Schön Nino, Gunduz Deniz Cihan, Yu Shicheng, Tempel Hermann, Schierholz Roland, Hausen Florian
Forschungszentrum Jülich, Institute of Energy and Climate Research, IEK-9, 52425 Jülich, Germany.
RWTH Aachen University, Institute of Physical Chemistry, 52074 Aachen, Germany.
Beilstein J Nanotechnol. 2018 May 28;9:1564-1572. doi: 10.3762/bjnano.9.148. eCollection 2018.
Correlative microscopy has been used to investigate the relationship between Li-ion conductivity and the microstructure of lithium aluminum titanium phosphate (LiAlTi(PO), LATP) with high spatial resolution. A key to improvement of solid state electrolytes such as LATP is a better understanding of interfacial and ion transport properties on relevant length scales in the nanometer to micrometer range. Using common techniques, such as electrochemical impedance spectroscopy, only global information can be obtained. In this work, we employ multiple microscopy techniques to gain local chemical and structural information paired with local insights into the Li-ion conductivity based on electrochemical strain microscopy (ESM). Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) have been applied at identical regions to identify microstructural components such as an AlPO secondary phase. We found significantly lower Li-ion mobility in the secondary phase areas as well as at grain boundaries. Additionally, various aspects of signal formation obtained from ESM for solid state electrolytes are discussed. We demonstrate that correlative microscopy is an adjuvant tool to gain local insights into interfacial properties of energy materials.
相关显微镜技术已被用于以高空间分辨率研究锂离子电导率与磷酸锂铝钛（LiAlTi(PO₄)₃，LATP）微观结构之间的关系。改进诸如LATP之类的固态电解质的关键在于更好地理解在纳米到微米范围内相关长度尺度上的界面和离子传输特性。使用诸如电化学阻抗谱等常规技术，只能获得全局信息。在这项工作中，我们采用多种显微镜技术来获取局部化学和结构信息，并基于电化学应变显微镜（ESM）对锂离子电导率进行局部洞察。扫描电子显微镜（SEM）和能量色散X射线光谱（EDX）已应用于相同区域，以识别诸如AlPO次生相之类的微观结构成分。我们发现在次生相区域以及晶界处锂离子迁移率显著降低。此外，还讨论了从固态电解质的ESM获得的信号形成的各个方面。我们证明相关显微镜技术是一种辅助工具，可用于深入了解能量材料的界面特性。
