All-solid-state batteries (ASSBs) require solid electrolytes with high ionic conductivity, stability, and deformability for optimal energy and power density. We developed lithium-deficient lithium yttrium bromide (LYB) solid electrolytes, Li_3–xYBr_6–x (0 ≤ x ≤ 0.50), using a comelting method with controlled lithium deficiency. These electrolytes exhibit favorable mechanical properties such as high moldability and sliceability. The Li_2.65YBr_5.65 composition has an ionic conductivity of 4.49 mS cm^–1 at 25 °C and an activation energy of 0.28 eV. Compared to Li₃YBr₆, Li_2.65YBr_5.65 demonstrates improved rate performance and cycling stability in ASSBs. High-resolution X-ray diffraction confirms the formation of the LYB phase with a C2/m space group. Structural analysis reveals increased cation disorder and larger polyhedral volumes for x > 0 in Li_3–xYBr_6–x , contributing to reduced Li⁺ migration energy barriers. Bond valence site energy calculations and molecular dynamics simulations reveal enhanced 3D lithium-ion transport. NMR spectroscopy further highlights increased Li⁺ dynamics and impurity elimination.

中文翻译：

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用于全固态电池的可切片、可模塑和高导电电解质


全固态电池 （ASSB） 需要具有高离子电导率、稳定性和可变形性的固体电解质，以实现最佳能量和功率密度。我们使用受控缺锂缺乏锂的共熔方法开发了缺锂溴化钇锂 （LYB） 固体电解质 Li_{3–x YBr6–x} （0 ≤ x ≤ 0.50）。这些电解质表现出良好的机械性能，例如高成型性和可切片性。Li_2.65YBr_5.65 成分在 25 °C 时的离子电导率为 4.49 mS cm^–1，活化能为 0.28 eV。与 Li₃YBr₆ 相比，Li_2.65YBr_5.65 在 ASSBs 中表现出更好的倍率性能和循环稳定性。高分辨率 X 射线衍射证实了 LYB 相的形成与 C2/m 空间群。结构分析显示 Li_3–xYBr_6–x 中 x > 0 的阳离子无序增加和多面体体积增大，有助于减少 Li⁺ 迁移能垒。键价位点能量计算和分子动力学模拟揭示了增强的 3D 锂离子传输。NMR 波谱进一步突出了 Li⁺ 动力学和杂质消除的增加。