Be2B monolayer as a well-balanced performance anode for lithium-ion batteries with ultrahigh theoretical capacity and low diffusion barrier

Lithium-ion batteries (LIBs) are the most crucial part of energy storage systems. The lower molar weight of anodes can achieve a higher theoretical capacity. We explore the performance of a Be2B monolayer as an anode for LIBs. By first-principles calculations, we reveal that the Be2B monolayer shows excellent tensile strength, which suggests that it can deal with the volume expansion during the adsorption process. Furthermore, the Be2B monolayer can stably adsorb Li atoms with an adsorption energy of −0.98 eV. Moreover, the Be2B monolayer exhibits a low diffusion barrier (0.066 eV), an ultra-high theoretical capacity (3717 mA h g−1), and a moderate open circuit voltage (0.59 V). We also confirm the wettability of the Be2B monolayer in common electrolytes and investigate the adsorption and diffusion properties of Li on Be2B/graphene heterostructure. The introduction of graphene enhances the migration behavior of Li, suggesting the fast charging/discharging capability. Based on the above-mentioned properties, we propose that the Be2B monolayer can act as a high-performance anode material.