Anion‐Engineering Modified Halide Electrolyte Li _3.25 Zr _0.75 Cl ₃ O _1.125 F with High‐Voltage Stability for all‐Solid‐State Lithium Batteries

ABSTRACT Inorganic solid‐state electrolytes (SEs) with high ionic conductivities and high‐voltage stability are essential for all‐solid‐state lithium batteries (ASSLBs) with high energy densities. Herein, a series of zirconium‐based halide solid electrolytes (LZCOF‐x, 0.25≤x≤1.75) is prepared by anion‐engineering modified strategy, which exhibit high ionic conductivity exceeding 1 mS cm −1 and high‐voltage compatibility up to 4.8 V. The multiple pathways for facile Li + diffusion and the formation of disordered Zr‐Cl/O/F polyhedrons enable high ionic conductivities and high‐voltage stability for LZCOF‐x. Remarkably, the ASSLBs with the Li 3.25 Zr 0.75 Cl 3 O 1.125 F electrolyte and different high‐voltage cathodes exhibit an impressive electrochemical performance. The enhanced electrochemical performance is attributed to the elevated oxidation potential of LZCOF‐x and robust interfacial stability between cathode and electrolyte. This work provides a feasible strategy for designing tri‐anion Zr‐based halide electrolytes with high ionic conductivity and high‐voltage compatibility to achieve ASSLBs with high energy densities.