POWER STORAGE DEVICE PACKAGING MATERIAL, METHOD FOR PRODUCING POWER STORAGE DEVICE PACKAGING MATERIAL, AND POWER STORAGE DEVICE

There is provided a power storage device packaging material that maintains high adhesion between a barrier layer having a corrosion-resistant film and an adhesive layer, even when water enters into the power storage device. A power storage device packaging material comprising a laminate comprising at least a base material layer, a barrier layer, an adhesive layer, and a heat-sealable resin layer in this order, wherein the adhesive layer is a cured product of a resin composition containing a compound having an isocyanate group; a corrosion-resistant film is provided on at least a surface of the barrier layer facing the adhesive layer; when the corrosion-resistant film is analyzed using time-of-flight secondary ion mass spectrometry, a P ratio of peak intensity P derived from PO- to peak intensity P derived from CrPO- is in the range of 6 to 120; when the corrosion-resistant film is analyzed by X-ray photoelectron spectroscopy, a peak P derived from C1s of O-C=O bonds in the range of 287 eV to 290 eV and a peak P derived from C1s of C-C bonds at 285 eV are detected; and a value of peak height ratio P obtained by dividing a height of the peak Poco by a height of the peak P is in the range of 0.10 or more and 0.50 or less.