Facile Way of Preparing Activated Carbon (AC) Electrodes from the Local Jack-Wood for Supercapacitors
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Date
2020
Journal Title
Journal ISSN
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Publisher
Uva Wellassa University of Sri Lanka
Abstract
Supercapacitors (SCs) are used as high power density energy storage devices in many
applications. Based on the charge-discharge mechanism, SCs are divided into three main
classes; electrochemical double-layer capacitors (EDLCs), pseudo-capacitors, and hybrid
capacitors. High specific surface area electrodes need to be developed using chemically
and physically stable materials to prepare high energy density EDLCs having a long cycle
life. By increasing the porosity of electrodes, the effective surface area of the interface
can be enhanced. This study introduces a facile way of preparing activated carbon (AC)
electrodes starting from the local Jack-wood. Besides, in this research, a novel low-cost
SC is prepared using AC electrodes fabricated from Jack wood charcoal without using a
binder or additive. The activation is done using a NaOH solution. AC electrodes of the
size,1 cm × 2 cm × 0.5 cm, were used for SCs preparation. Platinum (Pt) electrodes were
used as current collectors, and for this purpose, Pt was coated on one side of the carbon
electrodes. The EDLCs were assembled using activated carbon electrodes and 5 M
potassium hydroxide (KOH) electrolyte. For this purpose, polytetrafluoroethylene (PTFE)
membrane filter paper separator having 0.2-µm pore size was sandwiched between two
AC electrodes. To characterize EDLCs assembled, complex impedance, charge-discharge
measurements, and cyclic voltammograms (CV) were measured with the help of
PGSTAT128N – Metrohm Auto-Lab setup. The high chemical stability of the
EDLCswithin, the charge-discharge window +0.5 V to -0.5 V, can be inferred from CV.
The highest gravimetric capacitances of the SCs were 71.89 F g-1
. Power density of
342.12 W kg-1
and the energy density of 0.27 Wh kg-1 were exhibited by the EDLC
prepared using Jack-wood AC electrodes. The prepared low-cost Supercapacitor is
suitable for many applications that need power for a short period.
Keywords: Activated carbon, Electrical double layer, Gravimetric capacitance Jack-wood,
and Supercapacitor
Description
Keywords
Materials Sciences, Mineral Sciences, Electronic Engineering, Jack-wood