In this work we investigated a novel approach to prepare Li-La-Zr-O solid-state electrolyte films by the suspension plasma spray process. This process offers several advantages that make it a promising low-cost, rapid and robust production method for garnet-type Li-ion conductors. A cubic garnet-type, Li_6.75La₃Zr_1.75Nb_0.25O₁₂, ethanol-based suspension was plasma sprayed on stainless-steel substrates using two torch power levels, 30.9 and 77.1 kW, at different stand-off distances. Solid-state electrolyte films of ~14 μm thickness were deposited in ~0.1 h of spraying. Maximum Li-ion conductivity as high as 7.3·10⁻⁶ S cm⁻¹ at 22 °C has been obtained for the samples sprayed at 30.9 kW and stand-off distance of 25 mm. These samples contained a majority of amorphous phase (67.0 wt%), 20.2 wt% of Li_6.75La₃Zr_1.75Nb_0.25O₁₂, and the balance of 12.8 wt% of the pyrochlore phase (La₂Zr₂O₇). We associate this result with the relatively high value of Li number density, 2.2·10²² cm⁻³, and the lowest content of La₂Zr₂O₇. The higher torch power level and/or longer stand-off distance leads to a reduction in Li number density and higher content of La₂Zr₂O₇, likely due to evaporative loss of Li species during the spray process. These factors also translate to a decrease in Li-ion conductivity. The knowledge that has been acquired in this preliminary study provides guidelines for further development and optimization of this rapid deposition technique of garnet-type solid-state electrolyte films.

在这项工作中，我们研究了一种通过悬浮等离子体喷涂工艺制备 Li-La-Zr-O 固态电解质膜的新方法。该工艺提供了多种优势，使其成为一种很有前景的石榴石型锂离子导体的低成本、快速和稳健的生产方法。立方石榴石型 Li _6.75 La ₃ Zr _1.75 Nb _0.25 O ₁₂乙醇基悬浮液使用两个火炬功率水平，30.9 和 77.1 kW，以不同的间隔距离等离子喷涂在不锈钢基材上。在约 0.1 小时的喷涂中沉积了约 14 μm 厚的固态电解质膜。最大锂离子电导率高达 7.3·10 ^-6  S cm ^-1对于以 30.9 kW 和 25 mm 的间隔距离喷涂的样品，已经获得了在 22 °C 的温度。这些样品包含大部分无定形相(67.0wt%)、20.2wt%的Li _6.75 La ₃ Zr _1.75 Nb _0.25 O ₁₂和12.8wt%的烧绿石相(La ₂ Zr ₂ O ₇ )。我们将此结果与相对较高的 Li 数密度值 2.2·10 ²²  cm ^-3和最低的 La ₂ Zr ₂ O ₇含量联系起来. 较高的火炬功率水平和/或较长的间隔距离导致 Li 数密度降低和 La ₂ Zr ₂ O ₇含量较高，这可能是由于喷涂过程中 Li 物质的蒸发损失。这些因素也转化为锂离子电导率的降低。在这项初步研究中获得的知识为进一步开发和优化这种石榴石型固态电解质薄膜的快速沉积技术提供了指导。