FILM PACKAGE ENERGY STORAGE DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a film package energy storage device which ensures an accurate operation of a safety valve by eliminating an adverse effect by creep for a long period of time. SOLUTION: The film package energy storage device 1 includes a joining valve part 18 which is formed on a part of a sealed outer edge 14 a film package 10, and conducts an inside and outside of the package 10 by opening at least partly when inner pressure of an electrode body unit storing space is raised to a predetermined level. The joining valve part 18 includes a main joining part 15 having joining intensity corresponding to a predetermined pressure and a sub-joining part 16 having a lower joining intensity than the main joining part 15. COPYRIGHT: (C)2007,JPO&INPIT