The effect of vacuum annealing and HDDR processing on the electrochemical characteristics of activated carbon and graphene oxide for the production of supercapacitors electrodes
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2018
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CONGRESSO BRASILEIRO DE ENGENHARIA E CIÊNCIA DOS MATERIAIS, 23.
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Electric double-layer capacitors or electrochemical supercapacitors prepared using
activated carbons have been subjected to vacuum heat treatments at low and high
temperatures (200, 400, 600, 800 and 1000°C). The activated carbon electrodes have
been tested at a window potential of 1.1 V employing a KOH electrolyte (1.0 mol.L-1).
The effect of thermal treatment (vacuum or HDDR) upon the electrical properties has
been investigated by cyclic voltammetry and electrochemical impedance spectroscopy
(EIS). It has been shown that the specific capacitance at 5 msV-1 increases from 50
Fg-1 to 130 Fg-1 after a heat treatment at 400°C for 1 hour under back pump vacuum.
At this temperature the diminution in the specific capacitance with higher scanning rate
(10 msV-1) was much less pronounced (from 130 Fg-1 to 109 Fg-1). Equivalent series
resistance (ESR) and equivalent parallel resistance of supercapacitors electrodes
have also been investigated. Internal resistances of the supercapacitors were
calculated using the galvanostatic curves at several current densities (10-100 mAg-1).
BET analysis of the starting carbon and after thermal treatments have also been
carried out in this investigation. The activated structures have been studied using
scanning electron macroscopy (SEM) and X-ray diffraction. A compositional and
morphological evaluation of these electrodes showed no significant change on the
activated carbon structure. Reduced graphene oxide electrodes have also been
prepared in this investigation for a comparison.
Como referenciar
CRUZ, P.D.; COSENTINO, I.C.; GALEGO, E.; YOSHIKAWA, D.; FARIA, R.N. The effect of vacuum annealing and HDDR processing on the electrochemical characteristics of activated carbon and graphene oxide for the production of supercapacitors electrodes. In: CONGRESSO BRASILEIRO DE ENGENHARIA E CIÊNCIA DOS MATERIAIS, 23., 04-08 de novembro, 2018, Foz do Iguaçu, PR. Resumo... p. 660-660. Disponível em: http://repositorio.ipen.br/handle/123456789/29648. Acesso em: 09 May 2024.
Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.