| 摘要 |
PROBLEM TO BE SOLVED: To reduce internal resistance, to facilitate assembly for a battery pack, and to improve liquid sealing performance. SOLUTION: In a positive electrode external terminal 4A, a liquid pouring opening 20 communicating the inside and the outside of a battery can 10 mutually is bored, and the liquid pouring opening is sealed by a liquid pouring plug 22. A countersink 41 is formed around the liquid pouring opening, and a flange part 26 fitted in the countersink is arranged in the liquid pouring plug. The flange part 26 is fixed by laser beam welding. When the liquid pouring opening 20 is sealed while firmly fixing the liquid pouring plug to the liquid pouring opening, liquid sealing performance can be improved. With the liquid pouring opening and the liquid pouring plug arranged in the external terminal, formation of the liquid pouring opening in a battery can or a battery lid is not needed. In this way, the battery can and the battery lid can be formed of thin sheets. Even when steel sheets with high specific gravity are used as materials for the battery can and the battery lid, the weight of the vessel can be reduced. When a steel sheet is used, a welding part with extremely high strength can be formed. COPYRIGHT: (C)2011,JPO&INPIT
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