Dissertation
Fundamentals of the oxidative chemical vapor deposition of polyaniline and its applications in supercapacitors
Doctor of Philosophy (Ph.D.), Drexel University
Jul 2020
DOI:
https://doi.org/10.17918/00000054
Abstract
Compared to batteries, supercapacitors have higher power density but suffer from lower energy density. To improve energy density, conducting polymers can be used to store charge via energy-dense redox reactions. Together with their ease in synthesis and low cost, conducing polymers are promising electrode materials for supercapacitors. Among different conducting polymers, polyaniline (PANI) is attractive as it has one of the highest specific capacitance. Proposed by Simon and Gogotsi,[1] integrating conducting polymers including PANI with carbon supercapacitors can lead to a synergetic effect that takes advantage of both the carbon and conducting polymer materials. Traditional integration methods are based on liquid processing. Due to the low solubility of PANI and the wetting issues of liquids, these methods have limited abilities in effectively integrating PANI into nanoscale carbon materials. Here, a liquid-free oxidative chemical vapor deposition (oCVD) approach aims to overcome these challenges. Instead of relying on PANI solutions, oCVD utilizes vaporized aniline monomers and transition metal halide oxidants as precursors to synthesize solid PANI polymer thin films on surfaces under low pressure. By utilizing gas phase reactants, both reactants can easily diffuse through nanoscale carbon substrates, adsorb onto the surface and then initialize the polymerization, which will result in conformal and uniform coatings. Additionally, processing parameters of oCVD, including substrate temperature, operating pressure and reactant flow rates, can be easily and precisely tuned. Previous studies have shown that by optimizing the deposition conditions, emeraldine PANI, which is the electrically conductive state of PANI, can be conformally and uniformly deposited onto carbide derived carbon (CDC) supercapacitor electrodes. This composite showed enhanced charge storage ability.[2]
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Details
- Title
- Fundamentals of the oxidative chemical vapor deposition of polyaniline and its applications in supercapacitors
- Creators
- Xiaobo Li
- Contributors
- Kenneth K. S. Lau (Advisor)
- Awarding Institution
- Drexel University
- Degree Awarded
- Doctor of Philosophy (Ph.D.)
- Publisher
- Drexel University; Philadelphia, Pennsylvania
- Number of pages
- xv, 92 pages
- Resource Type
- Dissertation
- Language
- English
- Academic Unit
- Chemical (and Biological) Engineering (1970-2026); College of Engineering (1970-2026); Drexel University
- Other Identifier
- 991014695233704721