Recently, there has been strong interest in inorganic solid-state electrolytes for all-solid-state batteries, among which the garnet electrolyte LLZO has attracted much attention due to its excellent properties, such as high ionic conductivity and broad electrochemical stability. The aim of our study was to improve the performance of Ta-doped LLZO (LLZTO) by co-doping Ga and Y at the Li and La sites using conventional solid-phase synthesis methods. We thoroughly investigated how Ga and Y affect the microstructure and electrochemical properties of LLZTO. The results show that the relative density of Ga- and Y-doped LLZTO increases significantly up to 94% under the same sintering conditions. This doping resulted in a significant increase in ionic conductivity from 2.0 × 10 S·cm to 1.05 × 10 S·cm and a decrease in electronic conductivity from 2.16 × 10 S·cm to 9.18 × 10 S·cm. Subsequently, the symmetric cells were assembled and tested, and it was found that the interfaces of the doped solid-state electrolytes were much more stable and that the cycling time was longer. Thus, our study successfully coordinated the co-doping of Ga, Y, and Ta, providing valuable insights for the subsequent production of LLZO materials with higher densities and better performance. This study is a promising step toward the realization of safer all-solid-state batteries with higher energy densities.

中文翻译：

---

Ga和Y共掺杂增强LLZTO固态电解质的微观结构和电化学性能

近年来，人们对用于全固态电池的无机固态电解质产生了浓厚的兴趣，其中石榴石电解质LLZO因其优异的性能（例如高离子电导率和广泛的电化学稳定性）而备受关注。我们研究的目的是通过使用传统的固相合成方法在 Li 和 La 位点共掺杂 Ga 和 Y 来提高 Ta 掺杂 LLZO (LLZTO) 的性能。我们深入研究了 Ga 和 Y 如何影响 LLZTO 的微观结构和电化学性能。结果表明，在相同的烧结条件下，Ga和Y掺杂的LLZTO的相对密度显着增加至94%。这种掺杂导致离子电导率从 2.0 × 10 S·cm 显着增加到 1.05 × 10 S·cm，电子电导率从 2.16 × 10 S·cm 降低到 9.18 × 10 S·cm。随后，对对称电池进行组装和测试，发现掺杂固态电解质的界面更加稳定，循环时间更长。因此，我们的研究成功协调了Ga、Y和Ta的共掺杂，为后续生产具有更高密度和更好性能的LLZO材料提供了宝贵的见解。这项研究是朝着实现更安全、更高能量密度的全固态电池迈出的有希望的一步。