Solid Li-ion conductors require high ionic conductivity to ensure rapid Li⁺ transport within solid-state batteries, necessitating a thorough examination of the relationship between the structure and Li⁺ transport mechanisms. Factors such as crystal symmetries, anion electronegativity, and Li-anion bond lengths are critical in influencing the ionic conductivities of solid conductors. Furthermore, the relationship between Li⁺ transport and the dynamic behavior of anions, particularly through mechanisms such as the paddle-wheel effect, highlights the complexity of ionic transport in solid conductors. In this study, we focus on investigating the antiperovskite-type ionic conductor Li₂OHX (X = Cl or Br), which integrates various static structural features with dynamic anion behavior, to delve deeper into the structure–function relationship. Employing Rietveld refinement on neutron powder diffraction, maximum entropy method analysis, and ab initio molecular dynamics simulations, our findings reveal that Li⁺ transport is influenced not only by static structural properties like space groups, anion electronegativity, Li vacancies, and Li–O bond lengths but also, and more crucially, by the dynamics of OH^– anions. These insights highlight the pivotal role of anion dynamics and offer foundational guidelines for designing solid ionic conductors.

中文翻译：

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探索固体导体中的离子传输机制：静态结构特性和阴离子动力学的双重视角


固体锂离子导体需要高离子电导率，以确保固态电池内的锂 ⁺ 快速传输，因此需要彻底检查结构和锂 ⁺ 传输机制之间的关系。晶体对称性、阴离子电负性和锂阴离子键长等因素在影响固体导体的离子电导率方面至关重要。此外，Li ⁺ 传输与阴离子动态行为之间的关系，特别是通过桨轮效应等机制，突出了固体导体中离子传输的复杂性。在这项研究中，我们专注于研究反钙钛矿型离子导体 Li ₂ OHX（X = Cl 或 Br），它将各种静态结构特征与动态阴离子行为相结合，以更深入地研究结构-功能关系。采用中子粉体衍射的 Rietveld 精炼、最大熵法分析和从头分子动力学模拟，我们的研究结果表明，Li ⁺ 输运不仅受空间群、阴离子电负性、Li 空位和 Li-O 键长等静态结构特性的影响，而且更关键的是，还受到 OH ^– 动力学的影响阴 离子。这些见解突出了阴离子动力学的关键作用，并为设计固体离子导体提供了基础指南。