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Lithium cobaltate (LiCoO2) is one of the materials used to make cathodes for lithium-ion batteries. However, it is subject to various limitations, such as structural and thermal instability, low electrochemical capacity, irreversibility, and insecurity. Newer materials are designed and produced with rare earths a low concentration, to promote the better electrochemical performance of lithium-ion batteries. The europium ion (Eu3+) has advantageous properties, such as an ionic radius that is larger than the radii of lithium and cobalt, and thermomechanical and structural stability. In this paper, is reported on the production of crystalline lithium cobaltate (LiCoO2) powders doped with Eu3+ at different concentrations (0.01, 0.03, and 0.05 mol %). There are various methods for producing these powders, such as the solidstate, hydrothermal, and sol gel methods, among others. However, the sol-gel method makes it possible to obtain crystalline materials at low residence temperatures, to control variables during synthesis, and to produce materials of high purity at nanometric sizes. The materials obtained were analyzed by various characterization techniques such as, IR spectroscopy (FTIR), x-ray diffraction (XDR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM) to determine the morphological and compositional properties after doping with Eu3+. Structural analysis and Rietveld refinement showed a hexagonal structure at 800°C, with planes attributable to the R-3m space group. By means of FTIR, bands characteristic of LiCoO2 and the band corresponding to Eu3+ were observed. When the Eu3+ ion was added at different concentrations, the morphology of the particles was uniform and quasispherical. The elements were identified by EDS as cobalt and europium. Through TEM, the interplanar distance of the main plane of LiCoO2 doped with Eu3+ were obtained, that is, (003) and an increase in the plane took place when the Eu3+ was incorporated ion into the crystalline structure. [ABSTRACT FROM AUTHOR]

Abstract: One series of ionic liquids (IL), [TOA]+ [Y] (where [Y]− =[Cl]−, [HSO4]− or [H2PO4]−), and new ammonium salts, [OCD]+ [Y]− (where [Y]=[HSO4]−, [MeSO3]− or [MePhSO3]−), were evaluated as demulsifying agents for super-heavy crude oil, at API=6.39° (MO1) and API=7.13° (MO2), with 8.46 and 8.94wt.% of asphaltenes, respectively, at dosages of 1000 and 1500ppm, using a conventional heating bottle test. At 1000ppm, the ranking of water removal efficiency for the [TOA]+ [Y]− series (in MO1 and MO2, in order to reach 96.7% and 95.4%, respectively) was [Cl]− >[HSO4]− >[H2PO4]−. For the [OCD]+ [Y]− series, the rankings for efficiency at 360min were [HSO4]− >[MeSO3]−, reaching approximately 27% in MO2, whereas [MePhSO3]− reached 1% in MO2. At a dosage of 1500ppm, the [TOA]+ [Y]− series achieved 100% water removal, showing the same order at 1000ppm. For [OCD]+ [Y]−, the order at 24h was [HSO4]− >[MeSO3]− >[MePhSO3]− for MO1 and MO2 at maximums of 85.5% and 92.3%, respectively. [OCD]+ [HSO4]− was an efficient demulsifier in tests of long duration. Quantum parameters were obtained at the semiempirical RM1 level, in order to establish a correlation with the experimental results. The molecular volume (V M), molecular refractivity (MR), dipolar moment (μ) and mean polarizability (α) of the cation and anion fragments were important factors driving the dewatering process. V M, MR and α were shown to have a direct relationship with water removal efficiency. Furthermore, absolute softness and the electrophilicity index of the cation fragments were calculated at the density functional theory (DFT) level. An increase in the softness and electrophilicity of the cations correlated with lesser effectiveness as demulsifiers. Finally, the partition coefficient of the cations showed that if the viscosity of the crude oil is low, it is possible to use ILs with a low partition coefficient (log P), but if the viscosity is high, the log P of IL should be near the [TOA]+ [Cl]− value. [Copyright &y& Elsevier]