Exploring the potential of 2D beryllonitrene as a lithium-ion battery anode: a theoretical study

The development of new and high-capacity anode materials for Li-ion batteries (LIBs) can lead to significant improvements in energy storage technology, promoting sustainable practices, and enabling a wider adoption of clean energy solutions. Herein, the recently synthesized 2D beryllonitrene has been studied computationally to evaluate its Li⁺ capacity and feasibility as an anode material in LIBs. 2D BeN₄ can load a single layer of Li above and below the plane giving a theoretical capacity of 824 mA h g^-1. Upon binding with BeN₄, the Li become monocationic and the average adsorption energy per Li⁺ is -1.522 eV, lesser than the cohesive energy of bulk Li. The Li⁺ diffusion in BeN₄ is facilitated by low barrier energies of ∼0.4-0.8 eV and is consistent when an implicit solvent model is applied for ethylene carbonate. Ab initio molecular dynamics simulations reveal that Li⁺ have high diffusivity (4.5 × 10^-12 m² s^-1) in BeN₄, comparable to commercially available anodes. The surface intercalation density of BeN₄ is higher (1.00) compared to that calculated for graphite and single-walled carbon nanotubes. Thus, BeN₄ shows promising Li⁺ loading and diffusivity behaviour, is thermally and mechanically stable, and is predicted to be a high-capacity anode material for LIBs.