Magnesium-ion batteries (MIBs) are expected to be an alternative to lithium-ion batteries due to the lower cost and immanent safety of Mg. Presently, the major difficulty in breaking through MIBs technology is the lack of desirable anode materials. Based on first-principles calculations, we predict a two-dimensional material named the Be2B monolayer as an excellent anode material. The structural stability is confirmed by superior cohesive energy, positive phonon modes, excellent thermal stability, and strong mechanical stability. Afterward, we explore the performance of the Be2B monolayer as the anode material for MIBs. It exhibits stable Mg atom adsorption with an energy of −0.7 eV, low diffusion barrier (0.1 eV), ultra-high specific capacity (7436 mA h g−1), tiny lattice expansion (0.3%), and low average open-circuit voltage (0.29 V). Thereby, the above-mentioned intriguing findings suggest that the Be2B monolayer can act as a promising anode material for high performance MIBs.

中文翻译：

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Be2B单层作为超高性能镁离子电池负极材料的理论预测

由于镁的低成本和内在安全性，镁离子电池 (MIB) 有望成为锂离子电池的替代品。目前，MIBs技术突破的主要困难是缺乏理想的负极材料。基于第一性原理计算，我们预测一种名为 Be2B 单层的二维材料是一种优良的负极材料。优异的内聚能、正声子模式、优异的热稳定性和强的机械稳定性证实了结构稳定性。之后，我们探索了 Be2B 单层作为 MIB 阳极材料的性能。它表现出稳定的镁原子吸附，能量为-0.7 eV，低扩散势垒（0.1 eV），超高比容量（7436 mA hg-1），微小的晶格膨胀（0.3％）和低平均开路电压（0.29 伏）。从而，