Browsing by Author "Mamat, Nurul Fatin"

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    Influence of gamma irradiation exposure on the performance of supercapacitor electrodes made from oil palm empty fruit bunches
    (2015-08-18) Nor, Najah Syahirah Mohd; Deraman, Mohamad; Omar, Ramli; Awitdrus; Farma, Rakhmawati; Basri, Nur Hamizah; Dolah, Besek Nurdiana Mohd; Mamat, Nurul Fatin; Yatim, Baharudin; Daud, Mohd Norizam Md
    Carbon-monolith electrodes for supercapacitors were prepared from GMs (green monoliths) made from pre-carbonized fibers of oil palm EFB (empty fruit bunches) and GMs of pre-carbonized EFB fibers exposed to gamma radiation at 5 kGy, 15 kGy, and 20 kGy. GMs and irradiated GMs were carbonized and activated to prepare ACM (activated-carbon-monolith) electrodes. The gamma radiation affected the pore structure of the ACM electrodes and the electrochemical performance of the supercapacitors; irradiation doses of 0 kGy, 5 kGy, 15 kGy and 20 kGy produced specific capacitances of 121 F g 1, 196 F g 1, 11 F g 1, and 12 F g 1, respectively. The irradiation dose of 5 kGy appears to be optimum and produces a specific power and specific energy of 236 W kg 1 and 5.45 W h kg 1, respectively, representing 34% and 60% increases over ACM electrodes prepared from non-irradiated GMs.
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    A New Empirical Equation for Estimating Specific Surface Area of Supercapacitor Carbon Electrode from X-ray Diffraction
    (2015-08-18) Deraman, Mohamad; Daik, Rusli; Soltaninejad, Sepideh; Nor, Najah Syahirah Mohd; Awitdrus; Farma, Rakhmawati; Mamat, Nurul Fatin; Basri, Nur Hamizah; Othman, Mohd Amir Radhi
    The current trend of increasing research interest in supercapacitor is due to high demands for an energy storage device that can work in systems that require either low or high power-energy usage. In a supercapacitor using porous carbon electrodes, the energy storage mechanism involves the electrolyte ions in electrode pores and electronic charges in electrodes to form electric double layers at the electrode-electrolyte interface without undergoes any chemical reaction. The specific surface area of porous electrodes, which affect the performance of supercapacitor, have been widely investigated by many researchers using the nitrogen adsorption-desorption measurement. However, despite its simplicity, the X-ray diffraction method is rarely found being used to determine the specific surface area of porous electrodes. Therefore, in the present paper, we propose a new equation which expressed the specific surface area of electrodes as a function the electrode structural parameters obtained from the X-ray diffraction data, and duration of activation time employed during the electrode preparation. This equation is found to produce a satisfactory result and is expected to be beneficial for studying supercapacitor electrode materials