Superionic Conducting Halide Frameworks Enabled by Interface-Bonded Halides
Superionic Conducting Halide Frameworks Enabled by Interface-Bonded Halides
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DOI：
10.1021/jacs.2c09446
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发表时间：
2022-12-30
影响因子：
15
通讯作者：
Sun, Xueliang
中科院分区：
文献类型：
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作者：
Fu, Jiamin;Wang, Shuo;Sun, Xueliang
三元卤化物Li-M-X(M=Y，In，Zr等；X=F，Cl，Br)作为固体电解质(SSES)的复兴，由于其与高压阴极的直接兼容性和良好的室温离子导电性，在实现实用化的固态电池方面具有广阔的前景。已报道的大多数上离子卤化物SSE具有[MCl6]x-八面体的结构模式，并产生一个四面体辅助的Li+离子扩散途径。在这里，我们报道了一类新的类沸石卤化物骨架，例如，SmCl3，其中一维通道被[SmCl9]6-三顶三角棱柱包围，为Li+离子跃迁提供了两个八面体之间2.08埃的短跳跃距离。通过从头算分子动力学模拟，验证了Li+沿通道的快速扩散。与沸石类似，SmCl3骨架可以在不改变碱基结构的情况下接枝卤化物物种来获得可移动的离子，以氯化锂为吸附剂，在30℃下获得10-4 S cm-1以上的离子电导率。此外，还论证了一类骨架材料的界面键合行为和离子扩散的普遍性。结果表明，MCl3/卤化物复合材料(M=La-Gd)的离子电导率可能与接枝卤化物物种的离子电导率、界面成键和骨架组成/尺寸有关。这项工作揭示了一类潜在的卤化物结构，并为在卤化物材料中构建类沸石骨架开辟了新的前沿，这将促进快离子导体设计的创新，并有助于更广泛地选择卤化物SSE。
The revival of ternary halides Li-M-X (M = Y, In, Zr, etc.; X = F, Cl, Br) as solid-state electrolytes (SSEs) shows promise in realizing practical solid-state batteries due to their direct compatibility toward high-voltage cathodes and favorable room temperature ionic conductivities. Most of the reported superionic halide SSEs have a structural pattern of [MCl6]x- octahedra and generate a tetrahedron-assisted Li+ ion diffusion pathway. Here, we report a new class of zeolite-like halide frameworks, SmCl3, for example, in which 1-dimensional channels are enclosed by [SmCl9]6- tricapped trigonal prisms to provide a short jumping distance of 2.08 angstrom between two octahedra for Li+ ion hopping. The fast Li+ diffusion along the channels is verified through ab initio molecular dynamics simulations. Similar to zeolites, the SmCl3 framework can be grafted with halide species to obtain mobile ions without altering the base structure, achieving an ionic conductivity over 10-4 S cm-1 at 30 degrees C with LiCl as the adsorbent. Moreover, the universality of the interface-bonding behavior and ionic diffusion in a class of framework materials is demonstrated. It is suggested that the ionic conductivity of the MCl3/halide composite (M = La-Gd) is likely in correlation with the ionic conductivity of the grafted halide species, interfacial bonding, and framework composition/dimensions. This work reveals a potential class of halide structures for superionic conductors and opens up a new frontier for constructing zeolite-like frameworks in halide-based materials, which will promote the innovation of superionic conductor design and contribute to a broader selection of halide SSEs.