| 摘要 |
Provided are electrochemical cells and electrolytes used to build such cells. The electrolytes include imide salts and/or methide salts as well as fluorinated solvents capable of maintaining single phase solutions at between about −30° C. to about 80° C. The fluorinated solvents, such as fluorinated carbonates, fluorinated esters, and fluorinated esters, are less flammable than their non-fluorinated counterparts and improve safety characteristics of cells containing these solvents. The amount of fluorinated solvents in electrolytes may be between about 30% and 80% by weight not accounting weight of the salts. Linear and cyclic imide salts, such as LiN(SO2CF2CF3)2, and LiN(SO2CF3)2, as well as methide salts, such as LiC(SO2CF3)3 and LiC(SO2CF2CF3)3, may be used in these electrolytes. Fluorinated alkyl groups enhance solubility of these salts in the fluorinated solvents. In some embodiments, the electrolyte may also include a flame retardant, such as a phosphazene, and/or one or more ionic liquids. |
| 主权项 |
1. An electrolyte for use in an electrochemical cell, the electrolyte comprising:
an electrolyte salt including an imide or methide having at least one fluorinated alkyl group of 1 to 8 carbon atoms; and a non-fluorinated carboxylic acid ester wherein the non-fluorinated carboxylic acid ester is selected from a group consisting of methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, methyl butyrate, and ethyl butyrate, and a fluorinated solvent selected from a group consisting of 1-methoxyheptafluoropropane, methyl nonafluorobutyl ether, ethyl nonafluorobutyl ether, 1,1,1,2,2,3,4,5,5,5-decafluoro-3-methoxy-4-(trifluoromethyl)-pentane, 3-ethoxy-1,1,1,2,3,4,4,5,5,6,6,6-dodecafluoro-2-trifluoromethyl-hexane, and 1,1,1,2,3,3-hexafluoro-4-(1,1,2,3,3,3-hexafluoropropoxy)-pentane, the fluorinated solvent being over 30% by weight of the electrolyte excluding the electrolyte salt; wherein the electrolyte is a one-phase solution at a temperature of about −30° C. |
