| 摘要 |
PROBLEM TO BE SOLVED: To suppress variation in the working pressure of a pressure release valve.SOLUTION: In a secondary battery, a case housing an electrode assembly has a pressure release valve 20 for releasing the pressure in the case. The pressure release valve 20 has a valve element 21 thinner than a lid member 14 having the pressure release valve 20. At least on one side of the lid member 14 having the pressure release valve 20, the secondary battery has a sedimentary layer 27 containing ceramic particles or metal particles, at least on the surface of the valve element 21. The pressure release valve 20 can ensure mechanical strength by the sedimentary layer 27, even if the temperature rises. Consequently, reduction in cleavage strength is less likely to occur in the pressure release valve 20, and variation of the working pressure can be suppressed. |
