Nanostructured materials for alternative energy devices : supercapacitors, ultracapacitors, and lithium ion batteries
Abstract/Contents
- Abstract
- Energy storage and generation are the biggest technological challenges of our generation. Among various devices attracting attention are supercapacitors and ultracapacitors. These devices have higher power densities than rechargeable batteries, meaning that energy can be withdrawn and inserted more quickly, but they currently have insufficiently high energy densities to become widespread within commercial applications. In addition, ultracapacitors tend to use expensive organic electrolytes while supercapacitors tend to use either scarce or expensive metal oxides, and both devices in academia tend to report results based on extremely low mass loadings of active materials (microgram scale). To enhance the commercial viability of supercapacitors and ultracapacitors as feasible complementary energy storage devices to lithium ion batteries such as during the fast time scale regenerative braking process in electric or hybrid cars, these energy density and cost issues must be addressed. In this dissertation, porous 3D metallic nickel foam is used as a high surface area catalyst and substrate for carbon nanofiber growth and ultimately enables mass loadings of carbon nanofibers one or two orders of magnitude higher (tens of milligrams per square centimeter) than in other academically demonstrated devices to enable superior top-down, per-area capacitance, energy density, and power density ultracapacitor results. A different study is also presented that demonstrates that by way of lithium ion battery charging and discharging steps, in which lithium ions are inserted and extracted during each cycle and leave porous voids behind in the host structures, nanostructures such as silicon nanowires, zinc oxide nanorods, and silver nanowires can achieve controllable, tunable porosities. This general method of tuning porosities of nanostructures should provide a novel tool for researchers to control nanostructure morphologies.
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 | McDonough, James Raymond |
|---|---|
| Associated with | Stanford University, Department of Materials Science and Engineering |
| Primary advisor | Cui, Yi, 1976- |
| Thesis advisor | Cui, Yi, 1976- |
| Thesis advisor | Clemens, Bruce A |
| Thesis advisor | Melosh, Nicholas A |
| Advisor | Clemens, Bruce A |
| Advisor | Melosh, Nicholas A |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | James R. McDonough. |
|---|---|
| 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 James Raymond McDonough
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