First-principles study of beryllium substituted borophene as an anode material for Li/Na-ion batteries

In this work, we predict the effects of beryllium (Be) doping on beta 12 borophene as an electrode material for lithium-ion batteries (LIBs) and sodium-ion batteries (NIBs) by using first principles methods. The optimized Li and Na adsorption sites are identified, and we found that Be doping enhances a single Li/Na ion adsorption on beta 12 borophene with increased adsorption energy (-2.174/-1.765 eV for Li/Na). Before to and following adsorption of Li/Na, the electrical conductivity of Be-doped borophene was revealed by the finite density of states at the Fermi level. Be-doped borophene provides adequate open circuit voltages (0.84/0.80 V for LIBs/NIBs). Besides these advantages, most remarkably, BeB19 has an extremely high theoretical specific capacity of 2869/2087 mA h g- 1 for LIBs/NIBs which is several times higher than the other discovered 2D materials. Our results support that Be doping has a positive effect on beta 12 borophene and can be used to create anodes with excellent electrochemical properties for both LIBs and NIBs.