Full text
| |
| Author(s): |
Maykel dos Santos Klem
Total Authors: 1
|
| Document type: | Master's Dissertation |
| Press: | Bauru. 2017-11-28. |
| Institution: | Universidade Estadual Paulista (Unesp). Faculdade de Ciências. Bauru |
| Defense date: | 2017-09-27 |
| Advisor: | Neri Alves |
| Abstract | |
In this study, we first produced a standard supercapacitor using stainless steel collectors and Aquadag® graphite electrodes. The device exhibited a maximum capacitance of 22 F/g, and an R(C(RW))(RC)(RC) circuit modeled its impedance spectrum. With this device was possible to test the production methods of supercapacitors, and identify its desirable characteristics. Two different printing techniques were tested to produce electrodes/current collectors. The active material used in the electrodes was PEDOT: PSS, with addition of graphene oxide, Aquadag® graphite and multi-walled carbon nanotubes (MWNT), in order to obtain conductive composites. Morphological and electrical characterizations were performed over the surfaces of printed electrodes onto filter, vegetable and bond paper. The electrode produced by screen-printing using the PEDOT: PSS/MWNT composite printed onto filter paper exhibited low sheet resistance (17 Ω /sqr), being used in the production of supercapacitors. Printed supercapacitor showed good capacitive behavior through impedance spectroscopy and cyclic voltammetry measurements. An R(RC)(C(RQ)(RC) circuit modeled the impedance spectrum, evidencing a high double layer capacitance. A maximum specific capacitance of 20.3 F / g was found for a charge/discharge current of 1 mA, and an equivalent series resistance of 60 Ω. These values led to energy and power densities of 3.1 Wh / kg and 420 W / kg, respectively. Simulations and curve fitting were also performed from DC analyzes, using a parallel RC circuit coupled with a series resistance, obtaining important parameters for the practical use of supercapacitors. (AU) | |
| FAPESP's process: | 15/18091-8 - Study of organic supercapacitors printed onto paper based on PEDOT:PSS |
| Grantee: | Maykel dos Santos Klem |
| Support Opportunities: | Scholarships in Brazil - Master |