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Browsing SWL-Mathematics and Natural Sciences by Subject "Activated carbon"
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Item COMPOSITE ELECTRODES OF ACTIVATED CARBON DERIVED FROM CASSAVA PEEL AND CARBON NANOTUBES FOR SUPERCAPACITOR APPLICATIONS(2014-07-01) Taer, Erman; Iwantono; Taslim, R; Subagio, A; Yulita, M; Salomo; Deraman, MIn this paper, composite electrode was prepared from a mixture of activated carbon derived from the pre-carbonization of cassava peel (CP) and carbon nanotubes (CNTs). The activated carbon was produced by pyrolysis process with ZnCl2 as activation agent. The result of N2 adsorption-desorption analysis indicated that the BET surface area of the activated carbon was 1336 m2 g-1. Difference percentage of CNT of 0, 5, 10, 15 and 20% and 5% of PVDF binder were added into CP based activated carbon to fabricate the composite electrodes. The morphology and structure of the prepared composite electrodes were investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. The SEM observation revealed the CNT was distributed in homogeny between the carbon particles and XRD result shown the amorphous structure. The supercapacitor cells were fabricated by using composite materials as electrodes, 316L stainless steel as current collector and 1 M acid sulfuric as an electrolyte. Electrochemical characterization was performed by using electrochemical impedance spectroscopy (EIS) method using a solatron 1286 instrumentation. The addition of CNT has been improved the resistance and capacitive properties of supercapacitor cell.Item Effects of Activation Time on the Performance of Supercapacitor Binderless Activated Carbon Electrodes Derived from Fibers of Oil Palm Empty Fruit Bunches(2015-09-07) Ishak; Deraman, Mohamad; Dollah, Besek Nurdiana Mohd; Othman; Omar, Ramli; Basri, Nur Hamizah; Nor, Najah Syahirah Mohd; Taer, Erman; Awitdrus; Farma, Rakhmawati; AzizGreen 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).Item Impedance spectroscopic analysis of composite electrode from activated carbon/conductive materials/ruthenium oxide for supercapacitor applications(2015-09-07) Taer, Erman; Deraman, Mohamad; Talib; Awitdrus; Farma, Rakhmawati; Ishak; Omar, Ramli; Dollah, Besek Nurdiana Mohd; Basri, Nur Hamizah; Othman; KanwalActivated carbon powders (ACP) were produced from the KOH treated pre-carbonized rubber wood sawdust. Different conductive materials (graphite, carbon black and carbon nanotubes (CNTs)) were added with a binder (polivinylidene fluoride (PVDF)) into ACP to improve the supercapacitive performance of the activated carbon (AC) electrodes. Symmetric supercapacitor cells, fabricated using these AC electrodes and 1 molar H2SO4 electrolyte, were analyzed using a standard electrochemical impedance spectroscopy technique. The addition of graphite, carbon black and CNTs was found effective in reducing the cell resistance from 165 to 68, 23 and 49 Ohm respectively, and increasing the specific capacitance of the AC electrodes from 3 to 7, 17, 32 F g-1 respectively. Since the addition of CNTs can produce the highest specific capacitance, CNTs were chosen as a conductive material to produce AC composite electrodes that were added with 2.5 %, 5 % and 10 % (by weight) electro-active material namely ruthenium oxide; PVDF binder and CNTs contents were kept at 5 % by weight in each AC composite produced. The highest specific capacitance of the cells obtained in this study was 86 F g-1, i.e. for the cell with the resistance of 15 Ohm and composite electrode consists of 5 % ruthenium oxide.Item PREPARATION OF BINDERLESS ACTIVATED CARBON MONOLITH FROM PRE-CARBONIZATION RUBBER WOOD SAWDUST BY CONTROLLING OF CARB ONIZATION AND ACTIVATION CONDITION(2014-07-01) Taer, Erman; Deraman, M; Taslim, R; IwantonoBinderless activated carbon monolith (ACM) was prepared from pre-carbonized rubber wood sawdust (RWSD). The effect of the carbonization temperature (400, 500, 600, 700, 800 dan 900oC) on porosity characteristic of the ACM have been studied. The optimum carbonization temperature for obtaining ACM with high surface area of 600 oC with CO2 activation at 800 "C for one hour. At this condition, the surface area as high as 733 m2 g-1 could be successfully obtained. By improved the activation temperature at 900 oC for 2.5 h, it was found that the surface area of 860 m2g-1. For this condition, the ACM exhibit the specific capacitance of 90Fg-1. In addition the termogravimertic (TG)-differential termografimertic (DTG) and field emission scanning electron microscope (FESEM) measurement were also performed on the ACMs and the result has been studied. Finally, it was conclude that the high surface area of ACM from RWSD could be produced by proper selections of carbonization and activation condition.