Pressing member and pouch cell including the same

Abstract

The present invention relates to a pouch cell capable of preventing or reducing the penetration of moisture, etc., from outside the pouch into the pouch through a passage through which gas inside the pouch is discharged to the outside. A pouch cell according to the present invention may include an electrode lead electrically connected to an electrode assembly housed inside a 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 in which a gas passage is formed when the internal pressure of the pouch rises above a set pressure, and a pressurizing member disposed outside the pouch and providing force to the passage portion so as to close the passage portion.

Description

Technology Field

[0001] The present invention relates to a pressurizing member and a pouch cell including the same, and more specifically, to a pressurizing member that pressurizes a passage portion of a pouch cell capable of charging and discharging, and a pouch cell including the same. Background Technology

[0002] Recently, with rising energy prices due to the depletion of fossil fuels and growing concern over environmental pollution, the demand for eco-friendly alternative energy sources has become an indispensable factor for future life. Accordingly, research on various power generation technologies, such as solar, wind, and tidal power, is ongoing, and there is also significant interest in power storage devices, such as batteries, to utilize this generated electrical energy more efficiently.

[0003] Furthermore, as technological development and demand for battery-powered electronic mobile devices and electric vehicles increase, the demand for batteries as an energy source is rapidly rising, and accordingly, much research is being conducted on batteries capable of meeting various requirements.

[0004] Batteries that store electrical energy can generally be classified into primary and secondary batteries. Primary batteries are disposable, consumable batteries, whereas secondary batteries are rechargeable batteries manufactured using materials capable of repeating oxidation and reduction processes between the electric current and the material. In other words, when a reduction reaction is performed on the material by the electric current, the power is charged, and when an oxidation reaction is performed, the power is discharged; electricity is generated as this charging and discharging cycle is repeatedly performed.

[0005] Secondary batteries can be classified into cylindrical cells, pouch cells, prismatic cells, etc., depending on their shape. Among these, pouch cells may include an electrode assembly in which a positive electrode, a negative electrode, a separator, etc., are stacked inside a pouch.

[0006] Meanwhile, gas may be generated inside the pouch as charging and discharging cycles are repeated. If the gas generated inside the pouch is not efficiently discharged, venting may occur due to an increase in internal pressure. Therefore, the pouch cell may require a configuration to release internal pressure to the outside.

[0007] In this regard, if the pouch cell includes a configuration for gas release, moisture may penetrate into the pouch through the gas release portion. Such moisture penetration may lead to additional problems, such as performance degradation of the pouch cell.

[0008] Therefore, there is a need for a pouch cell that can prevent or reduce the penetration of moisture from the outside into the pouch through the part where gas inside the pouch is released to the outside. The problem to be solved

[0009] The objective of the present invention is to provide a pouch cell capable of preventing or reducing the penetration of moisture, etc., from outside the pouch into the pouch through a passage through which gas inside the pouch is discharged to the outside. means of solving the problem

[0010] A pouch cell according to the present invention may include an electrode lead electrically connected to an electrode assembly housed inside a 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 passage portion in which a gas passage is formed when the internal pressure of the pouch rises above a set pressure; and a pressurizing member disposed outside the pouch and providing force to the passage portion to close the gas passage of the passage portion.

[0011] The above-mentioned pressurizing member may include a first member disposed on the outer surface of the pouch on one side relative to the electrode lead and pressurizing the passage portion in a direction toward the electrode lead, and a second member disposed on the outer surface of the pouch on the other side relative to the electrode lead and pressurizing the passage portion in a direction toward the electrode lead.

[0012] The above-mentioned pressurizing member may further include a connecting member that is connected to the first member and the second member, respectively, and provides a force to pressurize the passage portion to the first member and the second member.

[0013] The above connecting member can be connected to one end of the first member and one end of the second member, respectively.

[0014] The above connecting member may include a first connecting part connected to one end of the first member and one end of the second member, respectively, and a second connecting part connected to the other end of the first member and the other end of the second member, respectively.

[0015] The above connecting member may include an elastic member that provides an elastic restoring force to cause the first member and the second member to press the passage portion, a first extension member connecting the first member to the elastic member, and a second extension member connecting the second member to the elastic member.

[0016] The above elastic part has a curved shape such that elastic restoring force is generated when the shape changes, and the first extension part can be closer to the second extension part as it moves further away from the elastic part.

[0017] The above elastic part may have a shape wound like a spring so that elastic restoring force is generated when the shape changes.

[0018] The first and second members may further include a protective member positioned to contact the pouch and capable of deforming their shape to absorb shock, and a fixing member positioned on the opposite side of the pouch relative to the protective member to fix the protective member.

[0019] The above protective member may include rubber to allow for shape deformation and may be positioned at a location corresponding to the position of the passage portion.

[0020] A pressurizing member according to the present invention is disposed outside the pouch of a pouch cell and provides force to a passage portion so that a gas passage formed by the internal pressure of the pouch rises above a set pressure, and comprises a first member disposed to contact the pouch and pressurizing the passage portion, a second member disposed to contact the pouch on the opposite side of the first member relative to the pouch and pressurizing the passage portion, and a connecting member connected to the first member and the second member respectively and providing force to pressurize the passage portion to the first member and the second member, wherein the connecting member may include an elastic portion providing elastic restoring force to cause the first member and the second member to pressurize the passage portion; a first extension portion connecting the first member to the elastic portion; and a second extension portion connecting the second member to the elastic portion.

[0021] A battery module according to the present invention comprises a cell stack including a plurality of pouch cells and a frame in which the cell stack is accommodated, wherein the pouch cell comprises an electrode lead that is electrically connected to an electrode assembly accommodated inside the pouch and protrudes 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 passage portion in which a gas passage is formed when the internal pressure of the pouch rises above a set pressure, and a pressurizing member disposed outside the pouch and providing force to the passage portion to close the gas passage of the passage portion, wherein the pressurizing member comprises: a first member disposed on the outer surface of the pouch on one side relative to the electrode lead and pressurizing the passage portion in a direction toward the electrode lead; and a second member disposed on the outer surface of the pouch on the other side relative to the electrode lead and pressurizing the passage portion in a direction toward the electrode lead. The apparatus includes a connecting member that is connected to each of the first member and the second member and provides a force to press the passage portion to the first member and the second member, wherein the connecting member may include an elastic portion that provides an elastic restoring force to cause the first member and the second member to press 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.

[0022] The above frame includes a fixing rod having a shape that is disposed at one end in the longitudinal direction of the cell stack and extends in the stacking direction of the pouch cell, and the pressing member can be connected to be fixed to the fixing rod.

[0023] The battery module further includes a busbar assembly that is positioned at one end in the longitudinal direction of the cell stack to block the opening of the frame and electrically connects the pouch cells to each other, and a plurality of the pressure members may be connected to be fixed to the busbar assembly. Effects of the invention

[0024] A pouch cell according to the present invention may include an electrode lead electrically connected to an electrode assembly housed inside a 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 in which a gas passage is formed when the internal pressure of the pouch rises above a set pressure, and a pressurizing member disposed outside the pouch and providing force to the passage portion so as to close the passage portion.

[0025] Accordingly, after the gas inside the pouch has been sufficiently released to the outside, it is possible to prevent moisture, etc. from entering the inside of the pouch through the passage.

[0026] Through this, the functional degradation of the pouch cell can be prevented.

[0027] At the same time, since the pressurizing member is positioned so as not to interfere with the electrode lead, it may not affect the stability of the pouch cell.

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

[0029] The effects according to the present invention are not limited to those exemplified above, and various other effects are included in this specification. Brief explanation of the drawing

[0030] FIG. 1 is a schematic perspective view illustrating a pouch cell according to one embodiment of the present invention. FIG. 2 is a schematic plan view illustrating a pouch cell according to one embodiment of the present invention. Figure 3 is a part of a cross-sectional view schematically illustrating a cross-section cut along A-A' of Figure 2. Figure 4 is a schematic cross-sectional view of a section cut along B-B' of Figure 2. FIG. 5 is a schematic perspective view illustrating a pressure member of a pouch cell according to one embodiment of the present invention. FIG. 6 is a schematic perspective view illustrating a pressure member of a pouch cell according to another embodiment of the present invention. FIG. 7 is an exploded perspective view schematically illustrating a battery module according to one embodiment of the present invention. Specific details for implementing the invention

[0031] Hereinafter, preferred embodiments of the present invention are described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be embodied in various different forms and is not limited or restricted by the following embodiments.

[0032] In order to clearly explain the present invention, detailed descriptions of related prior art that are irrelevant to the explanation or that may unnecessarily obscure the essence of the invention have been omitted. Furthermore, when assigning reference numerals to the components of each drawing in this specification, identical or similar reference numerals are assigned to identical or similar components throughout the entire specification.

[0033] Furthermore, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0034] Pouch Cell

[0035] FIG. 1 is a schematic perspective view illustrating a pouch cell (10) according to one embodiment of the present invention, and FIG. 2 is a schematic plan view illustrating a pouch cell (10) according to one embodiment of the present invention.

[0036] Referring to FIG. 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 inside, and the electrode lead (100) may be electrically connected to the electrode assembly accommodated inside the pouch (200) and protrude outside the pouch (200). Additionally, 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).

[0037] The pouches (200) of the pouch cell (10) are composed of a pair facing each other, capable of accommodating an electrode assembly between them, and the pair of pouches (200) accommodating the electrode assembly inside can be joined together through a sealing process. Here, the sealing process may refer to a process of sealing the facing pouches (200) together using heat and pressure, etc. Additionally, the electrode assembly may refer to a structure in which an anode, a cathode, and a separator are stacked or wound together.

[0038] Meanwhile, the pouch (200) may include a resin layer and a metal layer, and an example of a material constituting the metal layer is aluminum (Al). In addition, the pouch (200) can be bonded as the resin layers melt each other due to heat during the sealing process described above.

[0039] The electrode lead (100) of the pouch cell (10) may be composed of a conductor and may be arranged to extend from the inside to the outside of the pouch (200). Additionally, the electrode lead (100) may include a negative lead and a positive lead. In this case, the negative lead and the positive lead may be arranged on one side of the pouch (200) or on both sides of the pouch (200), respectively. According to one embodiment of the present invention, the electrode lead (100) of the pouch cell (10) may be arranged on both sides of the pouch (200), respectively.

[0040] The lead film (300) of the pouch cell (10) can be placed between the electrode lead (100) and the pouch (200) to insulate them from each other. Accordingly, the lead film (300) may contain an insulating material. Specifically, the lead film (300) may be placed to wrap around a portion of the electrode lead (100). At this time, the portion of the electrode lead (100) wrapped by the lead film (300) may include an overlapping portion between the electrode lead (100) and the pouch (200).

[0041] Meanwhile, as the pouch cell (10) undergoes repeated charging and discharging, gas may be generated inside the pouch (200). The gas generated inside the pouch (200) can cause swelling of the pouch and lead to an explosion of the pouch (200). Therefore, to ensure the stability of the pouch cell (10), a configuration capable of discharging gas from the inside of the pouch (200) to the outside is required. 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) as an example of a configuration for discharging gas to the outside.

[0042] The passage portion (310) of the lead film (300) can form a gas passage when the internal pressure of the pouch (200) rises above a set pressure. For example, the passage portion (310) may have a weaker adhesion to the electrode lead (100) compared to other parts. Therefore, as the adhesion between the electrode lead (100) and the passage portion (310) is released by the internal pressure, a gas passage can be formed in the passage portion (310).

[0043] Gas inside the pouch (200) can move through the gas passage of the passage section (310) and pass through the lead film (300) to be discharged to the outside of the pouch (200). At this time, the gas can move at the molecular level and pass through the lead film (300) by diffusion. That is, the lead film (300) may include a material with high gas permeability. Specifically, the lead film (300) may include at least one material among polyolefin series, fluorine series, and porous ceramic series. For example, the lead film (300) may include at least one material among polyolefin series, fluorine series, and porous ceramic series that satisfies the gas permeability value for gas discharge. More specifically, for example, the polyolefin series material may include one or more materials selected from the group consisting of polypropylene, polyethylene, and polyvinyldifluoride (PVDF). In addition, fluorine-based materials may include one or more materials selected from the group consisting of polytetrafluoroethylene and polyvinylidenefluoride.

[0044] Gas generated inside the pouch (200) can travel through the gas passage of the passage section (310) and then pass through the lid film (300) to be released to the outside of the pouch (200). Accordingly, the venting phenomenon in which the pouch (200) opens due to the gas increasing the pressure inside the pouch (200) can be delayed or prevented.

[0045] Although not described in detail in one embodiment of the present invention, an additional component may be disposed between the electrode lead (100) and the lead film (300) to efficiently form a gas passage in the passage portion (310). In this case, the adhesive force between the passage portion (310) and the additional component is formed relatively weakly, and when the internal pressure of the pouch (200) rises above a set pressure, the space between the passage portion (310) and the additional component expands, thereby forming a gas passage in the passage portion (310).

[0046] Referring to FIG. 2, the passage section (310) may be formed to extend from the part where the electrode lead (100) and the pouch (200) overlap to the part where they do not overlap. Hereinafter, for convenience of explanation, the part of the passage section (310) corresponding to the part where the electrode lead (100) and the pouch (200) overlap is referred to as the inner passage section, and the part of the passage section (310) corresponding to the part where the electrode lead (100) and the pouch (200) do not overlap is referred to as the outer passage section.

[0047] At this time, the width of the inner passage and the width of the outer passage may differ from each other. Here, the width may refer to the length in the width direction of the electrode lead (100). In one embodiment of the present invention, the outer passage may have a wider width than the inner passage. This is merely one example, and the shape of the passage (310) may vary.

[0048] The passage portion (310) may be formed on both sides or on one side based on the electrode lead (100), but the passage portion (310) according to one embodiment of the present invention is described as being formed on one side based on the electrode lead (100).

[0049] FIG. 3 is a part of a cross-sectional view schematically showing a cross-section cut along A-A' of FIG. 2 with a gas passage formed in the passage section, and FIG. 4 is a cross-sectional view schematically showing a cross-section cut along B-B' of FIG. 2.

[0050] Referring to FIG. 3, when a gas passage is formed in the passage section (310) due to gas inside the pouch (200), the passage section (310) can become a passage through which gas can move. At this time, moisture, etc. can penetrate from the outside of the pouch (200) into the inside of the pouch cell (10) through the passage section (310) in which the gas passage is formed. The moisture, etc. that penetrates in this way can cause a decrease in the performance of the pouch cell (10). Therefore, as an example of a configuration to prevent moisture, etc. from penetrating into the inside of the pouch (200), the pouch cell (10) according to one embodiment of the present invention may include a pressurizing member (400).

[0051] The pressurizing member (400) of the pouch cell (10) is positioned outside the pouch (200) and can provide force to the passage section (310) so that the gas passage of the passage section (310) is closed. That is, the pressurizing member (400) can provide force to the passage section (310) so that the gas passage of the passage section (310) is closed again.

[0052] Referring to FIG. 4, the pressurizing member (400) can be positioned on the outer surface of the pouch (200) at a location corresponding to the part where the pouch (200) and the lead film (300) come into contact with each other. That is, the pressurizing member (400) can pressurize a part of the passage (310) where a gas passage is formed (see FIG. 2). Even if only a part of the pressurizing member (400) is closed, external moisture, etc. can be prevented from penetrating into the interior of the pouch (200).

[0053] In one embodiment of the present invention, the pressurizing member (400) is positioned outside the pouch (200), so no interference occurs with the electrode lead (100). Therefore, it may not affect the stability of the pouch cell (10). In addition, since the pressurizing member (400) is a separate member positioned outside the pouch (200), it can be applied to various types of pouch cells. Therefore, the usability of the pressurizing member (400) can be improved.

[0054] pressurizing member

[0055] FIG. 5 is a schematic perspective view illustrating a pressure member (400) of a pouch cell (10) according to one embodiment of the present invention.

[0056] Hereinafter, the shape of a pressure member (400) according to one embodiment of the present invention will be described in detail.

[0057] 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 FIG. 5, the first member (410) of the pressure member (400) is positioned on the outer surface of the pouch (200) on one side relative to the electrode lead (100) and can apply pressure to the passage portion (310) in a direction toward the electrode lead (100), and the second member (420) is positioned on the outer surface of the pouch (200) on the other side relative to the electrode lead (100) and can apply pressure to the passage portion (310) in a direction toward the electrode lead (100). Accordingly, the pressure member (400) can apply pressure to the passage portion (310) from both sides.

[0058] At this time, to connect the first member (410) and the second member (420) to each other, the pressurizing member (400) may further include a connecting member (430). The connecting member (430) may be connected to the first member (410) and the second member (420), respectively. Specifically, the connecting member (430) may include a first connecting part (431) connected to one end of the first member (410) and one end of the second member (420), respectively, and a second connecting part (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 part (431) and the second connecting part (432) may be connected to both ends of the first member (410) and the second member (420), respectively. Here, the first end and the other end of the first member (410) may refer to both ends based on the longitudinal direction of the first member (410). Likewise, the first end and the other end of the second member (420) may also refer to both ends based on the longitudinal direction of the second member (420).

[0059] Meanwhile, the connecting member (430) can provide a force to press the passage portion (310) to the first member (410) and the second member (420). Specifically, the connecting member (430) may include an elastic portion (4311, 4321) that provides an elastic restoring force to cause the first member (410) and the second member (420) to press the passage portion (310). It is sufficient for the elastic portion (4311, 4321) to be able to provide an elastic restoring force to the first member (410) and the second member (420), and its shape may vary.

[0060] As an example of a shape for providing force to the first member (410) and the second member (420), the elastic member (4311, 4321) according to one embodiment of the present invention may have a curved shape. Specifically, the elastic member (4311, 4321) may have a curved shape so as to generate an elastic restoring force when its shape changes. Since the elastic member (4311, 4321) has a curved shape, it is easy to install it outside the pouch (200), and there may be less interference with the pouch (200).

[0061] Meanwhile, if the elastic restoring force provided by the elastic part (4311, 4321) is too strong, a problem may occur in which the gas passage of the passage part (310) is not formed by the gas inside the pouch (200). Therefore, the elastic part (4311, 4321) may be formed so that the elastic restoring force is not too strong. At the same time, it must be able to provide enough force to close the gas passage of the passage part (310) after the gas inside the pouch (200) has been sufficiently discharged. The force of the elastic part (4311, 4321) can be controlled through the material constituting the elastic part (4311, 4321), the shape of the elastic part (4311, 4321), etc.

[0062] The connecting member (430) may include a first extension member (4312, 4322) connecting the elastic member (4311, 4321) and the first member (410), and a second extension member (4313, 4323) connecting the elastic member (4311, 4321) and the second member (420). Referring to FIG. 5, the first extension member (4312, 4122) may be arranged such that the distance from the second extension member (4313, 4323) decreases as it moves further away from the elastic member (4311, 4321), so that the first member (410) and the second member (420) can be efficiently pressed by the elastic restoring force provided by the elastic member (4311, 4321). If the first extension part (4312, 4122) and the second extension part (4313, 4323) are arranged in a manner that they become closer to each other as they move further away from the elastic part (4311, 4321), the pressure member (400) can be applied to pouch cells (10) of various thicknesses.

[0063] As an example of a configuration to prevent damage to the pouch (200), the first member (410) and the second member (420) of the pressurizing member (400) according to one embodiment of the present invention may include protective members (412, 422). Additionally, the first member (410) and the second member (420) may include fixing members (411, 421) to fix the protective members (412, 422).

[0064] Specifically, the protective members (412, 422) of the first member (410) and the second member (420) can be deformed in shape to absorb shock and can be positioned to contact the pouch (200). Additionally, the fixing members (411, 421) of the first member (410) and the second member (420) can be positioned on the opposite side of the pouch (200) relative to the protective members (412, 422) to fix the protective members (412, 422). Accordingly, the first member (410) and the second member (420) can each be composed of two layers.

[0065] Meanwhile, as an example of a configuration for absorbing shock, the protective member (412, 422) may include rubber to allow for deformation of shape. This is merely one example, and the protective member (412, 422) may include other materials for absorbing shock.

[0066] The pressurizing member (400) can prevent the outside of the pouch (200) from being damaged through the protective member (412, 422).

[0067] FIG. 6 is a schematic perspective view illustrating a pressure member (400') of a pouch cell according to another embodiment of the present invention.

[0068] In the following, a detailed description of a configuration identical to that of a pressurizing member (400) according to one embodiment of the present invention is omitted.

[0069] To reduce the possibility of interference with the pouch (200), the connecting member (430') of the pressurizing member (400') according to another embodiment of the present invention may be connected only to 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.

[0070] Since the connecting member (430') is connected to only one side of the first member (410') and the second member (420'), the space occupied by the connecting member (430') can be relatively reduced. Additionally, the possibility of interference between the connecting member (430') and the electrode lead (100) or the pouch (200) can be reduced.

[0071] 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 wound shape like a spring. Specifically, the elastic member (4301) may have a repeatedly wound shape so as to generate an elastic restoring force when its shape changes. In addition, the first extension member (4302) may be arranged in such a way that the distance from the second extension member (4303) decreases as it moves further away from the elastic member (4301) so that the first member (410') and the second member (420') can be efficiently pressed by the elastic restoring force provided by the elastic member (4301).

[0072] As an example of a configuration to prevent damage to the pouch (200), the first member (410') of the pressurizing member (400') according to another embodiment of the present invention may include a protective member (412'). At this time, for manufacturing economics and efficiency, the second member (420') may not include a protective member. That is, the passage portion (310) according to another embodiment of the present invention may be formed only on one side where the first member (410') is positioned relative to the electrode lead (100). Accordingly, only the first member (410') positioned in the part where the passage portion (310) is formed and which is relatively likely to be damaged may include a protective member (412').

[0073] Additionally, 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 placed only at a position corresponding to the position of the passage portion (310). More specifically, it may be placed only at a position corresponding to the position of the inner passage portion described in one embodiment of the present invention. As previously described, the position corresponding to the position of the passage portion (310) in the pouch (200) may be a part where the passage portion (310) is formed and is relatively likely to be damaged. Therefore, the protective member (412') of the first member (410') may be placed only at a position corresponding to the position of the passage portion (310). In this regard, if the lead film (300) includes a plurality of passage portions (310) spaced apart from each other, the protective member (412') may also be placed at a plurality of positions.

[0074] In another embodiment of the present invention, the pressurizing member (400') includes a protective member (412') that is positioned at a location corresponding to the position of the passage portion (310) only for the first member (410'), so manufacturing economic efficiency can be improved.

[0075] battery module

[0076] FIG. 7 is an exploded perspective view schematically illustrating a battery module according to one embodiment of the present invention.

[0077] In the following, a detailed description of a configuration identical to that of a pouch cell (10) according to one embodiment of the present invention is omitted.

[0078] In cases where more electrical energy is required, such as in automobiles, the energy provided by a single pouch cell may be insufficient. In this case, a battery module containing multiple pouch cells can be used to provide a larger amount of electrical energy. Alternatively, a battery pack containing multiple battery modules can be used to provide an even greater amount of electrical energy.

[0079] Referring to FIG. 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 accommodated in the frame (2).

[0080] Specifically, the cell stack (1) may be formed by stacking a plurality of pouch cells (10) side by side. Additionally, the frame (2) may have a U-shaped cross-section and may be composed of a bottom plate and side plates connected to both sides of the bottom plate so as to form a space for accommodating the cell stack (1). The shape of the frame (2) is merely one example, and the frame may have other shapes.

[0081] The pouch cell (10) of the cell stack (1) may include an electrode lead (100), a pouch (200), a lead film (300), and a pressurizing member (400), and the pressurizing member (400) may be disposed on the outside of the pouch (200).

[0082] Meanwhile, in order to ensure the stability of the pressure member (400) while the cell stack (1) is accommodated inside the frame (2), a configuration for fixing the pressure member (400) may be required. As an example of a configuration for fixing the pressure member (400), the frame (2) of the battery module according to one embodiment of the present invention may include a fixing rod (20).

[0083] The fixing rod (20) is positioned at one end in the longitudinal direction of the cell stack (1) and may have a shape that extends in the stacking direction of the pouch cell (10). Additionally, both ends in the longitudinal direction of the fixing rod (20) may be connected to the side plates of the frame (2), respectively.

[0084] As previously described, the pressurizing 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, the connecting member (430) of the pressurizing member (400) may be positioned on both sides of the electrode lead (100) while a plurality of pouch cells (10) are placed inside the frame (2). At this time, one of the connecting members (430) positioned on both sides of the electrode lead (100) may be connected to a fixing rod (20). Here, the method of connecting the fixing rod (20) and the connecting member (430) may vary, such as by forming a structure in which the connecting member (430) can be fitted into the fixing rod (20).

[0085] When the pressure member (400) is connected to the fixed rod (20), the pressure member (400) is fixed to the frame (2), so the effect of stably closing the passage section (310) can be achieved even in the battery module.

[0086] Meanwhile, the frame (2) may include two fixed rods (20). If the frame (2) includes two fixed rods (20), both connecting members (430) positioned on both sides of the electrode lead (100) can be connected to the fixed rods (20). In this case, the pressing member (400) can be more stably fixed to the frame (2).

[0087] In a battery module according to another embodiment of the present invention, the position where the pressurizing member (400) is fixed may be different.

[0088] In this regard, the battery module may further include a busbar assembly (3). The busbar assembly (3) is positioned at both longitudinal ends of the cell stack (1) to block the opening of the frame (2) and can electrically connect the pouch cells (10) to each other. A pressure member (400) may be fixed to one of the busbar assemblies (3) positioned at both longitudinal ends of the cell stack (1). The manner in which the pressure member (400) is fixed to the busbar assembly (3) may vary.

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

[0090] If the frame (2) includes a pressure member (400), the pressure member (400) and the pouch cell can be connected after the cell stack (1) including the pouch cell without the pressure member (400) is received in the frame (2). Accordingly, the pressure member (400) can be connected to the pouch cell more stably during the manufacturing process of the battery module.

[0091] Similar to the frame (2), the busbar assembly (3) may include a pressure member (400). In this case, when the busbar assembly (3) is placed after the cell stack (1) is placed on the frame (2), 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 protects the cell stack (1) by being positioned on the opposite side of the cell stack (1) with respect to the busbar assembly (3), and a top plate that is positioned on the upper surface of the cell stack (1) and coupled with the frame (2).

[0093] Although the present invention has been described above by limited embodiments and drawings, the present invention is not limited thereto, and various implementations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs. Explanation of the symbols

[0094] 1: Cell stack 2: Frame 3: Busbar Assembly 10: Pouch Cell 20: Fixed rod 100: Electrode lead 200: Pouch 300: Lead film 310: Passage section 400, 400': Pressurizing member 410, 410': First part 411, 421: Fixed members 412, 412', 422: Absence of protection 420, 420': Second absence 430, 430': Connecting member 431: First connection 432: Second connection 4301, 4311, 4321: Elastic part 4302, 4312, 4322: 1st extension 4303, 4313, 4323: Second extension

Claims

Claim 1 Electrode leads electrically connected to an electrode assembly contained within 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, and including a passage portion in which a gas passage is formed when the internal pressure of the pouch rises above a set pressure; and a pressurizing member disposed outside the pouch and providing force to the passage portion to close the gas passage of the passage portion, wherein the pressurizing member comprises: a first member disposed on the outer surface of the pouch on one side relative to the electrode lead and pressurizing the passage portion in a direction toward the electrode lead; a second member disposed on the outer surface of the pouch on the other side relative to the electrode lead and pressurizing the passage portion in a direction toward the electrode lead; and a connecting member connected to the first member and the second member respectively and providing a force to pressurize the passage portion to the first member and the second member, wherein the connecting member comprises: an elastic portion providing an elastic restoring force to cause the first member and the second member to pressurize the passage portion; and a first extension portion connecting the first member to the elastic portion. A pouch cell comprising a second extension portion connecting the second member to the elastic portion. Claim 2 delete Claim 3 delete Claim 4 In claim 1, the connecting member is a pouch cell, each connected to one end of the first member and one end of the second member, respectively. Claim 5 A pouch cell according to claim 1, wherein the connecting member comprises: 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. Claim 6 delete Claim 7 In claim 1, the elastic part has a curved shape such that elastic restoring force is generated when the shape changes, and the first extension part becomes closer to the second extension part as it moves away from the elastic part, a pouch cell. Claim 8 In claim 1, the elastic part is a pouch cell having a shape wound like a spring so that elastic restoring force is generated when the shape changes. Claim 9 A pouch cell according to claim 1, wherein the first member and the second member further comprise: a protective member that is capable of deforming its shape to absorb shock and is positioned to contact the pouch; and a fixing member positioned on the opposite side of the pouch relative to the protective member to fix the protective member. Claim 10 In claim 9, the protective member comprises rubber to enable deformation of shape and is a pouch cell disposed at a position corresponding to the position of the passage portion. Claim 11 A pressurizing member disposed outside the pouch of a pouch cell and providing force to a passage portion to close a gas passage formed when the internal pressure of the pouch rises above a set pressure, comprising: a first member disposed to contact the pouch and pressurizing the passage portion; a second member disposed to contact the pouch on the opposite side of the first member relative to the pouch and pressurizing the passage portion; and a connecting member connected to the first member and the second member, respectively, and providing a force to pressurize the passage portion to the first member and the second member, wherein the connecting member comprises: an elastic portion providing an elastic restoring force to cause the first member and the second member to pressurize the passage portion; a first extension portion connecting the first member to the elastic portion; and a second extension portion connecting the second member to the elastic portion. Claim 12 A cell stack comprising a plurality of pouch cells; and a frame in which the cell stack is accommodated, wherein the pouch cells include: an electrode lead that is electrically connected to an electrode assembly accommodated inside the pouch and protrudes 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 passage portion in which a gas passage is formed when the internal pressure of the pouch rises above a set pressure; and a pressure member disposed outside the pouch and providing force to the passage portion to close the gas passage of the passage portion, wherein the pressure member comprises: a first member disposed on the outer surface of the pouch on one side relative to the electrode lead and pressurizing the passage portion in a direction toward the electrode lead; and a second member disposed on the outer surface of the pouch on the other side relative to the electrode lead and pressurizing the passage portion in a direction toward the electrode lead. A battery module comprising a connecting member that is respectively connected to the first member and the second member and provides a force to press the passage portion to the first member and the second member, wherein the connecting member comprises: an elastic portion that provides an elastic restoring force to cause the first member and the second member to press 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. Claim 13 In claim 12, the frame comprises a fixed rod having a shape that is disposed at one end in the longitudinal direction of the cell stack and extends in the stacking direction of the pouch cell, and the pressing member is connected to be fixed to the fixed rod, forming a battery module. Claim 14 A battery module according to claim 12, further comprising a busbar assembly disposed at one end in the longitudinal direction of the cell stack to block the opening of the frame and electrically connecting the pouch cells to each other, wherein a plurality of the pressurizing members are connected to be fixed to the busbar assembly.

Images