# Thermophysical Properties of Lithium Aluminum Germanium Phosphate with Different Compositions

Rohde, Magnus; Cui, Yuantao; Ziebert, Carlos; Seifert, Hans Jürgen

##### Abstract:
The NASICON system LAGP (Li$_{1+x}$Al$_{x}$Ge$_{2-x}$ (PO$_{4}$)$_{3}$ was studied, which is a candidate material for solid state electrolytes. LAGP substrates with different compositions (x = 0.3–0.7) were prepared using a melt quenching route with subsequent heat treatment. In order to develop a better understanding of the relationships between the structure and the ionic as well as the thermal conductivity, respectively, the samples were characterized by X-ray diffraction. The ionic conductivity was measured using impedance spectroscopy while the thermal diffusivity and the specific heat were determined by Laser Flash technique and differential scanning calorimetry, respectively. Additionally, thermal analysis was performed in order to evaluate the thermal stability a higher temperatures and, also to identify the optimum temperature range of the thermal post-processing. The measured values of the ionic conductivities were in the range of 10$^{-4}$Ω$^{-1}$·cm$^{-1}$ to 10$^{-3}$ Ω$^{-1}$·cm$^{-1}$ at room temperature, but exhibited an increasing behavior as a function of temperature reaching a level of the order 10$^{-2}$ Ω$^{-1}$· cm$^{-1}$ above 200 °C. ... mehr

 Zugehörige Institution(en) am KIT Institut für Angewandte Materialien - Angewandte Werkstoffphysik (IAM-AWP) Publikationstyp Zeitschriftenaufsatz Publikationsmonat/-jahr 03.2020 Sprache Englisch Identifikator ISSN: 0195-928X, 1572-9567 KITopen-ID: 1000105689 HGF-Programm 37.01.02 (POF III, LK 01)Components and Cells Erschienen in International journal of thermophysics Band 41 Heft 3 Seiten Art. Nr.: 31 Vorab online veröffentlicht am 30.01.2020 Schlagwörter Ionic conductivity, Solid electrolyte, Superionics, Thermal conductivity Nachgewiesen in ScopusWeb of Science
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