| 摘要 |
PROBLEM TO BE SOLVED: To provide a lithium ion secondary battery arranged so that the thermorunaway can be suppressed when an internal short circuit is caused.SOLUTION: The lithium ion secondary battery comprises: a positive electrode including a current collector, a positive electrode active material layer formed on the current collector, and including a lithium-containing complex oxide having a lamellar rock salt structure and expressed by the general formula, LiNiCoMnDO(where 0.2≤a≤1, b+c+d+e=1, 0≤e<1, D represents at least one element selected from Li, Fe, Cr, Cu, Zn, Ca, Mg, S, Si, Na, K, and Al, and 1.7≤f≤2.1), and a thermorunaway-suppression layer formed on the positive electrode active material layer, and including a lithium transition metal silicate salt; and a negative electrode including a negative electrode active material. In the positive electrode, the ratio of the mass of the lithium-containing complex oxide to the mass of the lithium transition metal silicate salt is 1.5 or more. |
