- Title
- Electrodeposited thin films of manganese dioxide for electrochemical capacitors
- Creator
- Cross, Andrew D.
- Relation
- University of Newcastle Research Higher Degree Thesis
- Resource Type
- thesis
- Date
- 2018
- Description
- Research Doctorate - Doctor of Philosophy (PhD)
- Description
- This thesis details the search for factors which influence the electrochemically capacitive performance of electrodeposited thin films of manganese dioxide (MnO₂). In the initial investigation (Chapter Two), the focus was on altering deposition conditions (i.e., solution composition, deposition potential, duration of deposition, and deposition solution temperature), and observing the resultant capacitive behaviour. From these experiments, the best performing materials showed an improvement in specific capacitance of at least 250% over other materials reported in the literature. Analysis of the results showed a link between slower mass transport characteristics of electro-active species during deposition, and an improvement on the resulting specific capacitance. Improved specific capacitance was thought to relate to an increase in the access of cycling electrolyte to the electrode surface, i.e., an increase in electrode surface area. Additionally, an inversely proportional relationship between deposition time and specific capacitance was also established. The second article (Chapter Three) compared films formed during constant-potential (chronoamperometry) and constant-current (galvanostatic) deposition protocols. While galvanostatic deposition protocols did not tend to yield higher specific capacitances than their equivalent chronoamperometric experiments, some possible insight into the deposition of manganese dioxide was gained. The third article (Chapter Four), more closely examines changes in mass during chronoamperometric electrodeposition. The work compared mass of electrode thin films calculated during deposition via three methods. This article discussed the results in terms of underlying assumptions associated with each of these methods, and any complicating factors which may influence mass calculation. The fourth and final article (Chapter Five), extends on from the work in Chapter Four, with a focus on the effect of altering the anions present during deposition. Anomalous behaviour of the chloride-containing system were hypothesised to be due to a combination of the enhanced stability of the Mn(III) intermediate in certain solution conditions, and the tendency of the available chloride ions to complex with this manganese species. In these final two studies, the capacitive behaviour of the manganese dioxide thin films was also compared.
- Subject
- electrochemistry; electrochemical capacitors; manganese dioxide; thin films; electrodeposition; energy storage; thesis by publication
- Identifier
- http://hdl.handle.net/1959.13/1388292
- Identifier
- uon:32739
- Rights
- Copyright 2018 Andrew D. Cross
- Language
- eng
- Full Text
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| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | ATTACHMENT01 | Thesis | 7 MB | Adobe Acrobat PDF | View Details Download | ||
| View Details Download | ATTACHMENT02 | Abstract | 5 MB | Adobe Acrobat PDF | View Details Download |