韩国首尔大学Kisuk Kang团队报道了调节阳离子有序无序的三角卤化物超离子导体设计。相关研究成果于2023年11月3日发表于国际一流学术期刊《科学》。

锂金属卤化物已成为一类固体电解质，它可以提供与最先进的硫化物电解质相当的超离子导电性，以及适用于高压（>4V）操作的电化学稳定性。研究表明，在三元卤化物（如Li₃MCl₆[其中金属（M）为Y或Er]）中的超离子传导受平面内锂渗流路径和堆叠层间距离的控制。这两个因素通过M的部分占据而相互反相关，M既是扩散抑制剂，又是保持层间距离的支柱。

这些发现表明，在三角卤化物中存在M的临界范围或有序性，研究人员通过调整简单的M比率（每Cl或Li）来展示高离子电导率的实现。研究人员提供了超离子三元卤化物电解质的通用设计标准。

附：英文原文

Title: Design of a trigonal halide superionic conductor by regulating cation order-disorder

Author: Seungju Yu, Joohyeon Noh, Byunghoon Kim, Jun-Hyuk Song, Kyungbae Oh, Jaekyun Yoo, Sunyoung Lee, Sung-O Park, Wonju Kim, Byungwook Kang, Donghyun Kil, Kisuk Kang

Issue&Volume: 2023-11-03

Abstract: Lithium-metal-halides have emerged as a class of solid electrolytes that can deliver superionic conductivity comparable to that of state-of-the-art sulfide electrolytes, as well as electrochemical stability that is suitable for high-voltage (>4 volt) operations. We show that the superionic conduction in a trigonal halide, such as Li3MCl6 [where metal (M) is Y or Er], is governed by the in-plane lithium percolation paths and stacking interlayer distance. These two factors are inversely correlated with each other by the partial occupancy of M, serving as both a diffusion inhibitor and pillar for maintaining interlayer distance. These findings suggest that a critical range or ordering of M exists in trigonal halides, and we showcase the achievement of high ionic conductivity by adjusting the simple M ratio (per Cl or Li). We provide general design criteria for superionic trigonal halide electrolytes.

DOI: adg6591

Source: https://www.science.org/doi/10.1126/science.adg6591