南方科技大学卢周广团队揭示了三元旋转聚阴离子耦合实现四氟硼酸盐离子掺杂的，反钙钛矿Li₂OHCl固体电解质中的快速锂离子动力学。相关研究成果于2024年4月16日发表于国际一流学术期刊《德国应用化学》。

富锂反钙钛矿（LiRAP）羟基卤化物由于其低熔点、低成本和易于扩大规模，正成为全固态锂金属电池（ASSLMBs）的有吸引力的固体电解质。旋转聚阴离子的引入可以降低活化能，从而提高SE的锂离子电导率。

该文中，研究人员提出了一种三元旋转聚阴离子耦合策略，以固定四氟硼酸盐（BF₄^–）离子掺杂的LiRAP Li₂OHCl中的Li离子传导。借助第一性原理计算、粉末X射线衍射、固态磁共振和电化学阻抗谱，证实了锂离子在BF₄离子掺杂的Li₂OHCl中的传输与OH^–、BF₄^–和Li₂–O–H八面体之间的旋转耦合密切相关，这使锂离子的电导率提高了1.8倍以上，活化能降低了0.03eV。

该项工作为设计具有多聚阴离子的高性能超离子导体提供了新的视角。

附：英文原文

Title: Ternary Rotational Polyanion Coupling Enables Fast Li Ion Dynamics in Tetrafluoroborate Ion Doped Antiperovskite Li2OHCl Solid Electrolyte

Author: Juncao Bian, Sifan Ling, Bei Deng, Haibin Lin, Ruo Zhao, Long Kong, Huimin Yuan, Jinlong Zhu, Songbai Han, Liping Wang, Ruiqin Zhang, Yusheng Zhao, Zhouguang Lu

Issue&Volume: 2024-04-16

Abstract: Li-rich antiperovskite (LiRAP) hydroxyhalides are emerging as attractive solid electrolyte (SEs) for all-solid-state Li metal batteries (ASSLMBs) due to their low melting point, low cost, and ease of scaling-up. The incorporation of rotational polyanions can reduce the activation energy and thus improve the Li ion conductivity of SEs. Herein, we propose a ternary rotational polyanion coupling strategy to fasten the Li ion conduction in tetrafluoroborate (BF4–) ion doped LiRAP Li2OHCl. Assisted by first-principles calculation, powder X-ray diffraction, solid-state magnetic resonance and electrochemical impedance spectra, it is confirmed that Li ion transport in BF4– ion doped Li2OHCl is strongly associated with the rotational coupling among OH–, BF4– and Li2–O–H octahedrons, which enhances the Li ion conductivity for more than 1.8 times with the activation energy lowering 0.03 eV. This work provides a new perspective to design high-performance superionic conductors with multi-polyanions.

DOI: 10.1002/anie.202400144

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202400144