Quantifying the impact of disorder on Li-ion and Na-ion transport in perovskite titanate solid electrolytes for solid-state batteries
Quantifying the impact of disorder on Li-ion and Na-ion transport in perovskite titanate solid electrolytes for solid-state batteries
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DOI：
10.1039/d0ta05343k
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发表时间：
2020-09
影响因子：
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通讯作者：
Adam R. Symington;J. Purton;Joel Statham;M. Molinari;Saiful M. Islam;S. C. Parker
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文献类型：
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作者：
Adam R. Symington;J. Purton;Joel Statham;M. Molinari;Saiful M. Islam;S. C. Parker
用于全固态电池的固体电解质作为提高其安全性、稳定性和性能的一种手段引起了相当大的研究兴趣。结构紊乱的控制对固体电解质结构具有重大影响，但通常没有得到充分表征。在这里，我们提出了一项全面的原子学研究，使用钙钛矿 Li3xLa(2/3)−xTiO3 (0 < x < 0.16) (LLTO) 及其钠类似物 Na3xLa(2/3)−xTiO3 (0 < x < 0.16) (NLTO) 作为模型固体电解质，量化结构无序对离子输运的影响。我们应用大规模原子模拟来分析烧结和合成条件对其阳离子无序和离子传输行为的影响。我们的结果预测高温合成会在两种电解质中产生高水平的 A 位无序。无序 LLTO 样品的电导率始终高于有序系统的电导率，表明无序与锂离子电导率之间呈正相关。这种行为也可以在 NLTO 中看到，但该系统的电导率非常低，这表明 NLTO 不是合适的电解质。我们讨论了有序-无序在离子电导率方面的作用，并提供了定制实验合成条件的指南，从而优化了高性能固体电解质。
Solid electrolytes for all-solid-state batteries are generating considerable research interest as a means to improving their safety, stability and performance. Manipulation of structural disorder has a significant impact on solid electrolyte structures, but is often not fully characterised. Here, we present a comprehensive atomistic study that quantifies the effect of structural disorder on ionic transport using the perovskite Li3xLa(2/3)−xTiO3 (0 < x < 0.16) (LLTO) and its sodium analogue Na3xLa(2/3)−xTiO3 (0 < x < 0.16) (NLTO) as model solid electrolytes. We apply large-scale atomistic simulations to analyze the impact of sintering and synthesis conditions on their cation disorder and ion transport behavior. Our results predict that high temperature synthesis imparts high levels of A-site disorder in both electrolytes. The conductivities for disordered LLTO samples are consistently higher than those of ordered systems, indicating the positive correlation between disorder and Li-ion conductivity. This behavior can also be seen in NLTO, but this system suffers from very low conductivity indicating that NLTO would not be a suitable electrolyte. We discuss the role of order–disorder in the context of ionic conductivity and provide guidelines to tailor experimental synthesis conditions that can lead to the optimization of high-performance solid electrolytes.