Controlled electrode aging and nanoscale electrolytes for solid oxide fuel cells
Abstract/Contents
- Abstract
- Solid oxide fuel cells (SOFCs) are a compelling energy conversion technology due to their high efficiency and fuel flexibility, but their commercialization has largely been limited by high operating temperatures (800-1000°C). Recent research efforts have focused on nanoscale SOFC membranes via MEMS-type fabrication and have demonstrated low-to-intermediate temperature operation (250-550°C) with improved device performance. Porous platinum is commonly used as the electrode material in these research devices, but it is unfortunately subject to coarsening at even moderate temperatures, leading to degradation of the electrodes and ultimately reduction of device performance. In order to investigate the evolution of porous Pt electrodes and evaluate nanoscale YSZ electrolytes, we fabricated two types of SOFCs with identical electrodes: bulk-YSZ (100um-thick) electrolyte with 115nm-thick porous Pt electrodes; and atomic layer deposited (ALD) nano-YSZ (30nm-thick, varying compositions) electrolyte with 115nm-thick porous Pt electrodes. This dissertation begins with a general introduction to solid oxide fuel cells, fundamentals of their operation, and key metrics for their evaluation. The second part of this dissertation focuses on bulk-YSZ SOFCs, which were the subject of an electrode pre-treatment study, and which also served as baseline devices for comparison with nano-YSZ SOFCs. In this pre-treatment study, we observed that cycling air and forming gas over the anode resulted in an immediate, sustained, and significant enhancement of the current density compared to devices tested without pre-treatment. The apparent enhanced current density was accompanied by a 10x enhancement of SOFC performance and a 93% reduction in total electrode resistance. The third and fourth parts of this dissertation focus on the ALD of YSZ and subsequent characterization of SOFCs fabricated with 30nm-thick YSZ membranes of varying composition. These SOFC membranes tested are among the thinnest reported.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2012 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Ginestra, Cynthia Natalie |
|---|---|
| Associated with | Stanford University, Department of Materials Science and Engineering |
| Primary advisor | McIntyre, Paul Cameron |
| Thesis advisor | McIntyre, Paul Cameron |
| Thesis advisor | Bent, Stacey |
| Thesis advisor | Prinz, F. B |
| Advisor | Bent, Stacey |
| Advisor | Prinz, F. B |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Cynthia Natalie Ginestra. |
|---|---|
| Note | Submitted to the Department of Materials Science and Engineering. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2012. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2012 by Cynthia Natalie Ginestra
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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