Journal of Energy Chemistry ›› 2023, Vol. 86 ›› Issue (11): 499-509.DOI: 10.1016/j.jechem.2023.07.028

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Synergy of I-Cl co-occupation on halogen-rich argyrodites and resultant dual-layer interface for advanced all-solid-state Li metal batteries

Han Yana, Ruifeng Songa, Ruonan Xua, Shulin Lia, Qiaoquan Linb, Xinlin Yanc, Zhenyu Wangd,*, Chuang Yue,*, Long Zhanga,b,*   

  1. aClean Nano Energy Center, State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, Hebei, China;
    bFujian Provincial Key Laboratory of Quantum Manipulation and New Energy Materials, College of Physics and Energy, Fujian Normal University, Fuzhou 350117, Fujian, China;
    cInstitute of Solid State Physics, Vienna University of Technology, Wiedner Hauptstr. 8-10, 1040 Vienna, Austria;
    dGuilin Electrical Equipment Scientific Research Institute Co. Ltd., Guilin 541004, Guangxi, China;
    eState Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430000, Hubei, China
  • Received:2023-06-10 Revised:2023-07-15 Accepted:2023-07-20 Online:2023-11-15 Published:2023-11-07
  • Contact: *E-mail addresses: wzy2012bg@163.com (Z. Wang), cyu2020@hust.edu.cn (C. Yu), longzhang2023@163.com (L. Zhang).

Abstract: The (electro)chemical stability and Li dendrite suppression capability of sulfide solid electrolytes (SEs) need further improvement for developing all-solid-state Li batteries (ASSLBs). Here, we report advanced halogen-rich argyrodites via I and Cl co-occupation on the crystal lattice. Notably, a proper I content forms a single phase, whereas an excessive I causes precipitation of two argyrodite phases like a superlattice structure. The resultant synergistic effect of the optimized composition allows to gain high ionic conductivities at room temperature and -20 °C, and enhances the (electro)chemical stability against Li and Li dendrite suppression capability. The Li|argyrodite interface is very sensitive to the ratio of I and Cl. A LiCl- and LiI-rich double-layer interface is observed from the cell using the SE with optimized composition, whereas too high I content forms only a single interface layer with a mixture of LiI and LiCl. This double-layer interface is found to effectively mitigate the Li/SE reaction. The proper designed argyrodite enables ASSLBs to achieve good electrochemical properties at a broad temperature range regardless of the electrode materials. This co-occupation strategy provides a novel exploration for advanced halogen-rich argyrodite system.

Key words: Sulfide solid electrolytes, Argyrodites, Dual doping, Li metal anode, Solid-state batteries