Battery packs and automobiles containing them

Abstract

A battery pack and an automobile including the same are disclosed. A battery pack according to one embodiment of the present invention includes a plurality of battery modules in which a plurality of battery cells are stacked, a pack case in which the plurality of battery modules are housed, and a lid member coupled to the pack case, wherein at least one of the lid members is formed to be deformable and has a double structure.

Description

Technical Field

[0001] The present invention relates to a battery pack and a vehicle including the same, and more particularly, to a battery pack in which heat is uniformly diffused and gas is smoothly discharged when a thermal event occurs, and a vehicle including the same.

[0002] This application claims priority based on Korean Patent Application No. 10-2024-0028132 filed on February 27, 2024, and all of the contents disclosed in the specification and drawings of the application are incorporated into this application.

Background Art

[0003] Generally, a secondary battery refers to a battery that can be repeatedly charged and discharged, such as a lithium-ion battery, a lithium polymer battery, a nickel cadmium battery, a nickel metal hydride battery, or a nickel zinc battery. A basic battery cell can provide an output voltage of about \(2.5V\) to \(4.2V\).

[0004] Recently, as such battery cells are applied to devices that require a high output voltage and a large charging capacity, such as electric vehicles and energy storage systems (ESS), a battery module configured by connecting a plurality of battery cells in series, in parallel, or in a combination of series and parallel, and a battery pack configured by further connecting such battery modules in series, in parallel, or in a combination of series and parallel are widely used.

[0005] Lithium secondary batteries have attracted attention due to advantages such as a high operating voltage and a much higher energy density. However, since an organic electrolyte is used, when a lithium secondary battery is overcharged, it induces overcurrent and overheating, and ultimately causes problems such as fires due to explosions and ignition.

[0006] Various types of rechargeable batteries include battery modules, in which multiple battery cells are stacked and placed in a module case, and which are equipped with a module case capable of protecting the battery cells; and battery packs, which include multiple battery modules.

[0007] Figure 1 is a cross-sectional view of a conventional battery pack.

[0008] Referring to Figure 1, in the case of a conventional battery pack 1, the lid member 3 that connects to the pack case 2 is fixed to the battery module 4 by fastening members 5 such as bolts, either in contact with or in close proximity to it. In other words, in the conventional battery pack 1, since one lid member 3 is firmly fixed to the pack case 2, even if a flame occurs, there is no margin or buffer space formed for the heat or gas from the flame to move.

[0009] In this state, if a flame occurs in the battery cell 6, the heat from the flame is blocked by the cover member 3 and does not dissipate, instead concentrating inside the battery module 4 where the flame originated. Furthermore, the gas generated inside the battery module 4 is not released, increasing the internal pressure and raising the likelihood of explosion of the battery module 4 or the battery pack 1.

[0010] In this scenario, if an explosion occurs in the battery module 4 where the flame originated, the flame may spread to other battery modules 4, causing a thermal runaway phenomenon. If the flame escapes to the outside due to such a thermal runaway phenomenon, there is a problem that the driver of the electric vehicle may be burned or put in a dangerous situation.

[0011] Alternatively, there is a problem in that the battery module 4 or battery pack 1 may be damaged or completely burned due to a chain reaction of flames caused by flame propagation, making it difficult to ensure the safety of the battery module 4 or battery pack 1. [Overview of the project] [Problems that the invention aims to solve]

[0012] The present invention aims to provide a battery pack and an automobile including it that have a uniform heat distribution by preventing heat concentration by ensuring that the heat from a flame generated in any one battery cell is uniformly diffused within the battery pack.

[0013] Another objective of the present invention is to provide a battery pack and an automobile including it, in which gas is easily discharged by facilitating smooth venting.

[0014] Furthermore, the present invention provides a battery module capable of preventing thermal runaway phenomena by preventing a chain reaction of flames caused by flame propagation, a battery pack including the same, and an automobile.

[0015] However, the technical problems that this invention aims to solve are not limited to those described above, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention below. [Means for solving the problem]

[0016] According to one aspect of the present invention, a battery pack may be provided that includes a plurality of battery modules in which a plurality of battery cells are stacked, a pack case in which the plurality of battery modules are housed, and a lid member coupled to the pack case, wherein the lid member is configured as a double structure in which at least one is formed to be deformable.

[0017] In one embodiment, the lid member may include a first lid which is formed to be deformable on at least one side, and a second lid which is separated from the first lid by a predetermined distance.

[0018] In one embodiment, the first lid may be located on the inside and the second lid on the outside.

[0019] In one embodiment, the pack case includes a lower frame on which the plurality of battery modules are mounted, a side frame extending upward from an edge of the lower frame, an inner frame extending upward from inside the lower frame and coupled to the side frame, and a partition frame coupled to the inner frame and interposed between the plurality of battery modules. At least one of the inner frame and the partition frame may have a fastening coupling portion to which the second lid is fastened.

[0020] In one embodiment, the fastening coupling portion may include a protruding portion protruding from at least one of the inner frame and the partition frame, and a fastening hole formed in the protruding portion.

[0021] In one embodiment, a through hole may be formed in the first lid at a position corresponding to the protruding portion.

[0022] In one embodiment, the through hole of the first lid may pass through the protruding portion, and the first lid may contact at least one of the inner frame and the partition frame.

[0023] In one embodiment, the second lid may be positioned above the first lid and fastened to the fastening coupling portion.

[0024] In one embodiment, the first lid is fastened at an edge, and a movement passage may be formed by deformation occurring in a portion excluding the edge by vent gas generated in the battery cell.

[0025] In one embodiment, the first lid may be deformed within the interval formed between the first lid and the second lid.

[0026] In one embodiment, a vent portion may be formed in the pack case.

[0027] In one embodiment, the vent portion may include a vent hole through which vent gas generated from the battery cell is discharged, and a vent valve that closes the vent hole and is opened when the internal pressure of the pack case exceeds a preset value.

[0028] In one embodiment, a movement passage is formed by deforming the first lid, and the vent gas can move to the vent portion through the movement passage.

[0029] According to another aspect of the present invention, an automobile including at least one of the above-described battery packs can be provided.

Effects of the Invention

[0030] According to an embodiment of the present invention, when a flame is generated from any one of the battery cells, it is possible to have a uniform heat distribution by preventing heat concentration by allowing the heat from the flame to be uniformly diffused inside the battery pack.

[0031] In addition, by facilitating venting, gas can be easily discharged.

[0032] In addition, a thermal runaway phenomenon can be prevented by preventing a chain reaction of flames due to flame propagation.

[0033] However, the effects of the present invention are not limited to the above-described effects, and other effects of the present invention not mentioned will be clearly understood by those skilled in the art from the description of the claims. <0​​​​​​​​​​​​ [Figure 2] This is a perspective view of a battery pack according to one embodiment of the present invention. [Figure 3] This is a perspective view of a disassembled battery pack according to one embodiment of the present invention. [Figure 4] Figure 3 shows how the first lid is attached to the pack case. [Figure 5] This is an enlarged view of section B in Figure 4. [Figure 6] This is a plan view showing a battery pack with the cover member removed, according to one embodiment of the present invention. [Figure 7] This diagram shows the vent portion of a battery pack according to one embodiment of the present invention. [Figure 8] This figure shows the vent holes in the vent section of Figure 7. [Figure 9] This is a cross-sectional view along line A-A' in Figure 2. [Figure 10] This figure shows how the first lid of Figure 9 has been deformed. [Figure 11] This is a diagram illustrating an automobile including a battery pack according to each embodiment of the present invention. [Modes for carrying out the invention]

[0036] 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 should not be interpreted in a manner limited to their ordinary or dictionary meanings, but rather in a manner consistent with the technical idea of ​​the present invention, in accordance with the principle that the inventor himself may appropriately define the concepts of terms in order to best describe the invention. Accordingly, 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 entirety of the technical idea of ​​the present invention, and that there may be a variety of equivalents and modifications that can be substituted therein at the time of this application.

[0037] The size of each component or specific part of a component in the drawings may be exaggerated, omitted, or shown schematically for the sake of clarity and ease of explanation. Therefore, the size of each component may not fully reflect its actual size. Specific descriptions of known functions or configurations related to the present invention will be omitted if they are deemed to unnecessarily obscure the gist of the invention.

[0038] As used herein, the terms “joining” or “connecting” include not only cases where one member is directly joined or directly connected to another member, but also cases where one member is indirectly joined or indirectly connected to another member via a connecting member.

[0039] Figure 2 is a perspective view of a battery pack according to one embodiment of the present invention, and Figure 3 is an exploded perspective view of the battery pack according to one embodiment of the present invention. Figure 4 shows the first lid of Figure 3 coupled to the pack case, and Figure 5 is an enlarged view of part B of Figure 4. Figure 6 is a plan view showing the battery pack according to one embodiment of the present invention with the lid member removed, and Figure 7 shows the vent portion of the battery pack according to one embodiment of the present invention. Figure 8 shows the vent hole of the vent portion in Figure 7, Figure 9 is a cross-sectional view along A-A' in Figure 2, and Figure 10 shows the first lid of Figure 9 in a deformed state.

[0040] Referring to Figures 2 and 3, a battery pack 10 according to one embodiment of the present invention may be configured to include a plurality of battery modules 100, a pack case 200, and a lid member 300.

[0041] Each battery module 100 has multiple battery cells 110 (see Figure 9) stacked on top of each other, and multiple battery modules 100 can be provided and arranged in various ways. For example, as shown in Figure 3, the battery modules 100 can be arranged in the horizontal and vertical directions, but are not limited to this.

[0042] Referring to Figure 9, the battery module 100 may comprise a plurality of battery cells 110 and a module case 120.

[0043] Multiple battery cells 110 can be stacked on top of each other. The battery cells 110 may have diverse structures, and multiple battery cells 110 can be stacked in diverse ways.

[0044] The battery cell 110 may have a structure in which multiple unit cells arranged in the order of positive electrode plate / separator / negative electrode plate, or bi-cells arranged in the order of positive electrode plate / separator / negative electrode plate / separator / positive electrode plate / separator / negative electrode plate are stacked according to the battery capacity.

[0045] The battery cell 110 may be provided with electrode leads. Electrode leads are a type of terminal exposed to the outside and connected to external devices, and may be made of a conductive material. Electrode leads may include a positive electrode lead and a negative electrode lead.

[0046] The positive electrode lead and the negative electrode lead may be positioned in opposite directions along the longitudinal direction of the battery cell 110, or they may be positioned in the same direction along the longitudinal direction of the battery cell 110.

[0047] The battery cell 110 may comprise a plurality of cartridges (not shown) that house the battery cell 110. Each cartridge (not shown) may be manufactured by plastic injection molding, and a plurality of cartridges (not shown) having a housing for housing the battery cell 110 may be stacked. A cartridge assembly formed by stacking a plurality of cartridges (not shown) may be provided with connector elements or terminal elements.

[0048] The connector element may include various forms of electrical connection components or connection members for connecting to, for example, a Battery Management System (BMS) (not shown) that can provide data relating to the voltage or temperature of the battery cell 110.

[0049] The terminal element is a main terminal connected to the battery cell 110, and includes a positive terminal and a negative terminal. The terminal element can be electrically connected to the outside by being provided with terminal bolts. On the other hand, the battery cell 110 can have a variety of shapes.

[0050] Referring to Figure 9, multiple battery cells 110 are stacked and housed in the module case 120. The module case 120 surrounds the multiple battery cells 110, thereby protecting the battery cells 110 from external vibrations and shocks.

[0051] The module case 120 may be formed in a shape corresponding to the shape of a stack of multiple battery cells 110. For example, if the stack of multiple battery cells 110 is formed in a hexahedral shape, the module case 120 may also be formed in a corresponding hexahedral shape. However, it is not limited to this. Here, the module case 120 may include an upper module case 120, a lower module case 120, and a side module case 120.

[0052] Furthermore, the module case 120 can be manufactured, for example, by bending a plate of metal material, thereby allowing the module case 120 to be manufactured as a single unit. When the module case 120 is manufactured as a single unit, it has the effect of simplifying the joining process. Alternatively, the module case 120 can be provided as a separate unit and joined by welding or the like. However, the material of the module case 120 is not limited to metal material.

[0053] Referring to Figures 3 and 6, the pack case 200 houses multiple battery modules 100. The pack case 200 may be composed of, for example, a lower frame 210, a side frame 220, an inner frame 230, and a partition frame 240.

[0054] The lower frame 210 is configured to accommodate multiple battery modules 100. The lower frame 210 may, but is not limited to, be formed in the shape of a rectangular plate. The lower frame 210 forms the bottom of the pack case 200.

[0055] The side frame 220 may be configured to extend upward from the edge of the lower frame 210. The side frame 220 defines the height of the pack case 200 and forms a predetermined space between it and the lower frame 210. Multiple battery modules 100 are mounted in the space between the side frame 220 and the lower frame 210. The side frame 220 may include long-side side frames with relatively long lengths and short-side frames with relatively long lengths. Alternatively, all of the side frames 220 may be of the same length.

[0056] The inner frame 230 extends upward from inside the lower frame 210 and connects to the side frame 220. One or more inner frames 230 may be provided, and multiple battery modules 100 may be arranged facing each other with respect to the inner frame 230.

[0057] The partition frame 240 is connected to the inner frame 230. The partition frame 240 is then interposed between multiple battery modules 100. In Figure 3, one partition frame 240 is positioned between two adjacent battery modules 100, but this is not the only configuration.

[0058] Here, at least one of the inner frame 230 and the partition frame 240 may have a fastening joint 250 to which the second lid 320 is fastened, but this will be described later.

[0059] The lid member 300 is connected to the pack case 200. The lid member 300 is composed of a double structure in which at least one of the layers is deformable.

[0060] Referring to Figure 3, the lid member 300 may include, for example, a first lid 310 and a second lid 320. The first lid 310 may be formed to be deformable on at least one side. The first lid 310 may be formed so that deformation occurs at various locations. For example, it may be formed so that deformation occurs at the center of the first lid 310.

[0061] Referring to Figure 4, the first lid 310 may be fixed by fastening with bolts or the like after contacting the joint 350 at its edge, while the central part is not fastened. Referring to Figure 3, the first lid 310 may be located inside the second lid 320.

[0062] Referring to Figure 9, the second lid 320 is separated from the first lid 310 by a predetermined distance 330. That is, a space can be formed between the first lid 310 and the second lid 320. Referring to Figure 3, the second lid 320 may be located outside the first lid 310.

[0063] Referring to Figure 3, as described above, the fastening joint 250 is formed in at least one of the inner frame 230 and the partition frame 240, and the second lid 320 can be fastened to the fastening joint 250 by fastening members such as bolts.

[0064] Referring to Figures 4 and 5, the fastening joint 250 may include a projection 251 and a fastening hole 252. The projection 251 may be formed to protrude from at least one of the inner frame 230 and the partition frame 240 (see Figure 3). The fastening hole 252 is formed in the projection 251. Here, the second lid 320 is located above the first lid 310 and can be fastened to the fastening joint 250.

[0065] More specifically, as shown in Figure 3, a through hole 311 may be formed in the first lid 310 at a position corresponding to the protrusion 251. Then, as shown in Figure 4, when the first lid 310 is mounted on the pack case 200 for coupling with the pack case 200, the through hole 311 of the first lid 310 passes through the protrusion 251, and the first lid 310 may come into contact with at least one of the inner frame 230 and the partition frame 240.

[0066] In other words, the first lid 310 is placed on the inner frame 230 and the bulkhead frame 240 without being fixed to the inner frame 230 and the bulkhead frame 240 by passing through the fastening joint 250, and the edge of the first lid 310 is fixed to the pack case 200, so if flames and gases are generated and the internal pressure of the battery module 100 increases, the shape of the center of the first lid 310 may be deformed (for example, changed so that the center bulges upward).

[0067] Here, the first lid 310 can be deformed within the gap 330 formed between it and the second lid 320.

[0068] For example, referring to Figure 9, under normal conditions, the first lid 310 is maintained in contact with the inner frame 230 and the bulkhead frame 240. However, if flames and gases are generated and the internal pressure of the battery module 100 increases, the first lid 310 deforms so that its center bulges upward, as shown in Figure 10. When the first lid 310 is deformed in this way, a passage 340 is formed between the deformed first lid 310 and the battery cell 110.

[0069] In other words, the flame and vent gas generated in the battery cell 110 cause deformation in the central part of the first lid 310, excluding the edges, and as shown by the arrows in Figure 10, the heat from the flame diffuses to the other battery modules 100 through the movement passage 340, resulting in a uniform heat distribution throughout, thus preventing heat concentration on any one of the battery modules 100.

[0070] As shown by the arrows in Figure 10, the vent gas can be moved through the moving passage 340 to the vent section 260 and discharged. Referring to Figures 7 and 8, the pack case 200 may have a vent section 260 formed therein.

[0071] The vent section 260 may include a vent hole 261 and a vent valve 262. Referring to Figure 8, the vent hole 261 is a hole through which vent gas generated from the battery cell 110 is discharged, and may be formed in the pack case 200, for example, the side frame 220, but is not limited thereto.

[0072] Referring to Figure 7, a vent valve 262 may be provided in the vent hole 261. The vent valve 262 can be configured in various ways. For example, the vent valve 262 may be configured to close the vent hole 261 and open when the internal pressure of the pack case 200 exceeds a preset value.

[0073] In other words, the vent valve 262 normally closes the vent hole 261, but if vent gas leaks from the battery cell 110 and the internal pressure of the pack case 200 exceeds a preset value or range, the vent valve 262 opens and the vent gas is discharged from the pack case 200 through the vent hole 261.

[0074] As described above, the flame and vent gas generated in the battery cell 110 cause deformation in the first lid 310, forming a movement passage 340 between the first lid 310 and the battery cell 110 as shown in Figure 10. The vent gas then moves along the movement passage 340 to the vent section 260 (see arrow in Figure 10), and the vent valve 262 is opened by the vent gas that has moved in this way, allowing the vent gas to be discharged to the outside of the pack case 200.

[0075] In other words, the movement passage 340 formed by the deformation of the first lid 310 facilitates venting, allowing gas to be easily discharged.

[0076] As mentioned above, the heat is diffused to the other battery modules 100 through the transfer passage 340, preventing heat concentration in any one of the battery modules 100, thereby enabling a uniform heat distribution.

[0077] Furthermore, the vent gas discharge is facilitated by the movement passage 340, which in turn prevents a chain reaction of flames caused by flame propagation and thus prevents thermal runaway.

[0078] Figure 11 is a diagram illustrating an automobile including a battery pack according to each embodiment of the present invention.

[0079] Referring to Figure 11, an automobile 20 according to one embodiment of the present invention may include one or more battery packs 10 according to the embodiments described above. Here, the automobile 20 includes various types of automobiles that use electricity, such as electric vehicles and hybrid vehicles.

[0080] In this specification, terms indicating direction such as up, down, left, right, front, and back are used. However, such terms indicate relative positions and are used only for the convenience of explanation. It is obvious to those skilled in the art that these positions can change depending on the position of the object in question, the observer's position, etc.

[0081] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and of course, various modifications and variations are possible within the equivalent scope of the technical concept of the present invention and the claims below by persons with ordinary skill in the art to which the present invention pertains. Therefore, the embodiments described above should be considered from an explanatory rather than restrictive viewpoint. That is, the true technical concept of the present invention is shown in the claims, and all differences within the equivalent scope thereto should be interpreted as being included in the present invention. [Industrial applicability]

[0082] The present invention relates to a battery pack and an automobile including the same, and is particularly applicable to the secondary battery industry.

Claims

1. Multiple battery modules, each consisting of multiple battery cells stacked on top of each other, A pack case in which the aforementioned multiple battery modules are housed, Includes a lid member that connects to the pack case, The battery pack is characterized in that the lid member is composed of a double structure in which at least one is formed to be deformable.

2. The aforementioned lid member is A first lid, in which at least one side is formed to be deformable, The battery pack according to claim 1, further comprising a second lid spaced at a predetermined interval from the first lid.

3. The battery pack according to claim 2, characterized in that the first lid is located on the inside and the second lid is located on the outside.

4. The aforementioned pack case is The lower frame on which the aforementioned multiple battery modules are mounted, A side frame extending upward from the edge of the lower frame, An inner frame extending upward from the inside of the lower frame and connected to the side frame, Includes a partition frame coupled to the inner frame and interposed between the plurality of battery modules, The battery pack according to claim 3, characterized in that at least one of the inner frame and the partition frame has a fastening joint portion formed therein, to which the second lid is fastened.

5. The fastening joint is, A protruding portion that protrudes from at least one of the inner frame and the partition wall frame, The battery pack according to claim 4, characterized in that it includes a fastening hole formed in the protruding portion.

6. The battery pack according to claim 5, characterized in that the first lid has a through hole formed at a position corresponding to the protruding portion.

7. The battery pack according to claim 6, characterized in that the through hole of the first lid passes through the protruding portion and the first lid contacts at least one of the inner frame and the partition frame.

8. The battery pack according to claim 4, characterized in that the second lid is located above the first lid and fastened to the fastening coupling portion.

9. The battery pack according to claim 2, characterized in that the first lid is fastened at its edge, and deformation occurs in the portion excluding the edge due to vent gas generated in the battery cell, thereby forming a movement passage.

10. The battery pack according to claim 2, characterized in that the first lid is deformed within the gap formed between it and the second lid.

11. The battery pack according to claim 2, characterized in that a vent portion is formed in the pack case.

12. The aforementioned vent section is, A vent hole through which vent gas generated from the aforementioned battery cell is discharged, The battery pack according to claim 11, further comprising a vent valve that closes the vent hole and is opened when the internal pressure of the pack case exceeds a preset value.

13. The battery pack according to claim 12, characterized in that the first lid is deformed to form a passage, and the vent gas moves to the vent section through the passage.

14. An automobile comprising at least one battery pack according to any one of claims 1 to 13.

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