| 摘要 |
PROBLEM TO BE SOLVED: To provide a lithium secondary battery with high reliability and safety and sufficient anti-moisture permeability.SOLUTION: A thermal deposition sheet 7g having a long belt-like shape with transparent portions 10 at both ends is cut into an appropriate length and folded to a half, so that the transparent portions 10 come into contact with a positive electrode terminal 5 and a negative electrode terminal 6. A peripheral edge except for a folded portion is used as a thermal deposition section 8 and thermally deposited. In this manner, using the thermal deposition sheet 7g as an outer container of a lithium secondary battery, existence of foreign matters can be visually recognized at each portion near the positive electrode terminal 5 and the negative electrode terminal 6 with relatively high possibility that foreign matters are nipped in the thermal deposition section 8. Also, short-circuit is prevented between the positive electrode terminal 5 and the negative electrode terminal 6 by thermal deposition. |
