| 摘要 |
PROBLEM TO BE SOLVED: To accurately operate a safety valve when a battery inner pressure is increased by composing the safety valve of a sealing plate of a hole part provided in a lid plate and a metal foil covering its lower part, and setting the shape of the metal foil in the hole part to a projecting shape. SOLUTION: A sealing plate is a clad plate having an aluminum foil 2b pressure bonded to a flat lid plate 2a made of aluminum, and a safety valve 3 is provided. The safety valve 3 is constructed by pressure bonding the aluminum foil 2b to the lower surface of the safety valve hole part 4 of the lid plate 2a. The lid plate 2a and the metal foil 2b are both made of aluminum, and a case and the sealing plate are laser-welded to each other. If the aluminum foil 2b is arranged to be bent in a projecting shape inside the hole part 4 of the flat lid plate 2a made of aluminum in the safety valve part, when gas in the battery is accumulated to increase the inner pressure, the application of a gas pressure concentrates in the center of the vertex part of the projecting metal foil, and the operation of the safety valve 3 is stabilized. |
