Packaging material for power storage device, method of producing same, and power storage device
AssigneeDai Nippon Printing Co., Ltd.
InventorsDaisuke Yasuda, Takanori Yamashita, Tetsuya Ojiri, Hiroyuki Kotera, Tsuyoshi Ito, Yoshiko Kiyohara, Kazufumi Kodani
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Abstract
A power storage device is constituted by a laminate including, in the stated order, at least a substrate layer, a barrier layer, and an inside layer. The inside layer is provided with an adhesive layer and a heat-sealing resin layer from the barrier layer side; and if dynamic viscoelasticity is measured by tension with respect to the inside layer, the growth rate at 80° C. is 8.0% or lower.
Claims22
An exterior material for an electrical storage device, comprising a laminate that includes 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 contains a polypropylene-based resin and polyethylene,
- a sea-island structure is observed in a cross-sectional image acquired using a scanning electron microscope for a cross section of the adhesive layer in a direction parallel to a transverse direction (TD) and in a thickness direction,
- the cross-sectional image is a cross-sectional image acquired within a range from a surface of the adhesive layer on a side of the barrier layer to a portion having a thickness of 25% when a thickness of the adhesive layer is 100%, and
- in the cross-sectional image, a ratio of a total number of island portions having an area of less than 0.25 μm2 to a total number of island portions of the sea-island structure is 40% or more, wherein in the cross-sectional image of the adhesive layer, a ratio of a total number of island portions having an area of less than 0.10 μm2 to a total number of island portions of the sea-island structure is 10% or more.
Dependencies are inferred from the claim text.