The selection of a suitable two dimensional anode material is one of the key steps in the development of alkali metal ion batteries to achieve superior performance with an ultrahigh rate of charging/discharging capability. Here, we have used state of the art density functional theory (DFT) to explore the feasibility of two dimensional (2D) honeycomb boron arsenide (h-BAs) as a potential anode for alkali-metal (Li/Na/K)-ion batteries. The structural and dynamic stability has been confirmed from the formation energy and the non-negative phonon frequency. The h-BAs monolayer exhibits negative adsorption-energy values of −0.422, −0.321 and −0.814 eV, for the Li, Na, and K-ions, respectively. Subsequently, during the charging process the adsorption-energy increases considerably without an energy-barrier when any of the A-atoms achieve a crucial distance (∼8 Å). In addition, it has been observed that insertion of the mono alkali metal atom into the h-BAs surface results in the semi-conducting nature of the monolayer being transformed into a metallic-state. The low energy barriers for Li (0.522 eV), Na (0.248), and K (0.204 eV) active ion migration imply high diffusion over the h-BAs surface, hence suggesting it has a high charge/discharge capability. Moreover, we have obtained low average operating voltages of 0.49 V (Li), 0.35 V (Na) and 0.26 V (K) and high theoretical capacities of 522.08 mA h g⁻¹ (for Li and Na) and 209.46 mA h g⁻¹ (for K) in this study. The aforementioned findings indicate that a h-BAs monolayer could be a promising anode material in the search for low cost and high performance alkali metal ion batteries.

Solid-state systems serve as a candidate for clean energy applications driven by current technological demands. In this effort, density functional theory (DFT) has become a valuable asset to investigate the intrinsic electronic properties and holds a substantial promise for guiding the discovery of new materials. Herein, we have investigated the Li and Na decorated 2D boron phosphide (BP) monolayer as a potential candidate for hydrogen storage due to its lightweight and structural stability. Li and Na adatoms prefer to adsorb at the center of the hexagon with the binding energies 0.36 and 0.26 eV, respectively. The thermodynamic stabilities of BP monolayer in cases of 4Li@BP and 4Na@BP systems were evaluated at room temperature using ab initio molecular dynamics (AIMD) simulations. The study of the electronic structure revealed that the semiconducting BP sheets become metallic after the adatom adsorption. It was found that the dispersed Li and Na atoms on the monolayer surface significantly increase both the hydrogen binding energies and the hydrogen storage capacities. With one-sided coverage of Li and Na atoms, four H₂ molecules were adsorbed with a gravimetric capacity of 4.917 and 4.558 wt%, respectively. For double-sided adatom coverage, a total of 16H₂ molecules was captured around 4Li@BP and 4Na@BP complex with a gravimetric capacity of 7.402 and 6.446 wt%, respectively. These results suggest that boron phosphide (BP) can act as an effective substrate for H₂ storage by carefully engineering it with metal decoration.