| 摘要 |
PURPOSE:To improve the characteristic of charge and discharge, by using a solvent which is a mixture of 2,5-dimethyltetrahydrofuran and a compound having a polar double bond of >C=0 and/or >S=0, at a prescribed volume ratio, for an electrolytic solution, and by controlling the quantities of water and impurities. CONSTITUTION:The main constituent of an organic solvent for an electrolytic solution in which a lithium salt is dissolved in the solvent is a mixed solvent comprising 2,5-dimethyltetrahydrofuran and at least one of compounds having a polar double bond of >C=0 and/or >S=0, at a volume ratio of 90-40%. For example, the compounds having the polar double bond of >C=0 and/or >S=0 is ethylene carbonate, propylene carbonate, gamma-butylolactone and gamma- valerolactone. The water content and non-water impurity content of the electrolytic solution are not more than 400ppm and 25,000ppm, respectively. |
