As illustrated in FIG. 10, the wave shape is formed in advance on the side surface of the protrusion, the waves are extended, and it is possible to prevent the occurrence of wrinkling or cracking. As illustrated in FIG. 9, similar to the wave shape formed on the top surface of protrusion 103 of laminate film 101, the wave shape is also formed in side surface 114 of the protrusion.
At this time, the wave shape of side surface 114 of the protrusion is formed after the process of protrusion 103 is performed. According to the method, since, the wave shape is formed on the side surface of the protrusion after the protrusion, is formed as illustrated in FIG. 3, the wave shape in the side surface is not crushed.
Embodiment 8
FIG. 11 illustrates a state in which the protrusion is set in the laminate film, on the upper side and, in this state, upward or downward curvature is performed. FIG. 12 illustrates a state in which the protrusions are set on both sides of the laminate films on the upper side and the lower side, and upward or downward curvature is performed.
Protrusion 103 is set only on laminate film 101 on the upper side as illustrated in (A) of FIG. 11. Then, when the upward curvature is performed as illustrated in (B) of FIG. 11, extension stress acts on the wave shape formed on the top surface of protrusion 103 and the wave extends. As a result, the battery is curved without wrinkling.
