SEALANT FILM AND POWER STORAGE DEVICE EXTERIOR MATERIAL USING SAME

Provided are: a sealant film which has high heat sealing strength, has excellent drawing properties, and is capable of maintaining the amount of lubrication on the surface of the film in a suitable range even when aging is carried out after lamination, such that lubricity and high laminate strength can be achieved; and a power storage device exterior material which uses the sealant film. The sealant film is a three-layer laminated film including a surface layer A, a base material layer B, and a surface layer C, wherein a sea-island structure is observed in at least one of the surface layer A and the surface layer C as observed in an image acquired using a transmission electron microscope with respect to a cross section obtained by cutting the film parallel to the longitudinal direction, and, in the sea-island structure, the length of the island parts in the longitudinal direction of...