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PEMBUATAN NANOPAR TIKEL LixMn2O4 Wigayati, Etty Marti
Teknologi Indonesia Vol 32, No 2 (2009)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v32i2.10

Abstract

LixMn2O4 nanoparticle has been prepared using Li2CO3 and MnO2 as starting materials. Firstly, Li2CO3 and MnO2 were mixed using solid state reaction, then the powder was calcinated at 700oC and sintered at 800oC. The resulted pouder was characterized using SEM, XRD, and EIS (Electrochemical Impedance Spectroscopy). Henceforth, LixMn2O4 powder was processed into nanoparticle size through milling process using PBM (Planetary Ball Milling) for 80 hour and ultrasonificator with power of 300 watt for 2 hour. The characterization was conducted again using SEM, XRD, PSA and EIS. The result shows that there is no diffraction pattern change after the milling process. Examination using SEM shows particle changes from needles to round shapes with smaller sizes. Diffraction analyzes using Rietveld method results in lattice parameter of 8.23454 , cell unit volume of 558.3647 3 and the crystal structure is cubic with space group of Fd-3m. The particle size of the final product is analyzed using Particle Size Analyzer (PSA) which results in the value of 178 nm in average diameter. The measurement of electrical impedance gives values of 2 M ohm (before milling) and 8 M ohm (after milling).
SINTESIS LiBOB DAN ANALISA STRUKTUR KRISTALNYA [Synthesis and Analysis Crystalline Structure LiBOB] wigayati, etty marti
Metalurgi Vol 30, No 2 (2015): Metalurgi Vol.30 No.2 Agustus 2015
Publisher : Pusat Penelitian Metalurgi dan Material - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (571.753 KB) | DOI: 10.14203/metalurgi.v30i2.28

Abstract

Litium Bis(Oksalato) Borat atau LiBOB merupakan garam Lithium yang saat ini mulai dikembangkan sebagai elektrolit alternatif untuk baterai Li-Ion. Elektrolit padat LiBOB dianggap lebih ramah lingkungan, LiBOB juga memiliki stabilitas panas yang cukup tinggi yakni sebesar 302 °C. Penelitian ini bertujuan untuk mensintesis LiBOB kemudian untuk mengetahui struktur kristalnyadan untuk mengetahui durasi sintering yang optimum. Sintesis LiBOB (Lithium bis oksalat borat)dilakukan melalui metoda solid state reaction. Bahan awal dicampur hingga homogen. Kalsinasi dilakukan pada temperatur 120 °C,ditahan selama 2 jam dilanjutkan dengan sintering pada temperatur 240 °C dengan penahanan dilakukan secara bervariasi yaitu 2 jam, 3 jam, dan 4 jam. Untuk mengetahui fasa yang terbentuk dilakukan karakterisasi dengan XRD. Dari hasil analisis XRD dapat diidentifikasi fasa yang terjadi pada waktu penahanan 2 jam masih muncul fasa dari bahan awal, LiBOB hidrat dan beberapa fasa impuritas. Pada waktu penahanan 3 jam terbentuk fasa LiBOB hidrat dan H3BO3. Pada penahanan 4 jam muncul fasa LiBOB dan LiBOB hidrat serta beberapa fasa impuritas. Sampel dengan penahanan 4 jam merupakan sampel yang paling optimum mendekati karakteristik kristal LiBOB dan LiBOB Hidrat pada sampel LiBOB komersial. Struktur kristal LiBOB yang terbentuk adalah orthorombik dengan nilai a, b, dan c sebesar 5.74 Å, 6,79 Å, dan 14,45 Å dengan sudut α = β = γ = 90°, grup ruangPnma (62), serta nilai FoM 1,386. Sementara struktur kristal LiBOB Hidrat juga orthorombik namun dengan nilai a, b, dan c sebesar 16,119 Å, 15,913 Å, dan 5,6182 Å dengan sudut α = β = γ = 90°, grup ruang Pbca (61), serta nilai FoM 0,824. AbstractLithium Bis ( Oxalato ) Borate(LiBOB) as lithium salt that is currently being developed as an alternativeelectrolytes for Li - Ion battery. LiBOB electrolyte is considered more environmentally friendly, LiBOB alsohave a fairly high heat stability which is equal to 302 ºC.This research aims to synthesize LiBOB thentodetermine the crystal structure and the optimum duration of sintering.At present work, the synthesis ofLithium Bisoxalato Borate (LiBOB) was done by solid-state reaction method. The raw materials was mixedhomogeneously. These samples were calcinated at 120 ºC for about 2 hours then sintered at 240 ºC withvarious durations (2, 3, and 4 hours). XRD characterization was done for identifying phases. From XRDinterpretation, there are LiBOB Hydrate and other impurities at two-hour sintered sample. There are LiBOBHydrate and H3BO3 at three-our sintered sample. There are LiBOB, LiBOB Hydrate, and other impurities atfour-hour sintered sample. The sample with 240 ºC/4 hour parameter is the most optimum sample based onthe convergention to the LiBOB and LiBOB Hydrate phases at standard commercial LiBOB sample (SigmaAldric). The crystal system of the LiBOB phase is orthorombic with lattice parameters a = 5.74 Å, b = 6.79Å, c = 14.45 Å, α = β = γ = 90º, space groupPnma (62), and FoM 1.386. On the other hand, the crystal systemof LiBOB Hydrate phase is also orthorombic with lattice parameters a = 16.119 Å, b = 15.913 Å, c = 5.6182Å, α = β = γ = 90º, space group Pbca (61), and FoM 0.824.
Synthesis of LiBOB Fine Powder to Increase Solubility Wigayati, Etty Marti; Lestariningsih, Titik; Ratri, Christin Rina; Purawiardi, Ibrahim; Prihandoko, Bambang
Makara Journal of Technology Vol. 21, No. 1
Publisher : UI Scholars Hub

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Lithium bis (oxalate) borate or LiBOB compound has captured interest of researchers, because it is potentially viable to be used as electrolyte salt in lithium-ion battery system. This compound is easy to synthesize and considered to be more environmentally friendly compared to conventional electrolyte salt because LiBOB does not contain halogen element. This research focused on the synthesis of LiBOB fine powder, which main purpose is improving LiBOB salt solubility in liquid electrolyte solution. This will aid the ion transfer between electrodes which in turn will increase the electrolyte performance. Solid state reaction was employed in this experiment. Synthesis of LiBOB compound was performed by reacting oxalic acid dihydrate, lithium hydroxide monohydrate, and boric acid. The resulting powder was then processed into fine powder using ball milling technique with varying milling time (0, 6, 10, and 13) hour. Microstructure of the sample was then analyzed to obtain information regarding phase formation, functional groups, grain surface morphology, surface area, pore volume, solubility, and ionic conductivity. The analysis shown that LiBOB and LiBOB hydrate phase was formed during the reaction, there was no changed in existing phase during milling process, crystallinity index was shifted to lower value but there was no difference in functional groups. Highest value in surface area was found to be 83.11 m2/g, with pore volume of 1.21311e+02 A at 10 hours milling. Smaller powder size resulted in higher solubility, unfortunately the ionic conductivity was found to be decreased.