Sealing film for housing an energy storage device, housing for energy storage device and energy storage device

摘要

A sealing film has a structure of a laminated body having two or more layers. The laminated body includes a first resin layer 7 containing 50 mass% or more of a random copolymer containing propylene and a copolymer component other than propylene as copolymer components, and a second resin layer 8 formed of a mixed resin containing a first one An elastomer-modified olefin-based resin having a melting point of 155 ° C or more and a crystalline melting energy of 50 J / g or more and a second elastomer-modified olefin-based resin having a melting point of 135 ° C or more and a crystalline melting energy of 30 J / g or less. With this structure, when the internal pressure of an energy storage device is excessively increased, breakage (separation) occurs inside the sealing layer, causing gas release, which in turn can prevent bursting of the packaging material due to the increase in internal pressure.