Secondary battery module

Abstract

The present invention relates to a secondary battery module, and more particularly, to a secondary battery module including a plurality of secondary batteries. The present invention includes a plurality of secondary batteries in which electrode assemblies are accommodated in a battery case with sealed edges, and a housing in which an accommodation space for accommodating the plurality of secondary batteries is formed. The battery case includes at least one folding portion folded at the edge such that the end is wrapped inside, and at least one exhaust portion at the edge where the end is exposed outside, and when the internal pressure of the battery case becomes a predetermined pressure or more, the seal is released and the gas inside the battery case is discharged. The housing provides a secondary battery module in which at least one venting portion for venting the gas discharged from the exhaust portion to the outside is formed.

Description

Technical Field

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[0006]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0096405 filed on August 2, 2022 and Korean Patent Application No. 10-2023-0056993 filed on May 2, 2023, and all the contents disclosed in the documents of the Korean patent applications are incorporated herein by reference in their entirety.

[0002] The present invention relates to a secondary battery module, and more particularly, to a secondary battery module including a plurality of secondary batteries.

Background Art

[0003] Recently, secondary batteries have been attracting attention as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), etc., which are presented as a means to solve problems such as air pollution in existing gasoline vehicles and diesel vehicles that use fossil fuels.

[0004] For small mobile devices, one or two to three secondary batteries are used, whereas for medium and large-sized devices such as electric vehicles, due to the need for high power and large capacity, a secondary battery module in which a number of secondary batteries are electrically connected or a secondary battery pack in which a plurality of secondary battery modules are electrically connected to each other is used.

[0005] Currently, one of the most spotlighted secondary batteries among commercialized secondary batteries is the lithium secondary battery. The lithium secondary battery can be classified into a can type, a prismatic type, a pouch type, etc. according to the form of the exterior material. Among these, the pouch type secondary battery is widely used in medium and large-sized battery modules because of its advantages of high energy density and easy lamination.

[0006] On the other hand, in recent years, as the demand for secondary battery modules installed in vehicles has increased, customer needs for stability have been steadily rising. However, while customers are seeking to increase the energy density of secondary batteries within the limited space of the secondary battery module, this also leads to an increased risk of ignition and explosion of the secondary batteries.

[0007] In particular, pouch-type rechargeable batteries have a structure in which the electrode assembly is housed in a pouch-type battery case and the edges of the battery case are sealed. When a rechargeable battery ignites and its temperature rises, causing the electrolyte to vaporize inside the battery case and generate gas, the gas tends to escape from areas where the battery case is not sealed properly, rather than passing through a predetermined path.

[0008] In this scenario, if gas is ejected adjacent to the electrode leads or busbars, a critical problem can arise where sparks cause the secondary battery to ignite rapidly. Furthermore, if gas ejected from the secondary battery accumulates inside the module housing, it can lead to an increase in the module's withstand voltage.

[0009] Therefore, there is a need to develop technologies to solve the problems mentioned above. [Overview of the project] [Problems that the invention aims to solve]

[0010] The present invention has been derived to solve the above-mentioned problems, and the object of the present invention is to provide an invention relating to a secondary battery module that can minimize the risk of ignition by guiding the gas ejected from a secondary battery to a designated location when an emergency situation such as the ignition of a secondary battery occurs. [Means for solving the problem]

[0011] The present invention provides a secondary battery module comprising a plurality of secondary batteries, each having an electrode assembly housed in a battery case with a sealed edge, and a housing having a housing space formed inside for housing the plurality of secondary batteries, wherein the battery case includes at least one folding portion that is folded inward at the edge, and at least one exhaust portion that is exposed outward at the edge, and which releases the seal and discharges internal gas from the battery case when the internal pressure of the battery case exceeds a predetermined pressure, and the housing has at least one venting portion formed to exhaust the gas discharged from the exhaust portion to the outside.

[0012] The venting portion can be a hole structure that penetrates the housing.

[0013] The venting portion can be provided on the side of the housing.

[0014] The housing includes a support frame for supporting the stack of secondary batteries and a pair of end plates connected to the support frame and located on the front and rear surfaces of the plurality of secondary batteries, and the venting portion can be formed on the end plates.

[0015] The secondary battery includes electrode leads protruding from the battery case, the end plate is positioned to face the electrode leads, and the venting portion can be provided in a position facing the battery case.

[0016] The venting portion can be formed as a stepped hole structure inside the end plate.

[0017] The venting portion can be expanded from the inside to the outside of the end plate.

[0018] The housing further includes a cover portion attached to the housing corresponding to the position of the bending portion, and when the internal pressure of the accommodation space is less than a predetermined pressure, the cover portion seals the bending portion, and when the internal pressure of the accommodation space is greater than or equal to the predetermined pressure, it can rupture to open the bending portion.

[0019] The cover portion can have a porous material.

[0020] The exhaust portion can be folded at least once or more so that the end is exposed to the outside.

[0021] The folding portion is folded at least twice or more in one direction, and the exhaust portion can be folded in a direction opposite to that of the folding portion. <00所求翻译内容中包含多个英文标签,这些标签在翻译时应保持不变,因此需要将其与翻译后的文本进行整合。The housing further includes a cover portion attached to the housing corresponding to the position of the bending portion, and when the internal pressure of the accommodation space is less than a predetermined pressure, the cover portion seals the bending portion, and when the internal pressure of the accommodation space is greater than or equal to the predetermined pressure, it can rupture to open the bending portion. <000\

[0022] The exhaust portion can be folded a smaller number of times than the folding portion. <所翻译内容中包含多个英文标签,这些标签在翻译时应保持不变,因此需要将其与翻译后的文本进行整合。The housing further includes a cover portion attached to the housing corresponding to the position of the bending portion, and when the internal pressure of the accommodation space is less than a predetermined pressure, the cover portion seals the bending portion, and when the internal pressure of the accommodation space is greater than or equal to the predetermined pressure, it can rupture to open the bending portion.

[0019] The cover portion can have a porous material.

[0020] The exhaust portion can be folded at least once or more so that the end is exposed to the outside.

[0021] ]The exhaust portion is formed such that the distance between the inner surfaces provided to face each other by folding is larger than the distance between the inner surfaces provided to face each other by folding in the folding portion.

[0024] [[ID=2\

[0025] The folding portion can be formed at the remaining end other than the end where the electrode lead protrudes.

[0026] A plurality of the exhaust portions are formed at intervals along the longitudinal direction of the battery case, and the exhaust portions can be provided between the plurality of folding portions. [[ID=3\ On the one hand, the secondary battery module according to the present invention can further include a membrane portion that is folded such that both ends are connected to the exhaust portion and wrap the end of the exhaust portion.

[0028] When the internal pressure of the battery case is equal to or higher than a predetermined pressure and the exhaust portion is unsealed, the membrane portion can be deployed with both ends connected to the outer surface of the exhaust portion.

[0029] The membrane portion can be made of a porous material.

[0030] The secondary battery can further include an adhesive member attached to the outside of the folding portion so that the folded shape of the folding portion is maintained.

[0031] The secondary battery can have a sealing strength of the folding portion stronger than that of the exhaust portion.

Advantages of the Invention

[0032] The present invention has the effect of preventing an increase in the pressure resistance of the module by forming a venting portion in the housing and exhausting the gas generated from the secondary battery to the outside of the housing.

[0033] In addition, the present invention has the effect of minimizing the penetration of external foreign substances into the housing and easily securing a gas discharge path by forming the venting portion on the side portion of the housing.

[0034] In addition, the present invention further includes a cover portion provided corresponding to the position of the venting portion and sealing the venting portion when the internal pressure of the accommodation space is less than a predetermined pressure, thereby minimizing the penetration of external foreign substances into the housing and easily discharging the gas when the pressure resistance of the module increases.

[0035] Furthermore, the present invention has the effect of minimizing the risk of ignition by providing an exhaust port on the edge of the battery case with its end exposed to the outside, thereby guiding the gas generated from inside the battery case to dissipate to a designated location.

[0036] Furthermore, by further including a membrane portion connected to the exhaust portion, the present invention has the effect of discharging gas from inside the battery case and preventing external moisture or foreign matter from penetrating into the inside of the battery case.

[0037] This improves the stability of the secondary battery module under thermal runaway conditions. [Brief explanation of the drawing]

[0038] [Figure 1] This is an exploded perspective view showing a secondary battery module according to Embodiment 1 of the present invention. [Figure 2] Figure 1 is a detailed perspective view of the end plate. [Figure 3] Figure 1 is a detailed side view of the end plate. [Figure 4] Figure 3 is a partial cross-sectional view showing a portion of the cross-section in the AA direction. [Figure 5] This is a partial cross-sectional view showing a part of a secondary battery module according to Embodiment 2 of the present invention. [Figure 6] This is a front view of a secondary battery to which the present invention applies. [Figure 7] Figure 6 is a partial cross-sectional view showing a portion of the cross-section in the BB direction. [Figure 8] Figure 6 is a partial cross-sectional view in the CC direction, showing the situation before the gas is released through the exhaust section. [Figure 9] Figure 8 is a cross-sectional view showing how gas is released through the exhaust port. [Figure 10] This is a cross-sectional view showing the secondary battery module according to Embodiment 3 of the present invention before the gas is released through the exhaust section and the membrane section. [Figure 11]Figure 10 is a cross-sectional view showing how gas is released through the exhaust section and the membrane section. [Modes for carrying out the invention]

[0039] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, so that they can be easily implemented by a person with ordinary skill in the art to which the present invention pertains. However, the present invention can be realized in a variety of different forms and is not limited or restricted by the embodiments described below.

[0040] For the purpose of clearly describing the present invention, detailed descriptions of relevant prior art that are irrelevant to the description or that could obscure the gist of the invention have been omitted. In this specification, when assigning reference numerals to components in the drawings, the same or similar reference numerals are used for components that are the same or similar throughout the specification.

[0041] Furthermore, the terms and words used in this specification and the claims should not be interpreted in a manner limited to their ordinary or dictionary meanings, but rather should be interpreted in a manner consistent with the technical idea of ​​the present invention, in accordance with the principle that inventors may appropriately define the concepts of terms in order to best describe their invention.

[0042] The present invention provides a secondary battery module 100 comprising a plurality of secondary batteries 110, each having an electrode assembly 111 housed in a battery case 112 with a sealed edge, and a housing 120 having a housing space formed inside for housing the plurality of secondary batteries 110, wherein the battery case 112 includes at least one folding portion 112a that is folded inward at the edge, and at least one exhaust portion 112b that is exposed outward at the edge, and which releases the seal and discharges internal gas from the battery case 112 when the internal pressure of the battery case 112 exceeds a predetermined pressure, and the housing 120 has at least one venting portion 122a formed therein for exhausting gas discharged from the exhaust portion 112b to the outside.

[0043] First, the secondary battery 110 has a configuration in which an electrode assembly 111 is housed in a battery case 112 with a sealed edge, and can have various structures.

[0044] Here, the electrode assembly 111 has a configuration in which electrodes and separators are stacked, and can have various structures. For example, the electrode assembly 111 may have a structure in which the positive electrode current collector / positive electrode active material layer / separator / negative electrode active material layer / negative electrode current collector are stacked in that order, with the positive electrode active material layer facing one side of the separator and the negative electrode active material layer facing the other side. Note here that in the drawing, the electrode assembly 111 is housed inside the battery case 112 and is represented by a dotted line.

[0045] Such an electrode assembly 111 can be housed in a battery case 112 together with an electrolyte. Here, the battery case 112 has a sealed edge and can have various structures.

[0046] The battery case 112 described above may be provided with its edges folded in order to reduce the volume of the secondary battery 110 in order to improve energy density, or to further improve the sealing force of the battery case 112.

[0047] Furthermore, at least one exhaust port 112b and a folding portion 112a can be formed on the folded edge of the battery case 112 so that if gas is generated inside the battery case 112 due to the secondary battery 110 igniting or the like, the gas can be released to a designated location. A detailed explanation of the exhaust port 112b and the folding portion 112a will be given later.

[0048] Such a secondary battery 110 may further include electrode leads 113 that protrude from at least one end of the battery case 112. Here, the electrode leads 113 can be understood as having one end connected to an electrode assembly 111 inside the battery case 112 and the other end electrically connected to an external electrical device and / or secondary battery 110.

[0049] On the other hand, multiple secondary batteries 110 can be stacked and housed in a housing 120. Here, the housing 120 has a configuration in which a housing space for housing the multiple secondary batteries 110 is formed inside, and can have various structures.

[0050] Here, the housing 120 may be provided with at least one venting section 122a that can release gas ejected from the secondary battery 110 housed in the containment space to the outside. The venting section 122a is configured to release the gas to the outside at the moment gas is generated in the secondary battery 110, and has the effect of preventing an increase in the pressure withstand capacity of the secondary battery module 100.

[0051] Such a venting section 122a is configured to exhaust the gas discharged from the exhaust section 112b to the outside, and can have various structures. For example, the venting section 122a can be formed as a hole structure that penetrates the housing 120.

[0052] Furthermore, the venting portion 122a can be provided at various positions in the housing 120. Here, the user can selectively shape the position of the venting portion 122a to guide the gas to vent at a specified location, thereby minimizing the risk of ignition.

[0053] If the venting portion 122a is formed on the upper part of the housing 120, a problem may arise in which foreign matter or water falling from the outside can easily penetrate into the inside of the housing 120 through the venting portion 122a. Also, if the venting portion 122a is formed on the lower part of the housing 120, it may be difficult to secure a gas exhaust passage. Therefore, it is preferable that the venting portion 122a be provided on the side of the housing 120.

[0054] On the other hand, in order to explain in more detail the formation position of the venting portion 122a, we will first specifically describe the structure of the housing 120.

[0055] The housing 120 may include, as shown in Figure 1, a support frame 121 for supporting the stack of secondary batteries 110, and a pair of end plates 122 that are coupled to the support frame 121 and located on the front and rear surfaces of the stack of secondary batteries 110.

[0056] Here, the support frame 121 is configured to support the secondary battery 110 and can have various structures. For example, as shown in Figure 1, the support frame 121 can have a U-shaped structure to support the lower and side portions of the secondary battery 110. However, the shape of the support frame 121 is not limited to this, and other shapes of frames, such as a monoframe that covers the four sides of the secondary battery 110 other than the corners from which the electrode leads 113 protrude, may be used instead.

[0057] Furthermore, a cover frame 123 can be provided on the open upper part of the support frame 121, as shown in Figure 1. The cover frame 123 can be coupled to the upper part of the support frame 121 and is provided above the secondary battery 110, and together with the support frame 121 can form the housing space of the housing 120.

[0058] On the other hand, the pair of end plates 122 are connected to the support frame 121 and are positioned on the front and rear surfaces of the plurality of secondary batteries 110, and can have various structures. Here, the front and rear surfaces of the plurality of secondary batteries 110 can be understood as surfaces provided in the secondary battery 110 in the direction from which the electrode leads 113 protrude.

[0059] Specifically, the end plate 122 can be connected to the support frame 121 by welding or bolting. A busbar assembly 140 can be further provided between the end plate 122 and the secondary battery 110. This allows the end plate 122 to protect the busbar assembly 140 and the various electrical components connected thereto from external impacts.

[0060] Here, the busbar assembly 140 comprises a plurality of electrically conductive busbars and a busbar frame that supports the busbars, and the busbars can be provided to contact electrode leads 113 protruding from the secondary battery 110.

[0061] Such an end plate 122 may have a structure that includes a main body made of a metal material that protects the busbar assembly 140, other electrical components, and secondary battery 110 from external impacts, and an insulating cover that is connected to the main body, is made of an insulating material, and maintains insulation from the busbar assembly 140, other electrical components, and secondary battery 110.

[0062] On the other hand, at least one of the venting portions 122a can be formed on the end plate 122. Here, as shown in Figure 1, the end plate 122 has a structure that extends longitudinally along the arrangement direction of the multiple secondary batteries 110 (relative to Figure 1, parallel to the Y-axis), and can be positioned so as to face one side of each of the parallel-arranged secondary batteries 110. Here, one side of the secondary battery 110 can be understood as the side on which the electrode leads 113 protrude.

[0063] Therefore, when a venting portion 122a is formed on the end plate 122, the gas can be quickly discharged to the outside regardless of the position of the secondary battery 110 that has generated gas among the multiple secondary batteries 110. As a result, the multiple secondary batteries 110 can exhaust the gas sequentially rather than simultaneously, preventing explosions at the module level and controlling the ignition rate.

[0064] Furthermore, when a venting portion 122a is formed on the end plate 122, the venting portion 122a is provided on the side of the housing 120, which has the advantage of preventing the penetration of foreign objects falling from above and allowing for the easy formation of a gas discharge path.

[0065] On the other hand, at least one venting portion 122a can be formed on the end plate 122. For example, two venting portions 122a can be formed on the end plate 122, as shown in Figures 2 and 3.

[0066] Here, the venting portion 122a can be formed at any position on the end plate 122. However, it is preferable that the venting portion 122a be formed in such a way that it can guide the exhaust of gas to a location that is insulated or where there is little risk of electric sparks occurring, in order to effectively control the propagation speed after the secondary battery 110 ignites at the module level.

[0067] In particular, the end plate 122 can be positioned to face the electrode leads 113 of the secondary battery 110, and in this case as well, it is preferable that the venting portion 122a is formed at a position that is as far away from the electrode leads 113 as possible.

[0068] In other words, the electrode lead 113 is electrically connected to the electrode assembly 111 inside the battery case 112 and to an external electrical device or secondary battery 110. When gas inside the housing 120 is exhausted to the outside, if it passes in close proximity to the electrode lead 113, a spark may occur, potentially leading to a rapid ignition. As a result, there is a very high possibility that an external short circuit will occur in the secondary battery module 100, accelerating thermal runaway propagation between multiple secondary batteries 110.

[0069] Therefore, as shown in Figure 4, the venting portion 122a can be provided on the end plate 122, which is positioned opposite the electrode lead 113, but not opposite the electrode lead 113, and instead opposite the battery case 112. As a result, when gas is generated in the internal housing space of the secondary battery module 100, the generation of flames due to sparks can be minimized by venting the gas to the outside before it moves toward the electrode lead 113. In this case, the occurrence of a two-wire-to-ground fault can be prevented, and the propagation of thermal runaway between multiple secondary batteries 110 can be suppressed and delayed.

[0070] In Figure 4, a busbar assembly 140 is shown on one side of the venting portion 122a. It should be noted that the busbar assembly 140 is configured to avoid the venting portion 122a between the end plate 122 and the secondary battery 110, and is not configured to close the venting portion 122a. The same applies to Figure 5 below.

[0071] On the other hand, the venting portion 122a described above can have various structures that allow gas from inside the secondary battery module 100 to be discharged to the outside. For example, the venting portion 122a can be formed as a hole structure that penetrates the end plate 122.

[0072] Here, the venting portion 122a can be formed as a stepped hole structure inside the end plate 122. More specifically, as shown in Figure 4, the venting portion 122a can expand from the inside to the outside of the end plate 122 and have a stepped hole structure.

[0073] In this case, the region of the stepped hole structure of the venting portion 122a that has a relatively wide diameter and is open to the outside can be used as a region into which a jig used for transporting or fixing the secondary battery module 100 is inserted. Here, the end of the jig can be fixed in contact with the inner wall 122a' formed by the step in the venting portion 122a, thereby preventing interference with the internal secondary battery 110 and allowing the secondary battery module 100 to be easily transported and fixed.

[0074] On the other hand, the secondary battery module 100 according to the present invention may further include a cover portion 150 that is attached to the housing 120 in a position corresponding to the venting portion 122a. Here, adhesive double-sided tape or the like can be interposed between the cover portion 150 and the housing 120 to fix the cover portion 150 to the housing 120.

[0075] Specifically, the cover portion 150 can be understood as being configured to seal the venting portion 122a when the internal pressure of the containment space is below a predetermined pressure, and to rupture and open the venting portion 122a when the internal pressure of the containment space is above the predetermined pressure.

[0076] The cover portion 150 can be provided at any position that covers the venting portion 122a. If the venting portion 122a has a stepped hole structure inside the end plate, the cover portion 150 can be provided inside the end plate 122.

[0077] Specifically, as shown in Figure 5, the cover portion 150 can be fixed by having its edge attached to the inner wall 122a' formed by a step in the venting portion 122a. In this case, the cover portion 150 is located inside the end plate 122 and is protected from external impacts, minimizing the occurrence of problems such as damage or detachment from its fixed position.

[0078] Such a cover portion 150 can be made of a porous material. This has the effect of allowing gas inside the housing 120 to be released to the outside, while preventing external moisture and foreign matter from penetrating into the housing 120.

[0079] On the other hand, the venting portion 122a described above is preferably provided at a position corresponding to the exhaust portion 112b of the battery case 112 of the present invention, so that the gas discharged from the secondary battery 110 can be quickly exhausted to the outside. The detailed structure of the folding portion 112a and the exhaust portion 112b of the battery case 112 of the present invention will be described below.

[0080] As shown in Figure 6, the battery case 112 according to the present invention may include at least one folding portion 112a that is folded inward at the edge and at least one exhaust portion 112b that is exposed outward at the edge.

[0081] As a result, if a certain amount of gas is generated from inside the battery case 112, the gas can be released first from the exhaust section 112b, which is relatively easier to release gas from than the folding section 112a. Therefore, in the battery case 112 with the above structure, the user can selectively position the exhaust section 112b on the battery case 112 to release the gas to a specified location, thereby minimizing the risk of the secondary battery 110 catching fire.

[0082] First, the folding section 112a is configured such that its end is enclosed inward at the edge of the battery case 112, and can have various structures.

[0083] Specifically, as shown in Figure 7, the folding portion 112a is provided on the edge of the battery case 112, and the end portion 112aa of the folding portion 112aa can be enclosed by the opposing inner surface when folded.

[0084] As a result, the folding section 112a has an end 112aa from which gas can be released to the outside enclosed inward, making it a structure from which gas is relatively difficult to release compared to the exhaust section 112b, which has an end exposed to the outside. This can be understood as a configuration that induces the release of gas from the exhaust section 112b.

[0085] Furthermore, the folding portion 112a has its end portion 112aa enclosed inward, making it relatively difficult for external moisture and air to penetrate, and can be understood as a configuration that improves the sealing force of the battery case 112.

[0086] The folding portion 112a described above can have any structure as long as the end portion 112aa is enclosed inward. For example, the folding portion 112a can have a structure that folds at least twice in one direction so that the end portion 112aa is enclosed inward at the edge of the battery case 112.

[0087] Furthermore, the folding portion 112a can also be formed such that the opposing inner surfaces are in contact with each other or adjacent to each other when folded, in order to minimize gas movement even when gas flows into the folding portion 112a.

[0088] An adhesive member can be attached to the outside of the folding portion 112a. The adhesive member can fix the folding portion 112a so that the inwardly folded folding portion 112a maintains its folded shape. Here, the adhesive member may be an insulating tape or the like. When the adhesive member is attached to the outside of the folding portion 112a, the folding portion 112a can be subjected to a force that tries to maintain its inwardly folded shape, and gas release may become even more difficult than with the exhaust portion 112b, whose end is exposed to the outside. In other words, the adhesive member can guide the gas to be discharged more efficiently from the exhaust portion 112b.

[0089] On the other hand, the present invention may include an exhaust section 112b that releases the seal and discharges gas from inside the battery case 112 when the internal pressure of the battery case 112 exceeds a predetermined pressure.

[0090] Specifically, the exhaust portion 112b may be provided on the edge of the battery case 112, as shown in Figure 8, and may have a structure in which the end portion 112ba of the exhaust portion 112b is exposed to the outside.

[0091] As a result, the exhaust section 112b has an end 112ba from which gas can be released to the outside that is exposed to the outside, and has a structure that makes gas release relatively easier than the folding section 112a in which the end 112ba is enclosed inward. It can be understood that the exhaust section 112b is configured to operate before the folding section 112a when gas is generated inside the battery case 112 and be used as a gas release passage.

[0092] The exhaust section 112b described above can have any structure as long as its end 112ba is exposed to the outside. For example, the exhaust section 112b can have a structure that is folded at least once so that its end 112ba is exposed to the outside. Here, the exhaust section 112b may be folded in the opposite direction to the folding section 112a, or it may be folded fewer times than the folding section 112a.

[0093] Furthermore, when gas flows into the exhaust section 112b, it is preferable that the spacing between the inner surfaces, which are arranged to face each other by folding, is larger than the spacing between the inner surfaces, which are arranged to face each other by folding, in the folding section 112a, in order to maximize the movement of the gas.

[0094] As shown in Figure 8, such an exhaust section 112b can maintain a sealed state if no gas is generated inside the battery case 112, or if the gas pressure inside the battery case 112 is below a predetermined pressure.

[0095] Furthermore, as shown in Figure 9, the exhaust section 112b can release its seal and induce the release of gas when gas is generated inside the battery case 112 and the internal pressure of the battery case 112 exceeds a predetermined pressure, thereby reducing the internal pressure of the battery case 112.

[0096] In relation to the manufacturing process, the present invention has different folding directions for the folding portion 112a and the exhaust portion 112b. Therefore, it is necessary to separate the folding portion 112a and the exhaust portion 112b so that they can be separated and folded in different directions. Specifically, after the positions corresponding to the folding portion 112a and the exhaust portion 112b are sealed, a cut can be made between the two so that the positions corresponding to the folding portion 112a and the exhaust portion 112b can be folded independently of each other. Here, there can be various methods of cutting, and the sealing state of the cut portion can be maintained. The section between the folding portion 112a and the exhaust portion 112b is cut, so that the folding portion 112a and the exhaust portion 112b can be folded independently in different directions.

[0097] On the other hand, the exhaust section 112b can be arranged in various ways within the battery case 112.

[0098] However, the secondary battery 110 according to the present invention may further include electrode leads 113 that protrude from at least one end of the battery case 112, as described above, in which case it is preferable that the exhaust portion 112b is formed at a position that is as far away from the electrode leads 113 as possible.

[0099] This is because the electrode lead 113 is electrically connected to the electrode assembly 111 inside the battery case 112 and to an external electrical device or secondary battery 110, and if the gas released from the exhaust section 112b is discharged in close proximity to the electrode lead 113, a spark may occur, potentially leading to a rapid ignition.

[0100] Therefore, as shown in Figures 6 to 7, when the electrode lead 113 protrudes from at least one end of the battery case 112, it is preferable that the exhaust portion 112b be formed on the remaining end other than the end on which the electrode lead 113 protrudes. Here, the folding portion 112a described above can also be formed on the remaining end other than the end on which the electrode lead 113 protrudes.

[0101] On the other hand, the exhaust section 112b described above can be provided in various numbers and positions on the battery case 112, taking into consideration the amount of gas generated inside the battery case 112.

[0102] As an example, one exhaust portion 112b may be formed and provided in the center of the edge of the battery case 112. As another example, multiple exhaust portions 112b may be formed and provided spaced apart along the longitudinal direction of the battery case 112. In this case, the exhaust portions 112b may be provided between multiple folding portions 112a.

[0103] The folding portion 112a and the exhaust portion 112b may have different manufacturing processes so that when the internal pressure of the battery case 112 exceeds a predetermined pressure, gas is discharged from the exhaust portion 112b. Specifically, the sealing strength at the location where the exhaust portion 112b is formed may be lower than the sealing strength at the location where the folding portion 112a is formed. More specifically, the folding portion 112a may be sealed more thickly than the exhaust portion 112b. Therefore, when the internal pressure of the battery case 112 exceeds a predetermined pressure, gas can be discharged to the outside of the battery case 112 through the exhaust portion 112b, which has relatively less airtight seal.

[0104] On the other hand, the secondary battery 110 according to the present invention may further include a membrane portion 160 that is folded to enclose the end of the exhaust portion 112b.

[0105] Specifically, as shown in Figures 10 to 11, the membrane portion 160 is configured such that both ends are connected to the exhaust portion 112b and it folds to enclose the end of the exhaust portion 112b, and it can have various structures.

[0106] More specifically, the membrane portion 160 may have a structure that folds to enclose the end of the exhaust portion 112b when the internal pressure of the battery case 112 is below a predetermined pressure and the exhaust portion 112b is sealed, as illustrated in Figure 10.

[0107] Here, the membrane portion 160 can be provided such that, when the exhaust portion 112b is sealed, the folded portion of the membrane portion 160 is separated from the end of the exhaust portion 112b by a predetermined distance, so that both ends of the membrane portion 160 are connected to the exhaust portion 112b even when the seal of the exhaust portion 112b is released.

[0108] On the other hand, as shown in Figure 11, the membrane portion 160 may have a structure in which, when the internal pressure of the battery case 112 is above a predetermined pressure and the exhaust portion 112b is released from its seal, both ends of the membrane portion 160 are connected to the outer surface of the exhaust portion 112b.

[0109] Such a membrane portion 160 can be made of a porous material. This has the effect of allowing gas inside the battery case 112 to be released to the outside when the exhaust portion 112b is released, while preventing external moisture and foreign matter from penetrating into the battery case 112. More specifically, the membrane portion 160 can be made of a thin film formed by heating and spreading a Teflon® resin, resulting in numerous small holes. Therefore, particles such as moisture penetrating from the outside cannot pass through the membrane portion 160, while gas generated inside can pass through sufficiently and be discharged to the outside. Furthermore, the membrane portion 160 can be connected to the exhaust portion 112b in various ways. For example, as shown in Figures 10 to 11, the membrane portion 160 can be connected to the exhaust portion 112b by interposing an adhesive substance 160' between the inner surface of the membrane portion 160 and the outer surface of the exhaust portion 112b. The adhesive material 160' can be used to join the membrane portion 160 and the exhaust portion 112b by heat fusion or the like.

[0110] The present invention allows gas generated inside the battery case 112 to be guided to be discharged to the outside of the housing 120 along a desired path. Therefore, risks generated inside the secondary battery module 100 due to large amounts of gas can be dealt with more efficiently. Similarly, in the event of thermal runaway caused by a fire, where a large amount of gas is generated inside the secondary battery module 100, a relatively efficient solution is possible. In other words, the stability of the secondary battery module 100 can be improved in relation to problems caused by internal gas.

[0111] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and various implementations are possible by persons with ordinary skill in the art to which the present invention pertains, within the equivalent scope of the technical concept of the present invention and the claims described below. [Explanation of Symbols]

[0112] 100 secondary battery modules 110 Secondary battery 111 Electrode assembly 112 Battery Case 112a Folding section 112aa End of the folding section 112b Exhaust section 112ba end of exhaust section 113 Electrode Leads 120 Housing 121 Support frame 122 End Plate 122a Venting section 122a' Inner wall of the venting section 123 Cover Frame 140 Busbar Assembly 150 Cover section 160 Membrane section 160' sticky substance

Claims

1. Multiple secondary batteries, each containing an electrode assembly housed in a battery case with a sealed edge, It includes a housing in which a housing space for accommodating the plurality of secondary batteries is formed inside, The aforementioned battery case is The edge has at least one folding portion that is folded so that its end is enclosed inward, The edge includes at least one exhaust port, the end of which is exposed to the outside, and which releases the seal and discharges internal gas from the battery case when the internal pressure of the battery case exceeds a predetermined pressure, A secondary battery module, wherein the housing has at least one venting section formed therein, through which the gas discharged from the exhaust section is exhausted to the outside.

2. The secondary battery module according to claim 1, wherein the venting portion is a hole structure that penetrates the housing.

3. The secondary battery module according to claim 1, wherein the venting portion is provided on the side of the housing.

4. The aforementioned housing is A support frame that supports the stack of secondary batteries, It includes a pair of end plates that are connected to the support frame and are located on the front and rear surfaces of the plurality of secondary batteries, The venting portion is formed on the end plate, as described in claim 1, for the secondary battery module.

5. The secondary battery includes electrode leads protruding from the battery case, The end plate is positioned to face the electrode lead, The secondary battery module according to claim 4, wherein the venting portion is provided at a position facing the battery case.

6. The secondary battery module according to claim 4, wherein the venting portion is formed in a stepped hole structure inside the end plate.

7. The secondary battery module according to claim 6, wherein the venting portion expands from the inside to the outside of the end plate.

8. It further includes a cover portion that is attached to the housing in a position corresponding to the venting portion, The aforementioned cover portion is If the internal pressure of the containment space is below a predetermined pressure, the venting section is sealed. The secondary battery module according to claim 1, wherein if the internal pressure of the containment space exceeds a predetermined pressure, it ruptures and opens the venting section.

9. The secondary battery module according to claim 8, wherein the cover portion is made of a porous material.

10. The secondary battery module according to claim 1, wherein the exhaust portion is folded at least once so that its end is exposed to the outside.

11. The folding portion is folded at least twice in one direction. The secondary battery module according to claim 10, wherein the exhaust section is folded in the direction opposite to the one direction of the folding section.

12. The secondary battery module according to claim 10, wherein the exhaust section is folded in fewer steps than the folding section.

13. The aforementioned exhaust section is The secondary battery module according to claim 10, wherein the spacing between the inner surfaces that are arranged to face each other by folding is larger than the spacing between the inner surfaces that are arranged to face each other by folding in the folding portion.

14. The battery case further includes an electrode lead that protrudes from at least one end, The secondary battery module according to claim 1, wherein the exhaust portion is formed on the remaining end of the electrode lead other than the protruding end.

15. The secondary battery module according to claim 14, wherein the folding portion is formed on the remaining end of the electrode lead other than the protruding end.

16. Multiple exhaust units are formed spaced apart along the longitudinal direction of the battery case. The secondary battery module according to claim 1, wherein the exhaust section is provided between a plurality of the folding sections.

17. The secondary battery module according to claim 1, further comprising a membrane portion whose both ends are connected to the exhaust portion and which is folded to enclose the end of the exhaust portion.

18. The aforementioned membrane portion is The secondary battery module according to claim 17, wherein when the internal pressure of the battery case is above a predetermined pressure and the exhaust port is released from its seal, both ends are connected to the outer surface of the exhaust port.

19. The secondary battery module according to claim 17, wherein the membrane portion is made of a porous material.

20. The aforementioned secondary battery is The secondary battery module according to claim 1, further comprising an adhesive member attached to the outside of the folding portion so that the folding portion maintains its folded shape.

21. The aforementioned secondary battery is The secondary battery module according to claim 1, wherein the sealing strength of the folding portion is stronger than the sealing strength of the exhaust portion.

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