| 摘要 |
PROBLEM TO BE SOLVED: To suppress the occurrence of damage to a separator even in the case of an active material layer having a protrusion in its surface.SOLUTION: A secondary battery comprises an electrode assembly 12. The electrode assembly is arranged by laminating a positive electrode 21 and a negative electrode 25 with a separator 29 interposed therebetween. The positive electrode has a positive electrode metal foil 22, and a positive electrode active material layer 23 formed by coating the positive electrode metal foil 22 with a positive electrode active material. The negative electrode has a negative electrode metal foil 26, and a negative electrode active material layer 27 formed by coating the negative electrode metal foil with a negative electrode active material. The separator 29 has a higher elongation in MD direction than that in other direction. The MD direction in which the separator 29 has a higher elongation is orthogonal to CD direction which is a coating direction of the positive electrode active material in the positive electrode 21, and to CD direction which is a coating direction of the negative electrode active material in the negative electrode 25.SELECTED DRAWING: Figure 3 |
