Book/Dissertation / PhD Thesis

FZJ-2019-06295

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Micromechanical Characterization of Ceramic Solid Electrolytes for Electrochemical Storage Devices

Nonemacher, J. F. (Corresponding author)FZJ*

2020
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag Jülich
ISBN: 978-3-95806-461-4

Please use a persistent id in citations: http://hdl.handle.net/2128/25466  urn:nbn:de:0001-2020102045

Abstract: The use of solid electrolytes in solid-state batteries offers safer operation, higher performance in terms of energy storage, as well as high thermal and chemical stability. Furthermore, solid electrolytes are expected to possess enhanced ionic conductivity and mechanical stability that warrants a safer separation of cathode and anode, and hence, potentially permits them to withstand long-term cycling operation. However, mechanical boundary conditions and operation as electrolyte under cyclic loading might still induce micro-cracks, dendrite growth, structural and mechanical failure that ultimately will terminate the battery life. Therefore, the mechanical reliability of solid electrolytes is important to warrant long-term reliability of solid state batteries. In this thesis, aiming at a characterization of reliability and life-time relevant aspects, the mechanical properties of Li$_{7}$La$_{3}$Zr$_{2}$O$_{12}$ for the application as solid electrolyte are studied on amicro-scale and the correlation to the materials microstructural characteristics. Mechanical investigations are based on indentation testing, yielding elastic modulus hardness and fracture toughness, where the use of an advanced micro-pillar testing methodology permitted to gain insight into the fracture properties of individual grains. The results emphasis the importance of the materials microstructure as well as the used testing loads, which illustrate effects related to the local apparent plasticity, and for larger loads localized pores. Overall, combining nano- and micro-indentation testing yields elastic modulus, hardness and fracture toughness with respect to materials intrinsic properties and global properties, where the use of standard Vickers indentation and the novel micro-pillar splitting test permit assessment of the fracture toughness of individual grains and effects related to grain boundaries and pores.

Note: RWTH Aachen, Diss., 2019

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Contributing Institute(s):

1. Werkstoffstruktur und -eigenschaften (IEK-2)

Research Program(s):

1. 113 - Methods and Concepts for Material Development (POF3-113) (POF3-113)

Appears in the scientific report 2019

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Database coverage:
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