美国佐治亚理工学院Hailong Chen研究小组，通过调节集体阴离子运动，使固态卤化物电解质的超离子导电性成为可能。这一研究成果发表在2024年9月23日出版的国际学术期刊《自然—化学》上。

Li₃MX₆家族卤化物 (M=Y、In、Sc等; X =卤素)是新兴的全固态锂离子电池固体电解质材料。与现有的硫化物固体电解质相比，它们具有更高的化学稳定性和更宽的电化学稳定性窗口，但具有较低的室温离子电导率。

通过同步加速器X射线和中子散射表征，以及从头算分子动力学模拟，课题组发现Li₃YCl₆中的超离子跃迁是由阴离子的集体运动触发的。

基于这一发现，研究小组通过一种合理的设计策略来降低转变温度，从而提高这类化合物的室温离子电导率。研究小组据此合成了Li₃YCl_xBr_6-x和Li₃GdCl₃Br₃，并获得了非常高的室温电导率，Li₃YCl_4.5Br_1.5和Li₃GdCl₃Br₃分别为6.1和11 mS cm^-1。

这些发现为高性能固体电池的室温超离子导体的设计，开辟了新的途径。

附：英文原文

Title: Tuning collective anion motion enables superionic conductivity in solid-state halide electrolytes

Author: Liu, Zhantao, Chien, Po-Hsiu, Wang, Shuo, Song, Shaowei, Lu, Mu, Chen, Shuo, Xia, Shuman, Liu, Jue, Mo, Yifei, Chen, Hailong

Issue&Volume: 2024-09-23

Abstract: Halides of the family Li3MX6 (M=Y, In, Sc and so on, X=halogen) are emerging solid electrolyte materials for all-solid-state Li-ion batteries. They show greater chemical stability and wider electrochemical stability windows than existing sulfide solid electrolytes, but have lower room-temperature ionic conductivities. Here we report the discovery that the superionic transition in Li3YCl6 is triggered by the collective motion of anions, as evidenced by synchrotron X-ray and neutron scattering characterizations and ab initio molecular dynamics simulations. Based on this finding, we used a rational design strategy to lower the transition temperature and thus improve the room-temperature ionic conductivity of this family of compounds. We accordingly synthesized Li3YClxBr6x and Li3GdCl3Br3 and achieved very high room-temperature conductivities of 6.1 and 11mScm1 for Li3YCl4.5Br1.5 and Li3GdCl3Br3, respectively. These findings open new routes to the design of room-temperature superionic conductors for high-performance solid batteries.

DOI: 10.1038/s41557-024-01634-6

Source: https://www.nature.com/articles/s41557-024-01634-6