Microstructural impacts on ionic conductivity of oxide solid electrolytes from a combined atomistic-mesoscale approach
Microstructural impacts on ionic conductivity of oxide solid electrolytes from a combined atomistic-mesoscale approach
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DOI：
10.1038/s41524-021-00681-8
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发表时间：
2021-12
影响因子：
9.7
通讯作者：
T. Heo;Andrew C. Grieder;Bo Wang;M. Wood;Tim Hsu;S. Akhade;L. Wan;Long-qing Chen;N. Adelstein-N.-Ad
中科院分区：
文献类型：
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作者：
T. Heo;Andrew C. Grieder;Bo Wang;M. Wood;Tim Hsu;S. Akhade;L. Wan;Long-qing Chen;N. Adelstein-N.-Ad
尽管已经出现了具有固有高离子电导率的多种氧化物基固体电解质材料，但实际的加工和合成路线引入了可能干扰主传导通道的晶界和其他界面。为了直接探测这些影响，我们展示了一种有效的和通用的介观计算方法，能够通过复杂的多晶氧化物基固体电解质微结构预测有效的离子电导率，而不依赖于简化的等效电路描述。我们参数化的框架Li 7-xLa 3 Zr 2 O 12（LLZO）石榴石固体电解质相场模拟与分子动力学模拟的有序和无序系统的扩散系数相结合的合成微观结构。系统设计的模拟揭示了原子和介观微观结构对多晶LLZO的有效离子电导率的影响之间的相互依赖关系，通过新定义的表征复杂离子传输机制的指标进行量化。我们的研究结果提供了基本的理解的物理起源的基础上广泛的分析文献数据的离子电导率的变化，同时概述了实际的设计指导，以实现所需的离子传输性能的基础上的条件下，微观结构特征的敏感性是最高的。我们的研究结果的其他影响进行了讨论，包括离子传导行为和枝晶形成之间的可能联系。
Although multiple oxide-based solid electrolyte materials with intrinsically high ionic conductivities have emerged, practical processing and synthesis routes introduce grain boundaries and other interfaces that can perturb primary conduction channels. To directly probe these effects, we demonstrate an efficient and general mesoscopic computational method capable of predicting effective ionic conductivity through a complex polycrystalline oxide-based solid electrolyte microstructure without relying on simplified equivalent circuit description. We parameterize the framework for Li7-xLa3Zr2O12(LLZO) garnet solid electrolyte by combining synthetic microstructures from phase-field simulations with diffusivities from molecular dynamics simulations of ordered and disordered systems. Systematically designed simulations reveal an interdependence between atomistic and mesoscopic microstructural impacts on the effective ionic conductivity of polycrystalline LLZO, quantified by newly defined metrics that characterize the complex ionic transport mechanism. Our results provide fundamental understanding of the physical origins of the reported variability in ionic conductivities based on an extensive analysis of literature data, while simultaneously outlining practical design guidance for achieving desired ionic transport properties based on conditions for which sensitivity to microstructural features is highest. Additional implications of our results are discussed, including a possible connection between ion conduction behavior and dendrite formation.