Li4Ti5O12 (LTO) is one of the material that has the potential as anode in lithium ion battery that is safe to use and has a long life cycle. In this research, LTO was synthesed by sol-gel method using oxalic acid as chelating material, it is expected to produce materials with smaller particles and homogeneous distribution. The LTO sol-gel compared to commercial LTO. Characterization was carried out by X-ray diffraction (XRD), scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS). The measurement of LTO battery performance is carried out by charge discharge and electron impedance spectroscopy. The sol-gel LTO has a purity of 99%, which is higher than 57% commercial LTO. The average particle size is 1 μm, and the conductivity is 7.6x10−7 S.cm−1. While commercial LTO has a purity of 57%, the average particle size is 30 μm and conductivity is 7.4x10−7 S.cm−1. Batteries with synthesized LTO anodes have a capacity of 25.9% higher in the first cycle and 110% higher in fifth cycles incomparison with batteries used commercial LTO anodes.

Neutron imaging of lithium-ion coin cell battery was obtained using tomography technique at Neutron Scattering Laboratory in Multi-Purpose Research Reactor G. A. Siwabessy (RSG-GAS) Serpong facility. The coin cell battery was CR2032 (20d x 3.2t mm) type consisted of positive and negative cases made of stainless steel, a cathode layer from lithium Ferro phosphate coated on aluminum foil, polyethylene film as separator, lithium hexafluorophosphate solution in ethylene carbonate and diethyl carbonate as electrolyte, an anode layer from graphite coated on copper foil, and spacer as well as spring made of stainless steel. The neutron tomography was used to observe the inside structure of the full charged coin cell. The observation was carried out with a neutron flux of 107 n/s.cm2 at 15 MWatt of reactor power. The image of the object is obtained by a Charge Coupled Detector (CCD) and the reconstruction software based on a filtered back-projection algorithm. The neutron imaging clearly shows the cell structure inside the casing. Even though the cell is not at the center of the casing, but it appears that the cell component consists of a cathode, separator and anode neatly arranged. The cross-cut image shows the important role of spring and spacer in improving the contact between cell and casing. The results showed the ability of neutron tomography techniques at RSG-GAS to investigate in detail the inside structure of a coin battery without disassembly (non-destructive test).

ABSTRAK PENGGUNAAN ZEOLIT UNTUK STABILISASI FORMULA EKSTRAK KULIT BUAH DELIMA SEBAGAI ANTIBAKTERI.Telah dilakukan penelitian penggunaan zeolit untuk stabilisasi formula ekstrak antibakteri. Ekstrak antibakteri yang digunakan diperoleh dari ekstraksi kulit buah delima dengan etanol. Ekstrak antibakteri dicampur dengan zeolit selama 24 jam pada kecepatan 150 rpm dan suhu 27 C selanjutnya dipanaskan pada suhu 38 C selama 24 jam. Hasil pengamatan menunjukkan bahwa zeolit mampu menjaga stabilitas aktivitas antibakteri formula ekstrak. Pada pengamatan pertumbuhan bakteri Bacillus cereus selama 24 jam, gabungan formula ekstrak-zeolit yang telah dipanaskan mampu menghambat pertumbuhan bakteri pada jam ke dua sampai pada titik nol. Jika dibandingkan dengan formula ekstrak tanpa zeolit pada kondisi yang sama, tidak mampu menghambat pertumbuhan bakteri sampai dengan titik nol kurva pertumbuhan bakteri. Jumlah bakteri bertambah dari 10 6 sampai hampir mencapai 10 9 koloni bakteri. Kondisi ini menunjukkan gabungan ekstrakzeolit mampu mempertahankan aktivitas antibakteri dari formula ekstrak terhadap pemanasan pada suhu 38 C selama 24 jam.

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Abstract. Lithium-ion batteries (LIBs) have become widely used powder sources for portable electronics and electric vehicles. The discovery of lithium nickel manganese cobalt oxide (LiNi0.5Mn0.3Co0.2O2, NMC532), tremendous efforts have been paid to the development of Ni-rich layer-structured NMC532 materials due to its high capacity when charged to potentials higher than 4.3 V vs Li+/Li. In this work we report effect of Sodidium in NMC532 layer, the characterization was done by using X-Ray Diffractometer (XRD) to investigate the crystal structure, Electrochemical impedance spectroscopy (EIS) was used to illustrate the resistance change during cycling. The particles morphology and surface chemistry characterizations of both cathode and anode electrodes were performed on Scanning Electron Microscope (SEM). The XRD pattern of the sample shows diffraction peaks at 2θ = 18.663 o, 36.773 o, 44.459 o, 48.611 o, 58.604 o, 64.322 o, 65.069 o, 68.339 o and 77.798 o. Na does not affect the NMC532 lattice parameters, which means that Na which is expected to substitute for Li does not occur. The NMC532 conductivity with the addition of Na=0.03 showed a slightly lower value than the NMC532 conductivity with the addition of Na=0.01. Meanwhile, the highest conductivity was seen at NMC532 with the addition of Na=0.05. The addition of Na to NMC532 did not increase the conductivity linearly. SEM images of NMC532 and NMC532 with the addition of Na=0.01; Na = 0.03 and Na = 0.05 can be seen that the Na flakes wrap around the NMC532 granules. The Na flakes surrounding the NMC532 grains at Na = 0.01 were more abundant than the Na flakes surrounding the NMC532 at Na = 0.03.