Pressurizing member and pouch cell including same

Abstract

The present invention relates to a pouch cell that can prevent or reduce moisture or the like from permeating into the interior of the pouch through a passageway through which gas inside the pouch is discharged to the outside. The pouch cell according to the present invention includes: an electrode lead electrically connected to an electrode assembly housed inside the pouch and protruding outside the pouch; a lead film that covers a portion of the electrode lead to insulate the electrode lead from the pouch and includes a passageway through which a gas transfer path is formed when the internal pressure of the pouch rises above a predetermined pressure; and a pressure member disposed outside the pouch and pressurizing the passageway to close the passageway.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0029522, filed March 6, 2023, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a pouch cell that can be charged and discharged. [Background technology]

[0003] In recent years, with the depletion of fossil fuels causing rising energy costs and growing concerns about environmental pollution, the need for environmentally friendly alternative energy sources has become an essential factor for future life. Therefore, research into various electricity production technologies, such as solar, wind, and tidal power, is ongoing, and there has also been great interest in power storage devices such as batteries to more efficiently use the electrical energy produced in this way.

[0004] Furthermore, with the increasing demand for technological developments related to battery-based electronic mobile devices and electric vehicles, the demand for batteries as an energy source is increasing rapidly, and as a result, much research is being done on batteries that can meet various needs.

[0005] Batteries that store electrical energy can generally be divided into primary batteries and secondary batteries. While primary batteries are disposable, secondary batteries are rechargeable batteries made using materials that can be repeatedly oxidized and reduced by electric current. That is, when a reduction reaction occurs in the material due to electric current, the battery is charged, and when an oxidation reaction occurs in the material, the battery is discharged. Electricity is generated through this repeated charge-discharge cycle.

[0006] Secondary batteries are classified into cylindrical cells, pouch cells, prismatic cells, etc., depending on their shape. Among them, a pouch cell may include an electrode assembly in which a positive electrode, a negative electrode, a separator, etc. are stacked inside a pouch. Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a pouch cell that can prevent or reduce the penetration of moisture and the like from outside the pouch into the inside of the pouch through a passage portion through which gas inside the pouch is discharged to the outside. [Means for solving the problem]

[0008] The pouch cell according to the present invention may include: an electrode lead electrically connected to an electrode assembly accommodated inside a pouch and protruding outside the pouch; a lead film covering a portion of the electrode lead to insulate the electrode lead from the pouch, the lead film including a passage portion that forms a gas transfer path when the internal pressure of the pouch rises above a set pressure; and a pressure member disposed outside the pouch and pressurizing the passage portion to close the gas transfer path of the passage portion.

[0009] The pressure member may include a first member that is disposed on an outer surface of one side of the pouch relative to the electrode lead and pressurizes the passage portion in a direction toward the electrode lead, and a second member that is disposed on an outer surface of the other side of the pouch relative to the electrode lead and pressurizes the passage portion in a direction toward the electrode lead.

[0010] The pressure member may further include connecting members connected to the first member and the second member, respectively, to provide the first member and the second member with a force to press the passage portion.

[0011] The connecting member may be connected to one end of the first member and one end of the second member, respectively.

[0012] The connecting member may include a first connecting portion connected to one end of the first member and one end of the second member, respectively, and a second connecting portion connected to the other end of the first member and the other end of the second member, respectively.

[0013] The connecting member may include an elastic portion that provides an elastic restoring force so that the first member and the second member pressurize the passage portion, a first extension portion that connects the first member to the elastic portion, and a second extension portion that connects the second member to the elastic portion.

[0014] The elastic portion may have a curved shape to generate an elastic restoring force when the shape of the elastic portion changes, and the first extension portion may be closer to the second extension portion as it moves away from the elastic portion.

[0015] The elastic portion may have a coiled shape like a spring so as to generate an elastic restoring force when the shape of the elastic portion changes.

[0016] The first and second members may further include a protective member that is capable of deforming to absorb impact and is arranged to contact the pouch, and a fixing member that is arranged on the opposite side of the pouch relative to the protective member to fix the protective member.

[0017] The protective member may include rubber so as to be deformable, and may be disposed at a position corresponding to the position of the passage portion.

[0018] The pressurizing member according to the present invention is a pressurizing member that is disposed outside a pouch of a pouch cell, pressurizes a passage formed when the internal pressure of the pouch rises above a set pressure, and closes a gas transfer path of the passage when the internal pressure of the pouch falls below the set pressure, and includes a first member that is disposed in contact with the pouch and pressurizes the passage, a second member that is disposed on the opposite side of the first member relative to the pouch and in contact with the pouch and pressurizes the passage, and connecting members that are connected to the first member and the second member, respectively, and provide the first member and the second member with a force to pressurize the passage.

[0019] The battery module according to the present invention includes a cell stack including a plurality of pouch cells and a frame in which the cell stack is housed, wherein the pouch cells each include an electrode lead electrically connected to an electrode assembly housed inside the pouch and protruding outside the pouch, a lead film covering a portion of the electrode lead to insulate the electrode lead from the pouch, and including a passage portion that forms a gas transfer path when the internal pressure of the pouch rises above a set pressure, and a pressure member disposed outside the pouch and pressurizing the passage portion to close the gas transfer path in the passage portion.

[0020] The frame may include a fixed rod disposed at one end of the cell stack in a longitudinal direction and extending in a stacking direction of the pouch cells, and the pressure member may be fixedly connected to the fixed rod.

[0021] The battery module may further include a bus bar assembly disposed at one longitudinal end of the cell stack to close the opening of the frame and electrically connect the pouch cells to each other, and the pressing member may be fixedly connected to the bus bar assembly.

[0022] The pouch cell for a lithium secondary battery according to the present invention may include: an electrode lead electrically connected to the electrode assembly of the lithium secondary battery accommodated inside the pouch and protruding outside the pouch; a lead film covering a portion of the electrode lead to insulate the electrode lead from the pouch, the lead film including a passage portion that forms a gas transfer path when the internal pressure of the pouch rises above a set pressure; and a pressure member disposed outside the pouch and pressurizing the passage portion to close the gas transfer path of the passage portion.

[0023] The pressure member may be designed to close the gas transfer path of the passage portion when the internal pressure of the pouch drops below a set pressure. [Effects of the Invention]

[0024] The pouch cell according to the present invention may include: an electrode lead electrically connected to an electrode assembly accommodated inside the pouch and protruding outside the pouch; a lead film covering a portion of the electrode lead so as to insulate the electrode lead from the pouch and including a passage portion that forms a gas transfer path when the internal pressure of the pouch rises above a set pressure; and a pressure member disposed outside the pouch and pressurizing the passage portion so as to close the passage portion.

[0025] This makes it possible to prevent moisture and the like from flowing into the pouch through the passage after the gas inside the pouch has been sufficiently released to the outside.

[0026] This makes it possible to prevent the function of the pouch cell from being deteriorated.

[0027] Furthermore, the pressure member is positioned so as not to interfere with the electrode lead, and therefore does not affect the stability of the pouch cell.

[0028] In addition, since the pressure member is disposed outside the pouch, it can be applied to various existing pouch cells, thereby improving usability.

[0029] The effects of the present invention are not limited to the above-mentioned examples, and various other effects are included within the present specification.

[0030] In some of the accompanying drawings, corresponding components are given the same reference numerals. Those skilled in the art will understand that the drawings illustrate elements simply and clearly and are not necessarily drawn to scale. For example, to facilitate understanding of the various embodiments, the dimensions of some elements illustrated in the drawings may be exaggerated relative to other elements. Furthermore, elements of known technology that are useful or essential in commercially feasible embodiments may not be depicted in order to avoid obscuring the spirit of the various embodiments of the present invention. [Brief explanation of the drawings]

[0031] [Figure 1] 1 is a perspective view schematically illustrating a pouch cell according to an embodiment of the present invention; [Figure 2] 1 is a plan view schematically illustrating a pouch cell according to an embodiment of the present invention; [Figure 3] 3 is a part of a cross-sectional view schematically illustrating a cross section cut along the line AA' in FIG. 2. [Figure 4] 3 is a cross-sectional view schematically illustrating a cross section taken along line BB' in FIG. 2. FIG. [Figure 5] 1 is a perspective view schematically illustrating a pressure member of a pouch cell according to an embodiment of the present invention. [Figure 6] 10 is a perspective view schematically illustrating a pressure member of a pouch cell according to another embodiment of the present invention. FIG. [Figure 7] 1 is an exploded perspective view schematically illustrating a battery module according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0032] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The present invention will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can easily understand and practice the present invention. However, the present invention may be embodied in various different forms and should not be construed as being limited to the following embodiments.

[0033] In order to clearly explain the present invention, detailed descriptions of related known technologies that are irrelevant to the description or that may obscure the gist of the present invention are omitted, and in this specification, when referring to components in each drawing, the same or similar reference symbols are used throughout the specification for the same or similar components.

[0034] Furthermore, the terms and words used in this specification and claims should not be interpreted in a limited manner to their ordinary or dictionary meanings, but should be interpreted in a manner that is consistent with the technical idea of ​​the present invention, in accordance with the principle that inventors can appropriately define the concepts of terms in order to best explain their inventions.

[0035] Pouch cells used in pouch-type lithium secondary batteries may generate gas inside the pouch due to various chemical reactions as they are repeatedly charged and discharged. If the gas generated inside the pouch is not smoothly released, the pouch cell may experience a venting phenomenon in which the pouch opens due to an increase in internal pressure. Therefore, the pouch cell may require a structure for releasing the internal pressure of the pouch to the outside.

[0036] In this regard, if the pouch cell includes a structure for gas release, moisture may penetrate into the pouch from the outside through the portion where the gas is released to the outside of the pouch, which may cause further problems such as a decrease in the performance of the pouch cell.

[0037] Therefore, there is a need for a pouch cell that can prevent or reduce the penetration of moisture from outside the pouch into the inside of the pouch through a portion where gas inside the pouch is released to the outside.

[0038] Pouch Cell FIG. 1 is a perspective view that schematically illustrates a pouch cell 10 according to one embodiment of the present invention, and FIG. 2 is a plan view that schematically illustrates the pouch cell 10 according to one embodiment of the present invention.

[0039] 1 , a pouch cell 10 according to one embodiment of the present invention may include an electrode lead 100, a pouch 200, and a lead film 300. Specifically, the pouch 200 of the pouch cell 10 accommodates an electrode assembly therein, and the electrode lead 100 may be electrically connected to the electrode assembly accommodated inside the pouch 200 and protrude to the outside of the pouch 200. In addition, the lead film 300 may cover a portion of the electrode lead 100 so that the electrode lead 100 is insulated from the pouch 200.

[0040] The pouch cell 10 includes a pair of pouches 200 facing each other, which can house an electrode assembly therebetween. The pair of pouches 200 housing the electrode assemblies can be joined together by a sealing process. Here, the sealing process may refer to a process of sealing the facing pouches 200 together using heat, pressure, etc. The electrode assembly may also refer to a structure in which a positive electrode, a negative electrode, and a separator are stacked or wound together.

[0041] Meanwhile, the pouch 200 may include a resin layer and a metal layer, and an example of a material for the metal layer is aluminum (Al). In addition, the resin layers may melt together due to heat during the sealing process, thereby adhering the pouch 200.

[0042] The electrode lead 100 of the pouch cell 10 may be made of a conductor and may be arranged to extend from the inside to the outside of the pouch 200. The electrode lead 100 may also include a negative electrode lead and a positive electrode lead. Here, the negative electrode lead and the positive electrode lead may be arranged on one side of the pouch 200 or on both sides of the pouch 200, respectively. As shown in FIG. 1 , the negative and positive electrode leads 100 of the pouch cell 10 according to one embodiment of the present invention may be arranged on both sides of the pouch 200, respectively.

[0043] The lead film 300 of the pouch cell 10 includes an insulating material and can be disposed between the electrode lead 100 and the pouch 200 to insulate them from each other. Specifically, the lead film 300 can be disposed to wrap a portion of the electrode lead 100. Here, the portion of the electrode lead 100 wrapped by the lead film 300 can include a portion where the electrode lead 100 and the pouch 200 overlap, and insulation can be maintained between the electrode lead 100 and the pouch 200 due to the lead film 300 including an insulating material.

[0044] Meanwhile, as the pouch cell 10 is repeatedly charged and discharged, gas may be generated inside the pouch 200 due to various chemical reactions. The gas generated inside the pouch 200 may cause a swelling phenomenon in which the pouch expands, and if the swelling becomes severe, may cause the pouch 200 to explode. Therefore, as one method for addressing this phenomenon, the pouch 200 may include a gas exhaust passage that can exhaust the internal gas from the inside of the pouch 200 to the outside when the gas pressure inside the pouch 200 reaches a predetermined pressure. In this regard, the lead film 300 of the pouch cell 10 according to one embodiment of the present invention may include a passage portion 310 on one surface thereof as an example of a configuration for exhausting gas to the outside.

[0045] The passage portion 310 of the lead film 300 does not normally form a gas transfer path, but can form a gas transfer path when the internal pressure of the pouch 200 rises above a set pressure. As an example, the passage portion 310 of the lead film 300 can be formed so that the adhesive strength with the electrode lead 100 is weaker than that of other portions of the lead film 300. Therefore, when the gas pressure inside the pouch 200 rises above a set pressure, for example, the internal pressure releases the adhesive between the electrode lead 100 and the passage portion 310, thereby forming a gas transfer path in the passage portion 310.

[0046] Gas within the pouch 200 can move through the gas transfer path of the passage 310, and the internal gas that has moved to the passage 310 can be discharged to the outside of the pouch 200 by permeating the lead film 300. Here, the gas can permeate the lead film 300 by diffusion, moving in molecular units. That is, the lead film 300 can include a material with high gas permeability to facilitate the discharge of internal gas through diffusion. Specifically, the lead film 300 can include at least one material selected from the group consisting of polyolefin, fluorine, and porous ceramic. For example, the lead film 300 can include at least one material selected from the group consisting of polyolefin, fluorine, and porous ceramic that meets the gas permeability requirements for gas discharge. The polyolefin material can include one or more materials selected from the group consisting of polypropylene, polyethylene, and polyvinyldenefluoride (PVDF). The fluorine-based material may also include one or more materials selected from the group consisting of polytetrafluoroethylene and polyvinylidenefluoride.

[0047] The gas generated inside the pouch 200 moves through the gas movement path of the passage 310, and then passes through the lead film 300 to be released to the outside of the pouch 200. Therefore, it is possible to delay or prevent the venting phenomenon in which the gas increases the pressure inside the pouch 200 and causes the pouch 200 to open.

[0048] In one embodiment of the present invention, an additional structure may be disposed between the electrode lead 100 and the lead film 300 so that the passage 310 can efficiently form a gas transfer path. In this case, a relatively weak adhesive force is formed between the passage 310 and the additional structure, and when the internal pressure of the pouch 200 rises above a set pressure, the space between the passage 310 and the additional structure expands, thereby forming a gas transfer path in the passage 310.

[0049] 2, the passage 310 may be formed to extend from the overlapping portion of the electrode lead 100 and the pouch 200 to the non-overlapping portion. Hereinafter, for convenience of explanation, the portion of the passage 310 corresponding to the overlapping portion of the electrode lead 100 and the pouch 200 will be referred to as an inner passage, and the portion of the passage 310 corresponding to the non-overlapping portion of the electrode lead 100 and the pouch 200 will be referred to as an outer passage.

[0050] Here, the width of the inner passage portion and the width of the outer passage portion may be different from each other. Here, width may refer to the length in the width direction of the electrode lead 100. In the passage portion 310 according to one embodiment of the present invention, the outer passage portion may have a wider width than the inner passage portion. This is merely an example, and the shape of the passage portion 310 may vary. For example, the width of the outer passage portion may be narrower than the inner passage portion, or the width of the inner passage portion and the width of the outer passage portion may be substantially the same.

[0051] The passage portion 310 may be formed in all of the passage portions 310 on both sides based on the electrode lead 100 or may be formed in only one side passage portion 310, but in one embodiment of the present invention, the passage portion 310 will be described as being formed on one side based on the electrode lead 100.

[0052] FIG. 3 is a part of a cross-sectional view schematically illustrating a cross section cut along A-A' in FIG. 2 with a gas transfer path formed in the passage portion 310, and FIG. 4 is a cross-sectional view schematically illustrating a cross section cut along B-B' in FIG. 2.

[0053] 3, this corresponds to a case where a gas transfer path is formed in the passage portion 310 by gas inside the pouch 200, and the passage portion 310 may serve as a passage through which the gas can move. Here, for example, after the internal gas moves to the outside through the transfer path of the passage portion 310, moisture may permeate from the outside to the inside of the pouch 200 through the passage portion 310 where the gas transfer path of the pouch cell 10 is formed. Such permeated moisture may cause a decrease in performance of the pouch cell 10. Therefore, as an example of a configuration for preventing moisture from permeating from the outside to the inside of the pouch 200, the pouch cell 10 according to one embodiment of the present invention may include a pressure member 400 that applies pressure to a part or all of the passage portion 310 to close the passage portion 310 when the pressure inside the pouch 200 drops below a predetermined pressure.

[0054] The pressurizing member 400 of the pouch cell 10 is disposed outside the pouch 200 and can apply pressure or force to the passage 310 so that the gas transfer path of the passage 310, which is in an open state after the internal gas is discharged, closes when the pressure inside the pouch 200 drops below a predetermined pressure. That is, the pressurizing member 400 can apply pressure or force to the passage 310 so that the gas transfer path of the passage 310 closes again when the pressure inside the pouch 200 drops below a set pressure after the internal gas is discharged.

[0055] 4, the pressure member 400 may be disposed on the outer surface of the pouch 200 at a position corresponding to the contact area between the pouch 200 and the lead film 300. That is, the pressure member 400 may apply pressure to a portion of the passage 310 in which the gas transfer path is formed (see FIG. 2). The pressure member 400 may be designed to prevent external moisture from penetrating into the pouch 200 even when only a portion of the pressure member 400 is closed, or to prevent external moisture from penetrating into the pouch 200 when the entire pouch is closed.

[0056] The pressure member 400 according to one embodiment of the present invention is disposed outside the pouch 200, and therefore does not interfere with the electrode lead 100. Therefore, it does not affect the stability of the pouch cell 10. In addition, since the pressure member 400 is a separate member disposed outside the pouch 200, it can be applied to pouch cells of various shapes. Therefore, the usability of the pressure member 400 can be improved.

[0057] Pressure member FIG. 5 is a perspective view that schematically illustrates a pressure member 400 of a pouch cell 10 according to one embodiment of the present invention.

[0058] The shape of the pressure member 400 according to one embodiment of the present invention will be described in detail below.

[0059] As an example of a configuration for efficiently applying force to the passage portion 310, the pressure member 400 of the pouch cell 10 according to one embodiment of the present invention may include a first member 410 and a second member 420. Referring to Figures 4 and 5, the first member 410 of the pressure member 400 is disposed on the outer surface of one side of the pouch 200 relative to the electrode lead 100 and can apply pressure to the passage portion 310 in a direction from the outer surface of the pouch 200 toward the electrode lead 100, and the second member 420 is disposed on the outer surface of the other side of the pouch 200 relative to the electrode lead 100 and can apply pressure to the passage portion 310 in a direction from the outer surface of the pouch 200 toward the electrode lead 100. Thus, the pressure member 400 can apply pressure to the passage portion 310 from both sides using the first member 410 and the second member 420.

[0060] Here, the pressing member 400 may further include a connecting member 430 to connect the first member 410 and the second member 420 to each other. The connecting member 430 may connect the first member 410 and the second member 420 to each other. Specifically, the connecting member 430 may include a first connecting portion 431 connected to one end of the first member 410 and one end of the second member 420, respectively, and a second connecting portion 432 connected to the other end of the first member 410 and the other end of the second member 420, respectively. That is, the first connecting portion 431 and the second connecting portion 432 may be connected to both ends of the first member 410 and the second member 420, respectively. Here, the one end and the other end of the first member 410 may refer to both ends of the first member 410 based on the longitudinal direction. Similarly, the one end and the other end of the second member 420 may refer to both ends of the second member 420 based on the longitudinal direction.

[0061] Meanwhile, the connecting member 430 can provide a force that presses the passage portion 310 to the first member 410 and the second member 420. Specifically, the connecting member 430 can include elastic portions 4311 and 4321 that provide an elastic restoring force so that the first member 410 and the second member 420 press the passage portion 310. The elastic portions 4311 and 4321 generate an inward force due to the elasticity of their material, and this is the force that causes the first member 410 and the second member 420 to press the passage portion 310. Although the elastic portions 4311 and 4321 are illustrated as having one shape, they are not limited thereto and can have various shapes as long as they are able to provide an elastic restoring force (inward) to the first member 410 and the second member 420.

[0062] As an example of a form for applying force to the first member 410 and the second member 420, the elastic members 4311 and 4321 according to an embodiment of the present invention may have a curved shape. Specifically, the elastic members 4311 and 4321 may have a curved shape so that an elastic restoring force (directed inward) can be generated when the shape is changed. Because the elastic members 4311 and 4321 have a curved shape, they can be easily installed on the outside of the pouch 200, and interference with the pouch 200 can be relatively reduced.

[0063] On the other hand, if the elastic restoring force provided by the elastic portions 4311 and 4321 is too strong, a problem may occur in which the gas inside the pouch 200 does not form a gas transfer path in the passage portion 310. Therefore, the elastic portions 4311 and 4321 are configured to have an appropriate elastic restoring force, and may be formed so that the elastic restoring force is not too strong, for example, taking into consideration the magnitude of the internal gas pressure. At the same time, the elastic portions 4311 and 4321 must be able to provide a force sufficient to close the gas transfer path in the passage portion 310 after the gas inside the pouch 200 has been sufficiently discharged. To this end, the force of the elastic portions 4311 and 4321 can be adjusted depending on the material constituting the elastic portions 4311 and 4321, the shape of the elastic portions 4311 and 4321, etc.

[0064] The connecting member 430 may include first extensions 4312 and 4322 that connect the elastic portions 4311 and 4321 to the first member 410, and second extensions 4313 and 4323 that connect the elastic portions 4311 and 4321 to the second member 420. Referring to Fig. 5, the first extensions 4312 and 4322 may be arranged such that the distance between them and the second extensions 4313 and 4323 increases as they are spaced apart from the elastic portions 4311 and 4321, so that the first member 410 and the second member 420 can efficiently pressurize the passage portion 310 due to the elastic restoring force provided by the elastic portions 4311 and 4321. When the first extensions 4312, 4322 and the second extensions 4313, 4323 are arranged in a manner such that the further they are from the elastic portions 4311, 4321, the closer they are to each other, the more the pressure member 400 can be applied to pouch cells 10 of various thicknesses.

[0065] The first member 410 and the second member 420 of the pressure applying member 400 according to one embodiment of the present invention may include protective members 412 and 422, respectively, as an example of a configuration for preventing damage to the pouch 200. Furthermore, the first member 410 and the second member 420 may include fixing members 411 and 421, respectively, for fixing the protective members 412 and 422.

[0066] According to one embodiment, the protective members 412, 422 of the first member 410 and the second member 420 are deformable to absorb impact and can be arranged to contact the pouch 200. In addition, the fixing members 411, 421 of the first member 410 and the second member 420 can be arranged on the opposite side of the pouch 200 with respect to the protective members 412, 422 so as to fix the protective members 412, 422. Therefore, the first member 410 and the second member 420 can each be made up of two layers.

[0067] Meanwhile, as an example of a configuration for absorbing shock, the protective members 412 and 422 may include a rubber material so that they can deform in shape, but this is just one example, and the protective members 412 and 422 may include other materials for absorbing shock.

[0068] The pressure member 400 can prevent the exterior of the pouch 200 from being damaged by the protective members 412 and 422.

[0069] 6 is a perspective view schematically illustrating a pressure member 400' of a pouch cell according to another embodiment of the present invention. The pressure member 400' is similar to the pressure member 400 according to the embodiment of the present invention, and the numbers and descriptions of components related to similar configurations of the pressure member 400' are the same as those of the pressure member 400.

[0070] Therefore, in the following, detailed description of the same configuration as the pressure member 400 according to one embodiment of the present invention will be omitted.

[0071] To reduce the possibility of interference between the pressure member 400′ according to the embodiment and the pouch 200, the connecting member 430′ of the pressure member 400′ according to another embodiment of the present invention may be connected to only one end of the first member 410′ and the second member 420′. That is, the connecting member 430′ may be connected to one end of the first member 410′ and one end of the second member 420′, respectively.

[0072] In the case of a pressure member 400′ according to another embodiment of the present invention, the connecting member 430′ is connected to only one side of the first member 410′ and the second member 420′, which can reduce the space occupied by the connecting member 430′ and can also reduce the possibility of interference between the connecting member 430′ and the electrode lead 100 or the pouch 200.

[0073] As an example of a form for providing force to the first member 410′ and the second member 420′, the elastic member 4301 according to another embodiment of the present invention may have a coiled shape like a spring. Specifically, the elastic member 4301 may have a repeatedly coiled shape so that it can generate an elastic restoring force (a force that deflects the coil) when its shape changes. In addition, the first extension member 4302 may be disposed in a form in which the distance between it and the second extension member 4303 increases as it moves away from the elastic member 4301, so that the first member 410′ and the second member 420′ are efficiently compressed by the elastic restoring force provided by the elastic member 4301.

[0074] As an example of a configuration for preventing damage to the pouch 200, the first member 410' of the pressing member 400' according to another embodiment of the present invention may include a protective member 412'. Here, the second member 420' may not include a protective member. That is, the passage 310 according to another embodiment of the present invention may be formed only on one side where the first member 410' is located, based on the electrode lead 100. Therefore, only the first member 410', which is located in a portion where the passage 310 is formed and is relatively likely to be damaged, may include the protective member 412'.

[0075] Furthermore, according to another embodiment of the present invention, the protective member 412' of the first member 410' may have a cross-sectional area smaller than that of the fixing member 411. Specifically, the protective member 412' of the first member 410' may be disposed only at a position corresponding to the passage 310. More specifically, the protective member 412' may be disposed only at a position corresponding to the inner passage described in the embodiment of the present invention. As described above, the position corresponding to the passage 310 in the pouch 200 may be a portion where the passage 310 is formed and is therefore relatively likely to be damaged. Therefore, the protective member 412' of the first member 410' may be disposed only at a position corresponding to the passage 310. In this regard, when the lead film 300 includes a plurality of passages 310 spaced apart from one another, the protective members 412' may also be disposed at a plurality of positions.

[0076] In the pressure member 400' according to another embodiment of the present invention, only the first member 410' includes the protection member 412' disposed at a position corresponding to the position of the passage portion 310, thereby improving manufacturing economy.

[0077] Battery module 7 is an exploded perspective view schematically illustrating a battery module according to one embodiment of the present invention. The numbers and descriptions of components having configurations similar to those of the pouch cell 10 of FIG. 1 are the same as those of the pouch cell 10 described in detail above.

[0078] Therefore, in the following, detailed description of the same configuration as the pouch cell 10 according to one embodiment of the present invention will be omitted.

[0079] When more electrical energy is required, such as in an automobile, the electrical energy provided by a single pouch cell may be insufficient. In this case, a battery module including multiple pouch cells can be used to provide a larger amount of electrical energy. A battery pack including multiple battery modules can also be used to provide a larger amount of electrical energy.

[0080] 7, a battery module according to one embodiment of the present invention may include a cell stack 1 and a frame 2. The cell stack 1 may include a plurality of pouch cells 10, and the cell stack 1 may be housed in the frame 2.

[0081] Specifically, the cell stack 1 may be formed by stacking a plurality of pouch cells 10 in parallel. The frame 2 may have a U-shaped cross section and may be made up of a bottom plate and side plates connected to both sides of the bottom plate to form a space for accommodating the cell stack 1. The shape of the frame 2 in this embodiment is merely an example, and the frame may have other shapes.

[0082] The pouch cell 10 of the cell stack 1 can include an electrode lead 100 , a pouch 200 , a lead film 300 and a pressure member 400 , and the pressure member 400 can be disposed outside the pouch 200 .

[0083] Meanwhile, a structure for fixing the pressing member 400 may be necessary for the stability of the pressing member 400 when the cell stack 1 is housed inside the frame 2. As an example of a structure for fixing the pressing member 400, the frame 2 of the battery module according to an embodiment of the present invention may include a fixing rod 20.

[0084] The fixed rod 20 is disposed at one end in the longitudinal direction of the cell stack 1, and may have a shape extending in the stacking direction of the pouch cells 10. In addition, both ends in the longitudinal direction of the fixed rod 20 may be connected to the side panels of the frame 2, respectively.

[0085] As described above, the pressure applying member 400 may include a first member 410, a second member 420, and a connecting member 430 connecting the first member 410 and the second member 420. Referring to Fig. 7, when a plurality of pouch cells 10 are disposed inside the frame 2, the connecting members 430 of the pressure applying member 400 may be disposed on both sides of the electrode lead 100. Here, one of the connecting members 430 disposed on both sides of the electrode lead 100 may be connected to the fixing rod 20. Here, various methods for connecting the fixing rod 20 and the connecting member 430 may be used, such as forming a structure in which the connecting member 430 is fitted into the fixing rod 20.

[0086] When the pressure member 400 is connected to the fixed rod 20, the pressure member 400 is fixed to the frame 2, and therefore the passage portion 310 can be stably closed in the battery module.

[0087] Meanwhile, the frame 2 may include two fixing rods 20. When the frame 2 includes two fixing rods 20, the connecting members 430 disposed on both sides of the electrode lead 100 can be connected to the fixing rods 20. In this case, the pressing member 400 can be fixed to the frame 2 more stably.

[0088] In battery modules according to other embodiments of the present invention, the position at which the pressing member 400 is fixed (attached) may differ. In this regard, the battery module may further include bus bar assemblies 3. The bus bar assemblies 3 are arranged at both ends of the cell stack 1 in the longitudinal direction so as to cover the opening of the frame 2, and may electrically connect the pouch cells 10 to each other. The pressing member 400 may be fixed to one of the bus bar assemblies 3 arranged at both ends of the cell stack 1 in the longitudinal direction. The manner in which the pressing member 400 is fixed to the bus bar assembly 3 may vary.

[0089] Meanwhile, the frame 2 of the battery module may include the pressing member 400. In this case, the pouch cells of the cell stack 1 may not include the pressing member. Specifically, after the cell stack 1 is placed inside the frame 2 during the manufacturing process of the battery module, each pouch cell may be connected to the pressing member 400 of the frame 2.

[0090] If the frame 2 includes the pressing member 400, the pressing member 400 can be connected to the pouch cells after the cell stack 1 including the pouch cells without the pressing member 400 is housed in the frame 2. Therefore, the pressing member 400 can be connected to the pouch cells more stably during the manufacturing process of the battery module.

[0091] Like the frame 2, the bus bar assembly 3 may also include a pressure member 400. In this case, after the cell stack 1 is placed on the frame 2, when the bus bar assembly 3 is placed, the pressure member 400 and the pouch cell can be connected.

[0092] Referring to FIG. 7, the battery module may further include an end plate that is disposed on the opposite side of the cell stack 1 relative to the busbar assembly 3 to protect the cell stack 1, and a top plate that is disposed on the top surface of the cell stack 1 and is coupled to the frame 2.

[0093] The present invention has been described above using limited embodiments and drawings, but the present invention is not limited thereto, and various implementations are possible within the technical spirit of the present invention and the scope of the claims set forth below by a person having ordinary skill in the art to which the present invention pertains. [Explanation of symbols]

[0094] 1 Cell stack 2 frames 3 Busbar Assembly 10 pouch cells 20 Fixed rod 100 electrode leads 200 pouches 300 Lead Film 310 Passage section 400, 400' pressure member 410, 410' First member 411, 421 Fixing member 412, 412', 422 Protective members 420, 420' Second member 430, 430' connecting member 431 1st connection part 432 2nd connection part 4301, 4311, 4321 Elastic part 4302, 4312, 4322 1st extension 4303, 4313, 4323 2nd extension

Claims

1. an electrode lead electrically connected to the electrode assembly housed inside the pouch and protruding outside the pouch; a lead film that covers a portion of the electrode lead so as to insulate the electrode lead from the pouch, and that includes a passage portion that forms a gas transfer path when the internal pressure of the pouch rises above a set pressure; a pressure member disposed outside the pouch and pressurizing the passage portion so as to close a gas transfer path in the passage portion.

2. The pressure member is a first member disposed on an outer surface of one side of the pouch with respect to the electrode lead, and pressurizing the passage portion in a direction toward the electrode lead; The pouch cell according to claim 1 , further comprising: a second member disposed on the outer surface of the pouch on the other side relative to the electrode lead, the second member applying pressure to the passage in a direction toward the electrode lead.

3. The pouch cell according to claim 2 , wherein the pressure member further includes connecting members connected to the first member and the second member, respectively, to provide the first member and the second member with a force to press the passage portion.

4. The pouch cell according to claim 3 , wherein the connecting member is connected to one end of the first member and one end of the second member, respectively.

5. The connecting member is a first connecting portion connected to one end of the first member and one end of the second member, The pouch cell according to claim 3 , further comprising: second connecting portions connected to the other end of the first member and the other end of the second member, respectively.

6. The connecting member is an elastic portion that provides an elastic restoring force so that the first member and the second member pressurize the passage portion; a first extension portion connecting the first member to the elastic portion; The pouch cell according to claim 3 , further comprising a second extension portion connecting the second member to the elastic portion.

7. the elastic portion has a bent shape so as to generate an elastic restoring force when the shape of the elastic portion changes; The pouch cell according to claim 6 , wherein the distance between the first extension portion and the second extension portion decreases as the first extension portion moves away from the elastic portion.

8. The pouch cell according to claim 6 , wherein the elastic portion has a spring-like wound shape so as to generate an elastic restoring force when the shape of the elastic portion changes.

9. The first member and the second member are A protective member that can be deformed to absorb impact and is arranged to contact the pouch; The pouch cell according to claim 2 , further comprising a fixing member disposed on the opposite side of the pouch relative to the protective member so as to fix the protective member.

10. The pouch cell according to claim 9 , wherein the protective member includes rubber so as to be deformable, and is disposed at a position corresponding to a position of the passage portion.

11. A pressure-generating member is disposed outside a pouch of a pouch cell, pressurizing a passage formed when the internal pressure of the pouch rises above a set pressure, and closing a gas transfer path of the passage when the internal pressure of the pouch falls below the set pressure, a first member that is disposed so as to come into contact with the pouch and pressurizes the passage portion; a second member that is disposed on the opposite side of the first member with respect to the pouch so as to come into contact with the pouch and pressurize the passage portion; a pressure member connected to the first member and the second member, respectively, and providing the first member and the second member with a force that presses the passage portion.

12. a cell stack including a plurality of pouch cells; a frame in which the cell stack is housed, The pouch cell comprises: an electrode lead electrically connected to the electrode assembly housed inside the pouch and protruding outside the pouch; a lead film that covers a portion of the electrode lead so as to insulate the electrode lead from the pouch, and that includes a passage portion that forms a gas transfer path when the internal pressure of the pouch rises above a set pressure; a pressurizing member disposed outside the pouch and pressurizing the passage portion so as to close a gas transfer path in the passage portion; a battery module including:

13. the frame is disposed at one end of the cell stack in the longitudinal direction and includes a fixing rod extending in the stacking direction of the pouch cells; The battery module according to claim 12 , wherein the pressing member is fixedly connected to the fixed rod.

14. a bus bar assembly disposed at one end of the cell stack in a longitudinal direction so as to close the opening of the frame and electrically connect the pouch cells to each other; The battery module according to claim 12 , wherein the pressure member is fixedly coupled to the bus bar assembly.

15. A pouch cell for a lithium secondary battery, an electrode lead electrically connected to the electrode assembly of the lithium secondary battery housed inside the pouch and protruding outside the pouch; a lead film that covers a portion of the electrode lead so as to insulate the electrode lead from the pouch, and that includes a passage portion that forms a gas transfer path when the internal pressure of the pouch rises above a set pressure; a pressure member disposed outside the pouch and pressurizing the passage portion so as to close a gas transfer path in the passage portion.

16. 16. The pouch cell for a lithium secondary battery according to claim 15, wherein the pressure member is designed to close the gas transfer path of the passage portion when the internal pressure of the pouch drops below a set pressure.

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