As a potential solid-state electrolyte material, Li-containing A-site deficient perovskite oxides have attracted the attention of researchers because of their high Li-ion conductivity and the relationship between Li-ion conduction and structural characteristics, which has been intensively investigated. We have recently confirmed a quasi-periodic ordered arrangement of La and vacancies (Vac) at the perovskite A-sites of Li_xLa_(1-x)/3NbO₃ (LLNO) using a combination of density functional theory (DFT), Monte Carlo simulations, and electron diffraction. Interestingly, two types of modulated arrangements, namely closed and striped structures, coexist in the La-rich layer, which affect Li-ion migration. In this study, DFT-derived force-field molecular dynamics (FFMD) simulations were performed to investigate the effect of a modulated structure on the migration behavior of Li ions in LLNO compounds. The results indicate that the type of modulated arrangements of La/Vac has a significant influence on the migration of Li ions. Moreover, the estimated diffusion coefficients of the modulated structures are higher by a factor of 10 than those of La/Vac disordered models at 800 K. The migration energy in the ab plane appeared to be much lower than along the c-axis, controlling the modulated arrangement of LLNO is beneficial to eliminate La-ion blockage during long-distance migration. Accordingly, the present study reveals that the controlling cation/Vac arrangement at perovskite A-sites is crucial for achieving high Li-ion conductivity. At the same time, the research scheme of this work is also applicable to other solid electrolyte materials, which provides research guidance for high-throughput material retrieval.

作为一种潜在的固态电解质材料，含锂 A 位缺陷钙钛矿氧化物因其高锂离子电导率以及锂离子传导与结构特性之间的关系而引起了研究人员的关注，并已得到深入研究。我们最近在 Li _x La _(1-x)/3 NbO ₃的钙钛矿 A 位点证实了 La 和空位 (Vac) 的准周期有序排列(LLNO) 结合使用密度泛函理论 (DFT)、蒙特卡罗模拟和电子衍射。有趣的是，两种类型的调制排列，即封闭结构和条纹结构，共存于富 La 层，影响锂离子迁移。在这项研究中，进行了 DFT 衍生的力场分子动力学 (FFMD) 模拟，以研究调制结构对 LLNO 化合物中锂离子迁移行为的影响。结果表明，La/Vac 的调制排列类型对锂离子的迁移有显着影响。此外，调制结构的估计扩散系数比 800 K 时 La/Vac 无序模型的扩散系数高 10 倍。 ab 平面中的迁移能量似乎远低于沿 c 轴的迁移能量，控制LLNO的调制排列有利于消除长距离迁移过程中的La离子阻塞。因此，本研究表明，控制钙钛矿 A 位的阳离子 / Vac 排列对于实现高锂离子电导率至关重要。同时，本工作的研究方案也适用于其他固体电解质材料，为高通量材料检索提供了研究指导。