Battery module configured to prevent thermal propagation between cell banks

Abstract

The present invention relates to a battery module comprising: a cell stack comprising multiple pouch-type battery cells stacked in the width direction; a frame accommodating the cell stack and having an open top; and a top plate covering the top of the frame. The present invention provides a battery module structure in which a resin layer is applied to the top surface of the cell stack, and the resin layer is in contact with the top plate in the upward direction. The resin layer may extend in the horizontal direction. The space between the cell stack and the top plate may be divided into multiple spaces in the horizontal direction by the resin layer.

Description

Cell module with heat transfer prevention between cell banks

[0001] This application claims the benefit of priority from Republic of Korea Patent Application No. 10-2023-0116146, dated September 1, 2023, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a structure of a battery module that includes a stack of a plurality of pouch-shaped battery cells, wherein heat transmission between the battery cells is prevented.

[0003] Secondary batteries, which boast high electrical properties such as high energy density and easy applicability across a wide range of product groups, are widely used not only in portable devices but also in electric or hybrid vehicles powered by electrical power sources, as well as in power storage devices. These batteries are attracting attention as a new energy source for environmental friendliness and energy efficiency, not only because they can dramatically reduce fossil fuel use, but also because they produce no byproducts from energy use.

[0004] While small mobile devices typically use one or two or three battery cells per device, medium- to large-sized devices, such as automobiles, require high output and large capacity. Therefore, medium- to large-sized battery modules, which electrically connect multiple battery cells, are used.

[0005] Since it is desirable to manufacture medium- to large-sized battery modules with as small a size and weight as possible, square batteries and pouch-type batteries that can be stacked with high integration and have a small weight per capacity are mainly used as battery cells for medium- to large-sized battery modules.

[0006] Figure 1 illustrates the structure of a pouch-type battery cell. Referring to this, a typical pouch-type battery cell (110) is formed by folding a metal pouch in half to accommodate an electrode assembly, and then fusing and sealing the pouch at a sealing portion (111) provided at the upper portion and terrace portions provided at both longitudinal ends. A pair of electrode leads (112) protrude through the terrace portions to connect the electrode assembly to the outside.

[0007] Figures 2 and 3 illustrate the structure of a typical battery module. Referring to these drawings, a typical battery module (M) is configured to include a cell stack (1) in which a plurality of battery cells (110) are stacked in the width direction, and a housing (2) that accommodates them. The housing (2) typically includes a frame (21) that is open at the top and a top plate (22) that covers the top of the frame (21). At this time, due to reasons such as assembly tolerances, an empty space is formed between the cell stack (1) and the top plate (22).

[0008] Meanwhile, the battery cell (110) may ignite due to a short circuit, impact, or other reasons. When the battery cell (110) ignites, high-temperature gas and flame are discharged from the battery cell (110). These high-temperature gas and flame are mainly discharged through the sealing portion (111) that is fused and sealed.

[0009] If one battery cell ignites, the high-temperature gas and flames discharged through the sealing portion (111) may spread through the space between the cell stack (1) and the top plate (22), thereby spreading heat to other battery cells that have not ignited. This heat spread between cells may cause a chain reaction of ignitions, potentially leading to thermal runaway in the module unit.

[0010] In addition, a plurality of the battery modules (M) may be integrated to form a battery pack. In the battery pack, the battery modules (M) are typically connected to each other in the front and rear directions through which the electrode leads (112) are provided. Therefore, when the battery cell (110) ignites, the high-temperature gas and flames discharged in the front and rear directions may cause thermal runaway in the pack unit through heat transfer between modules.

[0011] Therefore, when the battery cell (110) is ignited, a structure of a battery module is required that can prevent heat transmission between cells due to high-temperature gas and flames discharged upwards, and can prevent heat transmission between modules due to high-temperature gas and flames discharged forward and backwards.

[0012] The present invention was created under the background of the above-described prior art, and its purpose is to provide a structure of a battery module that prevents heat transmission between cells and between modules due to gas and flame.

[0013] Specifically, the present invention aims to provide a structure of a battery module in which gas and flame discharge paths are partitioned by cell bank.

[0014] In addition, the present invention aims to provide a structure of a battery module that prevents gas and flames caused by ignition from being discharged to the front and rear of the module in which electrode leads and terminals are provided.

[0015] Another advantage of the present invention is that it can provide a structure of a battery module in which the flow of the cell stack within the housing is prevented and the heat generated from the cell stack can be dissipated to the outside of the housing.

[0016] The technical objectives of the present invention are not limited to the aforementioned purposes. Other unmentioned objectives and advantages of the present invention can be understood through the following description and will be more clearly understood through the embodiments of the present invention. Furthermore, it will be readily apparent that the objectives and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims.

[0017] In order to solve the above problem, the present invention provides a battery module comprising a cell stack in which a plurality of pouch-shaped battery cells are stacked in the width direction; a frame open at the top for accommodating the cell stack; and a top plate covering the top of the frame; wherein a resin layer is applied to the upper surface of the cell stack, and the resin layer is in contact with the top plate upward.

[0018] The resin layer may include a thermally conductive material. Accordingly, the resin layer may conduct heat generated in the cell stack to the top plate and release it to the outside of the battery module.

[0019] The resin layer may include a heat-resistant or fire-resistant material. Accordingly, the resin layer may not melt or deform even when exposed to high-temperature gases and flames.

[0020] The resin layer may extend horizontally. Accordingly, the space between the cell stack and the top plate may be divided into a plurality of spaces in the horizontal direction by the resin layer. The division may mean that the flow of gas and / or flame between any two points in the space between the cell stack and the top plate is delayed or blocked by the resin layer.

[0021] The resin layer may include a first resin layer applied so as to extend in the longitudinal direction. At this time, the space between the cell laminate and the top plate may be divided into a plurality of spaces in the width direction by the first resin layer.

[0022] The cell stack may include a plurality of cell banks, each of which includes a plurality of battery cells and is separated in the width direction by a barrier member that is laminated together with the battery cells. At this time, the first resin layer may be applied longitudinally along the upper end of the barrier member, and the space between the cell stack and the top plate may be divided into a plurality of spaces in the width direction by the first resin layer to correspond to the cell banks. In other words, each of the cell banks may have an independent venting space that is isolated by the barrier member and the first resin layer. Accordingly, heat propagation between the respective cell banks may be prevented, and thermal runaway of the entire module unit may be prevented.

[0023] The top plate may include a plurality of venting holes. The first resin layer may be provided in a location where the venting holes are not provided. In this case, gas and flames emitted from a single battery cell may be discharged directly upward through the venting holes without being transmitted to other cell banks other than the cell bank containing the battery cell.

[0024] The resin layer may include a second resin layer applied so as to extend in the width direction. At this time, the space between the cell laminate and the top plate may be divided into a plurality of spaces in the length direction by the second resin layer.

[0025] At the upper end of the battery cell, a sealing portion protruding upward and extending in the longitudinal direction may be provided. Gas and flames discharged from the battery cell may be discharged primarily upward through the sealing portion. At this time, the second resin layer may be applied in the width direction at a position corresponding to one end of the longitudinal direction of the sealing portion, and by the second resin layer, the space between the cell stack and the top plate may be partitioned into a space including the sealing portion and a space not including the sealing portion in a plan view.

[0026] Preferably, the second resin layer can be applied in the width direction at positions corresponding to both longitudinal ends of the sealing portion, and by the second resin layer, the space between the cell laminate and the top plate can be divided into a space including the sealing portion and a space not including the sealing portion in a plane.

[0027] The height of the second resin layer may be equal to or greater than the distance between the top plate and the tip of the sealing portion. Preferably, the height of the second resin layer may be equal to or greater than the distance between the top plate and the base of the sealing portion. Accordingly, high-temperature gas and flame discharged through the sealing portion may not be discharged forward and backward in the space between the cell stack and the top plate, and heat transmission to other battery modules adjacent to the battery module in the front and rear directions may be prevented.

[0028] The top plate may include a plurality of venting holes, and the second resin layer may be provided at a location where the venting holes are not provided.

[0029] The second resin layer may be applied in the width direction to the outside of one longitudinal end of the region in which the venting hole is provided in the top plate, and by the second resin layer, the space between the cell laminate and the top plate may be partitioned into a space including the venting hole and a space not including the venting hole in a plane.

[0030] Preferably, the second resin layer may be applied in the width direction on the outer sides of both longitudinal ends of the area in which the venting hole is provided in the top plate, and by the second resin layer, the space between the cell stack and the top plate may be partitioned into a space including the venting hole and a space not including the venting hole in a plan view. In this case, the gas and flame discharged from the battery cell may be discharged directly upward without being transmitted forward and backward.

[0031] The present invention also provides a battery pack having the battery module built in and a structure of a vehicle having the battery pack built in. The battery pack may be configured by integrating a plurality of battery modules so that they are adjacent to each other in front and rear and connected in series and / or in parallel.

[0032] The battery pack may include a pack frame that accommodates the battery modules. The pack frame may include a venting device that allows high-temperature gases and flames emitted upward from the battery modules to be discharged.

[0033] The above battery pack can be installed in a vehicle as a power source. The vehicle can be a hybrid vehicle or an electric vehicle.

[0034] The present invention can provide a structure of a battery module in which the space between the cell stack and the top plate is partitioned by a resin layer for each cell bank, thereby isolating the exhaust path of gas and flame for each cell bank, thereby preventing thermal runaway of the module unit due to heat propagation between cells.

[0035] The present invention can provide a structure of a battery module in which heat transfer between modules is prevented by preventing high-temperature gas and flames from being emitted to the front and rear of a cell laminate by a resin layer.

[0036] Another advantage of the present invention is that the cell stack is connected to the top plate by a thermally conductive resin layer, thereby preventing the cell stack from flowing and providing a structure of a battery module in which heat generated from the cell stack can be dissipated to the outside of the housing.

[0037] In addition, the present invention may have various other effects, which will be described in each embodiment, or the description of effects that can be easily inferred by a person skilled in the art will be omitted.

[0038] Figure 1 shows the structure of a pouch-type battery cell.

[0039] Figures 2 and 3 show the structure of a typical battery module.

[0040] Figures 4 and 5 show the structure of a battery module according to one embodiment of the present invention.

[0041] Figure 6 shows the structure of a cell stack according to one embodiment of the present invention.

[0042] Fig. 7 shows a cross-section of the battery module of Fig. 4.

[0043] Figure 8 shows the cell stack of Figure 6 as viewed from one side in the longitudinal direction.

[0044] Fig. 9 shows a cross-section of the battery module of Fig. 4.

[0045] [Explanation of symbols]

[0046] 1: Cell stack

[0047] 11: Cell Bank

[0048] 110: Battery cell

[0049] 111: Sealing part

[0050] 112: Electrode lead

[0051] 12: Absence of barrier

[0052] 13: Resin layer

[0053] 131: First resin layer

[0054] 132: Second resin layer

[0055] 2: Housing

[0056] 21: Frame

[0057] 22: Top plate

[0058] 220: Venting Hall

[0059] 23: End plate

[0060] 240: Busbar frame

[0061] 241: Busbar

[0062] M: Battery module

[0063] H1: Height of the second resin layer

[0064] H2: Distance between the top plate and the tip of the sealing part

[0065] H3: Distance between the top plate and the base of the sealing part

[0066] The above-described objects, features, and advantages will be described in detail below with reference to the accompanying drawings, so that those skilled in the art can easily practice the technical idea of ​​the present invention. In describing the present invention, if it is determined that a detailed description of known technologies related to the present invention may unnecessarily obscure the gist of the present invention, a detailed description thereof will be omitted. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

[0067] Although the terms "first" and "second" are used to describe various components, these components are not limited by these terms. These terms are used solely to distinguish one component from another, and unless otherwise specified, a "first" component may also be a "second" component.

[0068] Throughout the specification, unless otherwise specifically stated, each element may be singular or plural.

[0069] Hereinafter, the phrase "any configuration is placed on (or below)" a component or "on (or below)" a component may mean that any configuration is placed in contact with the upper surface (or lower surface) of said component, and that other configurations may be interposed between said component and any configuration placed on (or below) said component.

[0070] Additionally, when it is described that a component is "connected," "coupled," or "connected" to another component, it should be understood that the components may be directly connected or connected to one another, but that other components may also be "interposed" between the components, or that each component may be "connected," "coupled," or "connected" through another component.

[0071] As used herein, singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as "consisting of" or "comprising" should not necessarily be construed to include all of the components or steps described in the specification, and should be construed to mean that some of the components or steps may not be included, or that additional components or steps may be included.

[0072] Throughout the specification, when we refer to "A and / or B", this means A, B, or A and B, unless otherwise stated, and when we refer to "C to D", this means C or more and D or less, unless otherwise stated.

[0073] For convenience of explanation, this specification includes expressions related to directions such as front-back, left-right, up-down, length, width, and height. However, these directions are not necessarily orthogonal to each other or related to a specific direction such as the direction of gravity. Rather, they may be appropriately selected to intersect or be parallel to each other, as long as the present invention's solution is maintained.

[0074] Hereinafter, a preferred embodiment of the present invention will be described with reference to the attached drawings.

[0075] Figure 1 illustrates the structure of a pouch-type battery cell. Referring to this, the battery cell (110) may include an electrode assembly and a pouch that accommodates the electrode assembly.

[0076] The above pouch accommodates the electrode assembly and can be folded in half and sealed at the sealing portion (111).

[0077] The above sealing may be achieved by fusion. In this case, the sealing portion (111) may be additionally sealed by folding or attaching tape after being fusion-sealed.

[0078] The battery cell (110) may include an electrode lead (112) extending from the electrode assembly and protruding outside the pouch.

[0079] Meanwhile, the battery cell (110) may ignite due to impact, short circuit, heating, etc. When the battery cell (110) ignites, high-temperature gas and flame generated from the electrode assembly may be discharged outside the pouch. At this time, the gas and flame may be discharged upward from the battery cell (110) where the sealing portion (111) is provided as the fusion portion of the sealing portion (111) melts.

[0080] Figures 4 and 5 illustrate the structure of a battery module according to one embodiment of the present invention, and Figure 6 illustrates the structure of a cell stack according to one embodiment of the present invention. Referring to these drawings, a battery module (M) according to one embodiment of the present invention may include a cell stack (1) and a housing (2) that accommodates the cell stack (1).

[0081] The above cell stack (1) can be formed by stacking a plurality of battery cells (110) in the width direction.

[0082] At this time, the electrode lead (112) may protrude toward both sides in the longitudinal direction of the cell stack (1), and the sealing portion (111) may face upward. As the sealing portion (111) faces upward, when any one battery cell (110) included in the cell stack (1) ignites, gas and flame may be discharged upward.

[0083] A resin layer (13) may be applied to the upper surface of the cell laminate (1). The resin layer (13) may include a curable synthetic resin that hardens over time after application. The resin layer (13) may include a thermally conductive material. The resin layer (13) may include a heat-resistant or fire-resistant material.

[0084] The housing (2) may include a frame (21) that is open at the top and a top plate (22) that covers the top of the frame (21). The top plate (22) may include a plurality of venting holes (220) formed through the top plate (22) so that, when the battery cell (110) ignites, gas and flames discharged upward through the sealing portion (111) can be discharged to the outside of the housing (2).

[0085] The above frame (21) can be opened at the front and rear. At this time, the housing (2) can include a pair of end plates (23) that cover the front and rear of the frame (21).

[0086] The above resin layer (13) can be in contact with the top plate (22) upward. In other words, the above resin layer (13) can vertically connect the upper surface of the cell stack (1) and the lower surface of the top plate (22).

[0087] When the top plate (22) includes the venting hole (220), the resin layer (13) can come into contact with the top plate (22) at a portion where the venting hole (220) is not formed.

[0088] When the resin layer (13) includes a thermally conductive material, the resin layer (13) can have a heat dissipation function so that heat generated from the cell stack (1) is conducted to the top plate (22) and released to the outside.

[0089] When the above resin layer (13) includes a heat-resistant or fire-resistant material, the resin layer (13) can maintain its structure without melting or burning due to high-temperature gas and flame even when the cell laminate (1) is ignited.

[0090] The resin layer (13) may extend horizontally. In this case, the space between the cell stack (1) and the top plate (22) may be divided into a plurality of spaces in the horizontal direction. The division may mean that the flow of gas or flame between any two points in the space between the cell stack (1) and the top plate (22) is delayed or blocked by the resin layer (13).

[0091] The above resin layer (13) may include a first resin layer (131) extending in the longitudinal direction. By the first resin layer (131), the space between the cell stack (1) and the top plate (22) may be divided into a plurality of spaces in the width direction.

[0092] The above resin layer (13) may include a second resin layer (132) extending in the width direction. By the second resin layer (132), the space between the cell stack (1) and the top plate (22) may be divided into a plurality of spaces in the length direction.

[0093] Fig. 7 illustrates a cross-section of the battery module of Fig. 4. Referring to this, the cell stack (1) may include a barrier member (12) that is laminated in the width direction together with the battery cells (110). The battery cells (110) may form a plurality of cell banks that are isolated from each other by the barrier member (12). In other words, the cell stack (1) may be formed by laminating a plurality of cell banks, each of which includes a plurality of battery cells (110), in the width direction with the barrier member (12) interposed therebetween.

[0094] The first resin layer (131) may be applied longitudinally along the upper end of the barrier member (12). At this time, by the first resin layer (131), the space between the cell stack (1) and the top plate (22) may be divided into a plurality of spaces in the width direction to correspond to the cell bank (11).

[0095] According to one embodiment of the present invention, by the second resin layer (132), high-temperature gas and flame generated when one battery cell (110) ignites can be prevented from being transmitted to another cell bank adjacent to the cell bank (11) to which the battery cell (110) belongs through the space between the cell stack (1) and the top plate (22). That is, according to one embodiment of the present invention, a structure of a battery module can be provided in which the venting path of gas and flame is divided by cell bank, so that the ignition of one cell bank does not lead to the ignition of another cell bank and thermal runaway of the module unit.

[0096] FIG. 8 shows a view of the cell stack of FIG. 6 from one side in the longitudinal direction. Referring to this, the second resin layer (132) can be applied in the width direction at a position corresponding to one end in the longitudinal direction of the sealing portion (111). The one end in the longitudinal direction of the sealing portion (111) refers to an end in the extended direction of the sealing portion (111), and may refer to one end of the upper end of the battery cell (110), or may refer to one end of a section having a portion in the upper end where the electrode assembly is provided as the base portion. That is, the one end in the longitudinal direction of the sealing portion (111) may be a section spaced apart from the upper end of the battery cell (110) by a predetermined section in the longitudinal direction.

[0097] Referring back to FIG. 6, the second resin layer (132) according to one embodiment of the present invention may be formed as a pair applied in the width direction at positions corresponding to both longitudinal ends of the sealing portion (111). At this time, by the second resin layer (132), the space between the cell laminate (1) and the top plate may be divided into a space including the sealing portion (111) on a plane and a space not including the sealing portion (111).

[0098] Fig. 9 shows a cross-section of the battery module of Fig. 4. Referring to this, the height (H1) of the second resin layer (132) may be equal to or greater than the distance (H2) between the top plate (22) and the tip of the sealing portion (111). Preferably, the height (H1) of the second resin layer (132) may be equal to or greater than the distance (H3) between the top plate (22) and the base of the sealing portion (111). Accordingly, the second resin layer (132) can prevent gas and flame discharged through the sealing portion (111) from being discharged outward in the longitudinal direction in the space between the top plate (22) and the cell stack (1). As a result, heat propagation between modules and thermal runaway of pack units due to gas and flame discharged to the front and rear of the battery module (M) can be prevented.

[0099] The present invention also provides a battery pack having the battery module built in and a structure of a vehicle having the battery pack built in. The battery pack may be configured by integrating a plurality of battery modules so that they are adjacent to each other in front and rear and connected in series and / or in parallel.

[0100] The battery pack may include a pack frame that accommodates the battery modules. The pack frame may include a venting device that allows high-temperature gases and flames emitted upward from the battery modules to be discharged.

[0101] According to one embodiment of the present invention, since the emission of gas and flames toward the front and rear of the battery module is prevented, heat transmission between modules is prevented, and thermal runaway of the entire battery pack can be prevented.

[0102] The above battery pack can be installed in a vehicle as a power source. The vehicle may be a hybrid vehicle or an electric vehicle. By preventing thermal runaway of the battery pack, casualties to vehicle occupants due to battery pack explosion can be prevented.

[0103] It should be understood that the above-described embodiments are illustrative in all respects and not restrictive, and the scope of the present invention will be determined by the claims that follow, rather than by the detailed description set forth above. Furthermore, the meaning and scope of the claims that follow, as well as all possible modifications and variations derived from their equivalent concepts, should be construed as encompassing the scope of the present invention.

[0104] Although the present invention has been described with reference to the drawings exemplified above, it is to be understood that the present invention is not limited to the embodiments and drawings disclosed herein, and that various modifications may be made by those skilled in the art within the scope of the technical idea of ​​the present invention. Furthermore, even if the operational effects according to the configuration of the present invention have not been explicitly described while describing the embodiments of the present invention, it is natural that the effects predictable by the corresponding configuration should also be acknowledged.

Claims

1. A cell stack in which a plurality of pouch-shaped battery cells are stacked in the width direction; a frame having an open top for accommodating the above cell stack; and In a battery module including a top plate covering the upper portion of the frame and having a plurality of venting holes; A heat-resistant or fire-resistant resin layer is applied to the upper surface of the above cell laminate, A battery module in which the resin layer extends from a portion where the venting hole is not provided and contacts the top plate upward, thereby dividing the space between the cell stack and the top plate into a plurality of spaces.

2. In claim 1, A battery module, wherein the resin layer comprises a thermally conductive material.

3. In claim 1, A battery module wherein the resin layer extends horizontally.

4. In claim 3, The above resin layer includes a first resin layer applied so as to extend in the longitudinal direction, A battery module, wherein the space between the cell stack and the top plate is divided into a plurality of spaces in the width direction by the first resin layer.

5. In claim 4, The cell stack comprises a plurality of cell banks, each of which includes a plurality of battery cells, and each of which is separated in the width direction by a barrier member laminated together with the battery cells. The first resin layer is applied longitudinally along the upper side of the barrier member, A battery module, wherein the space between the cell stack and the top plate is divided into a plurality of spaces in the width direction corresponding to the cell bank by the first resin layer.

6. In claim 3, The above resin layer includes a second resin layer applied so as to extend in the width direction, A battery module, wherein the space between the cell stack and the top plate is divided into a plurality of spaces in the longitudinal direction by the second resin layer.

7. In claim 6, At the upper end of the above battery cell, a sealing portion is provided that protrudes upward and extends in the longitudinal direction, The second resin layer is applied in the width direction at a position corresponding to one end of the longitudinal direction of the sealing portion, A battery module, wherein the space between the cell stack and the top plate is divided into a space including the sealing portion and a space not including the sealing portion on a plane by the second resin layer.

8. In claim 7, The second resin layer is applied in the width direction at positions corresponding to both longitudinal ends of the sealing portion, A battery module, wherein the space between the cell stack and the top plate is divided into a space including the sealing portion and a space not including the sealing portion on a plane by the second resin layer.

9. In claim 7, A battery module wherein the height of the second resin layer is equal to or greater than the distance between the top plate and the tip of the sealing portion.

10. In claim 9, A battery module wherein the height of the second resin layer is equal to or greater than the distance between the top plate and the base portion of the sealing portion.

11. In claim 6, The second resin layer is applied in the width direction on the outer side of one longitudinal end of the area where the venting hole is provided in the top plate, A battery module, wherein the space between the cell stack and the top plate is divided into a space including the venting hole and a space not including the venting hole on a plane by the second resin layer.

12. In claim 6, The second resin layer is applied in the width direction on the outer sides of both longitudinal ends of the area where the venting hole is provided in the top plate, A battery module, wherein the space between the cell stack and the top plate is divided into a space including the venting hole and a space not including the venting hole on a plane by the second resin layer.

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