Abstract Lithium garnet-like structure with the substitution of Zr 4+ sites by the same value of Ge 4+ in the Li 7 La 3 Zr 2 O 12 (LLZO) has been synthesized by a solid state reaction. The results indicate that doping Ge 4+ in the LLZO was able to reduce the sintering temperature as well as increase the density of the pellets. The prepared samples Li 7 La 3 Zr 2−x Ge x O 12 with cubic garnet like structure were characterized by X-ray diffraction and Raman spectra. The lithium ionic conductivity of all components was characterized by AC impendence at 20 °C, and the high ionic conductivity can be obtained with 4.78 × 10 −4 S/cm, while a low activation energy was only about 0.29 eV in the temperature range from 253 to 213 K. The solid electrolyte of Li 7 La 3 Zr 2−x Ge x O 12 possessed a wide electrochemical window. A full cell containing the Li 7 La 3 Zr 1.7 Ge 0.3 O 12 electrolyte was assembled to test the electrical performance, which demonstrates that the first discharge capacity can reach up to 139.1 mA g −1 at 0.1 C and the discharge capacity remains at 140.6 mA g −1 after 20 cycles. These excellent performances indicate that Ge doping LLZO could be a promising electrolyte candidate for all solid state Li ion batteries.

中文翻译：

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全固态锂离子电池Li 7 La 3 Zr 2-x Ge x O 12 石榴石状固体电解质的结构和离子电导率

摘要 通过固相反应合成了Li 7 La 3 Zr 2 O 12 (LLZO) 中Zr 4+ 位点被相同Ge 4+ 取代的类锂石榴石结构。结果表明，在LLZO中掺杂Ge 4+ 能够降低烧结温度并增加球团的密度。制备的具有立方石榴石结构的Li 7 La 3 Zr 2-x Ge x O 12 样品通过X射线衍射和拉曼光谱表征。所有组分的锂离子电导率在 20 °C 时均表现为交流阻抗，可以获得 4.78 × 10 -4 S/cm 的高离子电导率，而在 20 °C 的温度范围内，活化能仅为 0.29 eV 左右。 253 至 213 K。Li 7 La 3 Zr 2-x Ge x O 12 固体电解质具有较宽的电化学窗口。组装含有Li 7 La 3 Zr 1.7 Ge 0.3 O 12 电解液的全电池进行电学性能测试，结果表明0.1 C下首次放电容量可达139.1 mA g -1 ，放电容量保持在140.6 20 次循环后 mA g -1。这些优异的性能表明 Ge 掺杂的 LLZO 可能是全固态锂离子电池的有前途的电解质候选者。