| 摘要 |
PROBLEM TO BE SOLVED: To provide a battery wherein a lead is reliably fused by an outside short circuit and an outside short circuit current is broken so that heat generated inside the battery is stopped, by setting fusing limit current based on material and a cross section area of the lead connected to an electrode less then the outside short circuit current. SOLUTION: A constricted portion 7a with a width of 5mm is made at a center between an upper and lower sides of a negative electrode lead 7. An outside short circuit current when a positive electrode terminal 6 and a negative electrode terminal 8 of a battery is short-circuit outside if set for less than a fusing limit current value of a copper foil with a section area of 71μm×8mm, bit more then a fusing limit current value of a copper foil with a section area of 70μm×5mm. Accordingly, as for the negative electrode lead 7, only the fusing limit current of the constructed portion 7a becomes less than the outside short circuit current value. Thereby, the outside short circuit current continues of flow to a positive electrode 1 and a negative electrode 2 through a positive electrode lead 4 and the negative electrode lead 7, so that abnormal heat generation inside the battery is prevented and activation of a safety valve and rupture of the battery can be avoided.
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