| 主权项 |
1. A secondary battery comprising:
a battery element that includes a positive electrode and a negative electrode; a plurality of metal terminals that are respectively connected to the positive electrode and the negative electrode, the metal terminals each having an outer peripheral surface provided with a resin film; a first packaging material and a second packaging material each of which includes a lamination of at least a metal foil layer and a heat-sealable resin layer made of a polyolefin resin, the first packaging material and the second packaging material sandwiching the battery element therebetween so that the heat-sealable resin layer is located inside; a first package sealed portion that is formed in the first packaging material so as to be smaller in thickness than in a first peripheral region of the first packaging material, by sandwiching the resin film between a first edge portion of the first packaging material and a second edge portion of the second packaging material, and pressing and heat sealing the first packaging material and the second packaging material sandwiching the resin film therebetween, in a manner of clamping the first and second packaging materials from outside; a second package sealed portion that is formed in the second packaging material so as to be smaller in thickness than in a second peripheral region of the second packaging material, by sandwiching the resin film between the first edge portion of the first packaging material and the second edge portion of the second packaging material, and pressing and heat sealing the first packaging material and the second packaging material sandwiching the resin film therebetween, in a manner of clamping the first and second packaging materials from outside; and a film sealed portion that is formed in the resin film so as to be smaller in thickness than in a third peripheral region of the resin film, by sandwiching the resin film between the first edge portion of the first packaging material and the second edge portion of the second packaging material, and pressing and heat sealing the first packaging material and the second packaging material sandwiching the resin film therebetween, in a manner of clamping the first and second packaging materials from outside, the film sealed portion being in intimate contact with the first packaging material and being in intimate contact with the second packaging material, wherein positions at which the first package sealed portion, the second package sealed portion, and the film sealed portion are formed in a perpendicular direction to an end face of the first edge portion are within a range where the resin film is arranged in the perpendicular direction to the end face of the first end portion, and a specific heat of fusion of the film sealed portion measured according to JIS K 7122 is greater than a specific heat of fusion of a portion of the resin film other than the film sealed portion. |
