/BLE-P) vdW heterostructure can be a capable anode material for power-driving lithium-ion batteries (LIBs), as it exhibits a large theoretical capacity, together with a relatively strong binding strength compared with the individual BLK-P and BLE-P monolayers. Our calculation results show that the Li adatom prefers to intercalate into the interlayer of the BLK-P/BLE-P vdW heterostructure due to the synergistic interfacial effect, resulting in a high binding strength and a diffusivity comparable to the BLK-P and BLE-P monolayers. Subsequently, the theoretical specific capacity is found to be as high as 552.8 mA h g^-1, which can be attributed to the much higher storage capacity of Li adatoms in the BLK-P/BLE-P vdW heterostructure. Furthermore, electronic structure calculations reveal that a large amount of charge transfer assists in semiconductor to metallic transition upon lithiation, which would ensure good electrical conductivity. These simulations prove that the BLK-P/BLE-P heterostructure has great potential in LIBs and is essential for future battery design.