Li_1+xAl_xGe_2–x(PO₄)₃ (LAGP) is a solid lithium-ion conductor belonging to the NASICON family, representing the solid solution of LiGe₂(PO₄)₃ and AlPO₄. The typical syntheses of LAGP either involve high-temperature melt-quenching, which is complicated and expensive, or a sol–gel process requiring costly organic germanium precursors. In this work, we report a simple method based on aqueous solutions without the need of ethoxide precursors. Using synchrotron and neutron diffraction, the crystal structure, the occupancies for Al and Ge, and the distribution of lithium were determined. Substitution of germanium by aluminum allows for an increased Li⁺ incorporation in the material and the actual Li⁺ content in the sample increases with the nominal Li⁺ content and a solubility limit is observed for higher aluminum content. By means of impedance spectroscopy, an increase in the ionic conductivity with increasing lithium content is observed. Whereas the lithium ionic conductivity improves, due to the increasing carrier density, the bulk activation energy increases. This correlation suggests that changes in the transport mechanism and correlated motion may be at play in the Li_1+xAl_xGe_2–x(PO₄)₃ solid solution.

中文翻译：

---

水溶液制备的Li _{1+ x} Al _x Ge _{2– x}（PO ₄）₃（LAGP）中的输运和结构性质相关

Li _{1+ x} Al _x Ge _{2– x}（PO ₄）₃（LAGP）是属于NASICON系列的固体锂离子导体，代表LiGe ₂（PO ₄）₃和AlPO ₄的固溶体。LAGP的典型合成要么涉及复杂且昂贵的高温熔融淬火，要么涉及需要昂贵有机锗前体的溶胶-凝胶工艺。在这项工作中，我们报告了一种基于水溶液的简单方法，不需要乙醇前体。使用同步中子和中子衍射，确定晶体结构，Al和Ge的占有率以及锂的分布。铝取代锗可以增加材料中的Li ⁺掺入量，并且样品中的实际Li ⁺含量随标称Li ^+的增加而增加铝含量较高时，可观察到其含量和溶解度极限。通过阻抗光谱法，观察到离子电导率随锂含量的增加而增加。尽管锂离子电导率提高了，但是由于载流子密度的增加，整体活化能增加了。这种相关性表明，在Li _{1+ x} Al _x Ge _{2– x}（PO ₄）₃固溶体中，传输机制的变化和相关的运动可能正在起作用。