Erman Taer

PREPARATION OF ACTIVATED CARBON MONOLITH ELECTRODES FROM SUGARCANE BAGASSE BY PHYSICAL AND PHYSICAL-CHEMICAL ACTIVATION PROCESS FOR SUPERCAPACITOR APPLICATION

Binderless activated carbon monoliths (ACMs) for supercapacitor electrodes were prepared from sugarcane bagasse by two different methods of physical and combination of physical-chemical activation process. The CO2 gas was used as physical activation agent and 0.3 M KOH was chosen as chemical activation agent. The ACMs were tested as electrodes in two-electrode systems of the coin tape cell supercapacitor that consists of stainless steel as current collectors and 1 M H2SO4 as an electrolyte. The improving of resistive, capacitive and energy properties of combination of physical-chemical ACMs electrodes were shown by an impedance spectroscopy, a cyclic voltammetry and a galvanostatic charge-discharge method. The improving of resistive, capacitive and energy properties as high as 1 to 0.6 Ω, 146 to 178 F g-1, 3.83 to 4.72 W h kg-1, respectively. The X-ray diffraction analysis and field emission scanning electron microscope were performed to characterize the crystallite and morphology characteristics. The results showed that the combination of physical-chemical activation process have given a good improving in performance of the bagasse based ACMs electrodes in supercapacitor application.

Eggs Shell Membrane as Natural Separator for Supercapacitor Applications

Various eggs shell membranes (ESMs) have been used as a separator for supercapacitor application. The separator was prepared from different membranes such as chicken eggs shell membrane (CESM), duck eggs shell membrane (DESM) and goose eggs shell membrane (GESM). The ESMs were tested as a separator in a two-electrode system, the sandwich-type supercapacitor cell consists of two activated carbon monoliths as electrodes, two stainless steel as current collectors and 1 M H2SO4 solution as an electrolyte. The electrochemical performance of the ESMs was characterized by an electrochemical impedance spectroscopy, a cyclic voltammetry and a galvanostatic charge-discharge. The results of this study exhibit all of the ESMs as a good candidate for supercapacitor separator. However, the CESM was shown excellence electrochemical properties, such as low resistance, high energy density and power density. The scanning electron microscope (SEM) micrograph and X-ray diffraction analysis were also proved that the ESMs are a promising low-cost separator for supercapacitor application.

Carbon/Carbon Nanotubes (CNTs) Composites from Green Pellets Contain CNTs and Self‐adhesive Carbon Grains from Fibres of Oil Palm Empty Fruit Bunch

Nano composites green pellets (GPs) were prepared from the mixtures of carbon nanotubes (CNTs) at varying percentage (0, 2, 4, 6, 8 and 10%) and self‐adhesive carbon grains (SACG) from fibres of oil palm empty fruit bunch. These GPs were carbonized and CO2 activated to produce activated carbon/CNTs composites in the form of pellets (ACPs). It was found that the density (ρ) and electrical conductivity (σ) of the ACPs varied nonlinearly with CNTs content; as for the CNTs content of 3–5%, we observed the peak values of ρ and σ at 1.3781 gcm−3 and 3.4146 (Ωcm)−1 respectively. The presence of the agglomerated and individual particles of CNTs in the pores of the ACPs was clearly shown by the micrograph of the Field Emission Scanning Electron Microscope (FESEM). The nitrogen adsorption isotherm data showed the decrease in surface area, volume and diameter of pores due to the effect of CNTs. The effect of CNTs on the electrochemical behavior of the ACPs were investigated from the supercapacitor cells fabricated u...

Review of Energy and Power of Supercapacitor Using Carbon Electrodes from Fibers of Oil Palm Fruit Bunches

Energy and power capability of a supercapacitor is important because of its function to provide backup power or pulse current in electronic/electric products or systems. The choice of its electrode materials, typically such as carbon, metal oxide or conducting polymer determines the mechanism of its energy storage process. This short review focuses on the supercapacitors using porous carbon electrode prepared, respectively, from fibers of oil palm empty fruit bunches. The specific energy and specific power of these supercapacitors were analyzed to observe their trend of change with respect to the electrode preparation parameters affecting the porosity, structure, surface chemistry and electrical conductivity of electrodes, and thence influence the energy and power capability of a supercapacitor. This review found that the trend of change in specific energy and specific power was not in favor of the expectation that both the specific energy and specific power should be in increasing trend with a significant progress.

AC-MnO2-CNT Composites for Electrodes of Electrochemical Supercapacitors

Electrodes for electrochemical supercapacitors were fabricated by doctor blade method of composite of activated carbon (AC), MnO2 and carbon nanotubes (CNTs). The AC-MnO2-CNTs composites were synthesized by solution processing method with pH variation of 3, 7 and 11. The composites were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and impedance spectroscopy. The XRD pattern shown the crystalline structure and the SEM image observed that the distribution of CNTs was homogeneous between carbon particles. The electrodes were fabricated for supercapacitor cells with 316L stainless steel as current collector and 1 M Na2SO4 as electrolyte. An electrochemical characterization was performed by using an electrochemical impedance spectroscopy (EIS) method using a LCR Hi-Tester HIOKI 3522 instrument and the results showed an increase in the value of specific capacitance at the AC-MnO2-CNT on the acid reaction condition.

Effect of TiO2 on Duck Eggshell Membrane as Separators in Supercapacitor Applications

A study concerning the effect of TiO2 on duck eggshell membrane as separator in supercapacitor applications. Concentration of TiO2 on duck eggshell membrane are 1 %wt, 5 %wt and 10 %wt respectively. Construction capacitor cell is shaped sandwich system. Membrane separator placed in the midst of the two carbon electrodes containing H2SO4 solution. From the micrograph Scanning Electron Microscopy (SEM), it observed that TiO2 particles in all samples are uniform in size. At concentration of 1 %wt, TiO2 particles covered all fiber of duck eggshell membrane, but not many pore is formed while at concentration of 5%, the TiO2 particles fill the pores between the fibers, thus causing the pores between the fibers get smaller and multiplied in number. However, if the TiO2 particles added is the more than 10 %wt, the particles will actually cover the pores between the fibers of the membrane. Characteristics of the capacitor was measured by using Edaq cyclic voltameter. Maximum value of specifics capacitance (Csp) was 2.3 F / g, with current 0.007 mA and voltage of 0.002 V. This value occurs at a concentration of 5 wt% TiO2 on the charging time for 20 seconds.

Brief review: Preparation techniques of biomass based activated carbon monolith electrode for supercapacitor applications

The synthesis of activated carbon monolith electrode made from a biomass material using the hydrolytic pressure or the pelletization technique of pre-carbonized materials is one of standard reported methods. Several steps such as pre-carbonization, milling, chemical activation, hydraulic press, carbonization, physical activation, polishing and washing need to be accomplished in the production of electrodes by this method. This is relatively a long process that need to be simplified. In this paper we present the standard method and proceed with the introduction to several alternative methods in the synthesis of activated carbon monolith electrodes. The alternative methods were emphasized on the selection of suitable biomass materials. All of carbon electrodes prepared by different methods will be analyzed for physical and electrochemical properties. The density, degree of crystallinity, surface morphology are examples for physical study and specific capacitance was an electrochemical properties that has be...

Synthesis of a Carbon-activated Microfiber from Spider Webs Silk

Carbon fiber of spider web silk has been produced through the simple carbonization process. Cobwebs are a source of strong natural fiber, flexible and micrometer in size. Preparation of micro carbon fiber from spider webs that consist of carbonization and activation processes. Carbonization was performed in N2 gas environment by multi step heating profile up to temperature of 400 °C, while the activation process was done by using chemical activation with KOH activating agent assistance. Measurement of physical properties was conducted on the surface morphology, element content and the degree of crystallinity. The measurement results found that micro carbon fiber from spider webs has a diameter in the range of 0.5 -25 micrometers. It is found that the carbon-activated microfiber takes the amorphous form with the carbon content of 84 %.

SYNTHESIS AND CHARACTERIZATION OF GOLD NANOPLATES ONTO SOLID SUBSTRATES BY SEED-MEDIATED GROWTH METHOD

A simple technique of seed-mediated growth has successfully been performed to grow gold nanoplates onto solid substrates. The growth of gold nanoplates have been carried out attemperature of 28-30°C in the presence of a binary surfactant mixture: CTAB (cetyl trimethyl ammonium bromide) and PVP (poly-vinylpyrrolidone) with their various concentrations. Characterizations of the samples have been carried out by using UV-Vis spectroscopy, XRD and FESEM.UV-Vis spectra showed that the gold particles have grown with a various geometrical forms, such as spherical and others. XRD results informed that the presence of two peaks at 2θ: 38.195o and 44.393o indicated the gold nanoplates, with their crystal orientation of (111) and (200). FESEM images showed the edge-length size of nanoplates was dominated in the range of 11nm to 50 nm, with various morphologies of nanoplates, such as hexagonal,truncated hexagonal, triangular, square and spherical shapes.