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Abstract: LiMF6 (M=Ta, Nb) was prepared by the reaction between LiF and MF5 (M=Ta, Nb) in F2 gas. Pure LiMF6 (M=Ta, Nb) salts were obtained by using the reaction at temperatures higher than 473K under 80kPa (F2) for 24h. The x values in LiMF x (M=Ta, Nb) were confirmed as 5.7–6.0 by XRD–Rietveld analysis. Results showed that LiMF6 (M=Ta, Nb) has a trigonal structure (, Z =3). The respective lattice parameters of LiTaF6 and LiNbF6 are a 0 =0.533nm, c 0 =1.362 and a 0 =0.532nm, c 0 =1.360. The equivalent conductivities of both LiMF6 (M=Ta, Nb) in propylene carbonate (PC) are equal at 15.2Ω−1 cm2 mol−1 at 0.01moldm−3. The electrochemical potential window of TaF6 − is 7.0V, which is 0.4 and 0.2V wider, respectively, than those of BF4 − and PF6 −. [Copyright &y& Elsevier]

Highlights: [•] LiPF6 can be prepared from LiF, P, and ClF3, without HF and even at 0°C. [•] Using ClF3, LiPF6 can be made from LiF and P at lower temperature in higher yield. [•] LiPF6 prepared by using ClF3 can be used as the material for the electrolyte of LIB. [ABSTRACT FROM AUTHOR]

Abstract: The electrochemical properties and thermal stability of carbon coated LiFePO4 cathode were improved by the surface fluorination using NF3 gas at a pressure less than 6.67kPa at 25°C. Especially, in case of F1-LiFePO4, the discharge capacity was about 10% higher than that of untreated LiFePO4. Also it indicated the lowest resistance (R ct =35.55Ω) and largest exchange current density (i 0 =0.72mA) from the EIS results. However, in case of F2-LiFePO4, the electrochemical properties were negatively affected by the formation of some resistive fluoride films. In terms of thermal stability, the decomposition temperature (222.0°C) of F1-LiFePO4 was 14°C higher than that of untreated LiFePO4. Therefore, the surface fluorination led to the improvement of electrochemical properties and thermal stability of LiFePO4 as a promising cathode in high power lithium-ion cells for HEVs. [Copyright &y& Elsevier]

Abstract: The dispersion stability and photocatalytic activity of TiO2 particles were improved by the surface fluorination using fluorine gas (F2) at a pressure less than 50.5kPa at 25°C. Average particle sizes and zeta potentials of fluorinated TiO2 (F-TiO2) particles in all solvents were approximately 11 times smaller and 1.5 times larger, respectively, than those of untreated TiO2 particles (2.5×103 nm and −19mV). In the photocatalytic activity of TiO2, the UV–vis absorption range of F3-TiO2 with Ti3+ and Ti2+ valences expanded to about 500nm. Also, the degradation ratio of methylene blue (73%) with F-TiO2 was much higher than that (18%) with untreated TiO2 at 4h. However, TiOF2 in F4-TiO2 synthesized at 200°C severely affected the dispersion stability and the photocatalysis of TiO2. To optimize the beneficial effects of surface fluorination considering the dispersion stability and photocatalytic activity, it is necessary to control the fluorine content (x), 0< x <0.5 in TiO2−x F2x . [Copyright &y& Elsevier]

Abstract: Cerium-containing oxide fluoride glasses CeF3–BaF2–AlF3–SiO2 were prepared under CO and Ar atmospheres. The glass prepared in a CO atmosphere exhibited blue emission under UV irradiation because the hydrolysis of CeF3 to a Ce4+-containing compound during heating process was controlled. The emission spectrum was separable into three peak components by peak analysis. X-ray photoelectron spectroscopy (XPS) spectra were measured to investigate the valency of the elements in the glass. Oxide and fluoride ions in the glass respectively have different electronic states from those in CeO2 and CeF3. The electronic state of cerium ion in the oxide fluoride glass differed from that in CeO2 and CeF3. [Copyright &y& Elsevier]

Abstract: Tetragonal PbSnF4 was prepared by precipitation method with Pb(NO3)2 and SnF2 aqueous solutions. The product was characterized using X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XFS), and the other chemical analyses. Tetragonal PbSnF4 exhibited the highest electric conductivity of 3.2Sm−1 at 473K in air as a fluoride ion conductor. We have investigated the possibility of COF2 formation using CO2 and F2 in an electrochemical cell with PbSnF4 as a solid electrolyte. At same time, we tried to produce an electric power from an electrochemical cell. This CO2/F2 electrochemical cell was constructed with a tetragonal PbSnF4 disk having Au electrodes. The electromotive force was about 0.9V at room temperature for 0.1MPa CO2/(0.01MPa F2 +0.09MPa Ar). However, the short circuit current density was 0.24Am−2, which was quite small. This current density was so small that no fluorocarbon compound was detected after 3h discharge using FT-IR. [Copyright &y& Elsevier]

Abstract: New glasses containing TbF3 have been prepared in a TbF3–BaF2–AlF3–GeO2 system. Their respective densities, refractive indexes, and glass transition temperatures are (5.42–6.07)×103 kgm−3, 1.72–1.73, and 605.1–675.2°C. Their magnetic susceptibilities are proportional to the contents of TbF3 in glasses obtained in this study. The values agree with the calculated values. The Curie constant of the 40TbF3–20BaF2–10AlF3–20GeO2 glass is 5.13Kemumol−1; its effective magnetic susceptibility is 9.96μ B. The atomic percentage of Tb3+ in the 40TbF3–20BaF2–10AlF3–20GeO2 glass is 11%, which is comparable to that of the oxide glass, which is reported as the material for Faraday components. [Copyright &y& Elsevier]