Banca de QUALIFICAÇÃO: DENIS FERNANDO ALVARENGA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : DENIS FERNANDO ALVARENGA
DATE: 29/07/2021
TIME: 14:00
LOCAL: Plataforma RNP
TITLE:

DEVELOPMENT OF FLEXIBLE ELECTRODE COMPOSITES OF CARBON NANOTUBE/CELLULOSE NANOFIBRILS FOR APPLICATION IN REDOX SUPERCAPACITORS

KEY WORDS:

Supercapacitors, composite film, cellulose nanofibrils, carbon nanotubes, redox electrolytes.

PAGES: 92
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Físico-Química
SPECIALTY: Eletroquímica
SUMMARY:

Currently, supercapacitors (SCs) stand out as high power density energy storage devices. However, many efforts have been made to maximize the energy density of these systems. Furthermore, with the growing demand for miniaturized, ultra-thin and flexible electronic devices, SCs made with electrode material that meet these characteristics are increasingly in demand. In this work, flexible electrodes based on composite films of carbon nanotubes/cellulose nanofibrils (NTC/NFC), also called buckypapers (BPs), were developed for application in redox SCs. The NFCs used were obtained from three different cellulosic matrices: Eucaliptus sp, Pinus sp and Bambusa vulgaris. Morphological, thermal, electrical, structural and hydrophilicity evaluations of all synthesized BPs were carried out. These nanocomposites were studied as redox SC electrodes in different media. It is a basic medium (3 M KOH) in the presence of potassium hexacyanoferrate redox additive and an acidic medium (1 M H 2 SO 4 ) containing methylene blue as an additive. All BPs have flexible structure, and electrical conductivity (maintained at up to 0.47 S cm -1 ) of an order higher than some carbon materials described in the redox SCs literature. And a 125% gain in tensile strength and 67% in maximum tensile strength, compared to a conventional NTC BP. The combination of these BPs with redox additives proved to be adequate, obtaining electrodes with specific capacitances of up to 167.64 F g -1 at 5 mA, and a capacitance retention of up to 98.15% after 12000 galvanostatic charge-discharge cycles.

BANKING MEMBERS:
Presidente - EUDES LORENCON
Externo ao Programa - MARIO GUIMARAES JUNIOR
Externo à Instituição - GARBAS ANACLETO DOS SANTOS JUNIOR