Soft-pack battery cell and battery module including the soft-pack battery cell

Abstract

A soft-pack battery cell according to one embodiment of the present disclosure includes: an electrode assembly including a positive electrode, a negative electrode and a separator interposed between the positive electrode and the negative electrode; and a battery case, the electrode assembly being attached to the battery case, wherein the battery case includes an upper case, a lower case and a receiving portion formed between the upper case and the lower case, wherein the battery case is formed with a sealing portion in which the outer peripheral surfaces of the upper case and the lower case are thermally welded to each other, and wherein one end of at least a portion of the sealing portion is recessed into the interior of the battery case.

Description

Technical Field

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Korean Patent Application No. 10-2020-0126271 filed in the Korean Intellectual Property Office on September 28, 2020, and Korean Patent Application No. 10-2021-0116871 filed in the Korean Intellectual Property Office on September 2, 2021, the disclosures of which are incorporated herein by reference in their entirety.

[0003] The present disclosure relates to a soft-pack battery cell and a battery module including the same, and more particularly, to a soft-pack battery cell that improves dimensional stability, delays venting caused by gas generated inside the battery cell, and prevents electrical corrosion of a sealing portion, and a battery module including the same. Background Art

[0004] With the development of technology and the increase in demand for mobile devices, the demand for batteries as energy sources is rapidly increasing. In particular, secondary batteries are attracting attention as energy sources for power-driven devices (e.g., electric bicycles, electric vehicles, hybrid vehicles) and mobile devices (e.g., mobile phones, digital cameras, laptops, and wearable devices).

[0005] According to the shape of the battery shell, these secondary batteries are classified into cylindrical batteries in which the electrode assembly is built into a cylindrical metal shell, prismatic batteries in which the electrode assembly is built into a prismatic metal shell, and soft-pack batteries in which the electrode assembly is built into a soft-pack shell formed by an aluminum laminate. Here, the electrode assembly built into the battery shell is an element that generates electricity, has a structure including a positive electrode, a negative electrode, and a separator inserted between the positive electrode and the negative electrode, and is capable of charging and discharging. The electrode assembly can be classified into a jelly-roll type electrode assembly and a stacked electrode assembly, the wound electrode assembly is configured to have a structure in which a long sheet-type negative electrode coated with an active material and a long sheet-type positive electrode are wound in a manner in which a separator is inserted between the negative electrode and the positive electrode, and the stacked electrode assembly is configured to have a structure in which a plurality of negative electrodes and positive electrodes are sequentially stacked in a manner in which a separator is inserted between the negative electrode and the positive electrode.

[0006] Among them, in particular, a soft-pack battery having a structure in which a stacked or stacked / folded electrode assembly is configured in a soft-pack battery case formed of an aluminum laminate has advantages such as low manufacturing cost, light weight, and easy deformation, and therefore, its usage is gradually increasing.

[0007] Figure 1 is a front view showing a conventional pouch battery cell.

[0008] Reference Figure 1 The soft pack battery cell 10 includes a battery case 14, which includes an upper case 12 and a lower case 13, wherein an electrode assembly (not shown) is built in the upper case 12 and the lower case 13. In addition, the battery case 14 includes a sealing portion 15 formed by heat-sealing the outer peripheral surfaces of the upper case 12 and the lower case 13 to seal the electrolyte contained in the electrode assembly.

[0009] Figure 2 It is shown Figure 1 An enlarged view of the side of a soft-pack battery cell. Figure 2 (a) is a picture of the battery cell before expansion. Figure 2 (b) is a picture of the battery cell after expansion. Figure 3 It shows that Figure 1 FIG. 1 is a diagram of an expanded area A of a soft-pack battery cell with side expansion.

[0010] Reference Figure 1 , when assembling a battery module or a battery pack, the soft pack battery cell 10 is used by press-bonding the soft pack battery cell 10 to the metal plates 20 located on both sides of the soft pack battery cell 10. Figure 2 and Figure 3 The soft pack battery cell 10 generates a large amount of gas inside the battery cell during the charge and discharge process, thereby generating high pressure inside the sealed housing, thereby causing an expansion phenomenon. The metal plate 20 prevents the soft pack battery cell 10 from expanding upward and downward, so that one side of the soft pack battery cell 10 expands like the expansion area A.

[0011] However, referring to Figure 3 In the case of a conventional soft-pack battery cell 10, when a swelling phenomenon occurs in one side portion of the soft-pack battery cell 10, the one side portion of the soft-pack battery cell 10 is separated from the metal plates 20 located at both sides of the soft-pack battery cell 10. As a result, the sealing portion 15 of the soft-pack battery cell 10 is likely to be damaged, which may cause problems such as internal gas being discharged to the outside and external gas or moisture flowing into the battery cell, thereby reducing battery performance.

[0012] In addition, refer to Figure 3, the sealing portion 15 is exposed to the outside, and therefore, when the soft-pack battery cell 10 is attached to a battery module (not shown), it may come into contact with other components. Therefore, when a negative potential is generated during the charge and discharge process, the metal portion exposed to the sealing portion 15 is electro-corroded, resulting in problems such as loss of moisture barrier function and battery function. Therefore, generally, in the prior art, the metal portion exposed to the sealing portion 15 is folded or wound and thereby placed inside, or an adhesive tape is additionally attached to the metal portion. However, in the case where the metal portion exposed from the sealing portion 15 is folded or wound and thereby placed inside, the sealing portion 15 itself is still exposed on the outer surface of the battery cell 10, and it is difficult to completely prevent the generation of electro-corrosion on the metal portion of the sealing portion 15. In addition, when a separate adhesive tape is attached to the metal portion, there is a problem that an additional additional process must be performed.

[0013] Therefore, there is a need to develop a soft pack battery cell 10 that can delay the deflation phenomenon and prevent electrical corrosion of a sealing portion while ensuring dimensional stability to prevent external deformation due to gas generated inside the soft pack battery cell 10 . Summary of the invention

[0014] Technical issues

[0015] An object of the present disclosure is to provide a soft pack battery cell that improves dimensional stability, delays a gas deflation phenomenon caused by gas generated inside the battery cell, and prevents electrical corrosion of a sealing portion, and a battery module including the soft pack battery cell.

[0016] The objects of the present disclosure are not limited to the above objects, and other objects not described herein should be clearly understood by those skilled in the art from the following detailed description.

[0017] Technical Solution

[0018] According to one aspect of the present disclosure, there is provided a pouch battery cell, comprising: an electrode assembly including a positive electrode, a negative electrode and a separator interposed between the positive electrode and the negative electrode; and a battery case, the electrode assembly being attached to the battery case, wherein the battery case includes an upper case, a lower case and a receiving portion formed between the upper case and the lower case, wherein the battery case is formed with a sealing portion in which outer peripheral surfaces of the upper case and the lower case are thermally fused to each other, and wherein one end of at least a portion of the sealing portion is recessed into the interior of the battery case.

[0019] The other end of at least a portion of the sealing portion may be bent in a direction adjacent to a side surface of the upper case or the lower case.

[0020] The other end of at least a portion of the sealing portion may be located inside the side surface of the battery case.

[0021] In the sealing portion, one end of the sealing portion formed on the outer peripheral surface located on both sides of the outer peripheral surface where the electrode lead is formed is recessed into the inside of the battery case.

[0022] Among the sealing portions, one ends of a pair of sealing portions facing each other on both side surfaces of the battery case may be recessed into the interior of the battery case.

[0023] The other ends of the pair of sealing portions may be bent in a direction adjacent to a side surface of the upper case or the lower case.

[0024] The other ends of the pair of sealing portions may be located inside the side surface of the battery case.

[0025] A pair of sealing portions may be respectively formed on peripheral surfaces located at both sides of a peripheral surface on which the at least one electrode lead is formed.

[0026] The receiving portion may include a first receiving portion formed in the upper case and a second receiving portion formed in the lower case, and recessed lengths of the first receiving portion and the second receiving portion may respectively correspond to lengths corresponding to a height of the electrode assembly.

[0027] The battery case may include a pouch case made of a laminate sheet having a resin layer and a metal layer.

[0028] The upper case and the lower case may have shapes symmetrical to each other.

[0029] According to another aspect of the present disclosure, a battery module is provided, comprising the above-mentioned soft-pack battery cell.

[0030] The battery module may further include a metal plate on at least one side surface of the pouch battery cell.

[0031] Beneficial Effects

[0032] According to an embodiment of the present disclosure, a portion of the sealing portion of the soft-pack battery has a structure that is recessed into the interior of the battery, which can improve dimensional stability, delay gas leakage caused by gas generated inside the battery cell, and prevent electrical corrosion of the sealing portion.

[0033] The effects of the present disclosure are not limited to the above-described effects, and other additional effects not described above will be clearly understood by those skilled in the art from the detailed description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a front view showing a conventional pouch battery cell.

[0035] Figure 2 It is shown Figure 1 An enlarged view of the side of a soft-pack battery cell.

[0036] Figure 3It shows that Figure 1 FIG. 1 is a diagram of an expanded area A of a soft-pack battery cell with side expansion.

[0037] Figure 4 is a front view of a soft-pack battery cell according to an embodiment of the present disclosure.

[0038] Figure 5 It is shown Figure 4 An enlarged view of the side of a soft-pack battery.

[0039] Figure 6 It shows that Figure 4 Figure 2 shows the expansion area on the side of a soft pack battery cell.

[0040] Figure 7 is a front view of a soft-pack battery cell according to another embodiment of the present disclosure. DETAILED DESCRIPTION

[0041] Hereinafter, various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the embodiments. The present disclosure can be modified in various different ways and is not limited to the embodiments set forth herein.

[0042] Parts not related to the description will be omitted to clearly describe the present disclosure, and the same reference numerals denote the same elements throughout the specification.

[0043] In addition, in the drawings, for the convenience of description, the size and thickness of each element are arbitrarily shown, and the present disclosure is not limited to what is shown in the drawings. In the drawings, for the sake of clarity, the thickness of layers, regions, etc. are exaggerated. In the drawings, for the convenience of description, the thickness of certain layers and regions is exaggerated.

[0044] Furthermore, throughout the specification, when a part is referred to as “including” a certain component, unless otherwise specified, it means that the part may further include other components without excluding the other components.

[0045] Furthermore, throughout the specification, when referred to as a “plane”, it means when the target portion is viewed from the upper side, and when referred to as a “cross section”, it means when the target portion is viewed from the cross section side cut vertically.

[0046] Now, the soft pack battery cell 100 according to an embodiment of the present disclosure will be described. However, the description is based on the front surface of the front and rear surfaces of the soft pack battery cell 100, but is not limited thereto, and the rear surface will be described with the same or similar content.

[0047] Figure 4 is a front view of a soft-pack battery cell according to an embodiment of the present disclosure.

[0048] Reference Figure 4 , a soft-pack battery cell 100 according to an embodiment of the present disclosure includes: an electrode assembly (not shown) including a negative electrode, a positive electrode, and a separator interposed between the negative electrode and the positive electrode; and a battery case 140 to which the electrode assembly is attached.

[0049] The battery case 140 includes an upper case 120, a lower case 130, and a receiving portion formed between the upper case 120 and the lower case 130. In addition, the receiving portion includes a first receiving portion formed in the upper case 120 and a second receiving portion formed in the lower case 130. In addition, the receiving portion may have a structure in which the first receiving portion of the upper case 120 and the second receiving portion of the lower case 130 are respectively recessed from the surfaces of the upper case 120 and the lower case 130, and the sum of the recessed lengths indicating their recessed degrees may correspond to the height of the electrode assembly. In one example, the upper case 120 and the lower case 130 may have shapes that are symmetrical to each other relative to the center line of the battery case 140.

[0050] Reference Figure 4 , the battery case 140 is formed with a sealing portion 150, and the outer peripheral surfaces of the upper case 120 and the lower case 130 are thermally fused to each other to the sealing portion 150. Here, the upper case 120 and the lower case 130 may respectively include a soft pack case made of a laminate sheet having a resin layer and a metal layer. In addition, the sealing portion 150 may be formed by sealing the resin layer of the upper case 120 and the resin layer of the lower case 130 to each other by heating and pressurizing.

[0051] Reference Figure 4 According to the present embodiment, at least one end of the sealing portion 150 may be recessed inside the battery case 140. That is, in order to form the sealing portion 150 in which one end of the upper case 120 and one end of the lower case 130 meet and seal each other, the sealing extension portion of the upper case 120 and the sealing extension portion of the lower case 130 may have a recessed shape. Figure 4 The internal shape of the battery cell 100 is shown.

[0052] Furthermore, in a modified embodiment, when assembling a battery module or a battery pack, the soft-pack battery cell 100 may be used by crimping the soft-pack battery cell 100 by the metal plates 200 located on both sides of the soft-pack battery cell 100. At this time, the expansion of the soft-pack battery cell 10 to the upper and lower parts is blocked due to the metal plates 200, and an expansion phenomenon occurs at the side of the soft-pack battery cell 100. Here, the soft-pack battery cell 100 according to the present embodiment has a structure in which one end of at least a portion of the sealing part 150 is recessed into the inside of the battery case 140, and thus dimensional stability can be ensured to prevent external deformation of the side of the soft-pack battery cell 100 due to the expansion phenomenon.

[0053] More specifically, one end of a pair of sealing portions 150 facing each other on both sides of the battery case 140 among the sealing portions 150 may be recessed into the interior of the battery case 140. That is, on the two side surfaces of the battery case 140 facing each other, the side surfaces of each of the first receiving portion of the upper case 120 and the second receiving portion of the lower case 130 may be inclined toward the interior of the battery case 140. In one example, the sealing portion 150 may be formed on the peripheral surface on one side surface or both side surfaces of the peripheral surface where at least one electrode lead 170 is formed. Alternatively, the sealing portion 150 may be formed on the peripheral surface where the electrode lead 170 is not formed.

[0054] Therefore, the soft-pack battery cell 100 according to the present embodiment has a structure in which one end of the sealing portion 150 is recessed into the inside of the battery case 140, which causes a swelling phenomenon to occur on each side where the sealing portion 150 is provided. In addition, when the sealing portion 150 is formed on the peripheral surface located on one side or both sides of the peripheral surface where at least one electrode lead 170 is formed, the electrical connection between the electrode sheet (not shown) of the soft-pack battery cell 100 and the electrode lead 170 is not disconnected due to the swelling phenomenon, thereby exhibiting high battery stability. In addition to this, the dimensional stability of the side portion of the soft-pack battery cell 100 can also be ensured.

[0055] Figure 5 It is shown Figure 4 An enlarged view of the side of a soft-pack battery. Figure 5 (a) is a picture of the battery cell before expansion. Figure 5 (b) is a picture of the battery cell after expansion. Figure 6 It shows that Figure 4 Figure 2 shows the expansion area on the side of a soft pack battery cell.

[0056] Reference Figure 5 and Figure 6 , when one end of the sealing portion 150 is recessed into the interior of the battery housing 140, considering the side of the battery cell before and after expansion, the soft-pack battery cell 100 according to the present embodiment can collect gas corresponding to the area corresponding to the primary expansion area B1 and the secondary expansion area B2. More specifically, when the primary expansion phenomenon occurs at the side of the soft-pack battery cell 100 according to the present embodiment, the side can expand by the area of ​​the primary expansion area B1. In addition, when the secondary expansion phenomenon occurs at the side of the soft-pack battery cell 100, the side can further expand by the area of ​​the secondary expansion area B2.

[0057] Compare Figure 3 and Figure 6The soft-pack battery cell 100 according to the present embodiment is configured such that the total area of ​​the primary expansion region B1 and the secondary expansion region B2 is relatively significantly increased relative to the expansion region A of the conventional battery cell 10 , and thus can collect more gas than the conventional battery cell 10 .

[0058] In addition, Figure 3 In the battery cell 10 of FIG. 1 , the expansion region A is quickly separated from the metal plate 20 when the expansion phenomenon occurs. Figure 6 In the soft-pack battery cell 100 according to the present embodiment, even if a primary expansion phenomenon occurs, the primary expansion region B1 is located within the size of the metal plate 200, so the dimensional stability of the soft-pack battery cell 100 can be further improved. The soft-pack battery cell 100 according to the present embodiment can collect more gas generated inside the battery cell, has the advantages of increasing dimensional stability and also delaying the deflation phenomenon caused by the internal gas. In addition, the battery module or battery pack can be easily manufactured using the soft-pack battery cell 100.

[0059] Furthermore, even in the sealing portion 150, when the sealing portion 150 formed on the outer peripheral surface without the electrode lead 170 is recessed into the inside of the battery case 140, the soft-pack battery cell 100 according to the present embodiment can expand the outer peripheral surface without the electrode lead 170. Therefore, the soft-pack battery cell 100 according to the present embodiment has the advantages of increasing dimensional stability and also delaying the deflation phenomenon due to internal gas without interfering with the electrical connection between the electrode sheet (not shown) of the soft-pack battery cell 100 and the electrode lead 170.

[0060] In addition, even if the soft-pack battery cell 100 according to the present embodiment is attached to the frame of a battery module or a battery pack, the soft-pack battery cell 100 will expand the outer peripheral surface without the electrode lead, thereby enabling the battery module or battery pack to be easily manufactured using the soft-pack battery cell 100 without interfering with the electrical connection between the electrode leads of the soft-pack battery cell 100 and the battery module or battery pack.

[0061] In addition, refer to Figure 4 , when one end of the sealing portion 150 is recessed into the interior of the battery case 140, the other end of the sealing portion 150 may be bent in a direction adjacent to one side surface of the upper case 120 or the lower case 130. That is, the other end of the sealing portion 150 may be bent adjacent to the side surface of the upper case 120 or the lower case 130.

[0062] More specifically, when one ends of a pair of sealing portions 150 facing each other on both sides of the battery case 140 are recessed into the interior of the battery case 140, the other ends of the pair of sealing portions 150 may be bent in a direction adjacent to the side surface of the upper case 120 or the lower case 130. That is, the other ends of the pair of sealing portions 150 may be bent adjacent to both side surfaces of the upper case 120 or the lower case 130, respectively.

[0063] Therefore, the other end of the sealing portion 150 can be located inside the battery housing 140 relative to the side surface of the battery housing 140, so the sealing portion 150 can be prevented from being exposed to the outside without the need for an additional additional process. In addition, since the sealing portion 150 is prevented from being exposed to the outside, the sealing portion 150 can be prevented from contacting other components when the soft-pack battery cell 100 is attached to a battery module (not shown). Thus, electrical corrosion caused by contact between the sealing portion 150 and other components can be prevented. In addition, the sealing portion 150 can also improve the insulation performance of the soft-pack battery cell 100. In addition, the soft-pack battery cell 100 according to the present embodiment can be more easily attached to the frame of the battery module or battery pack.

[0064] Figure 7 is a front view of a soft-pack battery cell according to another embodiment of the present disclosure.

[0065] Reference Figure 7 , similar to Figure 4 A battery cell 100 according to another embodiment of the present disclosure includes: an electrode assembly (not shown), the electrode assembly includes a positive electrode, a negative electrode and a separator interposed between the positive electrode and the negative electrode; and a battery case 140, the electrode assembly is attached to the battery case 140. In this embodiment, most of the descriptions of the components can be described as follows: Figure 4 The battery cell 100 is described in a similar manner, and the main description will be made with Figure 4 Different parts of the battery cell 100.

[0066] The battery cell 101 of this embodiment has the following structure: for the outer peripheral surface formed with the electrode lead 170, one of the outer peripheral surfaces on both sides of the battery housing 140 may be formed with a sealing portion 150, and the other outer peripheral surface may not be formed with a sealing portion 150. Figure 7 The left side portion of the battery cell 101 is not separately sealed on the surface on which the sealing portion 150 is not formed, and may be a surface on which the upper case 120 and the lower case 130 of the battery case 140 are integrated with each other.

[0067] In the present embodiment, for the outer peripheral surface where the electrode lead 170 is formed, in the portion where the sealing portion 150 is formed in the outer peripheral surface located on both sides of the battery case 140, one end of the sealing portion 150 may be recessed into the interior of the battery case 140. In addition, in the battery case 140, for the outer peripheral surface where the electrode lead 170 is formed, the portion where the sealing portion 150 is formed in the outer peripheral surface located on both sides may not be Figure 7 Concave like that.

[0068] Therefore, in the soft-pack battery cell 101 according to the present embodiment, in the battery case 140, for the outer peripheral surface on which the electrode lead 170 is formed, one end of the sealing portion 150 formed on one outer peripheral surface is recessed into the inside of the battery case 140 among the outer peripheral surfaces located on both sides, and a swelling phenomenon may occur on each side provided with the sealing portion 150. In addition, the sealing portion 150 is not formed on the other outer peripheral surface, so that the sealing force of the battery cell 101 can be further improved.

[0069] A battery module according to another embodiment of the present disclosure includes the above-mentioned soft-pack battery cell. Meanwhile, one or more battery modules according to this embodiment may also be packaged in a battery pack housing to form a battery pack.

[0070] The battery module and the battery pack including the battery module can be applied to various devices. Such devices can be applied to vehicles such as electric bicycles, electric vehicles or hybrid vehicles, but the present disclosure is not limited thereto and is applicable to various devices that can use the battery module within the scope of the present disclosure.

[0071] Although preferred embodiments of the present disclosure have been shown and described above, the scope of the present disclosure is not limited thereto, and those skilled in the art may make numerous other variations and modifications within the spirit and scope of the present disclosure using the basic principles of the invention defined in the appended claims.

[0072] [Description of Reference Numerals]

[0073] 100, 101: Soft pack battery cells

[0074] 120: Upper shell

[0075] 130: Lower housing

[0076] 140: Battery housing

[0077] 150: Sealing part

[0078] 200: Metal Plate

Claims

1. A soft pack battery cell, comprising: An electrode assembly, comprising a positive electrode, a negative electrode and a separator interposed between the positive electrode and the negative electrode; as well as a battery housing to which the electrode assembly is attached, The battery housing includes an upper housing, a lower housing, and a receiving portion formed between the upper housing and the lower housing. wherein the battery housing is formed with a sealing portion in which the outer peripheral surfaces of the upper housing and the lower housing are thermally welded to each other, wherein one end of at least a portion of the sealing portion is recessed into the interior of the battery housing, wherein the other end of at least a portion of the sealing portion is bent in a direction adjacent to a side surface of the upper shell or the lower shell, and The other end of at least a portion of the sealing portion is located inside the side surface of the battery case.

2. The soft-pack battery cell according to claim 1, wherein: In the sealing portion, one end of the sealing portion formed on the outer peripheral surface located on both sides of the outer peripheral surface where the electrode lead is formed is recessed into the inside of the battery case.

3. The soft-pack battery cell according to claim 1, wherein: Among the sealing portions, one ends of a pair of sealing portions facing each other on both side surfaces of the battery case are recessed into the interior of the battery case.

4. The soft-pack battery cell according to claim 3, wherein: The other ends of the pair of sealing portions are bent in a direction adjacent to a side surface of the upper case or the lower case.

5. The soft-pack battery cell according to claim 4, wherein: The other ends of the pair of sealing portions are located inside the side surface of the battery case.

6. The soft-pack battery cell according to claim 3, wherein: The pair of sealing portions are respectively formed on peripheral surfaces located on both sides of a peripheral surface on which at least one electrode lead is formed.

7. The soft-pack battery cell according to claim 1, wherein: The receiving portion includes a first receiving portion formed in the upper housing and a second receiving portion formed in the lower housing, and The recessed lengths of the first receiving portion and the second receiving portion respectively correspond to the height of the electrode assembly.

8. The soft-pack battery cell according to claim 1, wherein: The battery case includes a soft pack case made of a laminate sheet having a resin layer and a metal layer.

9. The soft-pack battery cell according to claim 1, wherein: The upper case and the lower case have shapes symmetrical to each other. 10 . A battery module comprising the soft-pack battery cell according to claim 1 . 11 . The battery module according to claim 10 , further comprising a metal plate on at least one side surface of the pouch battery cell.

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