Combined quantitative microscopy on the microstructure and phase evolution in Li1.3Al0.3Ti1.7(PO4)3 ceramics

Journal of Advanced Ceramics, vol. 9, pp. 149–161

Abstract

Abstract Lithium aluminum titanium phosphate (LATP) is one of the materials under consideration as an electrolyte in future all-solid-state lithium-ion batteries. In ceramic processing, the presence of secondary phases and porosity play an important role. In a presence of more than one secondary phase and pores, image analysis must tackle the difficulties about distinguishing between these microstructural features. In this study, we study the phase evolution of LATP ceramics sintered at temperatures between 950 and 1100 °C by image segmentation based on energy-dispersive X-ray spectroscopy (EDS) elemental maps combined with quantitative analysis of LATP grains. We found aluminum phosphate (AlPO4) and another phosphate phase ((Lix)PyOz). The amount of these phases changes with sintering temperature. First, since the grains act as an aluminum source for AlPO4 formation, the aluminum content in the LATP grains decreases. Second, the amount of secondary phase changes from more (Lix)PyOz at 950 °C to mainly AlPO4 at 1100 °C sintering temperature. We also used scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) to study the evolution of the LATP grains and AlPO4, and LATP grain size increases with sintering temperature. In addition, transmission electron microscopy (TEM) was used for the determination of grain boundary width and to identify the amorphous structure of AlPO4.

Authors 6

1. Deniz Cihan Gunduz corresponding Aachen Institute of Physical Chemistry

   Forschungszentrum Jülich · Helmholtz-Institute Münster · RWTH Aachen University

   Affiliation as printed

   Forschungszentrum Jülich, Institute of Energy and Climate Research (IEK-12: Helmholtz-Institute Münster: Ionics in Energy Storage), Münster, D-48149, Germany

   Forschungszentrum Jülich, Institute of Energy and Climate Research (IEK-9: Fundamental Electrochemistry), Jülich, D-52425, Germany

   RWTH Aachen University, Institute of Physical Chemistry, Aachen, D-52074, Germany

2. Roland Schierholz corresponding

   Forschungszentrum Jülich

   Affiliation as printed

   Forschungszentrum Jülich, Institute of Energy and Climate Research (IEK-9: Fundamental Electrochemistry), Jülich, D-52425, Germany

3. Shicheng Yu

   Forschungszentrum Jülich

   Affiliation as printed

   Forschungszentrum Jülich, Institute of Energy and Climate Research (IEK-9: Fundamental Electrochemistry), Jülich, D-52425, Germany

4. Hermann Tempel

   Forschungszentrum Jülich

   Affiliation as printed

   Forschungszentrum Jülich, Institute of Energy and Climate Research (IEK-9: Fundamental Electrochemistry), Jülich, D-52425, Germany

5. Hans Kungl

   Forschungszentrum Jülich

   Affiliation as printed

   Forschungszentrum Jülich, Institute of Energy and Climate Research (IEK-9: Fundamental Electrochemistry), Jülich, D-52425, Germany

6. Rüdiger‐A. Eichel Aachen Institute of Physical Chemistry

   Forschungszentrum Jülich · Helmholtz-Institute Münster · RWTH Aachen University

   Affiliation as printed

   Forschungszentrum Jülich, Institute of Energy and Climate Research (IEK-12: Helmholtz-Institute Münster: Ionics in Energy Storage), Münster, D-48149, Germany

   Forschungszentrum Jülich, Institute of Energy and Climate Research (IEK-9: Fundamental Electrochemistry), Jülich, D-52425, Germany

   RWTH Aachen University, Institute of Physical Chemistry, Aachen, D-52074, Germany