207804-61-3Relevant academic research and scientific papers
Physical and electrolytic properties of difluorinated dimethyl carbonate
Sasaki, Yukio,Takehara, Masahiro,Watanabe, Susumu,Nanbu, Noritoshi,Ue, Makoto
, p. 1205 - 1209 (2004)
The physical and electrolytic properties of difluorinated dimethyl carbonate (DFDMC) synthesized using F2 gas (direct fluorination) were examined. The dielectric constant and viscosity of DFDMC are higher than those of monofluorinated dimethyl carbonate (MFDMC) and dimethyl carbonate (DMC). The oxidative decomposition voltage of DFDMC is higher than those of DMC and MFDMC. The specific conductivity in DFDMC solution is considerably lower than those in MFDMC and DMC solutions. The ethylene carbonate (EC)-DFDMC equimolar binary solution containing 1 mol dm-3 LiPF6 shows a moderate conductivity of 6.91 mS cm-1 at 25 °C. The lithium electrode cycling efficiency (charge-discharge coulombic cycling efficiency of lithium electrode) in EC-DFDMC equimolar binary solution containing 1 mol dm-3 LiPF6 is higher than 80%. The EC-DFDMC solution is a good electrolyte for rechargeable lithium batteries.
Synthesis of fluorinated dimethyl carbonates by direct fluorination
Takehara, Masahiro,Watanabe, Susumu,Nanbu, Noritoshi,Ue, Makoto,Sasaki, Yukio
, p. 1367 - 1375 (2004)
Growing interest has been focused on the development of florinated solvents for lithium batteries, because they have a number of benefits such as excellent oxidation durability, wide liquidus ranges, and nonflammability. Flourination of dimethyl carbonate (DMC) is carried out using molecular flourine (15 vol.% F2/N2) at 5°C, and the flourinated derivatives of the DMC are identified and characterized. The selectivity of monoflourinated dimethyl carbonate (MFDMC) is ca. 90% at early stage of the flourination. The successive electrophilic substitution of a hydrogen with a fluorine is found to proceed for the direct fluorination of the DMC.
Physical properties of monofluorodimethyl carbonate
Takehara, Masahiro,Watanabe, Susumu,Nanbu, Noritoshi,Ue, Makoto,Sasaki, Yukio
, p. 338 - 339 (2004)
Partial fluorination of solvents can improve various physical properties because of the polar effect. We have investigated the temperature dependence of relative permittivity (εr), viscosity (η), refractive index (nD), and density (ρ) of monofluorodimethyl carbonate (MFDMC) over a range of 10 to 70°C and compared the physical properties with those of dimethyl carbonate (DMC). The εr, η, and ρ of the MFDMC are higher than those of the DMC, whereas the nD becomes lower.
PROCESS FOR THE PREPARATION OF FLUOROALKYL (FLUORO)ALKYL CARBONATES AND CARBAMATES
-
Page/Page column 13, (2011/02/24)
Fluoroalkyl alkyl carbonates and fluorosubstituted carbamates which are suitable as additives or solvents in lithium ion batteries are prepared from fluoroalkyl fluoro formates and the respective alcohol or amine. Methanol is the preferred alcohol, dimethylamine and diethylamine are preferred amines. Fluoromethyl methyl carbonate is the preferred compound to be produced. Fluoroalkyl fluoro formates can be prepared from aldehydes and carbonyl fluoride.
Polar effect of successive fluorination of dimethyl carbonate on physical properties
Nanbu, Noritoshi,Takehara, Masahiro,Watanabe, Susumu,Ue, Makoto,Sasaki, Yukio
experimental part, p. 1302 - 1306 (2009/06/20)
Successive fluorination of dimethyl carbonate (DMC) exerts a polar effect on various fundamental properties. We describe the temperature dependence of the mass density (ρ), refractive index (nD), relative permittivity (εr), dynamic viscosity (η), and kinematic viscosity (ν) of trifluorinated, difluorinated, and monofluorinated DMCs (TFDMC, DFDMC, and MFDMC, respectively). η decreased in essentially the same order as εr: DFDMC > TFDMC > MFDMC > DMC. However, ν and the boiling point of the TFDMC were lower than those of the MFDMC.
