2D g-GaN as interphase anode layer in Mg battery for capturing passivation species (MgO, Mg(OH)₂, MgCO₃) — A first-principles study

The first principles study has been carried out to analyse the performance of the 2D graphene-gallium nitride (g-GaN) as interphase material at the magnesium electrode (g-GaN@Mg) for capturing the passivation species such as magnesium oxide (MgO), magnesium hydroxide (Mg(OH)₂), and magnesium carbonate (MgCO₃) in rechargeable magnesium batteries (RMB). The current work shows that the calculated interphase binding energy (E_b) between the Mg and g-GaN layers are strong. Ab initio molecular dynamics (AIMD) simulation confirms the thermal stability of the g-GaN@Mg at 500 K. The excellent anodic properties of the g-GaN@Mg surface has been confirmed from adsorption energy and diffusivity of single Mg atom values, − 2.64 eV and 10⁻³ cm²/s, respectively. Interaction of passivation species MgO, (Mg(OH)₂) and (MgCO₃) with g-GaN@Mg surface demonstrates a weakening of the Mg–O and Mg–C bond distance. The findings mentioned above suggest that the g-GaN@Mg surface is a potential protective layer against the passivation species for Mg batteries.