Solid Halide Electrolytes with High Lithium‐Ion Conductivity for Application in 4 V Class Bulk‐Type All‐Solid‐State Batteries

Abstract

New lithium halide solid-electrolyte materials, Li YCl and Li YBr , are found to exhibit high lithium-ion conductivity, high deformability, and high chemical and electrochemical stability, which are required properties for all-solid-state battery (ASSB) applications, particularly for large-scale deployment. The lithium-ion conductivities of cold-pressed powders surpass 1 mS cm at room temperature without additional intergrain or grain boundary resistances. Bulk-type ASSB cells employing these new halide solid electrolyte materials exhibit coulombic efficiencies as high as 94% with an active cathode material of LiCoO without any extra coating. These superior electrochemical characteristics, as well as their material stability, indicate that lithium halide salts are another promising candidate for ASSB solid electrolytes in addition to sulfides or oxides.

Ni‐Rich Layered Cathode Materials with Electrochemo‐Mechanically Compliant Microstructures for All‐Solid‐State Li Batteries

“…Additionally, it should be noted that the results herein for FCG75 were obtained with the bare sample. Further improvement in performance could be possible by intensive interfacial engineering, such as the application of protective coatings and/or the development of advanced SE materials with improved oxidation stability, which will be our next mission in future.…”

Mechanochemical Synthesis: A Tool to Tune Cation Site Disorder and Ionic Transport Properties of Li3MCl6 (M = Y, Er) Superionic Conductors

“…Challenged by the oxidative instability of the thiophosphate‐based electrolyte, recently, the rare‐earth halides Li 3 YX 6 (X = Cl, Br) have attracted interest as they exhibit high ionic conductivity on the order of 1 mS cm −1 and have been reported to exhibit an enhanced oxidative stability to higher potentials . In addition, by combining multiple descriptors for fast ionic motion along with the need for high stability, Li 3 ErCl 6 , Li 3 LaI 6 , and Li 3 InCl 6 were found to exhibit a high ionic conductivity.…”

“…Using single‐crystal diffraction data, Steiner et al proposed an orthorhombic unit cell for Li 3 YCl 6 while recent studies suggest a trigonal unit cell for Li 3 YCl 6 and the isostructural Li 3 ErCl 6 . The structures of Li 3 M Cl 6 ( M = Y, Er; space group Pm1) can be described as M Cl 6 3− octahedra forming a trigonal lattice ( Figure 1 ), where the Wyckoff position 1 a are occupied by M 1.…”

Enhanced Surface Interactions Enable Fast Li+ Conduction in Oxide/Polymer Composite Electrolyte

“…Inorganic oxide (e.g., Ga/Ta‐doped garnet Li 7 La 3 Zr 2 O 12 ), sulfide (e.g., argyrodite Li 6 PS 5 Cl), and halide (e.g., Li 3 YCl 6 ) electrolytes, with a high room‐temperature Li + conductivity above 10 −3 S cm −1 have been identified. However, large interfacial resistance with electrodes, instability with Li‐metal anode, and the small critical current density at which the lithium dendrites penetrate the solid electrolyte and short circuit the cell limit the application of inorganic electrolytes in all‐solid‐state Li‐metal batteries .…”