| 摘要 |
PROBLEM TO BE SOLVED: To uniformly apply battery internal pressure induced by sudden heating by an internal short circuit to the inside of a battery, and to more reliably actuate a safety valve by communicating upper end surface side and lower end surface side spaces of an electrode body by a hollow electrode body core, and arranging at least a single pressure relief part on an end part peripheral surface of the electrode body core. SOLUTION: An electrode body 2 by winding a positive electrode plate 3 and a negative electrode plate 4 round a stainless steel core 30 through a separator 5 is inserted into a battery case l, and a battery lid 11 having positive/ negative electrode terminals 31 and 32 is welded to the battery case 1, and an electrolyte is filled/sealed in a vacuum. A safety valve 40 is arranged on a bottom surface of the battery case 1. Circular through holes communicated with an inside surface of the core 30, that is, pressure relief parts 20 are oppositely formed by two pieces on an end part peripheral surface positioned on the battery lid 11 side of the electrode body 2 of the core 30. Therefore, the safety valve 40 can be reliably actuated without straining the battery lid 11 and the battery cafe 1. |
