College of Integrated Circuit Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023, China.
College of Electronic and Optical Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023, China.
Phys Chem Chem Phys. 2023 Feb 22;25(8):6519-6526. doi: 10.1039/d2cp04433a.
High specific capacity and fast charge/discharge rate are important indicators for the development of next-generation ion batteries. Compared with conventional monovalent ion batteries like lithium-ion batteries and sodium-ion batteries, multivalent ion batteries have attracted extensive attention owing to their high energy densities. Here, we systematically explore the interactions between Mg atoms and α-beryllene monolayers by means of density functional theory calculations. Mg atoms can be adsorbed stably on α-beryllene monolayers with the adsorption energy of -0.24 eV. The low diffusion energy barriers (0.099/0.101 eV) indicate the rapid mobility of Mg during the charge/discharge process. Moreover, the α-beryllene monolayer exhibits an ultra-high theoretical specific capacity of 5956 mA h g for Mg, a low average open-circuit voltage of 0.24 V, and a tiny volume change of -1.08%. Finally, the constructed h-BN/α-beryllene heterostructure shows that h-BN can serve as a protective cover to preserve pristine α-beryllene in respect of metallicity, Mg adsorption capability, and fast ionic mobility. The above mentioned outstanding results make α-beryllene a promising anode material for magnesium-ion batteries.
高比容量和快速充放电率是下一代离子电池发展的重要指标。与传统的单价离子电池（如锂离子电池和钠离子电池）相比，多价离子电池因其高能量密度而引起了广泛关注。在这里，我们通过密度泛函理论计算系统地研究了 Mg 原子与α-氮化硼单层之间的相互作用。Mg 原子可以在α-氮化硼单层上稳定吸附，吸附能为-0.24 eV。较低的扩散能垒（0.099/0.101 eV）表明在充放电过程中 Mg 具有快速的迁移能力。此外，α-氮化硼单层的理论比容量高达 5956 mA h g ，平均开路电压低至 0.24 V，体积变化仅为-1.08%。最后，构建的 h-BN/α-氮化硼异质结表明 h-BN 可以作为保护层，保持原始α-氮化硼的金属性、Mg 吸附能力和快速离子迁移率。上述出色的结果使得α-氮化硼成为一种很有前途的镁离子电池的阳极材料。
