Battery modules, battery packs containing them, and automobiles

Abstract

A battery module, a battery pack including the same, and an automobile are disclosed. A battery module according to one embodiment of the present invention includes a battery cell stack in which a plurality of battery cells are stacked, a case in which the battery cell stack is housed, and a heat-shrinkable member that is bonded to the battery cells and shrinks with heat.

Description

Technical Field

[0001] The present invention relates to a battery module, a battery pack including the same, and a vehicle, and more particularly, to a battery module capable of protecting a battery cell from flame or high-temperature gas, a battery pack including the same, and a vehicle.

[0002] This application claims priority based on Korean Patent Application No. 10-2024-0021946 filed on February 15, 2024, and all 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 battery cell, which is the most basic secondary battery, 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] Although lithium secondary batteries have attracted attention due to advantages such as a high operating voltage and a much higher energy density, 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 explosion or ignition.

[0006] Various types of rechargeable batteries include battery modules in which multiple battery cells are stacked and enclosed in a case that can protect the battery cells, and battery packs that include multiple battery modules.

[0007] If a flame occurs in at least one of the battery cells inside the battery module case, the flame can spread to other battery cells, potentially causing a thermal runaway phenomenon. If such a thermal runaway occurs and the flame escapes to the outside, there is a risk of burns to the driver of the electric vehicle or putting them in a dangerous situation.

[0008] Alternatively, a chain reaction of flames caused by flame propagation can damage, completely burn, or explode the battery module or battery pack, making it difficult to ensure the safety of the battery module or battery pack. [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] The present invention aims to provide a battery module capable of protecting other battery cells that are not catching fire if a flame occurs in any one of the battery cells, a battery pack including the same, and an automobile.

[0010] Another objective of the present invention is to provide 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.

[0011] Furthermore, another objective is to provide a battery module that does not affect the gas pockets of battery cells under normal conditions, a battery pack including the same, and an automobile.

[0012] 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]

[0013] According to one aspect of the present invention, a battery module may be provided that includes a battery cell stack in which a plurality of battery cells are stacked, a case in which the battery cell stack is housed, and a heat-shrinkable member that is bonded to the battery cells and shrinks due to heat.

[0014] In one embodiment, the battery cell is a pouch-type battery cell in which a terrace portion is formed in the area where the electrode leads are located, and the heat-shrinkable member can be bonded to the battery cell at a position close to the terrace portion.

[0015] In one embodiment, the heat-shrinkable member may be configured to surround the terrace portion and the electrode lead.

[0016] In one embodiment, the heat-shrinkable member may be formed in a strip shape to surround the terrace portion, with an open hole formed therein so that the electrode lead is exposed to the outside.

[0017] In one embodiment, if a flame occurs in an adjacent battery cell, the heat from the flame causes the heat-shrinkable member to contract, thereby closing the terrace portion and the electrode lead.

[0018] In one embodiment, the heat-shrinkable members are provided in pairs, and the pair of heat-shrinkable members can be coupled to both ends of the battery cell.

[0019] In one embodiment, the heat-shrinkable member can be fitted and coupled to the battery cell.

[0020] In one embodiment, the heat-shrinkable member can be bonded to the battery cell by bonding.

[0021] In one embodiment, the heat-shrinkable member may include an outer portion made of a refractory material and a heat-shrinkable frame that is coupled to the outer portion inside the outer portion and shrinks by heat.

[0022] In one embodiment, an inner portion made of a heat-insulating material and coupled to the heat-shrinkable frame inside the heat-shrinkable frame may be included.

[0023] In one embodiment, a gas pocket portion is formed in the battery cell, and the heat-shrinkable member may be coupled to the battery cell while avoiding interference with the gas pocket portion.

[0024] In one embodiment, the heat-shrinkable member may be made of a polyolefin material.

[0025] In one embodiment, an upper heat-shrinkable member may be coupled to the upper portion of the battery cell laminate so as to cover the upper portion of the battery cell laminate.

[0026] In addition, according to another aspect of the present invention, a battery pack including at least one of the aforementioned battery modules may be provided, and an automobile including at least one of the aforementioned battery modules may be provided.

Advantages of the Invention

[0027] According to an embodiment of the present invention, when a flame occurs in any one of the battery cells, other battery cells in which no flame has occurred can be protected.

[0028] In addition, by preventing a chain reaction of flames due to flame propagation, a thermal runaway phenomenon can be prevented.

[0029] In addition, it does not affect the gas pocket of the battery cell during normal times.

[0030] However, the effects of the present invention are not limited to those described above, and other effects of the present invention not mentioned will be clearly understood by those skilled in the art from the following description of the invention.

[0031] The following drawings accompanying this specification illustrate preferred embodiments of the invention and, together with the detailed description of the invention, serve to further illustrate the technical idea of ​​the invention. Therefore, the invention should not be construed as being limited solely to what is shown in the drawings. [Brief explanation of the drawing]

[0032] [Figure 1] This is a schematic perspective view of a battery module according to one embodiment of the present invention. [Figure 2] This is a schematic exploded perspective view of a battery module according to one embodiment of the present invention, showing how the heat-shrinkable material is connected to the battery cell. [Figure 3] This is a schematic exploded perspective view of a battery module according to one embodiment of the present invention, showing the heat-shrinkable material separated from the battery cells. [Figure 4] This is a perspective view showing a battery cell in a battery module according to one embodiment of the present invention, illustrating how the heat-shrinkable material is separated from the battery cell. [Figure 5] This figure shows a battery cell in a battery module according to one embodiment of the present invention, and is a front view showing how a heat-shrinkable member is bonded to the battery cell. [Figure 6] Figure 5 is a perspective view. [Figure 7] This is an enlarged view of section A in Figure 6. [Figure 8] This figure shows a battery cell in a battery module according to one embodiment of the present invention, illustrating how a heat-shrinkable material is shrinking due to heat. [Figure 9] Figure 2 is a schematic exploded perspective view of a modified embodiment of the battery module. [Figure 10]This figure schematically shows the configuration of a battery pack according to each embodiment of the present invention. [Figure 11] Figure 10 is a diagram illustrating an automobile that includes a battery pack. [Modes for carrying out the invention]

[0033] 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 appropriate to 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 and configurations shown in the drawings described herein 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.

[0034] 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.

[0035] 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.

[0036] Figure 1 is a schematic perspective view of a battery module according to one embodiment of the present invention. Figure 2 is a schematic exploded perspective view of a battery module according to one embodiment of the present invention, showing how the heat shrinkable member is coupled to the battery cell. Figure 3 is a schematic exploded perspective view of a battery module according to one embodiment of the present invention, showing how the heat shrinkable member is separated from the battery cell. Figure 4 is a perspective view showing a battery cell within a battery module according to one embodiment of the present invention, showing how the heat shrinkable member is separated from the battery cell. Figure 5 is a front view showing a battery cell in a battery module according to one embodiment of the present invention, showing how the heat shrinkable member is coupled to the battery cell. Figure 6 is a perspective view of Figure 5. Figure 7 is an enlarged view of part A in Figure 6. Figure 8 is a diagram showing a battery cell within a battery module according to one embodiment of the present invention, showing how the heat shrinkable member is shrinking due to heat.

[0037] Referring to Figures 1 and 2, a battery module 10 according to one embodiment of the present invention includes a battery cell stack 100, a case 200, and a heat-shrinkable member 300.

[0038] The battery cell stack 100 may be configured such that a plurality of battery cells 110 are stacked on top of each other. The battery cells 110 may have diverse structures, and the plurality of battery cells 110 may be stacked in diverse ways.

[0039] 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.

[0040] The battery cell 110 may be provided with electrode leads 111. The electrode leads 111 are a type of terminal that is exposed to the outside and connects to external devices, and a conductive material may be used. The electrode leads 111 may include a positive electrode lead and a negative electrode lead.

[0041] The battery cell 110 may be a pouch-type battery cell 110 in which a terrace portion 112 (see Figure 4) is formed in the area where the electrode leads 111 are located. When the battery cell 110 is a pouch-type battery cell 110, the heat-shrinkable member 300, which will be described later, can be bonded to the battery cell 110 at a position close to the terrace portion 112, as shown in Figure 6.

[0042] Multiple battery cells 110 can be electrically connected by a busbar 115. The busbar 115 can be formed in a variety of forms.

[0043] The battery cell stack 100 may comprise a plurality of cartridges (not shown) that house the battery cells 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 cells 110 can be stacked. The cartridge assembly formed by stacking the plurality of cartridges (not shown) may be provided with connector elements or terminal elements.

[0044] 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.

[0045] 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.

[0046] Referring to Figures 1 and 2, the case 200 houses the battery cell stack 100. The case 200 may include an upper case 210 and a lower case 220. The case 200 surrounds the battery cells 110, thereby protecting them from external vibrations and shocks.

[0047] Case 200 may include a mica plate formed from mica that possesses both thermal insulation and heat resistance to prevent flame leakage. Here, the mica plate may include not only flat mica plates but also shapes that combine flat and curved surfaces. However, the material of Case 200 is not limited to this.

[0048] The case 200 can be formed in a shape that corresponds to the shape of the battery cell stack 100. For example, if the battery cell stack 100 is provided in a hexahedral shape with a square cross-section, the case 200 can also be provided in a corresponding hexahedral shape.

[0049] The case 200 can be manufactured, for example, by bending a plate of metal material, thereby allowing the case 200 to be manufactured as a single unit. When the case 200 is manufactured as a single unit, it has the effect of simplifying the joining process. Alternatively, the case 200 can be provided as a separate unit and joined by welding or other means. However, the material of the case 200 is not limited to metal material.

[0050] Referring to Figures 2, 5, and 6, the heat-shrinkable member 300 is configured to be attached to the battery cell 110 and to shrink due to heat (see Figure 8). The heat-shrinkable member 300 may be configured to surround the electrode leads 111 and the terrace portion 112.

[0051] Referring to Figure 4, the heat-shrinkable member 300 can be formed into various shapes. For example, it can be formed in a strip shape. Referring to Figures 5 and 6, when the heat-shrinkable member 300 is formed in a strip shape, the strip-shaped heat-shrinkable member 300 can be configured to surround the electrode lead 111 and the terrace portion 112. Here, an open hole 310 can be formed in the strip-shaped heat-shrinkable member 300 so that the electrode lead 111 is exposed to the outside.

[0052] Referring further to Figure 4, gas pockets 113 and 114 may be formed in the battery cell 110. The gas pockets 113 and 114 are portions formed to collect gas generated inside the battery cell 110.

[0053] For example, a gas pocket portion 113 may be formed inside a terrace portion 112 located adjacent to the electrode lead 111. Alternatively, a gas pocket portion 114 may be separately formed on the upper part of the battery cell 110, as shown in Figure 4.

[0054] Here, the heat-shrinkable member 300 is configured to be coupled to the battery cell 110 while avoiding interference with the gas pocket portions 113 and 114. If interference occurs between the heat-shrinkable member 300 and the gas pocket portions 113 and 114, the function of the gas pocket portions 113 and 114 will be impaired. To prevent this, the heat-shrinkable member 300 can be fitted and coupled to the battery cell 110 in a way that does not interfere with the gas pocket portions 113 and 114. Alternatively, the heat-shrinkable member 300 can be bonded to the battery cell 110 in a way that does not interfere with the gas pocket portions 113 and 114.

[0055] As a result, even when the heat-shrinkable member 300 is connected to the battery cell 110, a space is maintained between the heat-shrinkable member 300 and the battery cell 110, so that no flame is generated, and under normal operating conditions when the battery cell 110 is functioning normally, gas collection by the gas pockets 113 and 114 is performed smoothly.

[0056] Then, when a flame occurs in any of the battery cells 110, the heat from the flame causes the heat shrinkable member 300 to contract, as shown in Figure 8, and surround the electrode leads 111 and the terrace portion 112. In other words, when a flame occurs in another adjacent battery cell 110, the heat from the flame causes the heat shrinkable member 300 to contract, closing off the electrode leads 111 and the terrace portion 112.

[0057] As the heat-shrinkable member 300 shrinks and surrounds the electrode leads 111 and terrace portion 112 of the battery cell 110, flames or high-temperature gases cannot flow into the battery cell 110 (a normal battery cell 110 that is not generating flames), thereby preventing flame propagation and ultimately preventing thermal runaway or explosion.

[0058] Referring to Figures 5 and 6, the heat-shrinkable members 300 are provided in pairs, and the pair of heat-shrinkable members 300 can be coupled to both ends of the battery cell 110. However, the heat-shrinkable members 300 may be configured to cover the entire battery cell 110, or to cover a part of the battery cell 110.

[0059] Referring to Figure 7, the heat-shrinkable member 300 may further include an inner portion 340 in addition to the outer portion 320 and the heat-shrinkable frame 330.

[0060] The outer part 320 is located on the outside and can be made from various types of fire-resistant materials. When the outer part 320 is made from fire-resistant material, it can protect the normally functioning battery cells 110 from flames generated by other battery cells 110.

[0061] The heat-shrinkable frame 330 is bonded to the outer portion 320 on the inside of the outer portion 320 and is configured to shrink when heated. The heat-shrinkable frame 330 can be made of a variety of materials. For example, it can be made from polyolefin material, but the material of the heat-shrinkable frame 330 is not limited to this.

[0062] The inner portion 340 is bonded to the heat-shrinkable frame 330 inside the heat-shrinkable frame 330 and can be made from various types of insulating materials. The inner portion 340 prevents heat from the inside of the battery cell 110 from being transferred to the outside (thermal conduction).

[0063] The heat-shrinkable member 300, having the configuration described above, provides primary protection to the normally functioning battery cell 110 from external flames (by the fire-resistant outer portion 320), and secondarily protects the battery cell 110 by preventing flames or hot gases from flowing into the battery through the heat of the flames causing the heat-shrinkable frame 330 to shrink and surround the electrode leads 111 and terrace portion 112.

[0064] Figure 9 is a schematic exploded perspective view of the battery module according to a modified embodiment of Figure 2.

[0065] The modified embodiment shown in Figure 9 differs from the first embodiment in that the upper heat-shrinkable member 400 is attached to the upper part of the battery cell stack 100. However, for parts of the second embodiment that are common with those described in the first embodiment, the explanation of the first embodiment described above will be used instead. Also, for parts of the second embodiment that are applicable to the first embodiment, they may be applied to the first embodiment.

[0066] Referring to Figure 9, the upper heat-shrinkable member 400 is attached to the upper part of the battery cell stack 100 so as to cover the upper part of the battery cell stack 100.

[0067] The upper heat-shrinkable member 400 shares the same basic structure and features as the aforementioned heat-shrinkable member 300 and protects the battery cell stack 100 within the normally functioning battery module 10 from flames generated from other battery modules 10. A detailed description of the upper heat-shrinkable member 400 is provided in place of the description of the heat-shrinkable member 300 mentioned above.

[0068] Figure 10 is a schematic diagram showing the configuration of a battery pack according to each embodiment of the present invention.

[0069] Referring to Figure 10, a battery pack 20 according to one embodiment of the present invention includes one or more battery modules 10 according to the embodiments described above.

[0070] Furthermore, the battery pack 20 may further include a pack case 21 for housing the battery module 10, and various devices for controlling the charging and discharging of the battery cells 110 housed in the battery module 10, such as a BMS, current sensor, fuse, etc.

[0071] Figure 11 is a diagram illustrating an automobile that includes the battery pack shown in Figure 10.

[0072] Referring to Figure 11, an automobile 30 according to one embodiment of the present invention may include one or more battery modules 10 or battery packs 20 according to the embodiments described above. Here, the automobile 30 includes various automobiles that use electricity, such as electric vehicles and hybrid vehicles.

[0073] 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.

[0074] 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]

[0075] The present invention relates to battery modules, battery packs containing the same, and automobiles, and is particularly applicable to the secondary battery industry.

Claims

1. A battery cell stack in which multiple battery cells are stacked, A case in which the aforementioned battery cell stack is housed, The battery cell is coupled to a heat-shrinkable member that shrinks due to heat, The aforementioned battery cell has a terrace portion formed in the area where the electrode leads are located. The heat-shrinkable member surrounds only a portion of the battery cell, including the terrace portion and the electrode leads, in a battery module.

2. The aforementioned battery cell is a pouch-type battery cell, The battery module according to claim 1, characterized in that the heat-shrinkable member is coupled to the battery cell at a position close to the terrace portion.

3. The battery module according to claim 2, characterized in that the heat-shrinkable member is formed in a strip shape and surrounds the terrace portion, and has openings formed so that the electrode leads are exposed to the outside.

4. The battery module according to claim 2, characterized in that, if a flame occurs in another adjacent battery cell, the heat of the flame causes the heat shrinkable member to contract, thereby closing the terrace portion and the electrode lead.

5. The heat-shrinkable members are provided in pairs. The battery module according to claim 2, characterized in that the pair of heat-shrinkable members are coupled to both ends of the battery cell.

6. The battery module according to claim 1, characterized in that the heat-shrinkable member is fitted and coupled to the battery cell.

7. The battery module according to claim 1, characterized in that the heat-shrinkable member is bonded to the battery cell by bonding.

8. The heat-shrinkable member is The outer part is made from fire-resistant material, The battery module according to claim 1, characterized in that it includes a heat-shrinkable frame that is bonded to the outer part on the inside of the outer part and shrinks due to heat.

9. The battery module according to claim 8, characterized in that the heat shrink member is bonded to the heat shrink frame inside the heat shrink frame and includes an inner portion made of an insulating material.

10. The aforementioned battery cell has a gas pocket portion formed therein. The battery module according to claim 1, characterized in that the heat-shrinkable member is coupled to the battery cell while avoiding interference with the gas pocket portion.

11. The battery module according to claim 1, characterized in that the heat-shrinkable member is made from a polyolefin material.

12. The battery module according to claim 1, characterized in that an upper heat-shrinkable member is bonded to the upper part of the battery cell stack so as to cover the upper part of the battery cell stack.

13. A battery pack comprising at least one battery module according to any one of claims 1 to 12.

14. An automobile comprising at least one battery module according to any one of claims 1 to 12.

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