LITHIUM ION NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

摘要

A lithium ion secondary battery having excellent charge/discharge cycle characteristics. The lithium ion secondary battery is obtained by housing an electrode body and a nonaqueous electrolyte solution in a case.  The electrode body contains a positive electrode having a positive electrode active material, a negative electrode having a negative electrode active material, and a separator.  The nonaqueous electrolyte solution contains a lithium salt, which serves as a supporting salt, in an organic solvent.  The positive electrode active material is a lithium-transition metal oxide having a lamellar structure.  The electrolyte solution contains ß mol of a compound represented by chemical formula (I) per a mol of the total moisture content entered in the battery, and ß satisfy the following formula: -1.3 = log(ß/a) = 1.