[Fakultät 5]
Microscopic and Spectroscopic Analysis of Thin-Films Solid-State Materials for Lithium-Ion Batteries Application,
Herr Alireza Mohammadian Kia, M.Sc.
Mittwoch, 14. Februar 2024, 09:00 Uhr
Raum 309, Institut für nanoskalige und biogene Materialien, Gustav-Zeuner-Straße 3
The integration of energy storage devices into microchips, driven by technological advancements, has resulted in higher power density and smaller device sizes. As a result, on-chip integration of solid-state thin-film batteries on Si substrates becomes a feasible solution for autonomous microsystems, with the added benefit of improved safety. This thesis centers on enhancing the performance of solid-state lithium-ion batteries (SS-LIBs) by gaining a comprehensive understanding of the interactions between different layers. Key factors impacting battery performance and lifespan are investigated, including functional interfaces, interaction mechanisms, chemical compositions, Li-ion distribution, and diffusion barrier layers. To accomplish this goal and gain accurate insights, a diverse set of analytical techniques, such as TEM, XPS, and ToF-SIMS, were employed. The research emphasizes the importance of incorporating various complementary analysis methods to achieve precise and comprehen-sive outcomes in the study of advanced materials.
[Fakultät 3]
Petrology, geochemistry, and geochronology of the Flamenco pluton: implications for the building of the Coastal Batholith (26° S) in northern Chile,
Frau Dipl.-Geol. Natalia Marlene Rodriguez Rodriguez
Mittwoch, 28. Februar 2024, 14:00 Uhr
Besprechungsraum Geophysik, Otto-Meißer-Bau, Gustav-Zeuner-Straße 12, 1. OG
The Flamenco pluton is the westernmost part of the Coastal Batholith in Chile at the latitude of 26°S and represents the earliest Cordilleran-type magmas emplaced in the magmatic arc during the onset of the Andean Cycle. The magmatic facies that constitute the Flamenco pluton and their host rocks have been studied using petrological and structural techniques to evaluate and establish the emplacement mechanism of the pluton. The techniques adopted included field mapping, petrography, mineral chemistry, thermobarometry, whole rock major and trace element geochemistry, U-P geochronology, and detailed structural study. Field relations, geochemistry, and geochronology of the magmatic facies revealed three distinguishable domains separated by metasedimentary septa. The Flamenco pluton was emplaced sequentially in upper crustal levels. The presence of transcurrent shear zones with transpressive segments favored the access of intruding magmas to the final emplacement level.
[Fakultät 4]
Reciprocal influence between MgO-C refractory materials with different MgO grade and a steel melt and the resulting effect on non-metallic inclusions, Herr Dipl.-Ing. Florian Kerber
Freitag, 22. März 2024, 09:30 Uhr
Hörsaal Silikattechnik, SIL-0118, Haus Silikattechnik, Agricolastraße 17, EG
The thesis addressed the effect of a varying MgO grade in MgO-C refractories on both their behavior in contact with a steel melt and the resulting effect on the non-metallic inclusion (NMI) population in the solidified steel. For this purpose, immersion tests were conducted in a semi-industrial steel casting simulator. In addition, the effect of the steel melting process parameters on the NMI population was thoroughly investigated, providing a guideline for the result interpretation for future experiments in the steel casting simulator. Here, a fundamental concept of data evaluation for the NMI characterization in a steel matrix using automated feature analysis was developed. The main NMI types detected in the solidified steel samples were Al2O3 and MnSi-based inclusions. Their number density depended on the steel melt’s temperature and amount of dissolved oxygen. A lower MgO grade refractory specimen in contact with the steel melt resulted in a higher proportion of low melting phases on its surface compared to a higher MgO grade specimen. These low-melting phases promoted the formation of MnSi-based inclusions and triggered NMI agglomeration leading to the formation of large Al2O3 inclusions.