Battery module to which a partition plate is applied and battery pack including the same.

Abstract

The present invention relates to a battery module that can delay the chain reaction of battery cell ignition to the greatest extent possible. [Solution] The battery module according to the present invention includes a module case, a cell stack consisting of a plurality of battery cells arranged in a stack in one direction and housed inside the module case, and at least one partition plate portion that partitions the housing space between the battery cells or between the inner wall of the module case and one side of the cell stack, adjacent to the electrode leads at both ends of the battery cells.

Description

Technical Field

[0001] This application claims priority based on Korean Patent Application No. 10-2022-0097740 filed on August 5, 2022, and all the contents disclosed in the specification and drawings of that application are incorporated herein by reference.

[0002] The present invention relates to a battery module, and more specifically, to a battery module that can make it difficult for combustion emissions, flames, hot air, etc. generated in a fired battery cell to transfer to other battery cells during internal ignition of the battery module, and can maximize the delay of chain ignition of the battery cells.

Background Art

[0003] A secondary battery, which can switch electrical energy into the form of chemical energy and repeatedly charge and discharge, is distinguished from a primary battery that cannot be reused after being used once, and is called a secondary battery.

[0004] Examples of secondary batteries include lithium secondary batteries, nickel cadmium (Ni-Cd) batteries, lead-acid batteries, nickel metal hydride (Ni-MH) batteries, air zinc batteries, alkaline manganese batteries, etc. Among these, lead-acid batteries and lithium secondary batteries can be said to be the most commercially popular secondary batteries.

[0005] In particular, lithium secondary batteries have advantages such as high energy storage density, the ability to achieve weight reduction and miniaturization, excellent safety, low discharge rate, and long life. Therefore, they have recently been widely used as electric vehicle batteries. For reference, lithium secondary batteries are generally classified into cylindrical, prismatic, and pouch types according to their manufacturing shapes, and their applications also cover batteries for energy storage systems (ESS) and other electrical devices in addition to electric vehicle batteries.

[0006] Currently, the operating voltage of a single lithium secondary battery cell is approximately 2.5V to 4.5V. Therefore, in order to use secondary batteries as an energy source for electric vehicles, a battery module is constructed by connecting multiple lithium-ion battery cells in series and / or parallel, and a battery pack is constructed by connecting these battery modules again in series and / or parallel.

[0007] On the other hand, because secondary batteries involve chemical reactions during charging and discharging, their performance may degrade if used in environments with temperatures higher than the appropriate temperature, and there is a possibility of unexpected ignition or explosion if the temperature cannot be controlled to the appropriate level. Furthermore, because battery modules have a structure in which such secondary batteries are concentrated inside the module housing, if thermal runaway occurs in any one of the secondary batteries (referred to as a trigger cell), heat and flames will rapidly spread to the surrounding secondary batteries, raising concerns that a chain reaction of ignition in the surrounding secondary batteries may be easily triggered.

[0008] Therefore, there is an urgent need for improvements to the battery pack structure that would prevent the battery pack from exploding by providing partitions between several cell units to minimize the propagation of a trigger cell malfunction to adjacent cells or the entire module, thereby ensuring sufficient time for users to evacuate in the event of a battery pack fire. [Overview of the project] [Problems that the invention aims to solve]

[0009] One objective of the present invention, created in view of the above-mentioned problems, is to provide a battery module that can prevent or delay to the maximum extent the propagation of heat and flames from a trigger cell experiencing thermal runaway to adjacent cells, thereby preventing the explosion of the battery pack and ensuring sufficient time for the user to evacuate in the event of battery pack ignition.

[0010] The technical problems that this invention aims to solve are not limited to those described above, and other problems not mentioned should be clearly understood by those skilled in the art from the description of the invention below. [Means for solving the problem]

[0011] The battery module according to the present invention may include a module case, a cell stack comprising a plurality of battery cells arranged in a stack in one direction and housed inside the module case, and at least one partition plate portion that separates the housing space between the battery cells or between the inner wall of the module case and one side of the cell stack, which is adjacent to the electrode leads at both ends of the battery cells.

[0012] The partition plate portion may include a top plate disposed on the upper surface of the cell stack, a busbar frame provided so as to be bent from both ends of the top plate and including lead slots through which the electrode leads pass, and a plurality of busbars electrically connected to the electrode leads, and a plurality of separation partitions protruding from the busbar frame that partition and separate the housing space along the stacking direction in which the battery cells are stacked.

[0013] The partition plate portion is positioned between the battery cells, but may further include flame-retardant pads whose ends penetrate and are exposed through the separation partition portion.

[0014] The separation partition wall portion may be provided with through holes through which the flame-retardant pad passes.

[0015] The upper plate and the busbar frame may be U-shaped with an open bottom.

[0016] The module case may include a case body having an open end and being hollow in shape so as to be able to fit the cell stack inside along its longitudinal direction, and a case cover facing one side of the cell stack and coupled to the open end of the case body.

[0017] An insulating plate may be provided on the upper plate, and a recessed portion for housing the insulating plate may be provided on the case body.

[0018] A first hinge portion may be provided between the upper plate and the busbar frame, which rotates with respect to the axis in the lateral direction (the stacking direction of the battery cells).

[0019] A second hinge portion may be provided between the busbar frame and the separation partition portion, which rotates with respect to a vertical axis (a direction perpendicular to the stacking direction of the battery cells).

[0020] According to another aspect of the present invention, a battery pack comprising one or more of the above-described battery modules may be provided.

[0021] According to yet another aspect of the present invention, an automobile including the battery pack may be provided. [Effects of the Invention]

[0022] According to one aspect of the present invention, a battery module is provided that can prevent or delay to the maximum extent the propagation of heat and flames from a trigger cell experiencing thermal runaway to adjacent cells, thereby preventing the explosion of the battery pack and ensuring sufficient time for the user to evacuate in the event of battery pack ignition.

[0023] That is, in the battery module according to the present invention, when a specific battery cell catches fire, the accommodation space inside the battery module (the space between the cell stack and the case cover) where hot air, flames, etc. can move is blocked and interrupted by the partition plate portion. Blocked by the partition plate portion, it becomes difficult for hot air, high-temperature particle particles, flames, etc. generated in the triggered cell that has caught fire to transfer to adjacent battery cells, and it becomes possible to maximally delay the chain ignition or explosion of the battery cells.

[0024] The following drawings attached to this specification illustrate the preferred embodiments of the present invention and are for the purpose of further understanding the technical idea of the present invention together with the content of the invention. Therefore, the present invention is not to be construed as being limited only to the matters described in the drawings.

Brief Explanation of Drawings

[0025] [Figure 1] It is a schematic perspective view of a battery module according to an embodiment of the present invention. [Figure 2] It is an exploded perspective view regarding the main components of the battery module of FIG. 1. [Figure 3] It is a schematic perspective view of the partition plate portion of FIG. 2. [Figure 4] It is a schematic front view of a cell stack and a partition plate portion according to an embodiment of the present invention. [Figure 5] It is a schematic cross-sectional view regarding a part of the battery module according to an embodiment of the present invention. [Figure 6] It is a schematic longitudinal sectional view regarding a part of the battery module according to an embodiment of the present invention. [Figure 7] It is a schematic perspective view of a state in which an insulating plate and a first hinge portion are attached to a partition plate portion according to another embodiment of the present invention. [Figure 8] It is a longitudinal sectional view of a state in which a partition plate portion according to another embodiment of the present invention is assembled to a cell stack and a module case. [Figure 9]This is a perspective view of a partition plate according to yet another embodiment of the present invention. [Figure 10] Figure 9 is a schematic cross-sectional view of a portion of the assembled battery module, specifically the partition plate section. [Modes for carrying out the invention]

[0026] Preferred embodiments of the present invention will now be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and in the claims are not to be interpreted in their usual or dictionary sense, but rather in a sense and concept corresponding to the technical idea of ​​the present invention, in accordance with the principle that the inventor himself may appropriately define the concept of terms in order to best describe the invention. Therefore, it should be understood that the embodiments described herein and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent the entire technical idea of ​​the present invention, and that there may be a variety of equivalents and modifications that can be substituted thereat the time of this application.

[0027] Figure 1 is a schematic perspective view of a battery module according to one embodiment of the present invention; Figure 2 is an exploded perspective view of the main components of the battery module of Figure 1; Figure 3 is a schematic perspective view of the partition plate portion of Figure 2; Figure 4 is a schematic front view of the cell stack and partition plate portion according to one embodiment of the present invention; Figure 5 is a schematic cross-sectional view of a portion of the battery module according to one embodiment of the present invention; and Figure 6 is a schematic longitudinal cross-sectional view of a portion of the battery module according to one embodiment of the present invention.

[0028] Referring to these drawings, a battery module 10 according to one embodiment of the present invention includes a module case 200, a cell stack 110, and a partition plate portion 300.

[0029] For the sake of ease of explanation, we will start by describing the cell laminate 110.

[0030] The cell stack 110 is an assembly of battery cells 111 formed by stacking multiple battery cells 111. That is, as shown in Figure 2, the cell stack 110 can be a collection of multiple pouch-type battery cells 111 stacked in one direction (X direction) with their wide surfaces facing upright. Multiple cell stacks can then come together to form a cell assembly.

[0031] The pouch-type battery cell 111 includes an electrode assembly, a pouch case housing the electrode assembly, and a pair of electrode leads 112 connected to the electrode assembly and extended to the outside of the pouch case to function as electrode terminals. The pair of electrode leads 112 are extended from both ends of the battery cell 111, i.e., in the longitudinal direction (+Y direction or -Y direction).

[0032] If necessary, the pouch-type battery cell 111 may have a shape in which the electrode leads 112 are located only at one end in the Y-axis direction, for example, at the end in the +Y-axis direction. On the other hand, the present invention is not limited in any way by the specific type, shape or form of such battery cell 111, and a wide variety of battery cells 111 known at the time of filing of the present invention can be used to constitute the cell stack 110 of the present invention.

[0033] The module case 200 is a component for protecting the cell laminate 110 from external impacts and the like, and is preferably made from a material with excellent mechanical rigidity. The module case 200 according to this embodiment includes a case body 210 and a case cover 220, as shown in Figures 1 and 2.

[0034] The case body 210 may be shaped like a square tube with open ends O at both ends in the longitudinal direction and a hollow structure with an empty interior, so that the cell laminate 110 can be fitted into it along its longitudinal direction. That is, the case body 210 may be configured so that the cell laminate 110 can be fitted into it by sliding or interlocking.

[0035] The case cover 220 faces one side of the cell stack 110 where the electrode leads 112 of the battery cells 111 are located, that is, the portion connected to the busbars 130 on the busbar frame 120 so as not to be exposed to the outside, and may be provided so as to be coupled to the open end O of the case body 210. The case cover 220 may be configured, for example, to be made of an insulating material on the inside and a metal material on the outside, and may be configured to be fixedly coupled to the case body 210 by welding.

[0036] On the other hand, although not shown in the diagram for ease of drawing, the case cover 220 may have partial holes or slits to expose components that need to be exposed to the outside, such as the positive and negative terminals or connectors of the battery module 10.

[0037] The partition plate portion 300 is provided between the battery cells 111 or on one side of the cell stack 110, and serves to partition the housing space between the battery cells 111 or between the inner wall of the module case 200 adjacent to the electrode leads 112 at both ends of the battery cells 111 and one side of the cell stack 110.

[0038] The partition plate section 300 mainly includes, as shown in Figure 3, a top plate 310 positioned on the upper surface of the cell stack 110, a busbar frame 320 provided so as to bend from both ends of the top plate 310 and including lead slots 321 through which the electrode leads 112 pass and a plurality of busbars 322 electrically connected to the electrode leads 112, and a plurality of separation partition sections 330 that protrude from the busbar frame 320 and partition the housing space along the stacking direction in which the battery cells 111 are stacked, and a flame-retardant pad 340 positioned between the battery cells 111, but with both ends exposed by passing through the separation partition sections 330.

[0039] The top plate 310 is provided to cover the upper surface of the cell stack 110 and has a predetermined width (for example, the thickness of six battery cells 111), and a pair of busbar frames 320 are connected to each other at both ends of the top plate 310. As a result, the arrangement of the top plate 310 and the busbar frames 320 takes on a U-shape with the lower part open.

[0040] The top plate 310 is positioned on the upper surface of the cell stack 110 and partitions the gap (play) space between the upper surface of the cell stack 110 and the case body 210, thereby preventing or delaying the primary propagation of heat and flames from a trigger cell experiencing thermal runaway to adjacent cells.

[0041] As shown in Figures 3 and 4, the busbar frame 320 is provided so as to be bent from both ends of the top plate 310, and is shaped like a plate that covers the front (+Y direction) or rear (-Y direction) of the cell stack 110. Since such a busbar frame 320 can be injection molded from an electrically insulating material together with the top plate 310, it plays a role in preventing or delaying the primary propagation of heat and flames from a trigger cell experiencing thermal runaway to adjacent cells.

[0042] The busbar frame 320 includes a plurality of lead slots 321 through which the electrode leads 112 of the pouch-type battery cell 111 can pass in the direction of the +Y axis or the -Y axis, and the plurality of lead slots 321 can be arranged along the stacking direction (X direction) of the battery cell 111. This makes it possible for the electrode leads 112 to pass through the lead slots 321.

[0043] As shown in Figure 4, the busbar 322 is provided between a pair of lead slots 321, and a pair of electrode leads 112 exposed through the lead slots 321 are bent toward the central busbar 322 side, welded to the surface of the busbar 322, and fixed in place for electrical connection. Multiple such busbars 322 are arranged along the stacking direction in which the battery cells 111 are stacked. Multiple busbars 322 are made of an electrically conductive material, such as a metal like copper, aluminum, or nickel, and are electrically connected to the electrode leads 112.

[0044] On the other hand, the drawing simplifies the configuration so that only the electrode leads 112 are exposed at both ends of the cell stack 110, i.e., on the front and rear surfaces. However, in addition to the electrode leads 112, additional components such as connectors, other printed circuit boards (PCBs), sensing means, etc., may also be provided, and a separate support structure may be attached to support and fix these additional components.

[0045] As shown in Figures 5 and 6, the separation partition 330 protrudes from the busbar frame 320 and partitions and separates the housing space between the inner walls of the module case 200 adjacent to the electrode leads 112 at both ends of the battery cell 111. Multiple separation partitions 330 can be provided to partition and separate the housing space into multiple sections along the stacking direction in which the battery cells 111 are stacked.

[0046] As shown in Figure 6, the height of the separation partition 330 is set to correspond to the height of the upper surface of the upper plate 310, and is positioned to abut against the bottom wall of the module case 200, so that there is no gap at the top or bottom of the housing space where the electrode leads 112 are arranged, allowing for complete partitioning and separation. Furthermore, the separation partition 330 is provided with through holes, through which both ends of the flame-retardant pad 340 can be exposed, protruding further outward relative to the ends of the separation partition 330.

[0047] Referring primarily to Figure 5, the flame-retardant pad 340 is positioned between the battery cells 111 to partition the gaps between them. Both ends of the flame-retardant pad 340 are positioned to pass through the through-holes in the separation partition wall 330 and be exposed to the housing space, and the tip of the flame-retardant pad 340 is positioned to abut against the inner wall of the case cover 220. Here, the flame-retardant pad 340 may be made of a material with low thermal conductivity and excellent heat resistance (for example, silicon, mica).

[0048] With this configuration, as shown in Figure 5, flame-retardant pads 340 are interposed in the gaps between battery cells 111, which minimizes the propagation of heat, high-temperature particles, and flames generated in the trigger cell that ignites during internal ignition of the battery module 10 to adjacent battery cells 111 in the stacking direction of the battery cells 111.

[0049] Furthermore, according to this implementation configuration, when the partition plate portion 300 is attached to the cell stack 110, and then the case body 210 and the case cover 220 are combined, as shown in Figures 5 and 6, the storage space between one side of the cell stack 110 and the adjacent case cover 220 is completely partitioned into spaces S1 and S2 by the separation partition portion 330 and the flame retardant pad 340. In this way, the separation partition portion 330 and the flame retardant pad 340 partition and separate the storage space, preventing the partial leakage and flow of hot air, high-temperature particles, flames, etc., from the ignited trigger cell into the storage space from propagating to the adjacent battery cell 111.

[0050] Furthermore, the battery cells 111 adjacent to the trigger cell, along with their electrode leads 112 and busbars 322, will not suffer as much thermal damage. As a result, the time it takes for all the battery cells 111 and the battery module to ignite or explode is extended, allowing the user to notice the fire before it spreads or ignites in the battery module 10, and providing sufficient time to evacuate in a safer environment.

[0051] Next, other embodiments of the battery module of the present invention will be briefly described based on Figures 7 to 10.

[0052] Figure 7 is a schematic perspective view of a partition plate portion according to another embodiment of the present invention with an insulating plate and a first hinge portion attached; Figure 8 is a longitudinal cross-sectional view of a partition plate portion according to another embodiment of the present invention assembled to a cell stack and a module case; Figure 9 is a perspective view of a partition plate portion according to yet another embodiment of the present invention; and Figure 10 is a schematic transverse cross-sectional view of a portion of a battery module in which the partition plate portion of Figure 9 is assembled.

[0053] The same part numbers as in the previous drawings refer to the same parts, and redundant explanations of the same parts are omitted. The explanation will focus on the differences from the previously described embodiment.

[0054] A battery module according to another embodiment of the present invention is provided with additional components in the partition plate portion 300A compared to the embodiment described above. Specifically, the top plate 310 is further provided with an insulating plate 311, the case body 210 is provided with a housing step portion 211 that accommodates the insulating plate 311, and a first hinge portion 350 that rotates with respect to a lateral axis may be provided between the top plate 310 and the busbar frame 320.

[0055] As shown in Figures 7 and 8, an insulating plate 311 is interposed between the top plate 310 and the case body 210, where the insulating plate 311 is a means for insulating the cell laminate 110 from the module case 200 which is made of a metal material for rigidity, and is made of an electrically insulating material such as plastic, and may be placed on top of the top plate 310.

[0056] Furthermore, the insulating plate 311 can also function to fill gaps or loose spaces when assembly tolerances are formed when the cell laminate 110 and the partition plate portion 300 connected thereto are assembled inside the case body 210.

[0057] Furthermore, the case body 210 is provided with a recessed section 211 into which the insulating plate 311 is housed, allowing the insulating plate 311 to be easily fitted into the interior of the case body 210 via the recessed section 211.

[0058] Furthermore, since the top plate 310 and the busbar frame 320 are arranged in a U-shape, which may make assembly difficult, they may be assembled to the cell laminate 110 with the busbar frame 320 expanded to align with the top plate 310 via the first hinge portion 350, or, after the top plate 310 is placed and assembled in the cell laminate 110, the busbar frame 320 may be rotated 90° via the first hinge portion 350 to expose the electrode leads 112 in the lead slots 321, and then welded together, making assembly easier.

[0059] At this point, the flame-retardant pad 340, which is already interposed in the battery cell 111, is also easier to assemble because the busbar frame 320 rotates.

[0060] On the other hand, in yet another embodiment of the present invention, the partition plate portion 300B of the battery module may be provided with a second hinge portion 360 that rotates between the busbar frame 320 and the separation partition wall portion 330 with respect to a vertical axis.

[0061] Furthermore, as needed, the separation partition 330 can rotate with respect to its vertical axis, as shown in Figures 9 and 10.

[0062] In other words, in the event that an event occurs in any battery cell 111, the separation partition 330B can be rotated manually or automatically via the second hinge 360 ​​to tilt the separation partition 330B at a predetermined angle relative to the busbar frame 320, compared to the configuration in which the separation partition 330 shown in Figures 5 to 7 is fixed. For example, depending on the degree of runaway and the amount of flame generated, the separation partition 330B on the right side in Figure 10 can be rotated clockwise by a predetermined angle via the second hinge 360, allowing the tilted separation partition 330B to actively block the flame and further easily partition and separate the spaces S1 and S2.

[0063] Conversely, the second hinge portion 360 may be positioned to rotate counterclockwise by a predetermined angle to temporarily avoid flames and protect the separation partition portion 330B or the flame-retardant pad 340. Furthermore, by varying the degree of angle of the separation partition portion 330B via the second hinge portion 360, it is possible to respond quickly to the occurrence of an event or a runaway state, thereby enabling proactive management of thermal damage.

[0064] On the other hand, a battery pack (not shown) according to the present invention may include one or more of the above-described battery modules 10. The battery pack according to the present invention may further include a master battery management system (BMS) for integrated control of the charging and discharging of one or more battery modules 10, a current sensor, a fuse, and a pack case for housing the above-described components.

[0065] The battery pack according to the present invention is applicable to energy storage devices or to automobiles such as electric scooters, electric vehicles, and hybrid vehicles.

[0066] Although the present invention has been described above with reference to limited embodiments and drawings, it goes without saying that the present invention is not limited thereto, and that various modifications and variations can be made by persons with ordinary skill in the art to which the present invention pertains, within the equivalent scope of the technical concept and claims of the present invention.

[0067] On the other hand, while directional terms such as up, down, left, right, front, and back have been used in this specification, these terms are used merely for ease of explanation, and it will be obvious to those skilled in the art that they may vary depending on the position of the object in question, the observer's position, etc. [Explanation of Symbols]

[0068] 10 Battery Modules 110-cell stack 111 Pouch-type battery cells 111 battery cells 112 Electrode Leads 120 Busbar Frame 130 Bus Bar 200 Module Case 210 Case Body 211 Enclosed stepped section 220 Case Cover 300 Plate section 300A Plate Section 300B Plate Section 310 Top plate 311 Insulating Plate 320 Busbar Frame 321 lead slots 322 Bus Bar 330 Separation wall section 330B Separation bulkhead 340 Flame-retardant pads 350 First hinge section 360 Second hinge section O open end

Claims

1. Module case and A cell stack consisting of multiple battery cells housed inside the module case and arranged in a stack in one direction, At least one partition plate portion that divides the housing space between adjacent battery cells or between the inner wall of the module case adjacent to the electrode leads of the battery cells and one side of the cell stack, In a battery module including, The aforementioned partition plate section is, An upper plate disposed on the upper surface of the cell stack, A busbar frame is provided so as to be bent from both ends of the upper plate, and includes lead slots through which the electrode leads pass, and a plurality of busbars electrically connected to the electrode leads, Multiple separation partitions are provided protruding from the busbar frame and divide the housing space along the stacking direction in which the battery cells are stacked, A battery module, including the battery module.

2. The battery module according to claim 1, wherein the partition plate portion further includes a flame-retardant pad disposed between the battery cells, the flame-retardant pad having both ends exposed through the separation partition portion.

3. The battery module according to claim 2, wherein the separation partition wall portion is provided with a through hole through which the flame-retardant pad passes.

4. The battery module according to claim 2, wherein the top plate and the busbar frame are U-shaped with an open bottom.

5. The aforementioned module case is A case body having an open end and being hollow in shape so that the cell laminate can be fitted inside along its longitudinal direction, A case cover is located opposite one side of the cell stack and is coupled to the open end of the case body, The battery module according to claim 2, including the following:

6. An insulating plate is provided on the upper plate. The battery module according to claim 5, wherein the case body is provided with a housing step portion in which the insulating plate is housed.

7. The battery module according to claim 6, wherein a first hinge portion is provided between the top plate and the busbar frame, the hinge portion rotates with respect to the axis in the stacking direction.

8. The battery module according to claim 6, wherein a second hinge portion is provided between the busbar frame and the separation partition portion, the hinge portion rotates with respect to an axis perpendicular to the stacking direction.

9. A battery pack comprising a battery module according to any one of claims 1 to 8.

10. An automobile comprising the battery pack described in claim 9.

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