Research Progress on Halide Solid‐State Electrolytes: Synthesis, Mechanism, and Modification

ABSTRACT Halide solid‐state electrolytes (HSSEs) have gained significant attention as key components for all‐solid‐state lithium ion batteries due to their notable advantages, including high ionic conductivity (> 1 mS cm −1 ), wide electrochemical window (> 4 V vs. Li/Li⁺), and good compatibility with high‐voltage cathodes. Despite progress, major challenges such as ionic conductivity, air stability, and interface compatibility still remain. This review systematically summarizes their representative classifications (e.g., Li a ‐M‐X 8 , Li a ‐M‐X 6 , Li a ‐M‐X 4 , Li a M b O c X d , M = In, Y, Al…; X = Cl, F, Br…), synthesis methods (e.g., solid phase, liquid phase, gas phase), and ion conduction…

• NN
  National Natural Science Foundation of China

  Awards: U20A20253, 22279116, 22379020, 52372235
• KL
  Key Laboratory of Engineering Dielectrics and Its Application (Harbin University of Science and Technology), Ministry of Education

  Award: KFM 202303
• SA
  Science and Technology Department of Zhejiang Province

  Award: 2023C01231
• NS
  Natural Science Foundation of Zhejiang Province

  Awards: LD25E020003, LQ23E020009