Computational study of Li3BO3 and Li3BN2 I: Electrolyte properties of pure and doped crystals
Computational study of Li3BO3 and Li3BN2 I: Electrolyte properties of pure and doped crystals
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DOI：
10.1103/physrevmaterials.5.085402
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发表时间：
2021-08
影响因子：
3.4
通讯作者：
Yan Li;Zachary D. Hood;N. Holzwarth
中科院分区：
文献类型：
--
作者：
Yan Li;Zachary D. Hood;N. Holzwarth
${\mathrm{Li}}_{3}{\mathrm{BO}}_{3}$ 和 ${\mathrm{Li}}_{3}{\mathrm{BN}}_{2}$ 材料都具有良好的性能，可用于全固态电池和其他依赖于具有显着离子电导率的电解质的技术。作为两部分研究的第一部分，本文报告了对这些材料的单斜晶形式的锂离子扩散的详细模拟分析。使用 NEB 和 MD 方法，很明显，通过空位机制的锂离子迁移在每种材料中提供了最有效的离子传输。虽然结果表明这些材料中的间隙缺陷在锂离子迁移中没有直接作用，但它们的相对稳定性似乎通过形成弗兰克尔型缺陷来增强空位的产生。这可以部分解释为什么通过最初含有单个锂离子空位的样品的MD模拟计算出的锂离子电导率与本工作中${\mathrm{Li}}_{3}{\mathrm{BO}}_{3}$的测量值以及文献中报告的两种材料的不良结晶样品的测量值相当一致。还研究了通过替代掺杂（${\mathrm{Li}}_{3}{\mathrm{BO}}_{3}$中的O为F，${\mathrm{Li}}_{3}{\mathrm{BN}}_{2}$中的B为C）来增加空位浓度的可能性，发现模拟的电导率与理想空位模型的电导率相当。
Both ${\mathrm{Li}}_{3}{\mathrm{BO}}_{3}$ and ${\mathrm{Li}}_{3}{\mathrm{BN}}_{2}$ materials have promising properties for use in all-solid-state batteries and other technologies dependent on electrolytes with significant ionic conductivity. As the first of a two-part study, this paper reports the analysis of detailed simulations of Li ion diffusion in the monoclinic forms of these materials. Using both NEB and MD methods, it is clear that Li ion migration via vacancy mechanisms provides the most efficient ion transport in each material. While the results suggest that interstitial defects in these materials do not play a direct role in Li ion migration, their relative stability seems to enhance vacancy production via the formation of Frenkel-type defects. This may partially explain why the Li ion conductivities computed from MD simulations of samples initially containing a single Li ion vacancy are in reasonable agreement with measured values of this work for ${\mathrm{Li}}_{3}{\mathrm{BO}}_{3}$ and those reported in the literature for poorly crystalline samples of both materials. The possibility of increasing vacancy concentrations by substitutional doping (F for O in ${\mathrm{Li}}_{3}{\mathrm{BO}}_{3}$ and C for B in ${\mathrm{Li}}_{3}{\mathrm{BN}}_{2}$) is also examined, finding simulated conductivities comparable to those of the ideal vacancy model.