Global Minima Search for Sodium- and Magnesium-Adsorbed Polymorphic Borophene

Monolayer allotropes of boron (borophene) are being explored extensively for alkali-ion battery anode materials due to their metallicity and ultralow molar mass. However, the inherited polymorphism borophene has made adsorption mechanisms abstruse. Previous computational studies rely on uniform-adsorption model, which fails capture adsorption-induced phase change in thus predicts nonrealistic values specific capacity. Here, we employ ab initio global-minima-search techniques gain atomistic insights into polymorphism-driven sodium- magnesium-ion binding process. Our well-designed method combines two different search techniques. It reveals nonidealities (e.g., bond cleavage, electroplating, transition, etc.), may assist future experimental efforts polymorphic borophene. In contrast earlier reports, our study finds be an outstanding candidate Mg-ion batteries (specific capacity 3648.54 mAh/g) but not so promising Na-ion storage relatively high formation energies (+0.09 eV/atom) Na-B compounds deformation upon adsorption.