| 摘要 |
PROBLEM TO BE SOLVED: To improve the flexibility and the property suitable for rolling by providing a three dimensional substrate and an active material mix held in the substrate, forming notch parts in the rim part regions at right angles to the longitudinal direction along the direction of the regions, and making the number of the notches in one side lower than that of the notches in the other side. SOLUTION: Notch parts 23 vertical to the longitudinal direction of rolling are formed at equal intervals in the side of a paste-type nickel positive electrode 21, which forms the outer circumference when being rolled, except for the region where a lead tab 2 is formed. Each notch part 23 has a V shape, and the interval L of the notch bottom parts is controlled to be 0. 1 mm, the depth H of each notch to be 0.05 mm, and the angle α of the notch bottom part to be 30 degrees. Notch parts are formed also in the rear side, and the interval L is controlled to be 0.5 mm and other sizes and the angle are made equal to those of the notches in the front side. Consequently, the number of the notches in the side, which becomes the inner circumference when being rolled, is equivalent to 20% of the number of the notches formed in the side which becomes the outer circumference. As a result, the curving width can be narrowed as compared with a positive electrode having no notch and warping can be avoided, even in the case the paste-filling density is increased for heightening capacity and flexibility is improved. |
