Packaging material for cell
A packaging material for a cell including a layered film in which at least a base-material layer, an adhesive layer, a metallic layer, and a sealant layer are layered in the stated order. The packaging material for a cell including a layered body in which at least a base-material layer, an adhesive layer, a metallic layer, and a sealant layer are layered in the stated order, wherein the packaging material for a cell can be imparted with highly exceptional moldability, and dramatically less prone to pinholing and cracking during molding by using, as the metallic layer, an aluminum foil having 0.2% yield strength of 58-121 N/mm 2 when a tensile test is performed in the direction parallel to the rolling direction.
1. A packaging material for a cell including a laminate with at least a base material layer, an adhesive layer, a metal layer and a sealant layer laminated in this order,
wherein the metal layer is an aluminum foil having a 0.2% yield strength of 64 to 85 N/mm 2 when a tensile test is conducted in a parallel direction with respect to a rolling direction,
wherein the aluminum foil satisfies a tensile rupture strength of 102 to 110 N/mm 2 when a tensile test is conducted in a parallel direction with respect to a rolling direction, and
wherein the aluminum foil satisfies a tensile rupture elongation of 10 to 13% when a tensile test is conducted in a parallel direction with respect to a rolling direction.
2. The packaging material for a cell according to claim 1 , wherein the base material layer is a biaxially stretched nylon film that satisfies the following physical properties (i) and (ii):
(i) the elongation in the width direction (EL TD ) is 80 to 120%, and the ratio of the elongation in the flow direction (EL MD ) to the elongation in the width direction (EL TD ) (EL MD /EL TD ) is 1 to 1.25; and
(ii) the tensile strength in the width direction (TS TD ) is 280 MPa or more, and the ratio of the tensile strength in the flow direction (TS MD ) to the tensile strength in the perpendicular direction (TS TD ) (TS MD /TS TD ) is 0.75 to 1.
3. The packaging material for a cell according to claim 1 , wherein the aluminum foil satisfies a 0.2% yield strength of 50 to 130 N/mm 2 when a tensile test is conducted in a perpendicular direction and a 45° direction with respect to a rolling direction.
4. The packaging material for a cell according to claim 1 , wherein at least one of the surfaces of the metal layer is subjected to a chemical conversion treatment.
5. The packaging material for a cell according to claim 1 , wherein the packaging material is a packaging material for a secondary battery.
6. A cell, wherein a cell element including at least a positive electrode, a negative electrode and an electrolyte is stored in the packaging material for a cell according to claim 1 .
7. The packaging material for a cell according to claim 3 , wherein the aluminum foil metal layer has a 0.2% yield strength of 60 to 90 N/mm 2 when the tensile test is conducted in the perpendicular direction and the 45° direction with respect to the rolling direction.
8. The packaging material for a cell according to claim 7 , wherein the aluminum foil metal layer has a 0.2% yield strength of 65 to 85 N/mm 2 when the tensile test is conducted in the perpendicular direction and the 45° direction with respect to the rolling direction.
9. The packaging material for a cell according to claim 2 , wherein the biaxially stretched nylon film satisfies the following properties (i) and (ii):
(i) the elongation in the width direction (EL TD ) is 90 to 110%, and the ratio of the elongation in the flow direction (EL MS ) to the elongation in the width direction (EL TD ) (EL MS /EL T ) is 1 to 1.2; and
(ii) the tensile strength in the width direction (TS TD ) is 280 MPa to 370 MPa, and the ratio of the tensile strength in the flow direction (TS MD ) to the tensile strength in the perpendicular direction (TS TD ) (TS MD /TS TD ) is 0.8 to 1.
10. The packaging material for a cell according to claim 9 , wherein the biaxially stretched nylon film satisfies the following properties (i) and (ii):
(i) the elongation in the width direction (EL TD ) is 95 to 100%, and the ratio of the elongation in the flow direction (EL MD ) to the elongation in the width direction (EL TD ) (EL MD /EL TD ) is 1 to 1.2; and
(ii) the tensile strength in the width direction (TS TD ) is 290 MPa to 350 MPa, and the ratio of the tensile strength in the flow direction (TS MD ) to the tensile strength in the perpendicular direction (TS TD ) (TS MD /TS TD ) is 0.9 to 1.
11. The packaging material for a cell according to claim 1 , wherein the aluminum foil satisfies a tensile rupture strength of 90 to 124 N/mm 2 when a tensile test is conducted in a perpendicular direction and a 45° direction with respect to the rolling direction.
12. The packaging material for a cell according to claim 11 , wherein the aluminum foil satisfies the tensile rupture strength of 94 to 122 N/mm 2 when the tensile test is conducted in the perpendicular direction and the 45° direction with respect to the rolling direction.
13. The packaging material for a cell according to claim 12 , wherein the aluminum foil satisfies the tensile rupture strength of 96 to 105 N/mm 2 when the tensile test is conducted in the perpendicular direction and the 45° direction with respect to the rolling direction.
14. A packaging material for a cell including a laminate, the laminate comprising:
a base material layer including a biaxially stretched nylon film that satisfies the following physical properties (i) and (ii):
(i) the elongation in the width direction (EL TD ) is 80 to 120%, and the ratio of the elongation in the flow direction (EL MD ) to the elongation in the width direction (EL TD ) (EL MD /EL TD ) is 1 to 1.25; and
(ii) the tensile strength in the width direction (TS TD ) is 280 MPa or more, and the ratio of the tensile strength in the flow direction (TS MD ) to the tensile strength in the perpendicular direction (TS TD ) (TS MD /TS TD ) is 0.75 to 1;
an adhesive layer laminated over the base material layer;
a metal layer laminated over the adhesive layer, the metal layer including an aluminum foil having:
a 0.2% yield strength of 64 to 85 N/mm 2 when a tensile test is conducted in a parallel direction with respect to a rolling direction;
a 0.2% yield strength of 50 to 130 N/mm 2 when a tensile test is conducted in a perpendicular direction and a 45° direction with respect to the rolling direction;
a tensile rupture strength of 102 to 110 N/mm 2 when a tensile test is conducted in the parallel direction with respect to the rolling direction;
a tensile rupture strength of 90 to 124 N/mm 2 when a tensile test is conducted in the perpendicular direction and the 45° direction with respect to the rolling direction;
a tensile rupture elongation of 10 to 13% when a tensile test is conducted in the parallel direction with respect to the rolling direction; and
a sealant layer laminated over the metal layer.
15. The packaging material for a cell according to claim 14 , wherein:
for the base material layer property (i), the elongation in the width direction (EL TD ) is 90 to 110%, and the ratio of the elongation in the flow direction (EL MD ) to the elongation in the width direction (EL TD ) (EL MD /EL TD ) is 1.0 to 1.25;
for the base material layer property (ii), the tensile strength in the width direction (TS TD ) is 280 MPa to 370 MPa, and the ratio of the tensile strength in the flow direction (TS MD ) to the tensile strength in the perpendicular direction (TS TD ) (TS MD /TS TD ) is 0.8 to 1.0; and
the metal layer satisfies:
a 0.2% yield strength of 60 to 90 N/mm 2 when a tensile test is conducted in the perpendicular direction and the 45° direction with respect to the rolling direction; and
a tensile rupture strength of 94 to 122 N/mm 2 when a tensile test is conducted in the perpendicular direction and the 45° direction with respect to the rolling direction.
16. The packaging material for a cell according to claim 15 , wherein:
for the base material layer property (i), the elongation in the width direction (EL TD ) is 95 to 100%, and the ratio of the elongation in the flow direction (EL MD ) to the elongation in the width direction (EL TD ) (EL MD /EL TD ) is 1.0 to 1.2;
for the base material layer property (ii), the tensile strength in the width direction (TS TD ) is 290 MPa to 350 MPa, and the ratio of the tensile strength in the flow direction (TS MD ) to the tensile strength in the perpendicular direction (TS TD ) (TS MD /TS TD ) is 0.9 to 1.0; and
the metal layer satisfies:
a 0.2% yield strength of 65 to 85 N/mm 2 when a tensile test is conducted in the perpendicular direction and the 45° direction with respect to the rolling direction; and
a tensile rupture strength of 96 to 105 N/mm 2 when a tensile test is conducted in the perpendicular direction and the 45° direction with respect to the rolling direction.