Energy Storage Science and Technology ›› 2023, Vol. 12 ›› Issue (8): 2412-2423.doi: 10.19799/j.cnki.2095-4239.2023.0236

• Energy Storage Materials and Devices • Previous Articles     Next Articles

Preparation of Sc/O-doped sulfide electrolyte for all-solid-state batteries

Zhengguang ZHAO1(), Zhenying CHEN2, Guangqun ZHAI1(), Xi ZHANG3, Xiaodong ZHUANG2,4()   

  1. 1.School of Materials Science and Engineering, Changzhou University, Changzhou 213164, Jiangsu, China
    2.The Meso-Entropy Matter Lab, State Key Laboratory of Metal Matrix Composites, Shanghai Key Laboratory of Electrical Insulation and Thermal Ageing, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University
    3.Intelligent Vehicle Research Institute, National Engineering Research Center of Automobile Power and Intelligent Control, School of Mechanical and Power Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
    4.Frontiers Science Center for Transformative Molecules, Zhang Jiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 201203, China
  • Received:2023-04-18 Revised:2023-05-05 Online:2023-08-05 Published:2023-08-23
  • Contact: Guangqun ZHAI, Xiaodong ZHUANG E-mail:20070305023@smail.cczu.edu.cn;zhai_gq@cczu.edu.cn;zhuang@sjtu.edu.cn

Abstract:

In recent years, sulfide solid-state electrolytes have attracted extensive attention from researchers due to their high safety, high ionic conductivity, wide electrochemical window, and several other advantages. Modification by doping is considered to be an effective approach to improve the electrochemical performance of sulfide solid-state electrolytes. Because of the unique electronic structure and functional properties of rare earth elements (REEs), doping these elements has emerged as one of the effective strategies to improve the ionic conductivity of solid electrolytes and reduce the grain boundary resistance. In this work, a series of modified sulfide solid electrolytes were synthesized using an REE compound, namely scandium oxide (Sc2O3), as a dopant. The doping of Sc2O3 was studied through X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and energy dispersive spectroscopy. The electrical conductivity was determined by the AC impedance method. The results showed that when the Sc2O3 doping amount was x=0.04 (Li6.08P0.96Sc0.04S4.94O0.06Cl), the sulfide solid-state electrolyte showed a high ionic conductivity of up to 3.17 × 10-3 S/cm. A lithium-lithium symmetric battery was assembled using the as-prepared sulfide solid-state electrolyte. The battery showed a high critical current density of 0.95 mA/cm2 and a stable cycling process over 300 h at a current density of 0.1 mA/cm2. The Li6.08P0.96Sc0.04S4.94O0.06Cl-based all-solid-state battery showed the first-cycle charge-discharge specific capacity of 249.0 and 191.2 mAh/g and the first-cycle charge-discharge efficiency of 76.78%. After 950 cycles, it could maintain a specific discharge capacity of 123 mAh/g. Even after exposure to the air for 90 min, the electrolyte exhibited good crystallinity and cycling performance for all-solid-state batteries. This work proposed a new dopant for improving the electrochemical performance of Li6PS5Cl-type sulfide solid-state electrolytes.

Key words: sulfide solid electrolyte, ionic conductivity, doping modification, all-solid-state battery

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