Explosion-proof valve device for battery, manufacturing method thereof and prismatic battery equipped with the explosion-proof valve device

摘要

PROBLEM TO BE SOLVED: To provide an explosion-proof valve device having superior leakage resistance, high safety and reliability, while being capable of accurately discharging the gas in response to a rise of the internal pressure of a battery, in misuse conditions or abnormal conditions of the battery. SOLUTION: A sealing plate 2, for sealing the opening part of a rectangular case 1 and provided with a hole part 4 of an explosion-proof valve 3 covered with an aluminum foil film 2a, is provided. In this case, the rectangular case 1 and the sealing plate 2 are welded to each other through laser-welding, and the sealing plate 2 is formed with the hole part 4 of the explosion-proof valve 3 by punching the sealing plate 2 from under thereof, and thereafter the hole part 4 is covered with the aluminum foil film 2a.