| 摘要 |
PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte secondary battery having a shutdown function being capable of shutting down stably.SOLUTION: The nonaqueous electrolyte secondary battery includes positive electrode containing a positive electrode active material which contains nickel cobalt manganese lithium, a negative electrode containing a negative electrode active material, a nonaqueous electrolyte, and a separator provided between the positive electrode and the negative electrode and having a shutdown function which shutting down migration of lithium ions between the positive electrode and negative electrode at the shutdown temperature. In the nonaqueous electrolyte secondary battery, the capacity ratio of the positive electrode and negative electrode satisfies following relation, 1.7≤negative electrode capacity/positive electrode capacity≤1.9, and thermal shrinkage of the separator is 20% or less (when it is left, as it is, at 150°C for one hour). |
