| 摘要 |
PROBLEM TO BE SOLVED: To open a safety valve material in response to a temperature for speedily discharging a gas generated inside a battery in the case when the battery is abnormally used and especially when the battery is left in over charged condition or at abnormally high temperature, in a flat battery comprising a laminate sheet type armor case mainly made of a resin film. SOLUTION: In a seal part of a laminate sheet type bag-shaped armor case, a safety valve material assembles a multi-layer sheet therein, wherein the multi- layer sheet comprises an inner layer of a resin film having a melting point lower than that of a resin film at a heat melt side of the sheet and another resin film which has sufficient heat melt characteristic in regard to the laminate sheet and is arranged outside of the inner layer. The low melting point resin film is softened, melted, and deformed in response to a temperature when the battery is left at abnormally high temperatures for opening the safety valve. |
