Packaging material for battery
A packaging material for batteries including a laminate in which at least a base material layer, a metal layer, and a sealant layer are laminated in order. The battery packaging material satisfies the relationships of: (A1−A2)≥60 N/15 mm; and (B1−B2)≥50 N/15 mm. A1 is a stress in elongation by 10% in the MD direction and B1 is a stress in elongation by 10% in the TD direction in the laminate, and A2 is a stress in elongation by 10% in the MD direction and B2 is a stress in elongation by 10% in the TD direction in the base material layer.
1. A battery packaging material comprising a laminate in which at least a base material layer, a metal layer, an adhesive layer, and a sealant layer are laminated in this order,
the laminate satisfying the relationship of A+B≥2.50, where A+B is a sum of a value A of a ratio of a stress in elongation by 40% to a stress in elongation by 10% in the MD direction and a value B of a ratio of a stress in elongation by 40% to a stress in elongation by 10% in the TD direction.
2. The battery packaging material according to claim 1 , wherein the metal layer is an aluminum foil in which the 0.2% yield strength when a tensile test is conducted in a direction parallel to the MD direction and the 0.2% yield strength when a tensile test is conducted in a direction parallel to the TD direction are each in the range of 55 to 140 N/mm 2 .
3. The battery packaging material according to claim 1 , wherein
the base material layer comprises:
at least one resin film layer consisting essentially of a polyamide resin, and
one or more additional resin film layers consisting essentially of a polyamide resin, polyethylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, or mixtures or copolymers thereof; and
the base material layer does not include polybutylene terephthalate.
4. The battery packaging material according to claim 1 , wherein
the base material layer is made of a single resin film layer consisting essentially of a polyamide resin.
5. The battery packaging material according to claim 1 , wherein
the base material layer is formed of a two layer resin film including a first layer consisting essentially of polyethylene terephthalate, and a second layer consisting essentially of a polyamide resin.
6. The battery packaging material according to claim 1 , wherein
the sealant layer is formed of two or more layers with an identical resin component or different resin components.
7. The battery packaging material according to claim 1 , wherein
the metal layer has a thickness greater than 50 μm.
8. A battery comprising a battery element including at least a positive electrode, a negative electrode and an electrolyte being stored in the battery packaging material according to claim 1 .
9. A method for producing a battery packaging material, the method comprising:
preparing a laminate in which at least a base material layer, a metal layer, and a sealant layer are laminated in this order,
wherein the laminate satisfies the relationship of A+B≥2.50, where A+B is a sum of a value A of a ratio of a stress in elongation by 40% to a stress in elongation by 10% in the MD direction and a value B of a ratio of a stress in elongation by 40% to a stress in elongation by 10% in the TD direction.
10. The method according to claim 9 , further comprising applying an adhesive layer between the metal layer and the sealant layer.
11. The method according to claim 10 , wherein the adhesive layer and the sealant layer are co-extruded and laminated on the metal layer.
12. The method according to claim 9 , wherein the sealant layer is formed of two or more layers comprising an identical resin component or different resin components.
13. The battery packaging material according to claim 1 , wherein the adhesive layer has a thickness of 2 μm or more and 15 μm or less.
14. The battery packaging material according to claim 1 , wherein the adhesive layer has a thickness of 15 μm or more and 30 μm or less.
15. The battery packaging material according to claim 1 , wherein the adhesive layer has a thickness of above 30 μm and 50 μm or less.
16. The battery packaging material according to claim 1 , further comprising a coating layer on a side of the base material layer opposite to the metal layer.