Stability and ionic mobility in argyrodite-related lithium-ion solid electrolytes
Stability and ionic mobility in argyrodite-related lithium-ion solid electrolytes
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DOI：
10.1039/c5cp01841b
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发表时间：
2015-01-01
影响因子：
3.3
通讯作者：
Adams, Stefan
中科院分区：
文献类型：
--
作者：
Chen, Hao Min;Chen Maohua;Adams, Stefan
在寻找用于开发具有高能量密度的安全可再充电全固态电池的快速锂离子传导固体的过程中，硫代磷酸盐和相关化合物已被证明是特别有前途的，因为它们的创纪录的离子传导率和它们通常低的电荷转移电阻。在这项工作中，我们探索了广泛的已知和预测的硫代磷酸盐，特别关注的立方argyrodite相与强大的三维网络的离子迁移途径。结构和水解稳定性的计算采用密度泛函方法与预测相关的临界反应的普遍适用的方法相结合。在这些argyrodites的离子迁移的活化能，然后使用经验的键价途径方法在我们的小组中开发的计算，而选定的argyrodites的带隙计算作为评估的电化学窗口的基础。锂化合物的调查结果也进行了比较，以前已知的铜argyrodites和假设的钠argyrodites。由此，在寻找实用的锂和钠固体电解质材料时，得到具有化学稳定性和离子导电性之间的最佳平衡的相的实验工作的指导方针。
In the search for fast lithium-ion conducting solids for the development of safe rechargeable all-solid-state batteries with high energy density, thiophosphates and related compounds have been demonstrated to be particularly promising both because of their record ionic conductivities and their typically low charge transfer resistances. In this work we explore a wide range of known and predicted thiophosphates with a particular focus on the cubic argyrodite phase with a robust three-dimensional network of ion migration pathways. Structural and hydrolysis stability are calculated employing density functional method in combination with a generally applicable method of predicting the relevant critical reaction. The activation energy for ion migration in these argyrodites is then calculated using the empirical bond valence pathway method developed in our group, while bandgaps of selected argyrodites are calculated as a basis for assessing the electrochemical window. Findings for the lithium compounds are also compared to those of previously known copper argyrodites and hypothetical sodium argyrodites. Therefrom, guidelines for experimental work are derived to yield phases with the optimum balance between chemical stability and ionic conductivity in the search for practical lithium and sodium solid electrolyte materials.