| 摘要 |
PROBLEM TO BE SOLVED: To prevent winding displacement in formation of an electrode group for improving yield of a battery and providing a battery with improved reliability even when an insulation tape is stuck to a welding position in a positive/negative electrode current collection tab. SOLUTION: In a spiral electrode group mounted inside an armor casing, a positive electrode plate 10, in which an active material 12 is applied to both faces of long metal foil 11, and a negative electrode plate 20, in which an active material 22 is applied to both faces of long metal foil 21, are wounded up face to face via a separator 40. An uncoated part 13, on which the active material 12 is not applied, is formed in the longitudinal intermediate part in the positive electrode plate 10, and the current collection tab 14 is connected to the uncoated part 13, while an insulting tape 15 is stuck to cover the uncoated part 13 and the current collection tab 14. A ratio of the surface roughness Ra1 of the insulation tape 15 to the surface roughness Ra2 of the positive electrode plate 10 ranges from 0.5 to 1.5 (0.5Ra2≤Ra1≤1.5Ra2). COPYRIGHT: (C)2007,JPO&INPIT |
