We explore the possibility and potential benefit of rolling a Si2BN sheet into single-walled nanotubes (NTs). Using density functional theory (DFT), we consider both structural stability and the impact on the nature of chemical bonding and conduction. The structure is similar to carbon NTs and hexagonal boron-nitride (hBN) NTs and we consider both armchair and zigzag Si2BN configurations with varying diameters. The stability of these Si2BN NTs is confirmed by first-principles molecular dynamics calculations, by exothermal formation, an absence of imaginary modes in the phonon spectra. Also, we find the nature of conduction varies from semiconducting over semimetallic to metallic, reflecting differences in armchair/zigzag-type structures, curvature effects, and the effect of quantum confinement. We present a detailed characterization of how these properties lead to differences in both the bonding nature and electronic structures.

In recent years, two-dimensional MXenes have been emerged as potential electrode materials for rechargeable batteries due to their unique properties such as exceptional safety, significant interlayer spacing, environmental flexibility, large surface area, high electrical conductivity, and excellent thermal stability. This review examined all of the recent advances in the field of MXenes and their composites (hybrid structures), which are found to be useful for the electrochemical applications of advanced rechargeable batteries. The main focus of this review is on metal-ion batteries and lithium–sulfur (Li–S) batteries. It is intended to show that the combination of recent improvements in the synthesis and characterization, greater control of the interlayer distance, and new MXene composites, together serve as an emerging and potential way for energy storage applications.

The emergence of compact lithium-sulfur (Li-S) batteries with improved performances is becoming one of the most desirable aspects of future energy technologies. Beyond Li-ion batteries, Li-S is of great relevance to follow as it adapts to the specificity of each application. It is among the most suitable elements for high-performance energy storage systems, given its high theoretical capacity (1674 mA h g-1) and energy density (2600 W h kg-1) relative to Li-ion batteries (300 W h kg-1). Nevertheless, the high-cell polarization and the shuttle effect constitute an enormous challenge toward the concrete applications of Li-S batteries. In the framework of this work, density functional theory calculations have been carried out to analyze the potential of h-BAs nanosheets as a promising host material for Li-S batteries. Binding and electronic characteristics of lithium polysulfides (LiPSs) adsorbed on h-BAs surface have been explored. Reported findings highlight the potential of the h-BAs monolayer as a moderate host material, given that the binding energies of different LiPSs vary from 0.47 to 3.55 eV. More detailed analysis of the complex binding mechanisms is carried out by investigating the components of van der Waals physical/chemical interactions. The defected surface of the h-BAs monolayer has optimum binding energies with LiPSs for Li-S batteries. All these findings provide valuable insights into the binding and electronic characteristics of the h-BAs monolayer as a moderate host material for Li-S batteries.

Graphite anode have shown commercial success for over two decades, since the start of their use in commercial Li-ion batteries, due to their high practical specific capacity, conductivity, and low lithiation potential. Graphite is to a large extent thermodynamically unfavorable for sodium-ion intercalation and thus limits advancement in Na-ion batteries. In this work, a β-phase arsenic-phosphorus monolayer is studied, which has recently been predicted to have semiconducting behavior and to be dynamically stable. First-principles calculations based on density functional theory are used to explore the role of β-AsP monolayer as a negative electrode for Na-ion batteries. Cohesive energy, phonon spectrum, and molecule dynamics simulations confirm the thermodynamic stability and the possibility of experimentally synthesizing this material. The Na-ion adsorption-energies are found to be high (>−1.2 eV) on both sides (As- and P-side). The ultra-fast energy barriers for Na (0.046/0.053 V) over both sides imply high diffusion of Na-ions on the surfaces of β-AsP. During the evaluation of Na-ion anode performance, the fully sodiated state is found to be Na₂AsP, which yields a high theoretical-specific capacity of 506.16 mAh g⁻¹ and low average sodiation potential of 0.43 V versus Na/Na+.