LITHIUM ION SECONDARY BATTERY

Japanese Patent JP2015005454

A

PROBLEM TO BE SOLVED: To provide a lithium ion secondary battery capable of properly functioning a current interruption mechanism.SOLUTION: This lithium ion secondary battery includes a positive electrode containing a lithium oxide having a composition expressed by the formula (1), a negative electrode, an electrolyte containing an additive polymerized to generate a gas under an overcharged condition, and a vessel for housing the positive electrode, the negative electrode, and the electrolyte. LiNiCoMnDO(1), where D in the formula (1) denotes at least one kind of element selected from a group composed of Mg and Zr, b, c, d in the formula (1) satisfy 1/3