Abstract:
Green monoliths (GMs) with different composition, labelled as GM1, GM2 and GM3,
were prepared from self-adhesive carbon grains (SACG) produced from fibers of oil palm empty fruit
bunches, SACG treated with 0.4 M H2SO4 and mixtures of SACG and carbon nanotubes (5 wt.%)
treated with 0.4 M H2SO4, respectively. Each GMs was carbonized and then activated with holding
time of 1 h and 2 h, respectively, to produce their respective activated carbon monoliths (ACMs).
These ACMs were used as electrodes to fabricate supercapacitor cells using H2SO4 electrolytes,
Teflon separator and stainless steel 316L current collector. The porosity of the ACMs, examined by
nitrogen adsorption-desorption isotherm method were found affected after prolonging the activation
time. From the electrochemical characterization of the ACMs electrodes using galvanic
charge-discharge methods, it was found that supercapacitor cells fabricated using the ACMs
produced by longer activation time (2 h) showed better performance, which had higher specific
capacitance (113 F/g), specific power (159 W/kg) and specific energy (3.35 W h/kg), compared to the
cells using ACMs produced by shorter activation time (1 h).