Secondary battery and secondary battery module comprising same

Abstract

The present invention relates to a secondary battery. The secondary battery according to an embodiment of the present invention may comprise: an electrode assembly; a pouch accommodating the electrode assembly; and separation straps attached to the pouch and provided so as to cut the pouch so that the electrode assembly can be separated from the pouch.

Description

Secondary battery and secondary battery module including the same

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority from Korean Patent Application No. 10-2023-0161286, filed November 20, 2023, the entire contents of which are incorporated herein by reference.

[0003] Technology field

[0004] The present invention relates to a secondary battery, and more particularly, to a pouch-type secondary battery in which an electrode assembly is wrapped with a pouch-type outer material.

[0005] Secondary batteries are highly applicable to a wide range of product groups and possess electrical properties that enable high energy density. These batteries are used not only in portable electronic devices but also in electric or hybrid vehicles powered by electrical power sources, as well as in power storage devices. Secondary batteries are attracting attention as a new energy source for environmental friendliness and energy efficiency, not only because they can dramatically reduce fossil fuel use, but also because they produce no byproducts from energy use.

[0006] In general, pouch-type secondary batteries can be manufactured by stacking or winding an electrode assembly comprising a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, embedding the electrode assembly in a battery case made of a pouch sheet, and then injecting or impregnating the battery with an electrolyte. The pouch-type secondary battery can be made airtight by sealing a pouch sheet protruding along the edge of the secondary battery.

[0007] However, high-temperature sealed pouch-type secondary batteries are difficult to disassemble and analyze for various purposes after production. Sharp tools used during disassembly can cause unnecessary damage to the battery's interior. Furthermore, the manual process of removing each pouch can be time-consuming.

[0008] Therefore, there is a need for a secondary battery that can be quickly separated from the pouch to check the internal structure without damaging the secondary battery when necessary.

[0009] The background technology described above is something that the inventor possessed or acquired in the process of deriving the disclosure of the present application, and cannot necessarily be said to be a publicly known technology disclosed to the general public prior to the present application.

[0010] The present invention has been devised to solve the above problems,

[0011] The problem to be solved by the present invention is to provide a secondary battery in which a pouch can be easily separated from an electrode assembly.

[0012] Another problem to be solved by the present invention is to provide a secondary battery capable of preventing damage to an electrode tab during the process of separating a pouch from an electrode assembly.

[0013] A secondary battery according to one embodiment of the present invention may include an electrode assembly, a pouch for accommodating the electrode assembly, and a separation strap coupled to the pouch and configured to cut the pouch so as to separate the electrode assembly from the pouch.

[0014] The above separation strap may be arranged to cut the pouch along the circumference of the pouch.

[0015] The above separation strap may be formed in the shape of a belt extending along the inner circumference of the pouch with a predetermined width.

[0016] The above separation strap may overlap between the electrode assembly and the pouch.

[0017] The above separation straps may be provided in multiple pieces.

[0018] A pair of said separation straps may be provided spaced apart in the longitudinal direction of the electrode assembly.

[0019] The above separation strap may include a first strap disposed around the circumference of the electrode assembly at a position adjacent to the positive tab of the electrode assembly, and a second strap disposed around the circumference of the electrode assembly at a position adjacent to the negative tab of the electrode assembly.

[0020] The above separation strap may include a cut portion that is adhered to the inner surface of the pouch along the perimeter of the electrode assembly, and a grip portion that extends from the cut portion and is provided to protrude outward from the pouch so as to apply force from the outside.

[0021] The above-mentioned grip portion may protrude from the side end of the pouch.

[0022] The above separation strap can be attached to the outer surface of the pouch.

[0023] The above separation strap may be formed of polyethylene material.

[0024] It can be provided as a secondary battery module according to the present invention, and the secondary battery module according to the present invention can include a plurality of secondary batteries reviewed above.

[0025] According to one embodiment of the present invention, a secondary battery can easily separate a pouch from an electrode assembly.

[0026] A secondary battery according to one embodiment of the present invention can prevent damage to an electrode tab during the process of separating a pouch from an electrode assembly.

[0027] In addition, the configurations according to the embodiments of the present invention may include effects that can be easily predicted by those skilled in the art.

[0028] FIG. 1 is a schematic diagram showing an electrode assembly accommodated in a secondary battery according to Example 1 of the present invention and a lead coupled thereto.

[0029] Figure 2 shows a schematic perspective view of a secondary battery according to Example 1 of the present invention.

[0030] Figure 3 is a perspective view showing the arrangement of the separation strap and pouch of the secondary battery according to Example 1 of the present invention.

[0031] Figure 4 shows the unfolded state of the pouch of the secondary battery according to Example 1 of the present invention before being sealed.

[0032] Figure 5 shows a partial perspective view of a secondary battery according to Example 1 of the present invention.

[0033] Figure 6 shows a partial perspective view of a secondary battery according to Example 2 of the present invention.

[0034] Figure 7 shows a schematic perspective view of a secondary battery according to Example 3 of the present invention.

[0035] Hereinafter, with reference to the attached drawings, preferred embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the invention. The following description is one of several aspects of the embodiments, and in describing one embodiment, detailed descriptions of well-known functions or configurations will be omitted to clarify the gist of the present invention.

[0036] In this specification, when adding reference signs to components in each drawing, the same or similar reference signs are attached to identical or similar components throughout the specification. Components included in one embodiment and components that have common functions will be described using the same names in other embodiments. Terms or words used in this specification and the claims should not be interpreted as limited to their usual or dictionary meanings, and should be interpreted as meanings and concepts that are consistent with the technical spirit of the present invention based on the principle that the inventor can appropriately define the concept of the term to best explain his or her invention.

[0037] Furthermore, the present invention is not limited to the embodiments described above, and those skilled in the art will readily appreciate that various modifications and variations can be made based on this disclosure. Therefore, the spirit of the present invention should not be construed as limited to the embodiments described above, and all variations equivalent to or equivalent to the claims, as well as the scope of the claims, are deemed to fall within the scope of the present invention.

[0038] Example 1

[0039] FIG. 1 is a schematic diagram showing an electrode assembly (10) accommodated in a secondary battery according to Example 1 of the present invention and a lead (20) coupled thereto.

[0040] Referring to Fig. 1, the electrode assembly (10) may be provided to be electrically connected to the electrode lead (20). The electrode assembly (10) may be electrically connected to the electrode lead (20) via an electrode tab (11) that is formed to protrude at an end. The electrode tab (11) of the electrode assembly (10) may have a form in which multiple layers of metal foil are overlapped and fixed. The electrode tab (11) may be provided, for example, in a state in which multiple layers of metal foil are ultrasonically welded and fixed to each other.

[0041] Electrode tabs (11) may be formed at both ends of the electrode assembly (10). The electrode tabs (11) include a positive electrode tab and a negative electrode tab, and a positive electrode tab may be provided at one end of the electrode assembly (10) and a negative electrode tab may be provided at the other end of the electrode assembly (10).

[0042] The electrode tab (11) and the electrode lead (20) of the electrode assembly (10) can be electrically / physically connected to each other and fixed to each other by welding. One end of the electrode tab (11) and one end of the electrode lead (20) can be welded to overlap each other. The electrode assembly (10) connected to the electrode lead (20) can be surrounded by a pouch (50) to be described later and accommodated in the pouch (50). At this time, the lead film (21) provided in the circumferential direction of the electrode lead (20) can be sealed together with the pouch (50) to ensure airtightness inside the pouch (50).

[0043] The connection portion (30) where the electrode tab (11) and the lead (20) are welded may be partially or completely damaged depending on external physical impact or welding conditions, which may impair the electrical stability of the secondary battery and reduce its quality. Therefore, it may be necessary to open the pouch (50), which will be described later, to check for damage to the connection portion (30). In other words, a situation may arise where the pouch (50) and the electrode assembly (10) must be separated from each other.

[0044] Figure 2 shows a schematic perspective view of a secondary battery according to Example 1 of the present invention.

[0045] Referring to FIG. 2, a secondary battery according to Example 1 of the present invention may include a pouch (50) that accommodates an electrode assembly, and a separation strap (40) coupled to the pouch.

[0046] The pouch (50) may be provided to accommodate the electrode assembly (10) therein. The pouch (50) may be provided in a form that surrounds the electrode assembly (10). The pouch (50) may be formed by folding a film-shaped outer sheet. The pouch (50) may be a laminate sheet including a metal layer such as aluminum or stainless steel, and a resin layer laminated on the metal layer. The pouch (50) may be sealed inside and outside by being sealed while surrounding the electrode assembly (10). As described below, the pouch (50) may be formed with a side portion (52) that is provided to be sealed by being sealed to each other.

[0047] A separation strap (40) may be provided to allow easy separation of the pouch (50) from the electrode assembly (10). The separation strap (40) may be coupled to the pouch (50). The separation strap (40) may be coupled to the inner surface of the pouch (50) surrounding the electrode assembly (10).

[0048] The separation strap (40) may be provided to cut the pouch (50). When the separation strap (40) is detached from the pouch (50) while being coupled to the inner surface of the pouch (50), the separation strap (40) cuts at least a portion of the pouch, thereby making it easy for the pouch (50) to be detached from the electrode assembly (10). In this case, tearing off the separation strap (40) may mean applying an external force to the separation strap (40) in a direction away from the pouch (50). For example, it may mean pulling the separation strap (40) in a direction away from the pouch (50).

[0049] The separation strap (40) may be provided to cut the pouch (50) along the circumference of the pouch (50). The separation strap (40) may be provided in the form of a band having a predetermined width. The separation strap (40) may be formed in a form extending along the inner circumference of the pouch (50) with a predetermined width. Therefore, when an external force is applied to the separation strap (40) to tear off the separation strap (40), the separation strap (40) may cut the pouch (50) along the circumference of the pouch (50) in the form of a band having a predetermined width.

[0050] The separation strap (40) may include a cut portion (41) and a grip portion (42).

[0051] The cut portion (41) can be joined to the inner surface of the pouch (50) along the circumference of the electrode assembly (10) accommodated inside the pouch (50). The cut portion (41) can be joined to the inner surface of the pouch (50) in a manner that it is adhered to the inner surface of the pouch (50), particularly to the cup portion (51) of the pouch (50) (see FIG. 3), as will be described later. The cut portion (41) can be provided to cut the pouch (50) in the circumferential direction. The cut portion (41) can form a closed surface and surround the electrode assembly (10) in the circumferential direction.

[0052] The grip portion (42) may extend from the cut portion (41). The grip portion (42) may be provided to protrude outwardly from the pouch (50) so as to be able to apply force from the outside. For example, the grip portion (42) may be provided in a form that protrudes from a side end of the pouch (50). Specifically, the grip portion (42) may be placed on the side portion (52) of the pouch (50). The grip portion (42) may protrude outwardly by penetrating the side portion (52) of the pouch (50). The grip portion (42) may be formed integrally with the cut portion (41). The grip portion (42) may be provided with the same width and material as the cut portion (41), but may have a form that protrudes and is separated from the pouch (50) so as to be able to be gripped and pulled.

[0053] The separation strap (40) may be made of an oxidation-resistant material so as not to cause chemical degradation when exposed to an electrolyte contained together with the electrode assembly (10) inside the pouch (50). The separation strap (40) may be formed of, for example, a polyethylene material.

[0054] A plurality of separation straps (40) may be provided. The plurality of separation straps (40) may be provided spaced apart in the longitudinal direction of the electrode assembly (10). That is, the plurality of separation straps (40) may be provided spaced apart in the longitudinal direction of the pouch (50).

[0055] The separation strap (40) may be provided as a pair, for example. The separation strap (40) may include a first strap (40a) arranged around the circumference of the electrode assembly (10) at a position adjacent to the positive electrode tab of the electrode assembly (10), and a second strap (40b) arranged around the circumference of the electrode assembly (10) at a position adjacent to the negative electrode tab of the electrode assembly (10). Here, the adjacent position may mean a position offset by a predetermined distance from the center of the electrode assembly (10) toward the positive electrode tab and the negative electrode tab, respectively, and is not limited to the position shown. The first strap (40a) and the second strap (40b) may be spaced apart from each other in the length direction of the electrode assembly (10) and may be arranged symmetrically. The first strap (40a) and the second strap (40b) may be placed parallel to each other. The grip portions (42) of the first strap (40a) and the second strap (40b) may be provided to protrude in the same direction from one end of the pouch (50). By cutting the pouch (50) through each of the first strap (40a) and the second strap (40b), it is possible to check for damage / defects in the connection portions (30) of the positive and negative tabs of the electrode assembly (10).

[0056] Figure 3 is a perspective view showing the arrangement of a separation strap (40) and a pouch (50) of a secondary battery according to Example 1 of the present invention.

[0057] Referring to FIG. 3, a pouch (50) of a secondary battery according to Embodiment 1 of the present invention may be provided to wrap an electrode assembly (10) in a foldable manner. The pouch (50) may include a cup portion (51) that is provided in a recessed shape and in which the electrode assembly (10) is accommodated, and a side portion (52) that is formed in a shape that surrounds the periphery of the cup portion (51) and is provided to be sealed by sealing each other. The shape of the cup portion (51) is not limited to that shown, and may be formed on one side or both sides of the pouch (50) based on the fold line (55). Part of the side portions (52) that are in contact with each other in a folded state based on the fold line (55) may be formed as a sealing area by sealing each other.

[0058] The separation strap (40) can be placed along the inner side of the pouch (50). The separation strap (40) can be coupled to the inner side of the pouch (50). The separation strap (40) can be coupled, for example, by being adhered to the inner side of the pouch (50), and can be closely fitted to the inner side of the pouch (50) without any play along the curves of the cup portion (51) and the side portion (52). For example, the cut portion (41) of the separation strap (40) can be placed on the cup portion (51) of the pouch (50), and the grip portion (42) can be provided such that a portion thereof protrudes outward through the side portion (52). By adopting this form, the separation strap (40) can be easily mounted and removed from the pouch, and the efficiency of the process can be improved.

[0059] Figures 4 and 5 illustrate a more detailed position of the separation strap (40) of the secondary battery according to Embodiment 1 of the present invention. Figure 4 illustrates the unfolded state of the pouch (50) of the secondary battery according to Embodiment 1 of the present invention before sealing. Figure 5 illustrates a partial perspective view of the secondary battery according to Embodiment 1 of the present invention.

[0060] Referring to FIGS. 4 and 5, the pouch (50) of the secondary battery according to the first embodiment of the present invention can wrap the electrode assembly (10) in a folding manner. Thereafter, the contacting side portions (52) of the pouch (50) can be sealed so that the inside and outside of the pouch (50) can be sealed. At this time, the electrode tab (11) of the electrode assembly (10) can be welded and connected to the lead (20), and a connection portion (30) in which the lead (20) and the electrode tab (11) are welded can be formed. The lead film (21) wrapping around the periphery of the lead (20) can be sealed and heat-sealed together with the pouch (50), thereby ensuring airtightness of the inside and outside of the pouch (50) wrapping the electrode assembly (10).

[0061] The separation strap (40) can be coupled to the inner surface of the pouch (50) that surrounds the electrode assembly (10). The separation strap (40) can be coupled to the pouch (50) by, for example, bonding the inner surface of the pouch (50) with an adhesive or by heat-sealing. The separation strap (40) can wrap around the circumference of the electrode assembly (10). The separation strap (40) can overlap between the electrode assembly (10) and the pouch (50). The separation strap (40) overlaps the electrode assembly (10) as described above, but can be positioned in an end region of the electrode assembly (10) adjacent to the connection portion (30) of the electrode tab (11) and the lead (20).

[0062] The separation strap (40) may include a cut portion (41) and a grip portion (42). The cut portion (41) may be arranged to overlap between the electrode assembly (10) and the pouch (50) so as to surround the electrode assembly (10), and may extend along the width direction of the pouch (50). The cut portion (41) may be located, for example, on the inner surface of the cup portion (51) of the pouch (50). The grip portion (42) may extend from the cut portion (41). The grip portion (42) may extend from an end of the cut portion (41) and may be provided to protrude beyond the boundary of the pouch (50). The grip portion (42) may be provided on the side portion (52) of the pouch (50). The grip portion (42) may be provided to protrude a predetermined portion outward from the side portion (52) of the pouch (50).

[0063] When an external force in a direction away from the pouch (50) is applied to the grip portion (42), the cutting portion (41) connected to the grip portion (42) can cut the pouch (50) along the circumferential direction. By adopting this configuration, not only can the pouch (50) be easily separated from the electrode assembly (10) to check the state of the connection portion (30) of the electrode tab (11) and the lead (20), but damage to the electrode tab (11) area that may occur during the separation process can also be significantly reduced.

[0064] Example 2

[0065] Figure 6 shows a partial perspective view of a secondary battery according to Example 2 of the present invention.

[0066]

[0067] In Embodiment 2 of the present invention, there may be a difference from Embodiment 1 in that a pair of leads (20) electrically connected to the electrode assembly are both provided at one end of the secondary battery, thereby forming a single separation strap (40). Except for the difference, it should be noted that the contents of the secondary battery according to Embodiment 1 of the present invention described above can be commonly applied to Embodiment 2 as well, and therefore, contents common to Embodiment 1 will be omitted as much as possible, and Embodiment 2 will be described focusing on the differences from Embodiment 1.

[0068] Referring to Fig. 6, the leads (20) of the secondary battery according to Embodiment 2 of the present invention are provided in pairs, and both pairs can be formed at one end of the secondary battery. In other words, the leads (20) connected to the positive and negative tabs of the electrode assembly (10) can be provided to protrude in the same direction.

[0069] In this case, since the connection portion (30) of the electrode tab (11) and the lead (20) are formed on the same side with respect to the electrode assembly (10), it is easy to confirm the connection portion (30) of the secondary battery simply by providing a single separation strap (40). The cut portion (41) of the separation strap (40) may surround the perimeter of one end region of the electrode assembly (10) so as to be adjacent to a pair of connection portions (30), and the grip portion (42) may be provided to extend from the cut portion.

[0070] Example 3

[0071] Figure 7 shows a schematic perspective view of a secondary battery according to Example 3 of the present invention.

[0072] In Embodiment 3 of the present invention, there may be a difference from Embodiment 1 in that the separation strap (40) is coupled to the outer surface of the pouch (50) rather than the inner surface. Except for the difference, it should be noted that the contents of the secondary battery according to Embodiment 1 of the present invention described above can be commonly applied to Embodiment 3 as well. Therefore, contents common to Embodiment 1 will be omitted as much as possible, and Embodiment 3 will be described focusing on the differences from Embodiment 1.

[0073] Referring to FIG. 7, the separation strap (40) of the secondary battery according to Example 3 of the present invention can be coupled to the outer surface of the pouch (50). In this case, for example, the separation strap (40) can be coupled to the outer surface of the pouch (50) by means of adhesive attachment or heat fusion.

[0074] The separation strap (40) may include a cut portion (41) formed in a band shape along the outer circumference of the pouch (50), and a grip portion (42) extending from the cut portion (41). When an external force in a direction away from the pouch (50) is applied to the grip portion (42), the cut portion (41) connected to the grip portion (42) may cut the pouch in the circumferential direction. In other words, the cut portion (41) may be torn off from the pouch (50) together with the outer circumferential surface of the pouch (50) at the bonded portion, thereby cutting the pouch (50).

[0075] Likewise, the separation strap (40) may be provided as a pair, including a first strap (40a) arranged around the circumference of the electrode assembly (10) at a position adjacent to the positive tab of the electrode assembly (10), and a second strap (40b) arranged around the circumference of the electrode assembly (10) at a position adjacent to the negative tab of the electrode assembly (10).

[0076] The present invention can be provided as a secondary battery module including a plurality of secondary batteries reviewed above.

[0077] In the above description, although the present invention has been described by limited embodiments and drawings, the above description is merely an example of the technical idea of ​​the present invention, and those skilled in the art to which the present invention pertains will be able to make various modifications and variations without departing from the essential characteristics of the present invention.

[0078] Accordingly, the embodiments disclosed in the present invention are intended to illustrate, rather than limit, the technical concept of the present invention, and the scope of the technical concept of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical concepts within the scope equivalent thereto should be construed as being included within the scope of the present invention.

[0079]

[0080] [Explanation of symbols]

[0081] 10: Electrode assembly

[0082] 11: Electrode tab

[0083] 20: Lead

[0084] 21: Lead Film

[0085] 30: Connection

[0086] 40: Separate strap

[0087] 40a: 1st strap

[0088] 40b: Second strap

[0089] 41: Incision

[0090] 42: The phage department

[0091] 50: Pouch

[0092] 51: Cup

[0093] 52: Side section

Claims

1. Electrode assembly; A pouch for accommodating the electrode assembly; and A secondary battery, comprising: a separation strap coupled to the pouch and configured to cut the pouch so as to separate the electrode assembly from the pouch.

2. In paragraph 1, A secondary battery, wherein the above separation strap is provided to cut the pouch along the circumferential direction of the pouch.

3. In paragraph 1, A secondary battery, wherein the above separation strap is formed in a band shape extending along the inner circumference of the pouch with a predetermined width.

4. In paragraph 3, A secondary battery, wherein the above separation strap overlaps between the electrode assembly and the pouch.

5. In paragraph 1, A secondary battery, wherein the above separation strap is provided in multiple pieces.

6. In paragraph 5, A secondary battery, wherein a pair of said separation straps are provided spaced apart in the length direction of the electrode assembly.

7. In paragraph 6, The above separation strap is, a first strap disposed around the circumference of the electrode assembly at a position adjacent to the positive tab of the electrode assembly; and A secondary battery, comprising a second strap arranged around the periphery of the electrode assembly at a position adjacent to the negative tab of the electrode assembly.

8. In paragraph 3, The above separation strap is, A cut portion adhered to the inner surface of the pouch along the perimeter of the electrode assembly; and A secondary battery, comprising a gripping portion extending from the above-mentioned cut portion and protruding outwardly from the pouch so as to allow force to be applied from the outside.

9. In paragraph 8, A secondary battery, wherein the above-mentioned portion protrudes from the side end of the pouch.

10. In paragraph 1, The above separation strap is a secondary battery that is attached to the outer surface of the pouch.

11. In paragraph 1, The above separation strap is formed of a polyethylene material, a secondary battery.

12. A secondary battery module comprising a plurality of secondary batteries described in paragraph 1.

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