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Priyono B.,University of Indonesia | Syahrial A.Z.,University of Indonesia | Yuwono A.H.,University of Indonesia | Kartini E.,Center for Science and Technology of Advanced Materials | And 2 more authors.
International Journal of Technology | Year: 2015

Lithium Titanate (Li4Ti5O12) or (LTO) has a potential as an anode material for a high performance lithium ion battery. In this work, LTO was synthesized by a hydrothermal method using Titanium Dioxide (TiO2) xerogel prepared by a sol-gel method and Lithium Hydroxide (LiOH). The sol-gel process was used to synthesize TiO2 xerogel from a titanium tetra-n-butoxide/Ti(OC4H9)4 precursor. An anatase polymorph was obtained by calcining the TiO2 xerogel at a low temperature, i.e.: 300°C and then the hydrothermal reaction was undertaken with 5M LiOH aqueous solution in a hydrothermal process at 135°C for 15 hours to form Li4Ti5O12. The sintering process was conducted at a temperature range varying from 550°C, 650°C, and 750°C, respectively to determine the optimum characteristics of Li4Ti5O12. The characterization was based on Scanning Thermal Analysis (STA), X-ray Powder Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared spectroscopy (FTIR), and Brunauer-Emmett-Teller (BET) testing results. The highest intensity of XRD peaks and FTIR spectra of the LTO were found at the highest sintering temperature (750°C). As a trade-off, however, the obtained LTO/Li4Ti5O12 possesses the smallest BET surface area (< 0.001 m2/g) with the highest crystallite size (56.45 nm). Source

Syahrial A.Z.,University of Indonesia | Priyono B.,University of Indonesia | Yuwono A.H.,University of Indonesia | Kartini E.,Center for Science and Technology of Advanced Materials | And 2 more authors.
International Journal of Technology | Year: 2016

Lithium titanate, Li4Ti5O12 (LTO) is a promising candidate as lithium ion battery anode material. In this investigation, LTO was synthesized by a solid state method using TiO2 xerogel prepared by the sol-gel method and lithium carbonate (Li2CO3). Three variations of Li2CO3 content addition in mol% or Li2CO3 molar excess were fabricated, i.e., 0, 50 and 100%, labelled as sample LTO-1, LTO-2 and LTO-3, respectively. The characterizations were made using XRD, FESEM, and BET testing. These were performed to observe the effect of lithium excess addition on structure, morphology, and surface area of the resulting samples. Results showed that the crystallite size and surface area of each sample was 50.80 nm, 17.86 m2/gr for LTO-1; 53.14 nm, 22.53 m2/gr for LTO-2; and 38.09 nm, 16.80 m2/gr for LTO-3. Furthermore, lithium excess caused the formation of impure compound Li2TiO3, while a very small amount of rutile TiO2 was found in LTO-1. A near-pure crystalline Li4Ti5O12 compound was successfully synthesized using the present method with stoichiometric composition with 0% excess, indicating very little Li+ loss during the sintering process. © IJTech 2016. Source

Erizal,Center for Application of Isotopes and Radiation | Abbas B.,Center for Application of Isotopes and Radiation | Sukaryo S.G.,Center for Science and Technology of Advanced Materials | Barleany D.R.,Sultan Ageng Tirtayasa University
Indonesian Journal of Chemistry | Year: 2015

A series of superabsorbent hydrogels were synthesized from partially neutralized acrylic acid with varying degree of neutralization (0-1) using gamma radiation. The effects of degree neutralization of acrylic acid on swelling ratio were studied. DSC measurement was performed to understand the type of end products resulting from irradiation. The morphologies of the hydrogels were examined using SEM. The chemical changes of the hydrogels were characterized using FTIR. At optimum conditions (10 kGy, 15 min), the hydrogels with neutralization degree 0.5 exhibited rapid swelling with the highest swelling ratio ~1000 g/g. The results of DSC studies confirmed the possible formation of the type hydrogels from irradiated partially neutralized acrylic acid, and the hydrogels showed large numbers of pores from SEM examination. © 2015, Gadjah Mada University. All rights reserved. Source

Jahja A.K.,Center for Science and Technology of Advanced Materials | Panitra M.,Center for Science and Technology of Advanced Materials | Honggowiranto W.,Center for Science and Technology of Advanced Materials | Mustofa S.,Center for Science and Technology of Advanced Materials | Yunasfi Y.,Center for Science and Technology of Advanced Materials
Ionics | Year: 2015

Spinel LiMn2O4 has been known to be a technologically important, environmental-friendly, and low-cost cathode material used in Li-based rechargeable batteries, and it is also widely available. Nanoparticle spinel LiMn2O4 has been synthesized by the top-down, high-energy milling, and hydrothermal methods. SEM images, X-ray diffraction patterns, and neutron high-resolution powder diffraction patterns have confirmed the nanocrystalline nature of the spinel LiMn2O4 samples. Raman and Fourier transform infrared (FTIR) measurements show typical absorption and vibration spectra typical for the spinel LiMn2O4 showing the formation of various metallic bonds in the sample. The strongest Raman and FTIR signals come from the higher frequency region, with weaker signals appearing in the lower frequency range. © 2015 Springer-Verlag Berlin Heidelberg Source

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