| 摘要 |
PURPOSE:To provide a nonaqueous electrolyte excellent in withstand voltage and electrical conductivity as well as in safety by using an electrolyte solvent containing trimethyl phosphate, a specific chain carbonic ester, and a cyclic carbonic ester. CONSTITUTION:An electrolyte solvent contains trimethyl phosphate, one or two kinds or more of chain carbonic esters represented by the formula (R<1> is a methyl group or ethyl group; R<2> is a chain, or branched, alkyl group of 1 to 3 carbons), and a cyclic carbonic ester. An electrolyte contains LiPF6, and trimethyl phosphate by 1 to 10vol% of the elecfrolyte solvent. A nonaqueous electrolyte thus obtained causes no decrease in the energy density of a battery even after repeated charge and discharge, and can secure sufficient safety even under severe conditions such as overcharging, an external short circuit, piercing, and crushing, etc. Also, the nonaqueous electrolyte is excellent in withstand voltage and electrical conductivity and has a high ignition point and therefore excellent in safety, as well as in load characteristic and low-temperature characteristic. |
