TWI832807B

A packaging material 1 for power storage devices includes a base material layer 2 made of a heat resistant resin, a sealant layer 3 as an inner layer, and a metal foil layer 4 arranged between the base material layer and the sealant layer. A protective layer 7 is laminated on a surface of the base material layer 2 opposite to a metal foil layer side. The protective layer 7 contains 40 mass % or more of a polyester resin formed by polyester polyol having a number average molecular weight of 5,000 to 50,000 and having a hydroxyl group or a carboxyl group independently at least at respective both ends thereof and a multifunctional isocyanate curing agent containing at least an aliphatic polyfunctional isocyanate compound.