Dissertation
Defect Engineering of Ceramic Oxide Materials
Washington State University
Doctor of Philosophy (PhD), Washington State University
12/2024
DOI:
https://doi.org/10.7273/000007174
Abstract
To gain an atomic scale understanding of defects in materials, density functional theory has become a widely used tool. Density functional theory allows to assess the thermodynamically accessible defects and their impacts on properties. This work looks at two different classes of materials, including the defect roles in yttrium doped CeO2 and their impacts on structural and mechanical properties. The filling of anti-bonding states at the Fermi level for certain defects is reported to lead to mechanical instabilities. Further work considers all solid-state lithium ion batteries using the garnet-type Li7La3Zr2O12 (LLZO) solid electrolyte. The effects of cross diffusion at the catholyte interface are investigated. The impact of Al-doping in the cathode LiCoO2 (LCO) on Li diffusion kinetics is elucidated where the Al is present due to diffusion from LLZO into LCO. Co-site doping promotes Li-ion diffusion following the monovacancy diffusion mechanism, but a wide distribution of Li migration barriers is found, and non-uniform Li incorporation and distribution is expected during cycling. Further, electronic effects in Co-doped LLZO are studied where Co is found due to diffusion from LCO into LLZO. Battery operation can be hindered due to increased electronic conductivity upon Co-doping of LLZO.
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Details
- Title
- Defect Engineering of Ceramic Oxide Materials
- Creators
- Jordan Alysia Barr
- Contributors
- Scott P. Becman (Chair)John McCloy (Committee Member)Soumik Banerjee (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- School of Mechanical and Materials Engineering
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Publisher
- Washington State University
- Number of pages
- 116
- Identifiers
- 99901195200601842
- Language
- English
- Resource Type
- Dissertation