Secondary battery and method for manufacturing secondary battery

Abstract

A secondary battery according to an embodiment of the present invention may comprise: an electrode assembly; a battery case including an accommodating portion for accommodating the electrode assembly and a side portion located outside the accommodating portion and folded at least once; and a fixing member attached to the battery case and fixing the side portion in the folded state. A tear line may be formed on the fixing member so as to be easily broken when an external force is applied to the fixing member.

Description

Technical Field

[0001] Cross-references to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2023-0133675, filed on October 6, 2023, and Korean Patent Application No. 10-2024-0008148, filed on January 18, 2024, the disclosures of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to a secondary battery and a method for manufacturing a secondary battery, and more specifically, to a secondary battery wherein a platform portion folded at least once is fixed by a fixing member and a method for manufacturing the secondary battery. Background Technology

[0004] Unlike primary batteries, secondary batteries are rechargeable and can be used in a wide range of applications, such as digital cameras, mobile phones, laptops, and hybrid electric vehicles. Secondary batteries can include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-metal hydride batteries, and lithium-ion batteries.

[0005] In the field of secondary batteries, lithium secondary batteries with high energy density and discharge voltage have been extensively studied, and recently, lithium secondary batteries have been used in the form of modules by connecting flexible pouch-type secondary batteries.

[0006] Rechargeable batteries can use various types of battery cases as the outer packaging material to cover the electrode assembly; for example, rechargeable batteries can use pouch-type battery cases or can-type battery cases. The electrode assembly has a structure in which a positive electrode plate and a negative electrode plate coated with electrode active material are stacked, and a separator is inserted between the positive and negative electrode plates. A positive contact is formed on one side of the positive electrode plate, and a negative contact is formed on one side of the negative electrode plate. Each contact is connected to an electrode lead for connection to an external circuit. The electrode assembly is sealed by the outer packaging material or battery case.

[0007] The battery case may include a housing portion that receives the electrode assembly therein, and a platform portion located at the periphery of the housing portion and sealing the electrode assembly. Additionally, a portion of the platform portion may be folded to increase energy density.

[0008] For example, the platform section can be folded on one side (SSF) or folded on both sides (DSF). When a predetermined amount of time has elapsed, the platform section will no longer remain folded, and a portion of the platform section may unfold and protrude outwards. To prevent this, a fixing member such as a strap can be used to secure the platform section in the folded state.

[0009] However, when flames or gases are generated by any abnormal operation of a secondary battery, the flames or gases are discharged through the electrode leads rather than the folded platform section due to the fixed components.

[0010] In a battery module or battery pack, when a flame or gas generated from any battery cell is discharged through the electrode leads, the flame spreads rapidly, causing thermal runaway in adjacent battery cells, and therefore a solution is needed. Summary of the Invention

[0011] Technical issues

[0012] This disclosure aims to provide a secondary battery for rapidly discharging flames or gases, and a method for manufacturing the secondary battery.

[0013] Technical solution

[0014] A secondary battery according to an embodiment of the present disclosure may include: an electrode assembly; a battery case including a receiving portion for receiving the electrode assembly and a side portion located outside the receiving portion and folded at least once; and a fixing member attached to the battery case and configured to secure the side portion in a folded state. The fixing member may have a break line to allow the fixing member to easily break when an external force is applied to it.

[0015] A break line can be formed by creating holes at predetermined intervals along one direction in a fixed component.

[0016] The break line can extend along the length of the side section.

[0017] The fixing member may also have a secondary break line extending in a direction intersecting the break line.

[0018] Secondary disconnect lines can be formed at predetermined intervals in the direction of extension of the disconnect line.

[0019] The break line can be formed at the location corresponding to the gap or boundary between the receiving part and the side part.

[0020] The fixing member may include: a first adhesive portion that is adhered to a receiving portion; a second adhesive portion that is adhered to a side portion; and a connecting portion that connects the first adhesive portion and the second adhesive portion.

[0021] Disconnections can be formed in the connection section.

[0022] The connecting portion may include: a first connecting portion located on the side where the side portion is folded and having a break line; and a second connecting portion located on the opposite side of the first connecting portion relative to the second adhesive portion.

[0023] A method for manufacturing a secondary battery according to embodiments of the present disclosure may include the following steps: folding a side portion of a battery case housing an electrode assembly at least once; preparing a fixing member having a break line along a predetermined direction; and attaching the fixing member to the battery case to fix the side portion in a folded state.

[0024] The steps of attaching a fixing member may include attaching the fixing member such that the break line is parallel to the length direction of the side portion.

[0025] The steps of attaching the fixing member may include attaching the fixing member such that the break line corresponds to the gap or boundary between the receiving portion and the side portion of the receiving electrode assembly.

[0026] Beneficial effects

[0027] According to an exemplary embodiment of this disclosure, when a fire occurs in a secondary battery, the fixing member of the fixed side portion can be easily broken, and gas and flames can be quickly discharged through the unsealed side portion.

[0028] In addition, during abnormal operation of the secondary battery, the side portion can be reliably kept in a folded state by means of a fixing component.

[0029] Additionally, it can prevent or delay the escape of gas or flame through the electrode leads. Therefore, in the battery module, thermal runaway in adjacent secondary cells due to rapid flame propagation can be minimized.

[0030] Furthermore, the effects of this disclosure may include those readily predictable by those skilled in the art based on exemplary embodiments of this disclosure. Attached Figure Description

[0031] The accompanying drawings illustrate exemplary embodiments of the present disclosure and are used, together with the following detailed description, to provide a better understanding of the technical aspects of the present disclosure; therefore, the present disclosure should not be construed as limited to the drawings.

[0032] Figure 1 This is an exploded view of a secondary battery according to an embodiment of the present disclosure.

[0033] Figure 2 This is a plan view of a secondary battery according to an embodiment of the present disclosure.

[0034] Figure 3 yes Figure 2 A cross-sectional view taken along line A-A'.

[0035] Figure 4 This is a plan view of a secondary battery according to another embodiment of the present disclosure.

[0036] Figure 5 This is a flowchart of a method for manufacturing a secondary battery according to another embodiment of the present disclosure. Detailed Implementation

[0037] In the following, exemplary embodiments of the present disclosure will be described in full detail with reference to the accompanying drawings to enable those skilled in the art to readily implement the disclosure. However, the present disclosure may be implemented in many different forms and is not limited to or construed as described below.

[0038] In order to clearly describe this disclosure, irrelevant or detailed descriptions of related known technologies that may unnecessarily obscure the essential points of this disclosure have been omitted, and throughout the specification, the same or similar reference numerals are attached to the same or similar elements when reference numerals are attached to elements in each figure.

[0039] Furthermore, the terms or words used in the specification and appended claims should not be construed as limited to their general and dictionary meanings, but should be interpreted based on their meanings and concepts corresponding to the technical aspects of this disclosure, on the basis of allowing the inventors to appropriately define the terms to obtain the best interpretation.

[0040] The accompanying drawings schematically illustrate each component of a secondary battery according to an embodiment of the present disclosure, and for ease of understanding, the dimensions of the components or the thickness of the lines may be expressed in a slightly exaggerated manner.

[0041] Figure 1 This is an exploded view of a secondary battery according to an embodiment of the present disclosure. Figure 2 This is a plan view of a secondary battery according to an embodiment of the present disclosure, and Figure 3 yes Figure 2 A cross-sectional view taken along line A-A'.

[0042] The secondary battery 1 according to embodiments of the present disclosure may include an electrode assembly 10 and a battery case 20. Hereinafter, as shown in the accompanying drawings, the description is based on the case where the battery case 20 is a pouch-type battery case. However, the scope of the present disclosure is not limited thereto.

[0043] The electrode assembly 10 can be formed by stacking positive and negative electrodes alternately, wherein a spacer is inserted between the positive and negative electrodes. That is, the electrode assembly 10 may include multiple electrodes and spacers inserted between the multiple electrodes to insulate them. The electrode assembly 10 can be housed together with the electrolyte solution in the battery case 20, more specifically, in the housing portion 22 described below.

[0044] Electrode assembly 10 can be provided in various types, such as stacked, wound, stacked and folded, etc., and the type of electrode assembly 10 is not limited to a specific type.

[0045] The electrode assembly 10 may include an electrode tab 11. The electrode tab 11 may be connected to each of the positive and negative electrodes of the electrode assembly 10 and protrude outward from the electrode assembly 10 to serve as a path for the movement of electrons between the interior and exterior of the electrode assembly 10.

[0046] The electrode tab 11 can be formed by customizing the uncoated portion of the electrode current collector or by ultrasonically welding the conductor component to the uncoated portion.

[0047] The electrode contacts 11 may include a positive contact 111 connected to the positive electrode and a negative contact 112 connected to the negative electrode. Each of the positive contact 111 and the negative contact 112 may protrude in different directions of the electrode assembly 10, but is not limited thereto, and may protrude in various directions. For example, the positive contact 111 and the negative contact 112 may protrude parallel to each other in the same direction from one side.

[0048] Electrode leads 12 can be connected to electrode contacts 11 of electrode assembly 10 to supply power to the external environment of secondary battery 1. Additionally, a portion of electrode leads 12 can be surrounded by an insulating portion 14. The insulating portion 14 can be sealed together with the first housing 21 and the second housing 22. Therefore, the insulating portion 14 insulates the electrode leads 12 relative to battery housing 20 and maintains the seal of battery housing 20. The insulating portion 14 typically includes an insulating strip that is easily attached to the electrode leads 12 and has a relatively small thickness, but is not limited thereto, and the insulating portion 14 can include various components capable of insulating the electrode leads 12.

[0049] One end of the electrode lead 12 can be connected to the electrode tab 11, and the other end can protrude outward from the battery case 13. The electrode lead 12 may include a positive lead 121 connected to the positive tab 111 and a negative lead 122 connected to the negative tab 112.

[0050] Electrode leads 12 can electrically connect electrode assembly 10 to the outside. In addition, since each of the positive leads 111 and negative leads 112 protrudes in different directions, each of the positive leads 121 and negative leads 122 can also extend in different directions.

[0051] The battery case 20 can house the electrode assembly 10. In particular, the pouch-shaped battery case can be formed by forming a laminate. More specifically, a portion of the laminate can be stretched to form a receiving portion 22 with a pouch-shaped receiving space when a flexible laminate is drawn using a die and a punch, thereby manufacturing the battery case 20.

[0052] The battery box 20 can accommodate the electrode assembly 10, such that a portion of the electrode leads 12 is exposed and can be sealed.

[0053] The battery box 20 may include a receiving portion 22 and platform portions 23, 26 located outside the receiving portion 22.

[0054] More specifically, the battery box 20 may include a first box 20a and a second box 20b, and at least one of the first box 20a and the second box 20b may have a receiving portion 22. In addition, the area surrounding the receiving portion 22 may form platform portions 23, 26.

[0055] The first box 20a and the second box 20b can be connected to each other via the folding portion 21. However, this disclosure is not limited thereto, and the first box 20a and the second box 20b can be separated and each can be manufactured individually.

[0056] The receiving portion 22 may define a receiving space for receiving the electrode assembly 10. The receiving portion 22 may have a bag shape.

[0057] The following description takes a first box 20a and a second box 20b, each having a receiving portion 22, as examples. Those skilled in the art will readily understand that either of the boxes 20a and 20b has a receiving portion 22.

[0058] The receiving portions 22 of the two boxes 20a and 20b can be arranged facing each other and can together accommodate the electrode assembly 10. That is, the receiving portions 22 of the two boxes 20a and 20b can be arranged facing each other to define a receiving space for accommodating the electrode assembly 10. In this case, compared with only one of the two boxes 20a and 20b having a receiving portion 22, the electrode assembly 20 can accommodate an electrode assembly 10 with a large thickness and high capacity.

[0059] The first box 20a and the second box 20b can be connected to the folding portion 21. When the first box 20a and the second box 20b are unfolded, a portion of the folding portion 21 can be located between the receiving portion 22 of the first box 20a and the receiving portion 22 of the second box 20b, and another portion of the folding portion 21 can be located between the platform portions 23, 26 of the first box 20a and the platform portions 23, 26 of the second box 20b.

[0060] When the folding portion 21 is folded, the first box 20a and the second box 20b can face each other. The folding portion 21 can extend parallel to the length direction of the electrode assembly 10, but is not limited thereto.

[0061] Each box 20a, 20b may include platform portions 23, 26 located around the receiving portion 22. More specifically, platform portions 23, 26 may include a first platform portion 23—where the electrode lead 12 protrudes—and a second platform portion 26 folded at least once.

[0062] As an example, such as Figure 1 and Figure 2 As shown, the first platform portion 23 may include a pair of first platform portions located on both sides of the receiving portion 22 in the length direction, and the second platform portion 26 may connect the pair of first platform portions 23 and be located on one side of the receiving portion 22 in the width direction. In this case, the first platform portion 23 may extend in the width direction of the receiving portion 22, and the second platform portion 26 may extend in the length direction of the receiving portion 22.

[0063] As another example, when the first box 20a and the second box 20b are separate components not connected by the folding portion 21, the first platform portion 23 may include a pair of first platform portions located on both sides of the receiving portion 22 in the length direction, and the second platform portion 26 may include a pair of second platform portions connecting the pair of first platform portions 23 and located on both sides of the receiving portion 22 in the width direction.

[0064] When the first box 20a and the second box 20b are connected to the folding portion 21, either the first platform portion 23 or the second platform portion 26 may be located on the opposite side of the folding portion 21 relative to the receiving portion 22.

[0065] As an example, such as Figure 1 and Figure 2 As shown, the second platform portion 26 can be located on the opposite side of the folded portion 21 relative to the receiving portion 22. In this case, the pair of first platform portions 23 can connect the folded portion 21 to the second platform portion 26. That is, the pair of electrode leads 12 can extend in opposite directions and protrude outward through each first platform portion 23.

[0066] As another example, the first platform portion 26 may be located on the opposite side of the folded portion 21 relative to the receiving portion 22. That is, the pair of electrode leads 12 may extend parallel to each other in a direction away from the folded portion 21 and protrude outward through the first platform portion 23. In this case, the second platform portion 26 may include a pair of second platform portions and connect the folded portion 21 to the first platform portion 23.

[0067] As described above, the extension direction and position of the first platform portion 23 and the second platform portion 26 are not limited to a specific extension direction and position, and can be changed as appropriate.

[0068] When the folding portion 21 is folded, the platform portions 23 and 26 of the first box 20a and the second box 20b can come into contact with each other. In this case, the insulating portion 14 of the electrode assembly 10 can be located between the platform portions 23 and 26 of the pair of boxes 20a and 20b. For example, the insulating portion 14 can be located between the first platform portions 23 of the pair of boxes 20a and 20b.

[0069] The platform portions 23 and 26 of the first box 20a and the second box 20b can be sealed to each other. The first platform portion 23 of the first box 20a and the second box 20b can be sealed to each other, and some portions thereof can be sealed with insulating portion 14. The second platform portion 26 of the first box 20a and the second box 20b can be sealed to each other.

[0070] At least some portions of the sealed platform portions 23 and 26 can be folded at least once. More specifically, the second platform portion 26 can be folded at least once. The second platform portion 26 can be folded on one side (SSF) or on both sides (DSF). Hereinafter, the second platform portion 26 is referred to as the side portion and is indicated by the same reference numeral '26'.

[0071] The secondary battery 1 may include a fixing member 30.

[0072] The fixing member 30 can be attached to the battery compartment 20 and secure the side portion 26 in a folded state. For example, the fixing member 30 can be a strap.

[0073] In this embodiment, the fixing member 30 may include a plurality of fixing members. The plurality of fixing members 30 may be arranged at predetermined intervals along the length of the side portion 30. The plurality of fixing members 330 may have equal lengths, but are not limited thereto.

[0074] Reference Figure 4 Each fixing member 30 may include a first adhesive portion 31 that is adhered to the receiving portion 22, a second adhesive portion 32 that is adhered to the side portion 26, and a connecting portion 33 that connects the first adhesive portion 31 and the second adhesive portion 32.

[0075] The first adhesive portion 31 may be located at the end of the fixing member 30. The first adhesive portion 31 may be adhered to the bottom surface 221 of the receiving portion 22.

[0076] The second adhesive portion 32 can be adhered to the outside of the side portion 26.

[0077] The connecting portion 33 may be located between the first adhesive portion 31 and the second adhesive portion 32. The connecting portion 33 may have a break line 40 as described below.

[0078] like Figure 4As shown, each of the two end portions of the fixing member 30 can be adhered to each receiving portion 22. The side portion 26 can be folded toward one receiving portion 22. In this case, the first adhesive portion 31 may include a pair of first adhesive portions, and the connecting portion 33 may also include a pair of connecting portions. More specifically, either of the pair of first adhesive portions 31 can be adhered to one receiving portion 22, and the other first adhesive portion can be adhered to the other receiving portion 22.

[0079] The connecting portion 33 may include a first connecting portion 33A and a second connecting portion 33B. The first connecting portion 33A connects either of the pair of first adhesive portions 31 to the second adhesive portion 32. The first connecting portion 33A may be located on the side where the side portion 26 is folded. The first connecting portion 33A may have a break line 40 as described below. The second connecting portion 33B connects the other of the pair of first adhesive portions 31 to the second adhesive portion 32. The second connecting portion 33B may be located on the opposite side of the first connecting portion 33A relative to the second adhesive portion 32. The second connecting portion 33B may also have a break line 40 as described below.

[0080] However, with Figure 4 Conversely, one end portion of the fixing member 30 may be adhered to a receiving portion 22, while the other end portion may be adhered to a side portion 26. That is, the first adhesive portion 31 may be located at one end portion of the fixing member 30, while the second adhesive portion 32 may be located at the other end portion of the fixing member 30. In this case, the connecting portion 33 may be located on the folded side of the side portion 26.

[0081] Meanwhile, in the event of a fire in the electrode assembly 10, the battery box 20 may be damaged, and gas may be released along with sparks or particles. In this case, as the gas is released via the electrode leads 12, there is a risk that heat and flame will rapidly spread to another adjacent secondary battery. To reduce or prevent this risk, it is preferable to first break the seal at the side portion 26 to release the gas, but the fixing member 30 may be an obstacle.

[0082] To address this issue, the fixing member 30 may have a break line 40 to allow the fixing member 30 to easily break when an external force is applied to it.

[0083] In this embodiment, at least one of the plurality of fixing members 30 may have a break line 40. Preferably, each fixing member 30 may have a break line 40.

[0084] When abnormal operation of the electrode assembly 10 generates high-temperature gas, the pressure in the battery compartment 20 may increase. In this case, when the folded side portion 26 unfolds, an external force can be applied to the fixing member 30. That is, tension acts on the fixing member 30. When an external force higher than a predetermined level acts on the fixing member 30, breakage may first occur at the break line 40. Therefore, the side portion 26 can unfold and become unsealed, and the gas and flame in the battery compartment 20 can be rapidly expelled.

[0085] The break line 40 may extend along the length of the side portion 26 (e.g., the length of the receiving portion 22). The break line 40 may extend from one edge of the fixing member 30 to the opposite edge.

[0086] The break line 40 can be formed by forming holes 41 in the fixing member 30 at predetermined intervals along one direction. The direction can be parallel to the length direction of the side portion 26. Each hole 41 can be an elongated hole extending along the aforementioned direction.

[0087] However, the configuration of the break line 40 is not limited to this, and the break line 40 can be designed to break more easily than the surrounding area. For example, a portion of the fixing member 30 can have a smaller thickness than the surrounding area, and the corresponding portion can form the break line 40.

[0088] The break line 40 can be formed at a location corresponding to the gap (g) or boundary between the receiving portion 22 and the side portion 26.

[0089] More specifically, the side portion 26 may form a predetermined gap (g) with the outer periphery 222 of the receiving portion 22. In this case, the break line 40 may be formed at a position corresponding to the gap (g) between the receiving portion 22 and the side portion 26.

[0090] However, the side portion 26 does not form a predetermined gap with the receiving portion 22 and can contact the outer periphery 222 of the receiving portion 22. In this case, the break line 40 can be formed at a position corresponding to the boundary between the receiving portion 22 and the side portion 26.

[0091] In other words, the break line 40 can be formed in the connection portion 33 of the aforementioned fixing member 30. Therefore, when an external force higher than a predetermined level is applied to the fixing member 30, the break line 40 can easily break. When the break line 40 is formed in the first adhesive portion 31 or the second adhesive portion 32 of the fixing member 30, the break line 40 may not break first.

[0092] A break line 40 may be formed in the first connecting portion 33A of the aforementioned fixing member 30. Relatedly, when the side portion 26 is unfolded by high pressure in the battery compartment 20, higher tension is applied to the first connecting portion 33A of the fixing member 30, while lower tension is applied to the second connecting portion 33B. Therefore, the break line 40 formed in the first connecting portion 33A can break more easily. However, the break line may be formed not only in the first connecting portion 33A but also in the second connecting portion 33B.

[0093] Figure 4 This is a plan view of a secondary battery according to another embodiment of the present disclosure.

[0094] In the following text, repeated descriptions that are not present in the foregoing are omitted, and differences in description are explained.

[0095] According to this embodiment, the fixing member 30 of the secondary battery can extend along the length direction of the side portion 26. For example, as... Figure 4 As shown, the fixing member 30 can be a single member extending along the length direction of the side portion 26. Therefore, the fixing member 30 may not completely break.

[0096] To facilitate easier breakage of the fixing member 30, the fixing member 30 may also have a secondary break line 50 extending in a direction intersecting the break line 40. More specifically, the secondary break line 50 may be formed in a direction perpendicular to the break line 40.

[0097] The secondary disconnect line 50 can be formed at predetermined intervals in the extension direction of the disconnect line 40. That is, the secondary disconnect line 50 can be formed at predetermined intervals in the length direction of the extension portion 26.

[0098] The secondary break line 50 can be formed by forming holes 51 in the fixing member 30 at predetermined intervals along one direction. The aforementioned direction can be parallel to the direction of the side portion 26 covered by the fixing member 30.

[0099] However, the configuration of the secondary break line 50 is not limited to this, and the secondary break line 50 can be designed to break more easily than the surrounding area. For example, a portion of the fixing member 30 can have a smaller thickness than the surrounding area, and the corresponding portion can form the secondary break line 50.

[0100] A secondary break line 50 may be formed in the connecting portion 33, particularly in the first connecting portion 33A of the fixing member 30. Preferably, the secondary break line 50 may extend from one edge of the fixing member 30 to the opposite edge.

[0101] Meanwhile, the fixing member 30 of the secondary battery 1 according to the aforementioned embodiment may also have a secondary disconnect wire 50.

[0102] Figure 5 This is a flowchart of a method for manufacturing a secondary battery according to another embodiment of the present disclosure.

[0103] In the following description, the method for manufacturing a secondary battery 1 according to the embodiments described above or another embodiment will be described as yet another embodiment of this disclosure.

[0104] According to another embodiment of the present disclosure, a method for manufacturing a secondary battery may include step S10 of folding a side portion 26 of a battery case 20 housing an electrode assembly 10 at least once, step S20 of preparing a fixing member 30 having a break line 40 along a predetermined direction, and step S30 of attaching the fixing member 30 to the battery case 20 to fix the side portion 26 in a folded state.

[0105] Step S10, which involves folding the side portion 26, may include preparing a secondary battery 1 in which the electrode assembly 10 is housed in the receiving portion 22, and the platform portions 23 and 26 of the battery case 20 are sealed. Subsequently, the second platform portion 26 or the side portion 26 of the battery case 20 may be folded toward the receiving portion 22 at least once. The side portion 26 may be folded on one side (SSF) or folded on both sides (DSF).

[0106] Step S20 of fabricating the fixing member 30 may include forming a break line 40 in the fixing member 30. Additionally, a secondary break line 50 intersecting the break line 40 may be further formed in the fixing member 30. The break line 40 and the secondary break line 50 can be formed by forming holes 41, 51 in one direction at predetermined intervals in the fixing member 30. However, the configuration of the break line 40 and the secondary break line 50 is not limited thereto, and the break line 40 and the secondary break line 50 may be designed to break more easily than the surrounding area.

[0107] Step S30 of attaching the fixing member 30 may include adhering two end portions of the fixing member 30 to the receiving portion 22, more specifically, to the bottom surface 221 of the receiving portion 22. However, this disclosure is not limited thereto, and one end portion of the fixing member 30 may be adhering to the receiving portion 22, more specifically, to the bottom surface 221 of the receiving portion 22, and the other end portion of the fixing member 30 may be adhering to the side portion 26.

[0108] Step S30 of attaching the fixing member 30 may include attaching the fixing member 30 such that the break line 40 is parallel to the length direction of the side portion 26. The fixing member 30 may be attached such that the break line 40 corresponds to the gap (g) or boundary between the receiving portion 22 and the side portion 26. That is, the fixing member 30 may be attached such that the break line 40 is located at the connecting portion 33, particularly at the first connecting portion 33A of the fixing member 30.

[0109] Through this series of steps, the secondary battery 1 can be manufactured. Subsequently, when abnormal operation of the electrode assembly 10 generates high-temperature gas, the pressure in the battery case 20 increases. In this situation, when the folded side portion 26 unfolds, an external force (tension) can be applied to the fixing member 30. When an external force higher than a predetermined level acts on the fixing member 30, the disconnect line 40 can break first. Therefore, the side portion 26 can unfold and become unsealed, and the gas and flame in the battery case 20 can be rapidly expelled.

[0110] The foregoing description has illustrated the technical aspects of this disclosure by way of example, and those skilled in the art to which this disclosure pertains will be able to make various modifications and changes without departing from the essential characteristics of this disclosure.

[0111] Therefore, the disclosed embodiments are provided to describe the technical aspects of this disclosure and are not intended to be limiting, and the technical scope of this disclosure is not limited by these embodiments.

[0112] The scope of protection of this disclosure shall be interpreted by the appended claims, and shall be interpreted as including all technical spirit within the equivalent scope within the scope of protection of this disclosure.

[0113] [List of reference numerals]

[0114] 10: Electrode assembly 12: Electrode leads

[0115] 14: Insulation part; 20: Battery box

[0116] 21: Folding section 22: Retaining section

[0117] 23: First platform section; 26: Second platform section, side section

[0118] 30: Fixing component; 31: First adhesive portion

[0119] 32: Second adhesive portion; 33: Connecting portion

[0120] 40: Disconnected wire 41: Hole

[0121] 50: Secondary disconnect wire; 51: Hole

Claims

1. A secondary battery, comprising: Electrode assembly; A battery case, the battery case including a receiving portion for accommodating the electrode assembly and a side portion located outside the receiving portion and folded at least once; as well as A fixing member is attached to the battery compartment and configured to secure the side portion in a folded state. The fixing member has a break line to allow it to break easily when an external force is applied to it.

2. The secondary battery according to claim 1, in, The break line is formed by forming holes in the fixing member at predetermined intervals along one direction.

3. The secondary battery according to claim 1, in, The break line extends along the length of the side portion.

4. The secondary battery according to claim 1, in, The fixing member also has a secondary break line extending in a direction intersecting the break line.

5. The secondary battery according to claim 4, in, The secondary break lines are formed at predetermined intervals in the extension direction of the break lines.

6. The secondary battery according to claim 1, in, The break line is formed at a location corresponding to the gap or boundary between the receiving portion and the side portion.

7. The secondary battery according to claim 1, in, The fixing component includes: A first adhesive portion, wherein the first adhesive portion is adhered to the receiving portion; A second adhesive portion, the second adhesive portion being adhered to the side portion; and A connecting portion that connects the first adhesive portion and the second adhesive portion.

8. The secondary battery according to claim 7, in, The break line is formed in the connection portion.

9. The secondary battery according to claim 7, in, The connection portion includes: A first connecting portion, located on one side of the folded side portion and having the break line; and The second connecting portion is located on the opposite side of the first connecting portion relative to the second adhesive portion.

10. A method for manufacturing a secondary battery, the method comprising the following steps: Fold the side portion of the battery compartment that houses the electrode assembly at least once; Prepare a fixed component with a break line along a predetermined direction; as well as The fixing member is attached to the battery box to secure the side portion in a folded state.

11. The method for manufacturing a secondary battery according to claim 10, in, The step of attaching the fixing member includes attaching the fixing member such that the break line is parallel to the length direction of the side portion.

12. The method for manufacturing a secondary battery according to claim 10, in, The step of attaching the fixing member includes attaching the fixing member such that the break line corresponds to the gap or boundary between the receiving portion and the side portion of the electrode assembly.

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