Battery cell and method for manufacturing the same

Abstract

To provide a battery cell that allows the user to adjust the gas venting direction at will when the internal pressure of the battery cell increases. [Solution] A battery cell 100 comprising an electrode assembly including a positive electrode, a negative electrode, and a separator membrane; and a battery case 300 including a sealing portion 320 that houses the electrode assembly and seals the outer periphery of the electrode assembly, wherein the sealing portion includes a first region A1 and a second region A2, the first region being a region of the battery case with a higher degree of crystallinity than the second region, and the sealing portion not containing cross-linked resin, wherein the sealing portion includes a first sealing portion 321 and a second sealing portion 325 located on both sides of the battery case, and a third sealing portion 327 which is one end between the first and second, the first and second sealing portions being sealing portions including a region in which the electrode lead 210 is located, and the second region being a part of the first sealing portion or a part of the second sealing portion.

Claims

1. Electrode assemblies including a positive electrode, a negative electrode, and a separator membrane; and The battery case includes a sealing portion that houses the electrode assembly and seals the outer periphery of the electrode assembly, The sealing portion includes a first region and a second region excluding the first region. A battery cell in which the first region is a region of the battery case with a higher degree of crystallinity than the second region.

2. The battery cell according to claim 1, wherein the sealing portion includes a first sealing portion and a second sealing portion located on both sides of the battery case, and a third sealing portion which is one end between the first sealing portion and the second sealing portion.

3. The first region is, The first sealing portion and the second sealing portion excluding a portion of the first sealing portion, or the first sealing portion and the second sealing portion excluding a portion of the second sealing portion, The battery cell according to claim 2, including the third sealing portion.

4. The battery cell according to claim 3, wherein the second region is a part of the first sealing portion or a part of the second sealing portion.

5. The battery cell according to claim 1, wherein the second region ruptures when the pressure inside the battery cell is above a certain pressure.

6. The sealing portion includes a metal layer, an internal resin layer formed on one surface of the metal layer, and an external resin layer formed on the other surface of the metal layer. The internal resin layer includes a third region and a fourth region excluding the third region. The battery cell according to claim 1, wherein the third region is a region in which the degree of crystallinity of the battery case is greater than that of the fourth region.

7. The battery cell according to claim 6, wherein the third region is a region in which the degree of crystallinity of the internal resin layer is greater than that of the fourth region.

8. The first region includes the third region, The battery cell according to claim 6, wherein the second region includes the fourth region.

9. Electrode assemblies including a positive electrode, a negative electrode, and a separator membrane; and The battery case includes a sealing portion that houses the electrode assembly and seals the outer periphery of the electrode assembly, The sealing portion includes a first region and a second region excluding the first region. The first region is a region in which the tensile strength of the battery case is greater than that of the second region, in a battery cell.

10. The battery cell according to claim 9, wherein the tensile strength of the first region is two to three times higher than the tensile strength of the second region.

11. The battery cell according to claim 10, wherein the tensile strength of the first region is 2.2 to 2.9 times higher than the tensile strength of the second region.

12. A method for manufacturing a battery cell, comprising an electrode assembly including a positive electrode, a negative electrode, and a separator membrane, and a battery case including a sealing portion that houses the electrode assembly and seals the outer periphery of the electrode assembly, The process of heat-sealing the sealing portion; and This process includes transferring heat to the remaining portion of the sealing portion, excluding one region of the sealing portion. A method for manufacturing a battery cell, wherein the remaining portion of the sealing portion, excluding one region of the sealing portion, is the first region.

13. The method for manufacturing a battery cell according to claim 12, wherein, in the process of transferring heat to the remaining sealing portion excluding one region of the sealing portion, the first region is a region that receives additional heat transfer from an external heat source.

14. The method for manufacturing a battery cell according to claim 13, wherein the external heat source maintains a certain distance from the battery case and transfers heat without contacting the battery case.

15. The method for manufacturing a battery cell according to claim 14, wherein the external heat source is one of a quartz tube, a carbon heater, a ceramic heater, and a halogen lamp.

16. The process of transferring heat to the remaining sealing portion excluding one region of the sealing portion is the process of transferring heat to the first region within a first temperature range; A process of transferring heat to the first region in a second temperature range; and A method for manufacturing a battery cell according to claim 12, further comprising a cooling step.

17. The method for manufacturing a battery cell according to claim 16, wherein the first temperature range is higher than the second temperature range.

18. The method for manufacturing a battery cell according to claim 16, wherein the process of transferring heat to the first region in the first temperature range is to heat the first region at 140°C to 160°C for 1 minute.

19. The method for manufacturing a battery cell according to claim 16, wherein the process of transferring heat to the first region in the second temperature range is to heat the first region at 100°C to 120°C for 1 minute.

20. The method for manufacturing a battery cell according to claim 16, wherein the cooling process involves cooling the battery cell to 20°C to 25°C.

21. A method for manufacturing a battery cell according to claim 12, further comprising the step of cutting the sealing portion.

22. The method for manufacturing a battery cell according to claim 12, further comprising the step of folding and taping a region of the sealing portion in which no electrode leads protruding from the electrode assembly were located.

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