Graphite is the most commonly used electrode material, which is mainly due to two key advantages, i.e., its layered structure acts a perfect framework for the accommodation and migration of ions, and the light atomic mass of carbon is conducive to obtaining a high specific capacity. As a neighbor of carbon in the periodic table, boron is even lighter than carbon, and it can also form various layered structures. Here, we systematically investigate boron-based layered compounds to explore their potential applications as electrode materials by means of first-principle calculations. Among various types of boron compounds, MXB4 (M = Li, Na, Mg; X = Al, Ga) with the YCrB4-type structure are found to be potentially excellent electrode materials for metal-ion batteries. The adsorption and migration of Li/Na/Mg in MXB4 have been presented, and migration barriers comparable with conventional electrode materials are observed. In particular, Li2AlB4 and Li2GaB4 are found to exhibit quite high specific capacities of 754 mA h g(-1) and 470 mA h g(-1) compared to the theoretical value of graphite (372 mA h g(-1)) as well as low average voltages of 0.71 V and 0.79 V, respectively, revealing that they may be good anode materials for Lithium ion batteries.
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机译:石墨是最常用的电极材料,主要是由于两个关键优点,即其层状结构作用于离子的容纳和迁移的完美框架,并且光原子碳的碳是有利于获得高特定容量的。作为周期表中碳的邻居,硼比碳均更轻,也可以形成各种层状结构。在这里,我们通过第一原理计算系统地研究基于硼的层状化合物以探讨它们作为电极材料的潜在应用。在各种类型的硼化合物中,发现具有YCRB4型结构的MXB4(M = Li,Na,Mg; X = Al,Ga)是金属离子电池的潜在优异的电极材料。已经提出了Li / Na / Mg在MXB4中的吸附和迁移,并且观察到与常规电极材料相当的迁移屏障。特别地,与石墨的理论值相比,发现Li2Alb4和Li 2 Gab4具有754 mA Hg(-1)和470mA Hg(-1)的相当高的特异性容量(372mA hg(-1))以及低平均电压分别为0.71V和0.79V,显示它们可以是锂离子电池的良好阳极材料。
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