AA-stacked borophene-graphene bilayer as an anode material for alkali-metal ion batteries with a superhigh capacity

As the lightest two-dimensional material, monolayer borophene exhibits great potential as electrode materials, but it suffers from stability issues in the free-standing form. Here, the striped-borophene and graphene bilayer (sB/Gr) is found to be a high-performance anode material for rechargeable alkali-metal ion batteries. The first-principles results show that all the three alkali-metal atoms, Li, Na, and K, can be strongly adsorbed on sB/Gr with ultra-low diffusion barriers than that on pristine borophene/graphene, indicating good charge-discharge rates. Remarkably, high storage capacities are proposed for LIBs (1880 mA·h/g), NIBs (1648 mA·h/g), and KIBs (470 mA·h/g) with relatively small lattice change rate (<2.9%) in the process of alkali-metal atoms intercalations. These intriguing features of sB/Gr make it an excellent choice for batteries.