2024 Annual Meeting of Japan Association of Mineralogical Sciences (JAMS)

Presentation information

Oral presentation

R2: Crystal structure, crystal chemistry, physical properties of minerals, crystal growth and applied mineralogy

Sat. Sep 14, 2024 9:00 AM - 12:00 PM ES024 (Higashiyama Campus)

Chairperson:Fumiya Noritake, Mariko Nagashima, Makoto Tokuda

11:30 AM - 11:45 AM

[R2-10] Study on the consistency of Li conductivity measurements of (Li,La)TiO3 with perovskite structure and Li migration during SIMS measurements

*Isao SAKAGUCHI1, Tsuyoshi Onishi1 (1. National Institute for Materials Science)

Keywords:Perovskite structure

Introduction
Research and development for carbon neutrality is widely conducted. Among of these, many resources are devoted to these regarding all-solid-state lithium secondary batteries. Many oxides are proposed as electrolytes for all-solid-state lithium batteries. Among of these, we focus on (Li,La)TiO3 with perovskite structure. Secondary ion mass spectrometry, which is advantageous for light element analysis, is impossible to analyze Li in this material at room temperature. This time, we tried a method to Li battery electrolytes.
Experiment
(Li,La)TIO3 (hereinafter referred to as LLT) can be purchased in plates, disks, powder, etc. from Toho Titanium Co., Ltd. At this time, we used a plate shape as a standard sample. A comparative sample for this was newly synthesized. The analysis used SIMS (CAMECA, IMS-4f) equipped with NIMS, and O- as primary ions was used and positive secondary ions were detected.
Results and Discussion
Figure 1 shows the analysis results of the purchased LLT. Figure 1(a) is Li image immediately after primary ion irradiation, and Li showed the uniform intensity, and some precipitates with high intensity were observed. Figure 1(b) is Li image after continuous irradiation with O-. Obvious non-uniformity of Li was observed in the image. Considering this, the Li intensity distribution in Figure 1(b) reflects the micro-structure within the sample. When primary ions, O-, are irradiated during analysis, the irradiated area becomes negative charge, and then Li with positive charge moves to compensate for its charge. The region where Li has changed to a high intensity is a large grain, and the Li conductivity reaches 1x10-3 S/cm. It is thought that because the current density of primary ions is small, Li that has migrated to the surface reacts with oxygen and generates LiOx. it is considered that such non-uniform Li intensity was generated because the amount of Li movement within the disk was small.
Summary
In materials such as the electrolyte in Li batteries, Li moves through the material at room temperature. This research revealed that Li can be moved by changing the charge state on the surface through primary ion irradiation, and that the migration path of Li is the same as that of movement known by electrical measurements.
R2-10