Battery module with improved vent structure

Abstract

The present invention provides a battery module structure that includes a battery cell stack formed by stacking a plurality of pouch-shaped battery cells and metal plates in the width direction, a U-frame that is open at the top, front, and rear and that houses the battery cell stack, a pair of end plates that cover the front and rear of the U-frame, and a top plate that covers the top of the U-frame, in which vent paths are improved to prevent heat propagation.

Description

Technical Field

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0182327 filed on December 22, 2022, and all the contents disclosed in the document of the Korean Patent Application are included as part of this specification.

[0002] The present invention relates to a structure of a battery module that houses a plurality of pouch-type battery cells, and improves thermal runaway delay and vent performance.

Background Art

[0003] Secondary batteries, which are highly applicable to a wide range of products and have electrical characteristics such as high energy density, are generally applied not only to portable devices but also to electric vehicles or hybrid vehicles driven by an electric drive source, power storage devices, and the like. These secondary batteries not only have the primary advantage of significantly reducing the use of fossil fuels, but also attract attention as a new energy source because they are environmentally friendly in that they do not generate any by-products from the use of energy and improve energy efficiency.

[0004] One or two or three battery cells are used per device for small mobile devices, while medium- to large-sized devices such as automobiles require a high output and large capacity. Therefore, medium- to large-sized battery modules in which a large number of battery cells are electrically connected are used.

[0005] Medium- to large-sized battery modules are preferably manufactured with a small size and weight if possible, and thus, prismatic batteries, pouch-type batteries, etc., which can be stacked with a high degree of integration and have a small weight-to-capacity ratio, are mainly used as battery cells for medium- to large-sized battery modules.

[0006] Figures 1 and 2 show the structure of a pouch-type battery cell and how venting occurs in the battery cell, respectively. Referring to these drawings, the pouch-type battery cell 11 consists of an electrode assembly and a metal pouch that surrounds and seals it. The pouch is sealed by fusion at first sealing portions 111 provided at both ends in the longitudinal direction and a second sealing portion 112 provided at one end in the height direction. Electrode leads 113 extend from the electrode assembly and protrude to the outside of the pouch through the first sealing portion 111.

[0007] Figures 3 and 4 are exploded perspective and perspective views, respectively, showing the structure of a typical battery module. Referring to these drawings, the battery module consists of a battery cell stack 1 in which a plurality of the battery cells 11 are stacked, busbar frames 2 connected to both ends of the battery cell stack 1 in the longitudinal direction, and a housing 3 that houses the battery cell stack 1. The housing 3 consists of a U-frame 31 that is open at the top, front, and rear, a pair of end plates 32 that cover the front and rear of the U-frame 31, respectively, and a top plate 33 that covers the top of the U-frame. The U-frame 31, the end plates 32, and the top plate 33 can be assembled by welding them together.

[0008] The battery cell 11 may ignite due to short circuit, impact, overheating, etc. In this case, a large amount of gas and thermal energy may be discharged from the battery cell 11. If this gas and thermal energy is propagated to other adjacent battery cells in the battery module, thermal runaway may occur, causing a chain reaction of ignition between the battery cells. The gas and thermal energy can be discharged through both sides in the longitudinal direction and one end in the height direction of the battery cell 11, where the first seal portion 111 and the second seal portion 112 are provided.

[0009] Multiple battery modules can be combined to form a battery pack. In this case, the gas and thermal energy generated from one battery module can propagate to adjacent battery modules. Alternatively, the gas and thermal energy generated in adjacent battery modules can propagate to the aforementioned battery module. In this case, thermal runaway may occur at the battery pack level. [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] The present invention was conceived against the background of the prior art described above, and aims to provide a battery module structure that prevents heat transfer between battery cells housed in a battery module, and also prevents heat transfer between battery modules housed in a battery pack.

[0011] The present invention also aims to provide a battery module structure that allows high-temperature gases and thermal energy generated when a battery cell ignites to be quickly discharged in the intended direction.

[0012] Another technical problem addressed by the present invention is to provide a battery module structure that prevents the discharged high-temperature gas and thermal energy from re-entering.

[0013] The technical problems of the present invention are not limited to the purposes mentioned above. Other purposes and advantages of the present invention not mentioned can be understood from the following description and will be more clearly understood from the embodiments of the present invention. Furthermore, it will be readily understood that the purposes and advantages of the present invention can be achieved by the means and combinations thereof described in the claims. [Means for solving the problem]

[0014] To solve the above problems, the present invention provides a battery module structure comprising: a battery cell stack formed by stacking a plurality of pouch-type battery cells and metal plates in the width direction; a U-frame that houses the battery cell stack and is open at the top, front, and rear; a pair of end plates that cover the front and rear of the U-frame; and a top plate that covers the top of the U-frame, wherein the top plate is provided with a plurality of vent holes, and the metal plate is provided with a plurality of lid portions corresponding to the vent holes, and each of the lid portions penetrates the top plate and protrudes upward and is bent to one side in the width direction to cover at least a portion of the area of ​​the vent holes.

[0015] The battery cell stack may include a plurality of unit cell stacks, each containing a plurality of the battery cells.

[0016] A metal plate may be laminated on the other side in the width direction of each of the battery cells or each of the unit cell stacks. In this case, the metal plate may be laminated directly on the other side in the width direction of the battery cell, or it may be laminated with a further layer interposed between it and the battery cell. Each stack containing one battery cell or unit cell stack and one metal plate can become a unit stack forming the battery cell stack.

[0017] Each of the aforementioned battery cells or the unit cell stack may be provided with one or more vent holes. If multiple vent holes are provided on the battery cell or the unit cell stack, the multiple vent holes may be arranged to be spaced apart from each other in the longitudinal or widthwise direction. This allows the portion of the top plate without vent holes to form a grille shape, thereby ensuring the necessary rigidity in the longitudinal and widthwise directions.

[0018] In this case, the cover portion may be provided so as to correspond to the vent holes. That is, the cover portion may be provided in a number corresponding to the number of vent holes, at positions corresponding to the location of the vent holes.

[0019] The battery cell stack may include an insulating pad laminated together with the battery cells and the metal plate. The insulating pad may be made of an insulating material and can be laminated in any position as long as it can prevent heat transfer between the battery cells or between adjacent battery modules when laminated together with the battery cells and the metal plate. For example, the insulating pad may be laminated on one or the other side of the width direction of the metal plate, or it may be interposed between any two adjacent battery cells in the width direction. Even when multiple battery cells are assembled to form the unit cell stack, the insulating pad may be interposed between the battery cells within the unit cell stack and laminated together.

[0020] The heat insulating pad may be made of a compressible material. In this case, the heat insulating pad can prevent heat transfer and absorb tolerances in the width direction of the metal plate and the battery cell, as well as deformation due to swelling.

[0021] The battery module may include a heat-resistant filler that fills at least a portion of the space between the battery cell stack and the end plate. In this case, the battery cell is provided with first seal portions at both ends in its longitudinal direction, and the heat-resistant filler can cover the first seal portions. This prevents gas and thermal energy from being released in the longitudinal direction if the battery cell ignites. The heat-resistant filler may include heat-resistant silicon. However, the heat-resistant filler is not limited to any particular material and may be made of any material that is heat-resistant and can be filled.

[0022] Each of the aforementioned lids may be folded to one side in the width direction, and a portion thereof may be welded to the top plate. Welding the lids to the top plate may improve the structural safety between the battery cell stack and the top plate.

[0023] The lid portion may include a first lid portion that penetrates the top plate through a predetermined first vent hole and covers a second vent hole adjacent to the first vent hole in the width direction.

[0024] The lid portion may include a second lid portion that penetrates the top plate through a slit provided in the top plate and covers the vent hole adjacent to the slit in the width direction. The slit may be provided adjacent to the other end portion in the width direction of the top plate, and the lid portion protruding from the metal plate disposed at the outermost periphery on the other side in the width direction of the battery cell laminate may be the second lid portion.

[0025] The first lid portion may contact the top plate at one end portion in the width direction of the first vent hole, and the second lid portion may contact the top plate at one end portion in the width direction of the slit.

[0026] When a bending moment of a predetermined value or more is applied to the thickness of the metal plate, it can be bent, and when a bending moment of a predetermined value or less is applied, an appropriate value can be selected so that it does not deform. For example, the metal plate can have a thickness of 1 mm to 2 mm. Preferably, the metal plate can have a thickness of 1.4 mm to 1.6 mm.

[0027] When the battery cell laminate is housed in the U-frame, a second seal portion may be provided at one end portion in the height direction of the battery cell, and the battery cell laminate may be arranged such that the second seal portion faces upward. At this time, the second seal portion may be provided along one long side in the width direction of one surface in the height direction of the battery cell.

[0028] When the battery cell in the battery module according to the present invention catches fire, gas and thermal energy can be discharged upward. Due to the gas and thermal energy discharged upward, the lid portion can be warped outward to open the vent hole, whereby the gas and thermal energy can be quickly discharged to the outside of the battery module. Since the vent holes located on other battery cells where no fire has occurred are covered by the lid portion, reflow of the gas and thermal energy into the battery module can be prevented.

Advantages of the Invention

[0029] The present invention can provide a structure of a battery module in which heat propagation due to conduction between battery cells is prevented by heat insulation and interruption between each battery cell and / or unit cell laminate.

[0030] According to the present invention, when a battery cell catches fire, high-temperature gas and thermal energy are guided to be discharged upward, and a structure of a battery module that can be discharged independently for each battery cell and / or unit cell laminate can be provided.

[0031] Still another advantage of the battery module according to the present invention is that it prevents the inflow and reflow of high-temperature gas and thermal energy discharged from other battery cells and / or unit cell laminates and other battery modules, thereby preventing heat propagation between battery cells and battery modules.

[0032] In addition, the present invention can achieve various effects. Regarding this, the description will be omitted for effects that will be described in each embodiment or effects that can be easily inferred by ordinary technicians.

Brief Description of the Drawings

[0033] [Figure 1] It is a diagram showing the structure of a pouch-type battery cell. [Figure 2] It is a diagram showing how a vent occurs in a battery cell. [Figure 3]This is an exploded perspective view showing the structure of a typical battery module. [Figure 4] This is a perspective view showing the structure of a typical battery module. [Figure 5] This figure shows the laminated structure of a unit cell laminate according to one embodiment of the present invention. [Figure 6] This figure shows a laminated structure of a battery cell, a metal plate, and a heat insulating pad according to one embodiment of the present invention. [Figure 7] Figure 6 shows a cross-section of the battery cell stack. [Figure 8] This is an exploded perspective view showing a battery module according to one embodiment of the present invention before the top plate is assembled. [Figure 9] This is a perspective view showing a battery module according to one embodiment of the present invention before the top plate is assembled. [Figure 10] This figure shows a cross-section of the battery module and the arrangement of the heat-resistant filler material. [Figure 11] This figure shows the battery module according to one embodiment of the present invention before the top plate is assembled. [Figure 12] This figure shows the battery module according to one embodiment of the present invention after the top plate has been assembled. [Figure 13] This figure shows a cross-section of the battery module shown in Figure 12. [Figure 14] This figure shows a battery module according to one embodiment of the present invention. [Figure 15] This figure shows a cross-section of the battery module shown in Figure 14. [Figure 16] This is a magnified view of the main part of Figure 15. [Figure 17] This figure shows how venting occurs in a battery module according to one embodiment of the present invention. [Figure 18] This figure shows a battery pack that incorporates another battery module as one embodiment of the present invention. [Figure 19] This diagram shows a car with the battery pack shown in Figure 18 installed inside. [Modes for carrying out the invention]

[0034] The aforementioned objectives, features, and advantages will be described in detail below with reference to the accompanying drawings, so that a person with ordinary skill in the art to which the present invention pertains can easily implement the technical concept of the present invention. In describing the present invention, if a specific description of known technology according to the present invention is deemed to obscure the gist of the present invention, the detailed description will be omitted. Hereafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings are used to indicate the same or similar components.

[0035] Although terms such as "first," "second," etc., are used to indicate various components, these components are not limited by these terms. These terms are simply used to distinguish one component from another, and unless otherwise specified, the first component may also be the second component.

[0036] In the entire specification, unless otherwise stated, each component may be singular or plural.

[0037] In the following, the placement of any configuration "above (or below)" a component or "above (or below)" a component means not only that the configuration is placed in contact with the upper (or lower) surface of the component, but also that other configurations may be interposed between the component and any configuration placed on (or below) it.

[0038] Furthermore, if it is stated that one component is “linked,” “joined,” or “connected” to another component, it should be understood that the components may be directly linked or connected to each other, but other components may also be “interposed” between them, or each component may be “linked,” “joined,” or “connected” through other components.

[0039] As used herein, singular expressions include plural expressions unless otherwise explicitly stated in the context. Terms such as “composed of” or “including” in this application should not be interpreted as necessarily including all of the multiple components or stages described in the specification, but rather as including some of the components or stages, or including further components or stages.

[0040] In the entire specification, "A and / or B" means A, B, or A and B unless otherwise specified, and "C to D" means C or greater and D or less unless otherwise specified.

[0041] The present invention provides a battery module structure in which the vent path is improved and heat propagation is prevented, comprising a battery cell stack formed by stacking a plurality of pouch-type battery cells and metal plates in the width direction, a U-frame that houses the battery cell stack and is open at the top, front and rear, a pair of end plates that cover the front and rear of the U-frame, and a top plate that covers the top of the U-frame.

[0042] The means for solving the problems of the present invention can be applied to battery modules and battery packs in which a plurality of battery cells having thickness are stacked on top of each other and housed together in a single housing.

[0043] Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

[0044] Figures 1 and 2 show the structure of a pouch-type battery cell and how venting occurs in the battery cell, respectively. Referring to these drawings, the battery cell 11 may be formed by a sheet material pouch housing and sealing an electrode assembly.

[0045] The electrode assembly may be formed by repeatedly stacking multiple positive and negative electrodes with a separation membrane in between. Electrode leads 113 may extend from the electrode assembly and protrude outside the pouch.

[0046] The pouch may be made of a metal material. The pouch may be coated with a synthetic resin layer on the inside and outside for insulation. The pouch may be folded in half to house the electrode assembly and sealed by fusing the internal insulating layer. However, the pouch may have a different material and structure than the above material and may be sealed in any other manner.

[0047] The pouch may be sealed by first sealing portions 111 provided at both ends in the longitudinal direction and a second sealing portion 112 provided at one end in the height direction. The electrode leads 113 may protrude to the outside of the pouch through the first sealing portion 111. The second sealing portion 112 may be provided along one long side in the width direction of one surface in the height direction of the battery cell 11. The second sealing portion 112 may be folded to one side in the width direction, then tape may be attached to it and it may be sealed again.

[0048] The battery cell 11 may ignite due to short circuit, impact, overheating, etc. In this case, a large amount of gas and thermal energy may be discharged from the battery cell 11. This gas and thermal energy can be discharged through both sides in the longitudinal direction and one end in the height direction of the battery cell 11, where the first seal portion 111 and the second seal portion 112 are provided.

[0049] Figure 6 shows a laminated structure of a battery cell, a metal plate, and a heat insulating pad according to one embodiment of the present invention. Referring to this, a metal plate 12 may be laminated on the other side in the width direction of the battery cell 11. In this case, the metal plate 12 may be laminated on the other side in the width direction of the battery cell 11 with a further layer interposed between it and the battery cell 11.

[0050] Alternatively, the battery cells 11 may be stacked in multiples to form a unit cell stack, and the metal plate 12 may be stacked on the other side in the width direction of the unit cell stack. In this case as well, the multiple battery cells 11 and the metal plate 12 may be stacked with further layers interposed between them.

[0051] The metal plate 12 may include a lid portion 121 that protrudes upward from one end in the height direction. Multiple lid portions 121 may be provided. The multiple lid portions 121 may be arranged in the length direction, or in particular, they may be arranged spaced apart in the length direction.

[0052] The battery cell 11 and the metal plate 12 may be laminated together with an insulating pad 13 made of an insulating material. The insulating pad 13 may be laminated interposed between one battery cell 11 and another adjacent battery cell 11, or it may be laminated on one or the other side in the width direction of the battery cell 11 or the metal plate 12. Since the pouch of the metal plate 12 and the battery cell 11 is made of a metal material and has a high rate of thermal conductivity, the insulating pad 13 can reduce the rate of heat propagation between the battery cells 11.

[0053] The heat insulating pad 13 may be made of a compressible material. In this case, if deformation occurs in the battery cell 11 due to swelling, or if there is a tolerance in the laminated structure of the battery cell 11, the heat insulating pad 13 can absorb the swelling and the tolerance.

[0054] According to one embodiment of the present invention, one heat insulating pad 13 may be laminated on the other side in the width direction of each battery cell 11. On the other side in the width direction of the heat insulating pad 13, the metal plate 12 may be laminated, with a plurality of lid portions 121 arranged spaced apart in the length direction. That is, each battery cell 11 can constitute a single unit laminate in which one heat insulating pad 13 and one metal plate 12 are sequentially laminated on its other side in the width direction.

[0055] In one modified example, multiple battery cells can be stacked with the heat insulating pads interposed between them to form a unit cell stack. One heat insulating pad may be stacked on the other side in the width direction of each unit cell stack. Metal plates, on which multiple lid portions are arranged spaced apart in the length direction, may be stacked on the other side in the width direction of the heat insulating pads. That is, each unit cell stack can constitute a single unit stack in which one heat insulating pad and one metal plate are sequentially stacked on its other side in the width direction.

[0056] In the following embodiment, we illustrate the case where each unit stack contains one battery cell 11. However, it is easy to understand that the means for solving the problems of the present invention can be directly applied even when each unit stack contains multiple battery cells 11.

[0057] Figure 6 shows a battery cell stack according to one embodiment of the present invention, and Figure 7 shows a cross-section of the battery cell stack of Figure 6. Referring to these drawings, a plurality of the battery cells 11, the metal plates 12 and / or the heat insulating pads 13 can be stacked in the width direction to form a battery cell stack 1. The battery cell stack 1 may also be formed by repeatedly stacking a plurality of the unit stacks.

[0058] A pair of busbar frames 2 may be connected to both ends of the battery cell stack 1 in the longitudinal direction.

[0059] In one embodiment of the present invention, the battery cell stack 1 may be formed by repeatedly stacking unit stacks, each in which one battery cell 11, one heat insulating pad 13, and one metal plate 12 are sequentially stacked on the other side in the width direction, and a pair of busbar frames 2 may be connected to both ends of the battery cell stack 1 in the length direction.

[0060] In one modified example, the battery cell stack 1 may include further heat insulating pads 13 that are stacked on the outermost edges of one and / or the other side in the width direction.

[0061] Figures 8 and 9 are exploded perspective and perspective views, respectively, showing a battery module according to one embodiment of the present invention before the top plate is assembled. Referring to these drawings, the battery cell stack 1 can be housed in the housing 3 to form a battery module.

[0062] The battery cell stack 1 can be housed in the housing 3 such that the second seal portion 112 faces upward. The upward orientation of the second seal portion 112 may result in the main direction of gas and thermal energy discharged from the battery cell 11 being upward. In this case, the second seal portion 112 may be positioned off-center to one side in the width direction relative to the center of the battery cell 11 in the width direction.

[0063] The housing 3 may include a U-frame 31 that is open at the top, front, and rear, and a pair of end plates 32 that cover the front and rear of the U-frame 31, respectively.

[0064] The U-frame and the end plate 32 can be joined together to form the housing. The U-frame 31 and the end plate 32 may each contain a metallic material. In this case, the U-frame 31 and the end plate 32 may be welded to each other. However, the material and joining method of the U-frame 31 and the end plate 32 are not limited to these, and they may be made of materials other than metallic materials and may be joined to each other by methods other than welding.

[0065] A battery module according to one embodiment of the present invention may include a housing 3 comprising the U-frame 31 and the pair of end plates 32, and a battery cell stack 1 housed in the housing 3 such that the second seal portion 112 faces upward. In this case, the direction toward which the second seal portion 112 faces and the direction toward which the lid portion 121 protrudes can coincide with each other, both facing upward.

[0066] Figure 10 shows a cross-section of the battery module and the arrangement of the heat-resistant filler material in Figure 9. Referring to this, the busbar frame 2 may include a slit 21 and a busbar 22. Multiple electrode leads 113 may pass through the slit 21 and be welded to the busbar 22. The busbar 22 can connect the multiple electrode leads 113 in series or in parallel with each other.

[0067] A gap may be formed between the battery cell stack 1 and the end plate. At least a portion of the gap may be filled with a heat-resistant filler 4. That is, the heat-resistant filler 4 can be filled into at least a portion of the gap formed between the battery cell stack 1 and the busbar frame 2, and between the busbar frame 2 and the end plate.

[0068] The heat-resistant filler 4 may be provided so as to cover the first seal portion 111 through which the electrode lead 113 protrudes. This prevents the release of gas and thermal energy through the first seal portion 111 when the battery cell 11 ignites.

[0069] Preferably, when the battery cell 11 ignites, the direction of gas and thermal energy discharge can be restricted to one direction in the height direction, i.e., upward. In other words, in this case, both sides in the width direction and the other in the height direction of the battery cell 11 are enclosed and sealed by the pouch, both sides in the length direction of the battery cell 11 are sealed by the heat-resistant filler 4 covering the first seal portion 111, and when the battery cell 11 ignites, gas and thermal energy can be discharged only through the second seal portion 112 provided on one side in the height direction. In this case, the gas discharge paths (vent paths) of the battery cell 11 are each formed independently within the housing 3, and each battery cell 11 may have its own vent path that is not shared with other battery cells.

[0070] The heat-resistant filler 4 may contain heat-resistant silicone. However, the heat-resistant filler 4 may be made of any material that has heat resistance and can fill the empty space and cover the first seal portion 111.

[0071] According to one embodiment of the present invention, the heat-resistant filler 4 may contain a heat-resistant silicon material and can fill the empty space formed between the battery cell laminate 1 and the busbar frame 2, and between the busbar frame 2 and the end plate, thereby completely covering the first seal portion 111.

[0072] Figures 11 and 12 show the battery module before and after the top plate is assembled according to one embodiment of the present invention, respectively, and Figure 13 shows a cross-section of the battery module of Figure 12. Referring to these drawings, the housing 3 may include a top plate 33 that covers the upper part of the U-frame 31. The top plate 33 may be made of a metallic material. The top plate 33 may be welded to the U-frame 31. However, the material of the top plate 33 and the method of joining it to the U-frame 31 are not limited to these, and they may be made of a material other than metallic material and may be joined to each other by a method other than welding.

[0073] The top plate 33 may be provided with vent holes 331 that penetrate vertically through the top plate 33. Multiple vent holes 331 may be provided.

[0074] The vent holes 331 may be provided one or more times on each of the battery cells 11. If multiple vent holes 331 are provided on each of the battery cells 11, the vent holes 331 may be arranged spaced apart from each other in the longitudinal direction. In this case, the vent holes 331 may be arranged in a grid pattern, leaving a grille-like structure on the top plate 33. This allows the top plate 33 to maintain appropriate rigidity in both the width and length directions, despite the presence of the vent holes 331.

[0075] Alternatively, one or more vent holes 331 may be provided on each of the unit cell stacks. When multiple vent holes 331 are provided on each of the unit cell stacks, the vent holes 331 may be arranged spaced apart from each other in the longitudinal direction, or spaced apart from each other in the width direction. In this case, the vent holes 331 may be arranged in a grid pattern, leaving a grille-like structure on the top plate 33. This allows the top plate 33 to have adequate rigidity in both the width and length directions, despite the presence of the vent holes 331.

[0076] In this case, the vent holes 331 and the lids 121 may be provided at corresponding positions to each other, or in corresponding numbers to each other. However, contrary to this, there may also be cases where the number of vent holes 331 is greater than the number of lids 121, and one lid 121 is provided at positions corresponding to multiple vent holes 331, or where the number of lids 121 is greater than the number of vent holes 331, and multiple lids 121 correspond to one vent hole 331.

[0077] The lid portion 121 may penetrate the top plate 33 and protrude upward. The top plate 33 may be provided with a slit 332 through which the lid portion 121 can pass. The slit 332 may be provided by punching it out separately, or it may be provided without being joined to the joint between the top plate 33 and the U-frame 31. The lid portion 121 can penetrate the top plate 33 through the vent hole 331, and it can also penetrate the top plate 33 through the slit 332.

[0078] The battery module according to one embodiment of the present invention may include the top plate 33, which is made of a metal material and may be welded to the U-frame 31, and may include the vent holes 331 arranged at intervals in the longitudinal direction at positions and in a number corresponding to the lid portion 121 on each of the battery cells 11, and the slits 332 arranged at intervals in the longitudinal direction adjacent to the other end of the top plate 33 in the width direction. In this case, each of the lid portions 121 may penetrate the top plate 33 and protrude upward through either the slits 332 or the vent holes 331.

[0079] Figure 14 shows a battery module according to one embodiment of the present invention, and Figure 15 shows a cross-section of the battery module of Figure 14. Referring to these drawings, the lid portion 121 may penetrate the top plate 33, protrude upward, and then be bent to one side in the width direction.

[0080] The cover portion 121 can be folded to cover at least a portion of the vent hole 331. This ensures that at least one of the vent holes 331 is covered by the cover portion 121. In this case, it is not necessary for one vent hole 331 to be covered by one cover portion 121. Furthermore, it is preferable that the vent hole 331 has a predetermined portion of its area that is not covered by the cover portion 121 and is open to the top. This is to prevent a sudden increase in the pressure resistance of the housing 3 by allowing a small amount of gas generated from the battery cell 11 to be released before full-blown thermal runaway or ignition begins.

[0081] According to one embodiment of the present invention, each of the lid portions 121 penetrates the top plate 33, protrudes upward, and is then bent inward in the width direction to cover a portion of either of the vent holes 331. In this case, the vent hole 331 may have a predetermined area that is not covered by the lid portion 121 and is open upward.

[0082] Figure 16 is a magnified view of the main part of Figure 15.

[0083] The cover portion 121 may include a first cover portion 121a that penetrates the top plate 33 through the vent hole 331. The first cover portion 121a can pass through a predetermined first vent hole 331a and cover a second vent hole 331b adjacent to the first vent hole 331a in the width direction. In this case, the first vent hole 331a can be determined differently for each of the first cover portions 121a, and thereby the second vent hole 331b can also be determined differently for each of the first cover portions 121a. For example, one of the vent holes may be the first vent hole in one first cover portion and the second vent hole in another first cover portion.

[0084] At this time, the first lid portion 121a can come into contact with the top plate 33 at one end in the width direction of the first vent hole. In other words, the first lid portion 121a may be bent to one side in the width direction, with one end in the width direction of the first vent hole 331a through which the first lid portion 121a passes as the boundary. If a roller is used to bend the first lid portion 121a, the first lid portion 121a may be bent to one side in the width direction by the force applied by the roller toward one side in the width direction, with one end in the width direction of the first vent hole 331a providing a corresponding reaction force. At this time, for structural safety reasons, it is preferable that the first lid portion 121a comes into contact with the inner surface of the first vent hole 331a adjacent to one end in the width direction of the first vent hole 331a and the upper surface of the top plate 33 simultaneously.

[0085] The top plate 33 may include a second cover portion 121b that penetrates the top plate 33 through the slit 332. The second cover portion 121b can pass through the slit 332 and cover the vent hole 331 adjacent to the slit 332 in the width direction.

[0086] At this time, the second lid portion 121b can come into contact with the top plate 33 at one end of the slit in the width direction. In other words, the second lid portion 121b may be bent to one side in the width direction, with one end of the slit 332 in the width direction through which the second lid portion 121b passes as the boundary. If a roller is used to bend the second lid portion 121b, the second lid portion 121b may be bent to one side in the width direction by the force applied by the roller to the second lid portion 121b toward one side in the width direction, with one end of the slit 332 in the width direction providing a corresponding reaction force. At this time, for structural safety reasons, it is preferable that the second lid portion 121b comes into contact with the inner surface of the slit 332 adjacent to one end of the slit 332 in the width direction and the upper surface of the top plate 33 simultaneously.

[0087] After the lid portion 121 is bent, a portion thereof may be joined to the top plate 33. For example, a portion of the lid portion 121 adjacent to the tip and / or base end from the bent portion may be welded to the inner surface of the vent hole 331 or the slit 332 through which the lid portion 121 passes and / or to the upper surface of the top plate 33. The joining may be by welding. By joining the lid portion 121 to the top plate 33, the safety of the arrangement between the lid portion 121 and the top plate 33 may be improved.

[0088] According to one embodiment of the present invention, the lid portion 121 may include a second lid portion 121b that protrudes from the metal plate 12 provided on the outermost edge on the other side in the width direction, penetrates the top plate 33 through the slit 332, and protrudes upward, and a first lid portion 121a, other than the second lid portion 121b, which each penetrates the top plate 33 through the vent hole 331 and protrudes upward. In this case, the first lid portion 121a and the second lid portion 121b may be in contact with one end in the width direction of the vent hole 331 and the slit 332, respectively, and a part thereof may be welded to the top plate 33.

[0089] Figure 17 shows how venting occurs in a battery module according to one embodiment of the present invention. Referring to this, if any of the battery cells 11 ignite, a large amount of gas and thermal energy can be discharged upward from the battery cells 11. At this time, the gas and thermal energy can be discharged through the second seal portion 112 located on one long side in the width direction of the upper surface of the battery cell 11.

[0090] In this case, each of the battery cells 11 or each of the unit cell stacks may have its own vent space surrounded by the metal plate 12 and the heat-resistant filler.

[0091] The lid portion 121 can be bent outward by the gas and thermal energy, which increases the pressure resistance of the vent space, thereby opening the vent hole 331 upward. At this time, a portion of the lid portion 121 may be welded to the top plate 33 so that only the lid portion 121 is opened without the metal plate 12 itself flowing or falling off. By opening the lid portion 121, the high-temperature gas and thermal energy inside the housing 3 can be discharged to the outside, preventing a further rise in the temperature of the battery cell 11 and delaying the progression of ignition.

[0092] At this time, the vent holes provided on the other battery cells, excluding the ignited battery cell 11, can still be covered by the lid. This prevents the gas and thermal energy discharged through the vent holes 331 that were opened from the ignited battery cell 11 from further flowing into the housing and heating the other battery cells. In addition, at this time, each of the battery cells 11 can be separated from each other by an insulating pad 13, thereby preventing the transfer of heat between the battery cells 11 by heat conduction.

[0093] If the metal plate is too thin, the lid is easily damaged and cannot adequately prevent gas inflow. If it is too thick, the bending and welding process becomes difficult, and despite the increased pressure resistance of the vent space due to ignition, it may not open. In this regard, the metal plate can have an appropriate thickness such that it can be easily bent when subjected to a force above a certain level, and has sufficient bending rigidity to not deform when subjected to a force below a certain level. For example, the metal plate can have a thickness of 1 mm to 2 mm. Preferably, the metal plate can have a thickness of 1.4 mm to 1.6 mm. By having the metal plate with an appropriately selected thickness as described above, it can effectively prevent both the discharge and inflow of gas and thermal energy.

[0094] In one embodiment of the present invention, each of the battery cells 11 has its own vent space insulated from each other by the heat insulating pad 13. If any of the battery cells 11 ignite, the cover 121 can open the vent hole 331, allowing high-temperature gas and thermal energy to be discharged from the vent space to the outside of the housing 3. Covers provided on other vent holes can prevent the discharged gas and thermal energy from flowing into other vent spaces. The heat insulating pad 13 can prevent heat propagation by conduction between the battery cells 11. Thus, this embodiment provides a battery module structure in which heat is discharged quickly and selectively, heat inflow is prevented, and chain reactions of ignition and thermal runaway due to heat propagation are prevented.

[0095] The present invention also provides a battery pack that houses the battery module and a structure for an automobile that houses the battery pack.

[0096] Figures 18 and 19 show a battery pack and an automobile, respectively, that house other battery modules in one embodiment of the present invention. Referring to these drawings, multiple battery modules (M) can be housed in a single pack frame to form a battery pack (P) due to their high voltage and / or high capacity. Multiple battery modules (M) can be connected in parallel or in series by pack busbars included in the battery pack (P), and the connected as a whole can have a high voltage and capacity. The battery pack (P) can be housed in an electric vehicle (V) powered by a secondary battery. The battery pack (P) can provide power to the automobile (V) via a motor housed in the automobile (V). The detailed structures of these battery packs and automobiles are known to the ordinary technician and will not be described in detail elsewhere in this specification.

[0097] The embodiments described above should be understood to be illustrative and not limiting in all respects, and the scope of the present invention is indicated more by the claims described below than by the detailed description above. The meaning and scope of the claims described below, as well as any modifications and deformable forms conceived from their equivalent concepts, should be interpreted as being included within the scope of the present invention.

[0098] As described above, the present invention has been explained with reference to the illustrative drawings. However, the present invention is not limited to the embodiments and drawings disclosed herein, and it is natural that various modifications can be made by an ordinary person within the scope of the technical concept of the present invention. Furthermore, even if the effects of the configuration of the present invention are not explicitly described and explained while embodiments of the present invention have been described above, it is natural that predictable effects from such configurations should also be acknowledged. [Explanation of symbols]

[0099] 1. Battery cell stack 11 battery cells 111 First seal section 112 Second seal section 113 Electrode Leads 12 Metal Plates 121 Lid 121a 1st lid part 121b 2nd lid part 13 Insulation pads 2 Busbar Frames 21 slits 22 Bus Bar 3 Housing 31 U-frame 311 Insulating film 32 End Plates 33 Top Plate 331 Vent holes 331a First vent hole 331b Second vent hole 332 Slits 333 Welded section 4. Heat-resistant filler (silicone) M Battery Module P Battery Pack V Automobile X-length direction Y width direction Z (height direction)

Claims

1. A battery cell laminate formed by stacking multiple pouch-type battery cells and metal plates in the width direction; A U-frame that houses the battery cell stack, with the top, front, and rear open; A pair of end plates covering the front and rear of the U-frame; and Includes a top plate that covers the upper part of the U-frame; The top plate is provided with a plurality of vent holes, The metal plate is provided with a plurality of lid portions corresponding to the vent holes, Each of the aforementioned lid portions extends upward through the top plate and is bent to one side in the width direction, thereby covering at least a portion of the area of ​​the vent hole. Battery module.

2. On the other side in the width direction of each of the aforementioned battery cells, the metal plates are stacked. Each of the aforementioned battery cells is provided with one of the aforementioned vent holes. The battery module according to claim 1.

3. On the other side in the width direction of each of the aforementioned battery cells, the metal plates are stacked. Each of the aforementioned battery cells is provided with multiple vent holes. The battery module according to claim 1.

4. Multiple vent holes are provided on each of the aforementioned battery cells, arranged at intervals along the length of the battery. The battery module according to claim 3.

5. The battery cell stack includes a plurality of unit cell stacks, each containing a plurality of the battery cells. On the other side in the width direction of each of the aforementioned unit cell stacks, the metal plates are stacked. Each of the aforementioned unit cell stacks is provided with one of the aforementioned vent holes. The battery module according to claim 1.

6. The battery cell stack includes a plurality of unit cell stacks, each containing a plurality of the battery cells. On the other side in the width direction of each of the aforementioned unit cell stacks, the metal plates are stacked. Each of the aforementioned unit cell stacks is provided with multiple vent holes. The battery module according to claim 1.

7. On each of the aforementioned unit cell stacks, a plurality of the aforementioned vent holes are provided, arranged at intervals along the length. The battery module according to claim 6.

8. Multiple vent holes are provided on each of the aforementioned unit cell stacks, arranged at intervals in the width direction. The battery module according to claim 6.

9. Includes an insulating pad laminated together with the battery cell and the metal plate, The battery module according to claim 1.

10. The heat insulating pad is laminated on one or the other side in the width direction of the metal plate. The battery module according to claim 9.

11. The aforementioned heat insulating pad is interposed between any two of the battery cells that are adjacent in the width direction. The battery module according to claim 9.

12. The aforementioned heat insulating pad is made of a compressible material, The battery module according to claim 9.

13. The heat-resistant filler material includes filling at least a portion of the space between the battery cell stack and the end plate, The battery module according to claim 1.

14. The aforementioned battery cell is provided with first sealing portions at both ends in the longitudinal direction. The heat-resistant filler covers the first seal portion. The battery module according to claim 13.

15. The heat-resistant filler includes heat-resistant silicone. The battery module according to claim 13.

16. Each of the aforementioned lid portions is folded to one side in the width direction, and then a portion of it is welded to the top plate. The battery module according to claim 1.

17. The cover portion includes a first cover portion that penetrates the top plate through a predetermined first vent hole and covers a second vent hole adjacent to the first vent hole in the width direction. The battery module according to claim 1.

18. The first lid portion is in contact with the top plate at one end in the width direction of the first vent hole, The battery module according to claim 17.

19. The aforementioned cover portion includes a second cover portion that penetrates the top plate through a slit provided in the top plate and covers the vent hole adjacent to the slit in the width direction. The battery module according to claim 1.

20. The second lid portion is in contact with the top plate at one end in the width direction of the slit, The battery module according to claim 19.

21. The aforementioned metal plate has a thickness of 1 mm to 2 mm. The battery module according to claim 1.

22. The metal plate has a thickness of 1.4 mm to 1.6 mm. The battery module according to claim 21.

23. The aforementioned battery cell is provided with a second seal portion at one end in the height direction. The battery cell stack is arranged such that the second sealing portion faces upward. The battery module according to claim 1.

24. The second sealing portion is provided along one long side in the width direction of one surface in the height direction of the battery cell, The battery module according to claim 23.

25. A battery module comprising the battery module described in any one of claims 1 to 24, Battery pack.

26. Includes the battery pack described in claim 25, car.

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