The origin of chemical inhomogeneity in garnet electrolytes and its impact on the electrochemical performance
The origin of chemical inhomogeneity in garnet electrolytes and its impact on the electrochemical performance
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DOI：
10.1039/d0ta04974c
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发表时间：
2020-07-28
影响因子：
11.9
通讯作者：
Aguadero, Ainara
中科院分区：
文献类型：
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作者：
Brugge, Rowena H.;Pesci, Federico M.;Aguadero, Ainara
固体电解质和锂金属电极之间的界面决定了全固态电池在要求高功率密度和防止锂枝晶形成的能力方面的性能。该界面强烈地取决于与金属阳极接触的固体电解质表面的性质。在石榴石电解质/锂系统中，大多数论文都集中在由锂金属电极中的空隙形成引起的电流不均匀性的作用以及在空气暴露后绝缘反应层的存在。然而，由化学和/或结构不均匀性引起的固体电解质中的扩展缺陷也可导致不均匀的电流分布，从而影响这些系统的性能。在这项工作中，我们使用互补的表面分析技术与不同的分析深度，以探测在表面和大量的石榴石型电解质的晶粒和晶界内的化学分布，以解释其电化学性能。我们发现，形态，后处理和储存条件可以极大地影响晶粒和晶界的表面化学分布。理解这些性质是重要的，因为它们将决定金属和电解质之间的界面区附近的离子和电子传输，这是确定化学机械稳定性的关键。
The interface between solid electrolytes and lithium metal electrodes determines the performance of an all-solid-state battery in terms of the ability to demand high power densities and prevent the formation of lithium dendrites. This interface depends strongly on the nature of the solid electrolyte surface in contact with the metallic anode. In the garnet electrolyte/Li system, most papers have focused on the role of current inhomogeneities induced by void formation in the Li metal electrode and the presence of insulating reaction layers following air exposure. However, extended defects in the solid electrolyte induced by chemical and/or structural inhomogeneities can also lead to uneven current distribution, impacting the performance of these systems. In this work, we use complementary surface analysis techniques with varying analysis depths to probe chemical distribution within grains and grain boundaries at the surface and in the bulk of garnet-type electrolytes to explain their electrochemical performance. We show that morphology, post-treatments and storage conditions can greatly affect the surface chemical distribution of grains and grain boundaries. These properties are important to understand since they will dictate the ionic and electronic transport near the interfacial zone between metal and electrolyte which is key to determining chemo-mechanical stability.