ELECTROLYTE SOLUTION AND LITHIUM ION SECONDARY BATTERY

摘要

In a lithium ion secondary battery using a positive electrode active material that is composed of a lithium manganese oxide containing lithium (Li) and tetravalent manganese (Mn) and has a layered rock-salt crystal structure, deterioration of the electrolyte solution due to redox decomposition or the like is suppressed by adding a compound selected from compounds (a)-(i) to the electrolyte solution. Consequently, storage capacity and recovery capacity are improved when the lithium ion secondary battery is stored at high temperatures, while suppressing an increase in internal resistance.