Physical and electrolytic properties of difluorinated dimethyl carbonate

• Published in: Journal of fluorine chemistry Vol. 125; no. 8; pp. 1205 - 1209
• Main Authors: Sasaki, Yukio, Takehara, Masahiro, Watanabe, Susumu, Nanbu, Noritoshi, Ue, Makoto
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.08.2004
• ISSN: 0022-1139; 1873-3328
• DOI: 10.1016/j.jfluchem.2004.05.008

The physical and electrolytic properties of difluorinated dimethyl carbonate (DFDMC), newly synthesized using F 2 gas, were examined. The ethylene carbonate (EC)-DFDMC equimolar binary solution containing 1 mol dm −3 LiPF 6 shows a moderate conductivity of 6.91 mS cm −1 at 25 °C. The lithium electrode cycling efficiency in the EC-DFDMC solution is higher than 80%. The physical and electrolytic properties of difluorinated dimethyl carbonate (DFDMC) synthesized using F 2 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 LiPF 6 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 LiPF 6 is higher than 80%. The EC-DFDMC solution is a good electrolyte for rechargeable lithium batteries.