| 摘要 |
PROBLEM TO BE SOLVED: To provide a highly reliable nonaqueous electrolyte secondary battery which can exhibit high tolerance during overcharge, while maintaining the battery performance.SOLUTION: A nonaqueous electrolyte secondary battery (e.g., a lithium ion secondary battery) is configured to house an electrode body having a positive electrode and a negative electrode, and a nonaqueous electrolyte containing a gas generating agent in a battery case. The battery case includes a current interruption mechanism which is actuated when the internal pressure of the case rises. The positive electrode includes a positive electrode collector, and a positive electrode active material layer formed on the collector and containing at least a positive electrode active material. Porosity of the positive electrode active material layer is 28 vol% or more, maximum frequency pore size of the positive electrode active material layer is 0.3 μm or more, and the ratio occupied by pores having pore size of 0.3 μm or more in the positive electrode active material layer is 30 vol% or more for 100 vol% of the whole air gap in the positive electrode active material layer. |
