Abstract: A packaging material for a power storage device, including a laminate structure of a substrate layer, a first adhesive layer, a barrier layer, a second adhesive layer, and a sealant layer, in this order, wherein at least one of the first adhesive layer and the second adhesive layer contains a urethane compound or a urea compound; the urethane compound is a polyol resin with a polyfunctional isocyanate compound; the urea compound is a polyfunctional isocyanate compound an amine compound or an amine derivative; and, when a peak intensity of infrared absorption spectrum at 1,700 to 1,800 cm?1 measured using infrared spectroscopy (A”), and a peak intensity of infrared absorption spectrum at 1,600 to 1,660 cm?1 measured using infrared spectroscopy (“B”), a value X that is defined by the following Formula (1), which is X={B/(A+B)×100, satisfies a relationship 0.1?X?7.0.

Abstract: A power storage device packaging material of the present disclosure includes: a laminate at least including a substrate layer, a barrier layer, and a sealant layer, which are disposed in this order; and an adhesive layer interposed between the substrate layer and the barrier layer, the adhesive layer containing a polyurethane-based compound made of a reaction product of at least one polyester polyol resin and at least one polyfunctional isocyanate compound, wherein the polyfunctional isocyanate compound contains an isocyanurate of isophorone diisocyanate, and a content of isocyanate groups derived from the isocyanurate of isophorone diisocyanate in the polyfunctional isocyanate compound is 5 mol % to 100 mol % relative to a total amount of isocyanate groups contained in the polyfunctional isocyanate compound of 100 mol %.