| abstract |
This lithium ion secondary battery is a secondary battery in which positive electrodes 30 and negative electrodes 40 are alternately stacked with separators 25 interposed therebetween, and the separators 25 are single layers and melt at least at 200 ° C. Alternatively, the insulating layer 70 is formed on the surface of the positive electrode 30 facing the separator 25 without being softened and having a heat shrinkage rate of 3% or less. |