12003-67-7Relevant articles and documents
Large-scale, surfactant-free, hydrothermal synthesis of lithium aluminate nanorods: Optimization of parameters and investigation of growth mechanism
Joshi, Upendra A.,Jae, Sung Lee
, p. 3176 - 3184 (2007)
Lithium aluminate nanorods were successfully synthesized from Al 2O3 nanoparticles and lithium hydroxide by a simple, large-scale hydrothermal process without any surfactant or template. The various reaction parameters were optimized to achieve the maximum yield. The as-obtained nanorods had orthorhombic β-lithium aluminate structure with edges in the range of 40-200 nm and lengths of 1-2 μm confirmed by SEM, TEM, XRD, and NMR. Upon calcination at 1273 K for 12 h it transformed to γ-lithium aluminate, yet maintained the initial morphology, demonstrating the thermal stability. The ratio of lithium hydroxide to aluminum oxide showed a significant effect on the morphology as Li/Al = 1 gives microroses , whereas Li/Al = 3 and Li/Al = 15 gave microbricks and nanorods , respectively. Investigation of the mechanism showed that the nanorods were formed via a rolling-up mechanism. As we used all-inorganic raw materials and a simple synthetic procedure under mild conditions, the scale-up of this process for large-scale production should be very easy.
Cation coordination and Fe3+ luminescence in LiAlO2 polymorphs prepared by a hydrothermal method
Kutty,Nayak
, p. 249 - 262 (1999)
The polymorphs α-, β-, and γ-LiAlO2 were synthesized by a hydrothermal method. The as-prepared product obtained at 240 °C was β-LiAlO2, which converted completely to γ-LiAlO2 above 1000 °C. α-LiAlO2 was obtained by the decomposition of LiAl(OH)4·H2O prepared by imbibition of LiOH into LiAl2(OH)7·2H2O hydrothermally at 140 °C. Solid state MAS NMR (magic-angle spinning nuclear magnetic resonance) studies indicate that Li+ uniquely occupies octahedral sites in all the polymorphs. This observation indicates that the results of XRD and crystal structure studies on β- and γ-LiAlO2 reported in the literature that indicate the presence of Li- in the tetrahedral site are apparently in error with respect to Li+ coordination. The other cation, Al3+, occupied octahedral sites in α-LiAlO2 and tetrahedral sites in the β- and γ-LiAlO2. The Fe3+ doped in the various polymorphic forms of this compound was found to uniquely occupy the octahedral Li+ site. EPR spectrum of the Fe3+ doped in these polymorphs indicates that during the transformation this site is distorted. The Fe3+ photoluminescent emission maximum was different for each polymorph. The difference in the luminescence characteristics among the polymorphic forms is due to the change in the site symmetry because of the distortion of the octahedra occupied by Fe3+ across the phase transition. The infrared spectrum indicates that site symmetry is lowered during the phase transition.
Thermochemical capture of carbon dioxide on lithium aluminates (LiAlO 2 and Li5AlO4): A new option for the CO 2 absorption
Avalos-Rendon, Tatiana,Casa-Madrid, Julio,Pfeiffer, Heriberte
, p. 6919 - 6923 (2009)
Lithium aluminates (LiAlO2 and Li5AlO4) were synthesized, characterized, and tested as possible CO2 captors. LiAlO2 did not seem to have good qualities for the CO2 absorption. On the contra
Subsolidus phase relations in the Al2O3-Li 2O-Ta2O5 (Nb2O5) systems
Zuev
, p. 424 - 426 (2007)
The phase composition has been studied and an equilibrium phase diagram has been designed for the Al2O3-Li2O-R 2O5 (R = Ta or Nb) systems in the subsolidus region up to 1000°C and 85 mol % Li2/s
Hydrothermal routes to various controllable morphologies of nanostructural lithium aluminate
Hu, Linfeng,Qiao, Bin,Tang, Zilong,Zhang, Zhongtai
, p. 1407 - 1413 (2007)
The α-LiAlO2 powders have been successfully prepared by a hydrothermal route based on using the surfactant of heax-adecyltrimethyl ammonium bromide (CTAB) as the template. One-dimensional (1D) nanorods with higher and lower aspect ratio, 2D mesoporous microsheets were respectively observed with different concentration of the surfactants. A high specific surface area up to 151 m2/g was obtained by this method. The formation mechanism of the nanostructural lithium aluminate was proposed.
Interaction of x-ray amorphous aluminum oxide with lithium carbonate: Effect of the chemical history of aluminum oxide
Sinitskii,Oleinikov,Murav'eva,Tret'yakov
, p. 280 - 284 (2003)
The high-temperature (950-1050°C) crystallization behavior of x-ray amorphous Al2O3 and its reaction with lithium carbonate in the range 500-700°C were studied using Al2O3 samples prepared by five different procedures: thermal decomposition of Al(NO 3)3·9H2O, Al2(C 2O4)3·nH2O, aluminum hydroxides synthesized via Al3+ precipitation from aluminum nitrate and aluminum chloride solutions by a 20% excess of a concentrated NH 4OH solution, and sol-gel-prepared aluminum hydroxide. The results demonstrate that the preparation procedure has a significant effect on the crystallization behavior and solid-state reactivity of x-ray amorphous aluminum oxide.
A study on the start-up and performance of a kW-class molten carbonate fuel cell (MCFC) stack
Zhou, Li,Lin, Huaxin,Yi, Baolian,Zhang, Huamin,Shao, Zhigang,Ming, Pingwen,Cheng, Mojie
, p. 5698 - 5702 (2006)
A kW-class internal-manifolded molten carbonate fuel cell (MCFC) stack (52 cells) was assembled with inorganic adhesive under a suitable stacking pressure. The organic compounds in the matrices were burnt out under the conditions of slow and uniform elevation of temperature and big flow of oxygen gas in the stack. The stacking pressure dropped with elevating temperature. The output power of the stack at 150 mA cm-2 was 1025.5 W when the reactant gas pressure and utilization were 0.5 MPa and 20%, respectively. The thermal-electrical efficiency of the stack was enhanced by increasing the pressure of the reactant. However, it was contrarily decreased when current density was increased.
Surfactant-free hydrothermal synthesis of lithium aluminate microbricks and nanorods from aluminium oxide nanoparticles
Joshi, Upendra A.,Chung, Soo Hyun,Lee, Jae Sung
, p. 4471 - 4473 (2005)
β-LiAlO2 microbricks and rectangular nanorods have been successfully synthesized from Al2O3 nanoparticles by a simple hydrothermal process without any surfactant or template, by simply changing the Li/Al molar ratio. The Royal Society of Chemistry 2005.
Synergistic use of Knudsen effusion quadrupole mass spectrometry, solid-state galvanic cell and differential scanning calorimetry for thermodynamic studies on lithium aluminates
Rakshit,Naik,Parida,Dash, Smruti,Singh, Ziley,Sen,Venugopal
, p. 1402 - 1412 (2008)
Three ternary oxides LiAl5O8(s), LiAlO2(s) and Li5AlO4(s) in the system Li-Al-O were prepared by solid-state reaction route and characterized by X-ray powder diffraction method. Equilibrium partial pr
Note on the Li-Cu-O system
Berger R.
, p. 33 - 44 (1991)
In the Li-Cu-O system two new ternary phases have been found, tentatively described by the stoichiometries LiCu3O3 and LiCu2O2, and both containing Cu1 and Cu11. They exhibit p-type 'hopping' conduction owing to localized charge carriers. Their powder patterns are successfully indexed on high-symmetry cells where the dimensions depend on a slightly variable stoichiometry. LiCu3O3 is tetragonal with a = 2.815 (·√2) angstrom and c = 8.88 angstrom. LiCu2O2 is orthorhombic with a = 5.72 angstrom, b = 2.86 angstrom and c = 12.4 angstrom. Li3Cu2O4, containing Cu11 and Cu111, is indexed on a C-centred monoclinic cell: a = 9.958 angstrom, b = 2.777, c = 7.281 angstrom and β = 118.77°. The solubility of lithium in CuO is maximally Li0.06Cu0.94O for supersaturation at 1100 K. The equilibrium solubility limit is about Li0.02Cu0.98O, for which the solid solution is still semiconducting. The temperature dependence of the magnetic susceptibility is similar to that of pure CuO but TN is considerably lower.
Effect of synthesis techniques on crystallite size and morphology of lithium aluminate
Carrera,Jimenez-Becerril,Bosch,Bulbulian
, p. 933 - 938 (1995)
γ-LiAlO2 considered as a candidate tritium breeder material for fusion reactors because of its thermophysical, chemical, and mechanical stability at high temperatures and its favorable neutron irradiation behavior. Crystallite size and shape could, however, alter these features. In this study the mean crystallite size, the crystallite size distribution, and the morphology of γ-LiAlO2 are correlated to the synthesis procedure. The characterization techniques were powder X-ray diffraction and scanning electron microscopy.
Effect of mechanical activation of Al(OH)3 on its reaction with Li2CO3
Isupov,Eremina
, p. 918 - 924 (2012)
The effect of preliminary mechanical activation of Al(OH)3 on its solid-state reaction with Li2CO3 at temperatures above 800°C has been studied by thermogravimetry, X-ray diffraction, in situ X-ray diffraction, electron mi
Chemical interaction between LiF and MgAl2O4 spinel during sintering
Rozenburg,Reimanis,Kleebe,Cook, Ron L.
, p. 2038 - 2042 (2007)
Reactions between LiF and MgAl2O4 at temperatures up to 1500°C are examined with a variety of tools, including differential scanning calorimetry, thermo-gravimetric analysis, X-ray diffraction, and scanning electron microscopy. LiAlO2 and MgF2 are found to be the active reaction products at these temperatures. A transient liquid phase comprising MgF2 and LiF forms at intermediate temperatures, but then is consumed at higher temperatures during the reformation of MgAl2O4. If processed as an uncompacted powder mixture, all of the initial LiF in the system eventually vaporizes at temperatures exceeding 1300°C. A new reaction sequence relevant to the densification of LiF-doped MgAl2O4 spinel is proposed.
Solid solution in the LiAlO2-LiCrO2 ternary oxide system
Poeppelmeier,Thong
, p. 291 - 297 (1989)
The solid solution LiAlxCr1-xO2 has been synthesized over the complete range 0 ≤ x ≤ 1. The syntheses at the high alumnium compositions (x ≥ 0.60) have been achieved through stabilization of the α-LiAlO2 structu
Effect of solvents on the preparation of lithium aluminate by sol-gel method
Oksuzomer, Faruk,Koc, S. Naci,Boz, Ismail,Gurkaynak, M. Ali
, p. 715 - 724 (2004)
γ-Lithium aluminate was prepared by sol-gel method using lithium methoxide and aluminum-sec-butoxide precursors in i-propanol, n- and tert-butanol. Clear gels could be obtained due to the addition of ethylacetoacetate and the dried solids were calcined at 550 and 900°C. The resulting solids were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), thermo-gravimetric analysis/differential thermal analysis (TGA/DTA). γ-Lithium aluminate with the highest purity was obtained with t-butanol solvent and LiAl5O8 was the second major phase.
Electronic structure and photocatalytic characterization of a novel photocatalyst AgAlO2
Ouyang, Shuxin,Zhang, Haitao,Li, Dunfang,Yu, Tao,Ye, Jinhua,Zou, Zhigang
, p. 11677 - 11682 (2006)
A novel photocatalyst, AgAlO2, was prepared by cation exchange reaction and characterized by powder X-ray diffraction. The result showed AgAlO2 crystallizes in the layered orthorhombic structure with space group was Pna21. The energy band and electronic structures of AgAlO2 were calculated based on the crystal structure. It was found that AgAlO2 is an indirect band gap semiconductor. The valence band top mainly consists of O-2p orbitals and Ag-4d orbitals and the conduction band bottom is mainly constructed of Ag-5s5p orbitals. The band gap of AgAlO 2 was estimated to be about 2.8(1) eV with UV-vis diffuse reflectance spectrometry. The photocatalytic activity of AgAlO2 was characterized by photocatalytically decomposing the dye alizarin red (AR) under visible light irradiation, and AR could be decomposed about 70% under 2 h of visible light irradiation.
FORMATION AND THERMAL DECOMPOSITION OF ALUMINIUM NITROXY COMPOUNDS.
Lapinski, Z.,Podsiadlo, S.
, p. 49 - 54 (1987)
During the reactions of lithium oxide with aluminum nitride, and of lithium nitride with aluminum oxide, the formation has been observed of a previously unknown compound, of composition Li//2AlNO. The course of its thermal decomposition has also been determined.
Degradation of magnesium aluminum spinel by lithium fluoride sintering aid
Villalobos, Guillermo R.,Sanghera, Jasbinder S.,Aggarwal, Ishwar D.
, p. 1321 - 1322 (2005)
The effect of LiF sintering aid on the degradation of transparent magnesium aluminate spinel during hot-pressing was studied. LiF is used to etch spinel particles during the hot pressing process. The LiF was found to react with the aluminum in the spinel
LITHIUM ION CONDUCTION IN SUBSTITUTED Li//5MO//4, M equals Al, Fe.
Esaka, T.,Greenblatt, M.
, p. 164 - 171 (1987)
The ionic conductivity of substituted Li//5AlO//4 and Li//5FeO//4 phases was measured by a complex impedance method. The high-temperature beta phase was obtained in quenched Li//5AlO//4 but not in Li//5FeO//4. The Zn-substituted quenched samples form beta
Formation of LiAlyNi1-yO2 solid solutions under high and atmospheric pressure
Shinova,Zhecheva,Stoyanova
, p. 3151 - 3158 (2006)
Three methods were used for the synthesis of LiAlyNi1-yO2 solid solutions with layered crystal structure: citrate and hydroxide precursor methods at atmospheric pressure and high-pressure synthesis in oxygen-rich atmosphere (3 GPa). Structural characterization of the oxides was performed by powder XRD analysis and electron paramagnetic resonance (EPR) spectroscopy. Irrespective of the different preparation techniques used, it was found that LiAlyNi1-yO2 solid solutions can be formed in the limited concentration range of 0 ≤ y ≤ 0.5 and 0.75 ≤ y ≤ 1.0. The unit cell parameter a decreases linearly with the Al content whereas the unit cell parameter c increases sharper as compared to the linear interpolation of the c parameter calculated for the two end compositions LiNiO2 and LiAlO2. In these compositions, aluminum substitutes for Ni in the NiO2-layer, the mean AlyNi1-y-O bond length decreasing. The extent of the trigonal distortion of AlyNi1-yO6 and LiO6-octahedra varies with the aluminum content and depends on the synthesis procedure used. The LiO6-octahedra are more flexible to tolerate the increased trigonal distortion as compared to the AlyNi1-yO6-octahedra. High-pressure synthesis favors the formation of oxides with a higher extent of trigonal distortion of both AlyNi1-yO6 and LiO6-octahedra. From EPR measurements, it was shown that local cationic distribution in LiAlyNi1-yO2 depends on the synthesis temperature. At atmospheric pressure, higher synthesis temperatures promote the reaction of cation mixing between the layers.
Low-temperature densification of Al-doped Li7La3Zr2O12: a reliable and controllable synthesis of fast-ion conducting garnets
El-Shinawi, Hany,Paterson, Gary W.,MacLaren, Donald A.,Cussen, Edmund J.,Corr, Serena A.
, p. 319 - 329 (2016/12/27)
The application of Li7La3Zr2O12 as a Li+ solid electrolyte is hampered by the lack of a reliable procedure to obtain and densify the fast-ion conducting cubic garnet polymorph. Dense cubic Li7La3Zr2O12-type phases are typically formed as a result of Al-incorporation in an unreliable reaction with the alumina crucible at elevated temperatures of up to 1230 °C. High Al3+-incorporation levels are also believed to hinder the three-dimensional movement of Li+ in these materials. Here, a new, facile hybrid sol-gel solid-state approach has been developed in order to accomplish reliable and controllable synthesis of these phases with low Al-incorporation levels. In this procedure, sol-gel processed solid precursors of Li7La3Zr2O12 and Al2O3 nanosheets are simply mixed using a pestle and mortar and allowed to react at 1100 °C for 3 h to produce dense cubic phases. Fast-ion conducting Al-doped Li7La3Zr2O12 phases with the lowest reported Al3+-content (～0.12 mol per formula unit), total conductivities of ～3 × 104 S cm1, bulk conductivities up to 0.6 mS and ion conduction activation energies as low as 0.27 eV, have been successfully achieved. The ease of lithium diffusion in these materials is attributed to the formation of dense cubic phases with low Al3+ dopant ratios. This approach is applicable to Li7xLa3Zr2xTaxO12 phases and opens up a new synthetic avenue to Li7La3Zr2O12-type materials with greater control over resulting characteristics for energy storage applications.
