Search

EP-4201651-B1 - APPARATUS FOR SEALING BATTERY CASE, AND SECONDARY BATTERY MANUFACTURED USING SAME

EP4201651B1EP 4201651 B1EP4201651 B1EP 4201651B1EP-4201651-B1

Inventors

  • KIM, GEUN HEE
  • OH, SE YOUNG
  • HA, JEONG MIN

Dates

Publication Date
20260513
Application Date
20211012

Claims (18)

  1. An apparatus for sealing a battery case (13), the apparatus comprises: a sealing tool (21) configured to seal a side of a pouch-type secondary battery (1), wherein the sealing tool (21,22) comprises: a body (211,221); and a sealing part (212,222) formed at one side of the body and configured to directly press the side so as to seal the side, wherein the sealing part (212) comprises: a pattern part (2122,2222) configured to seal an outer portion of the side (134) and formed by regularly repeating a rib (2123, 2223) formed to protrude outward and a groove formed to be recessed inward, characterized in that the sealing part (212) comprises: a weak sealing part (2121,2221) configured to seal an inner portion of the side (134) and formed to be recessed inward; and in that the groove of the pattern part is recessed deeper than the weak sealing part (2121,2221).
  2. The apparatus of claim 1, wherein the groove comprises a longitudinal groove (2124,2224) formed in a longitudinal direction of the pattern part.
  3. The apparatus of claim 2, wherein the groove (2124,2224) comprises a width groove (2225,2125) formed in a width direction of the pattern part.
  4. The apparatus of claim 1, wherein the weak sealing (2121,2221) part is recessed inward by a thickness of 10 µm to 20 µm.
  5. The apparatus of claim 1, wherein, in the pattern part (2122,2222), the groove is recessed inward by a thickness of 40 µm to 60 µm.
  6. The apparatus of claim 1, wherein the rib (2123, 2223) and the groove have the same width.
  7. The apparatus of claim 1, wherein the weak sealing part (2121,2221) has a rounded edge.
  8. The apparatus of claim 7, wherein, in the weak sealing part (2121,2221), the edge (R1) is rounded at a curvature radius of 0.7 mm to 0.8 mm.
  9. The apparatus of claim 1, wherein the pattern part (2122,2222) has a rounded edge.
  10. The apparatus of claim 9, wherein, in the pattern part (2122,2222), the edge (R3) is rounded at a curvature radius of 0.2 mm to 0.3 mm.
  11. The apparatus of claim 1, wherein the sealing tool (21,22) further comprises: a first sealing tool (21) configured to press one surface of the side; and a second sealing tool (22) that is in contact with the first sealing tool with the side therebetween to press the other surface of the side, wherein a first sealing part (212) of the first sealing tool comprises: a first weak sealing part (2121) configured to seal the inner portion of the side and formed to be recessed inward; and a first pattern part (2122) configured to seal the outer portion of the side and formed by regularly repeating a first rib formed to protrude outward and a first groove (2124) formed to be recessed inward, and a second sealing part (222) of the second sealing tool comprises: a second weak sealing part (2221) configured to seal the inner portion of the side and formed to be recessed inward; and a second pattern part (2222) configured to seal the outer portion of the side and formed by regularly repeating a second rib (2223) formed to protrude outward and a second groove (2224) formed to be recessed inward.
  12. The apparatus of claim 11, wherein, in the first pattern part (2122) and the second pattern part (2222), the first rib (2123) and the second groove (2224) are in contact with each other with the side (134) therebetween, and the second rib and the first groove are in contact with each other with the side therebetween.
  13. The apparatus of claim 1, wherein, in the sealing part (212,222), a groove, into which an electrode lead of the secondary battery is inserted, is formed to be recessed inward.
  14. A secondary battery (1) comprising: an electrode assembly (10) formed by alternately stacking electrodes and separators; and a battery case (13) in which the electrode assembly is accommodated and sealed, wherein the battery case comprises: a first case (131) in which a cup part (133) that is a space, in which the electrode assembly is accommodated, is formed; a second case (132) configured to cover the first case from above; and a side extending to the outside of the cup part to have an area on which the first case and the second case are sealed to each other, wherein the side (134) has an unevenness in a shape protruding from or recessed into an outer surface of the sealed area of the side characterized in that the side (134) of the battery case is sealed by using the apparatus for sealing the battery case of claim 1 so that the unevenness is formed by the pattern part (2122 and 2222), which are formed by regularly repeating the rib (2123 and 2223) formed to protrude outward and the groove (2124 and 2224) formed to be recessed inward, so that the unevenness formed on the side (134) in the protruding or recessed shape has a form and a width corresponding to the form and the width of each of the rib (2123 and 2223) and the grooves (2124 and 2224).
  15. The secondary battery (1) of claim 14, wherein the side (134) has an unevenness having a shape protruding from or recessed into an inner surface of the sealed area, wherein the unevenness formed on the inner surface has the protruding or recessed shape opposite to that of the unevenness formed on the outer surface.
  16. The secondary battery (1) of claim 14, wherein the unevenness has a length in a longitudinal direction of the side (134).
  17. The secondary battery (1) of claim 14, wherein the unevenness has a plurality of protruding or recessed shapes, and the protruding or recessed shapes are formed at regular intervals.
  18. The secondary battery (1) of claim 14, wherein the unevenness is formed in at least one of a rectangular shape or a rhombus shape in a cross-section of the protruding or recessed shape.

Description

CROSS-REFERENCE TO RELATED APPLICATION The present application claims the benefit of the priority of Korean Patent Application Nos. 10-2020-0131454, filed on October 12, 2020, and 10-2021-0134480, filed on October 08, 2021. TECHNICAL FIELD The present invention relates to an apparatus for sealing a battery case and a secondary battery manufactured using the same, and more particularly, to an apparatus for sealing a battery case, which reduces a size of a poly-ball and improves sealing force of a side, and a secondary battery manufactured using the same. BACKGROUND ART In general, secondary batteries include nickel-cadmium batteries, nickel-hydrogen batteries, lithium ion batteries, and lithium ion polymer batteries. Such a secondary battery is being applied to be used in small-sized products such as digital cameras, P-DVDs, MP3Ps, mobile phones, PDAs, portable game devices, power tools, E-bikes, and the like as well as large-sized products requiring high power such as electric vehicles and hybrid vehicles, power storage devices for storing surplus power or renewable energy, and backup power storage devices. In general, in order to manufacture the secondary battery, first, electrode active material slurry is applied to a positive electrode collector and a negative electrode collector to manufacture a positive electrode and a negative electrode. Then, the electrodes are stacked on both sides of a separator to form an electrode assembly. Also, the electrode assembly is accommodated in a battery case, and then the battery case is sealed after an electrolyte is injected therein. Such a secondary battery is classified into a pouch type secondary battery and a can type secondary battery according to a material of a case accommodating the electrode assembly. In the pouch type secondary battery, an electrode assembly is accommodated in a pouch made of a flexible polymer material. Also, in the can type secondary battery, an electrode assembly is accommodated in a case made of a metal or plastic material. A pouch, which is a case of the pouch type secondary battery, is manufactured by forming a cup part by performing press processing on a pouch film having flexibility. In addition, when the cup part is formed, an electrode assembly is accommodated in an accommodation space of the cup part, and then, a side of the cup part is sealed to manufacture a secondary battery. In a process of sealing the side, an apparatus for sealing the battery case is used, and the apparatus for sealing the battery case includes a sealing tool. However, in the sealing tool according to the related art, a surface of a sealing part is formed to be flat as a whole. Thus, an area sealed at the side of the secondary battery has also a flat outer surface, and a sealant layer sealed inside the side has also a surface sealed in a flat state. As a result, the sealing force of the side is reduced to cause a problem in which the side is easily bent even when a pressure inside the secondary battery slightly increases. If the pressure that presses the side increases by the sealing tool, a portion of the sealant layer is melted, and thus, a poly-ball protruding toward an accommodation space of a cup part is largely formed. If the size of the poly-ball is large, there is a problem in that the poly-ball are in contact with an electrode assembly accommodated in the cup part, and thus, the electrode assembly is contaminated by the poly-ball. Furthermore, as a thickness of the sealant layer on the side became thinner, there is also a problem in that insulation is defective. [PRIOR ART DOCUMENTS] (Patent Document 1) Korean Patent Registration No. 1296949. KR 2013 0080071 and KR 2014 0086907 relate to sealing device for battery. DISCLOSURE OF THE INVENTION TECHNICAL PROBLEM An object of the present invention is to provide an apparatus for sealing a battery case, which reduces a size of a poly-ball and improves sealing force of a side, and a secondary battery manufactured using the same. The objects of the present invention are not limited to the aforementioned object, but other objects not described herein will be clearly understood by those skilled in the art from descriptions below. TECHNICAL SOLUTION An apparatus for sealing a battery case according to an embodiment of the present invention for achieving the above object includes: a sealing tool configured to seal a side of a pouch-type secondary battery, wherein the sealing tool includes: a body; and a sealing part formed at one side of the body and configured to directly press the side so as to seal the side, wherein the sealing part includes: a weak sealing part configured to seal an inner portion of the side and formed to be recessed inward; and a pattern part configured to seal an outer portion of the side and formed by regularly repeating a rib formed to protrude outward and a groove formed to be recessed inward. In addition, the groove may include a longitudinal groove formed in a longitudinal directio