LITHIUM-ION BATTERY

摘要

A lithium ion battery capable of maintaining for a long time fire resistance of a nonaqueous electrolytic solution at a time of battery abnormality to secure safety is provided. In the lithium ion battery, two kinds of organic solvent, EC and DEC, are used for mixed organic solvent which forms the nonaqueous electrolytic solution, and liquid flame retardant formed by phosphazene A having a boiling point closely to that of EC and phosphazene B having a boiling point closely to that of DEC is added to the electrolytic solution. At battery abnormality, when the battery temperature goes up due to internal short circuit of positive and negative electrodes caused bymeltingof separators to decompose eachof EC and DEC, thephosphazene A and B, each having the boiling point closely to that of EC and DEC, decompose timely to function, thereby fire resistance of the electrolytic solution can be maintained for a long time to secure safety of the battery at the time of battery abnormality.