Battery pack

Abstract

The present invention discloses a battery pack including a base plate, an outer side wall coupled to an upper surface of the base plate, a plurality of battery cells positioned on the base plate to form an array, and a side structure positioned on the base plate, the side structure extending elongately along one side of the base plate to separate the plurality of battery cells from the base plate.

Description

[Technical Field]

[0001] The present invention relates to a battery pack.

[0002] This application claims priority based on Korean Patent Application No. 10-2023-0120715, filed on September 11, 2023, the entire contents of which are incorporated herein by reference in their entirety in the specification and drawings thereof. [Background technology]

[0003] As demand for portable electronic products such as laptops, video cameras, and mobile phones has grown rapidly and the commercialization of robots and electric vehicles has progressed in earnest, research into high-performance secondary batteries that can be repeatedly charged and discharged has been actively conducted.

[0004] Currently, commercially available secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium secondary batteries. Among these, lithium secondary batteries are attracting attention due to their advantages of being able to be freely charged and discharged since they have almost no memory effect compared to nickel-based secondary batteries, an extremely low self-discharge rate, and a high energy density.

[0005] Such lithium secondary batteries mainly use lithium-based oxides and carbon materials as positive and negative electrode active materials, respectively, and include an electrode assembly in which a positive electrode plate coated with the positive electrode active material and a negative electrode plate coated with the negative electrode active material are disposed with a separator interposed therebetween, and an exterior material, such as a battery case, that hermetically houses the electrode assembly together with an electrolyte.

[0006] Generally, lithium secondary batteries can be classified into can-type secondary batteries in which an electrode assembly is housed in a metal can and pouch-type secondary batteries in which an electrode assembly is housed in a pouch made of an aluminum laminate sheet, depending on the shape of the exterior material.

[0007] In recent years, secondary batteries have been widely used for driving and storing energy not only in small devices such as portable electronic devices but also in medium- to large-sized devices such as electric vehicles and energy storage systems (ESS). A plurality of such secondary batteries are electrically connected and housed together inside a module case to form a battery module. A plurality of such battery modules are connected to form a battery pack.

[0008] However, when multiple secondary batteries (battery cells) or multiple battery modules are densely packed in a small space, they may be vulnerable to thermal events. In particular, if an event such as thermal runaway occurs in one battery cell, high-temperature gas, flames, and heat may be generated. If such gas, flame, or heat spreads to other battery cells in the same battery module, an explosive chain reaction such as thermal propagation may occur. Furthermore, such a chain reaction may not only cause accidents such as fire or explosion in the battery module itself, but also cause fires or explosions in other battery modules.

[0009] Furthermore, in the case of medium- to large-sized battery packs such as those for electric vehicles, the risk of a chain reaction of thermal reactions may be even higher because a large number of battery cells and battery modules are included in order to increase output and / or capacity. Furthermore, in the case of a battery pack installed in an electric vehicle, users such as the driver may be present nearby. Therefore, if a thermal event occurring in a specific battery module cannot be properly controlled and a chain reaction occurs, it is highly likely to result in significant damage to property as well as loss of life. Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention aims to solve the above-mentioned problems and other problems.

[0011] Another object of the present invention is to provide a battery pack in which venting is easily controlled.

[0012] It is still another object of the present invention to provide a battery pack with improved assembly efficiency.

[0013] It is still another object of the present invention to provide a battery pack with improved energy density. [Means for solving the problem]

[0014] In order to solve the above problems, a battery pack according to one aspect of the present invention includes a base plate; an outer side wall coupled to an upper surface of the base plate; a plurality of battery cells positioned on the base plate, the plurality of battery cells forming an array; and a side structure positioned on the base plate, the side structure extending elongately along one side of the base plate to separate the plurality of battery cells from the base plate.

[0015] The side structure may also include a body that extends long and covers the sides of the plurality of battery cells.

[0016] The body may also include a curved portion formed along a side surface of the battery cell.

[0017] The side structure may further include a plurality of bottom ribs protruding from the body and a plurality of top ribs protruding from the body and positioned above the plurality of bottom ribs, and the plurality of battery cells may be attached between the plurality of bottom ribs and the plurality of top ribs.

[0018] The side structure may further include a partition protruding from the body and positioned between adjacent battery cells among the plurality of battery cells.

[0019] The side structure may include a head formed at one end of the body and covering the plurality of battery cells, and a vent hole formed in the head, the vent hole communicating with a gap between the plurality of battery cells and the base plate.

[0020] The vent hole may be open downward.

[0021] The height of the vent hole may be configured to be lower than the height of the bottom rib.

[0022] The nozzle may further include a guide pipe provided on an upper surface of the base plate and positioned between the head and the outer side wall, the guide pipe having an inlet facing the vent hole.

[0023] The head may further include a slot located above the vent hole, and the battery pack may further include a cooling unit attached to the slot.

[0024] The battery pack may further include a vent device attached to the exterior side wall.

[0025] A motor vehicle according to another aspect of the present invention includes a battery pack according to an aspect of the present invention. [Effects of the Invention]

[0026] According to one aspect of the present invention, venting of a battery pack can be easily controlled.

[0027] According to one aspect of the present invention, the thermal safety of a battery pack can be improved.

[0028] According to one aspect of the present invention, the rigidity of the battery pack can be improved.

[0029] According to one aspect of the present invention, the energy density of a battery pack can be improved.

[0030] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention, are intended to facilitate a further understanding of the technical concept of the present invention. Therefore, the present invention should not be analyzed limitedly by the matters described in the drawings. [Brief explanation of the drawings]

[0031] [Figure 1] 1 is a perspective view showing a battery pack according to an embodiment of the present invention; [Figure 2] 1 is an exploded view showing a partial configuration of a battery pack according to an embodiment of the present invention. [Figure 3] FIG. 2 is a perspective view showing a side structure of a battery pack according to an embodiment of the present invention. [Figure 4] 1 is a perspective view showing a side structure and a battery cell of a battery pack according to an embodiment of the present invention; [Figure 5] FIG. 5 is a diagram showing a part of the cross-sectional configuration along AA' in FIG. [Figure 6] FIG. 5 is a diagram showing a part of the cross-sectional configuration along the line BB' in FIG. [Figure 7] 3 is a bottom view of a side structure and a battery cell of a battery pack according to an embodiment of the present invention; FIG. [Figure 8] 2 is an exploded view illustrating a partial configuration of a cell array structure of a battery pack according to an embodiment of the present invention. FIG. [Figure 9] 1 is a diagram illustrating a cell array structure of a battery pack according to an embodiment of the present invention. [Figure 10] 2 is a bottom view of a cell array structure of a battery pack according to an embodiment of the present invention; FIG. [Figure 11] FIG. 11 is an enlarged view of part C in FIG. [Figure 12] FIG. 11 is an enlarged view of part D in FIG. [Figure 13] 1 is a view showing a guide pipe of a battery pack according to an embodiment of the present invention; [Figure 14] 1 is a diagram illustrating a cell array structure and a guide pipe of a battery pack according to an embodiment of the present invention. [Figure 15] 1 is a diagram illustrating a connection between a cell array structure and a guide pipe of a battery pack according to an embodiment of the present invention. [Figure 16] 1 is a perspective view showing a partial configuration of a battery pack according to an embodiment of the present invention. [Figure 17] FIG. 17 is a diagram showing a part of the cross-sectional configuration along the line EE' in FIG. [Figure 18] FIG. 18 is an enlarged view of part F in FIG. 17. [Figure 19] FIG. 18 is an enlarged view of part G in FIG. 17. [Figure 20] FIG. 17 is a diagram showing a part of the cross-sectional configuration taken along the line HH' in FIG. [Figure 21] FIG. 21 is an enlarged view of part I in FIG. 20. [Figure 22] FIG. 21 is an enlarged view of part J in FIG. 20. DETAILED DESCRIPTION OF THE INVENTION

[0032] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms and words used in the specification and claims are not interpreted as being limited to their general or dictionary meanings, but are interpreted as having meanings and concepts corresponding to the technical ideas of the present invention, in accordance with the principle that the inventors themselves can appropriately define the concepts of terms in order to best describe the invention.

[0033] Therefore, it should be understood that the embodiments described in this specification 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 various equivalents and modifications that can replace them at the time of this application.

[0034] Fig. 1 is a perspective view showing a battery pack according to an embodiment of the present invention, and Fig. 2 is an exploded view showing a partial configuration of the battery pack according to an embodiment of the present invention. Referring to Fig. 1 and Fig. 2, the battery pack according to an embodiment of the present invention may include a base plate 100, an outer side wall 200, a plurality of battery cells 310, and a side structure 320.

[0035] The base plate 100 may have a flat plate shape or a substantially rectangular shape.

[0036] The exterior side wall 200 may be fastened, coupled, fixed, or attached to the top surface of the base plate 100. The exterior side wall 200 and the base plate 100 may form an interior space.

[0037] A plurality of battery cells 310 may be housed in the internal space. The plurality of battery cells 310 may be arranged to form an array. The plurality of battery cells 310 may be located on the base plate 100. In this case, the battery cells 310 may represent secondary batteries. The battery cells 310 may also be cylindrical secondary batteries.

[0038] The side structure 320 may be located on the base plate 100. The side structure 320 may extend longitudinally along one side of the base plate 100. The side structure 320 may separate the plurality of battery cells 310 from the base plate 100. Alternatively, the side structure 320 may form a space between the plurality of battery cells 310 and the base plate 100.

[0039] According to this embodiment, venting of the battery pack can be easily controlled. When a thermal event occurs in the battery cell 310, vent gas, ignitable particles, etc. are discharged downward or in the -Z-axis direction. According to this embodiment, the vent gas, ignitable particles, etc. can flow through the space between the battery cell 310 and the base plate 100 and be discharged to the outside of the battery pack.

[0040] 1 and 2 , a battery pack according to an embodiment of the present invention may include a bus bar assembly 400 and a pack cover 500. The pack cover 500 may cover the interior space of the battery pack. The pack cover 500 may be plate-shaped. The pack cover 500 may have a shape similar to that of the base plate 100. The pack cover 500 may be fastened, coupled, fixed, or attached to the outer side wall 200.

[0041] The bus bar assembly 400 may be located between the plurality of battery cells 310 and the pack cover 500. The bus bar assembly 400 may be physically coupled to the upper sides of the plurality of battery cells 310. The bus bar assembly 400 may also be electrically connected to the plurality of battery cells 310.

[0042] The vent device 600 may be provided on the outer surface of the exterior side wall 200. When the internal pressure of the battery pack becomes high, the vent device 600 may release gas.

[0043] FIG. 3 is a perspective view showing a side structure 320 of a battery pack according to one embodiment of the present invention, FIG. 4 is a perspective view showing a side structure 320 and a battery cell 310 of a battery pack according to one embodiment of the present invention, FIG. 5 is a view showing a portion of a cross-sectional configuration along A-A' in FIG. 4, FIG. 6 is a view showing a portion of a cross-sectional configuration along B-B' in FIG. 4, and FIG. 7 is a view of the side structure 320 and a battery cell 310 of a battery pack according to one embodiment of the present invention viewed from below.

[0044] 3 to 7 , the side structure 320 of the battery pack according to an embodiment of the present invention may include a body 321 that extends long and covers the sides of the plurality of battery cells 310. The body 321 may extend long along the X-axis direction. The body 321 may support and house an array of the battery cells 310. Alternatively, the body 321 may align the plurality of battery cells 310 so that the battery cells 310 form an array. The body 321 may support and house the battery cells 310 on the left and right sides, respectively.

[0045] According to this embodiment, it is easy to align the plurality of battery cells 310. This can improve the energy density of the battery pack and the rigidity of the battery pack.

[0046] 3 to 7 , a body 321 of a side structure 320 of a battery pack according to an embodiment of the present invention may include a curved portion 326 formed along a side surface of a battery cell 310. The body 321 may include a curved portion 326 formed on its inner side. The curved portion 326 may bend along the side surface of the battery cell 310. The curved portion 326 may support the side surface of the battery cell 310. A plurality of curved portions 326 may be provided. The curved portions 326 may be provided to correspond one-to-one with the battery cells 310. The curved portions 326 may be provided on the left and right sides of the body 321.

[0047] According to this embodiment, the plurality of battery cells 310 are stably fixed and supported by the side structure 320. This can improve the rigidity of the battery pack.

[0048] 3 to 7 , the side structure 320 of the battery pack according to an embodiment of the present invention may include a plurality of bottom ribs 323 protruding from the body 321 and a plurality of top ribs 324 protruding from the body 321 and positioned above the plurality of bottom ribs 323. The plurality of battery cells 310 may be mounted between the plurality of bottom ribs 323 and the plurality of top ribs 324. The side structure 320 may include bottom ribs 323 protruding on both left and right sides. The side structure 320 may also include top ribs 324 protruding on both left and right sides. The top ribs 324 may be positioned higher than the bottom ribs 323. The top ribs 324 and the bottom ribs 323 may be provided in a one-to-one correspondence. The plurality of battery cells 310 may be fixed between the bottom rib 323 and the top rib 324. The plurality of battery cells 310 may be spaced apart from the base plate 100 by the height of the bottom ribs 323.

[0049] According to this embodiment, the plurality of battery cells 310 are stably fixed and supported by the side structure 320. In addition, a vent space can be formed below the battery cells 310.

[0050] 3 to 7 , the side structure 320 of the battery pack according to one embodiment of the present invention may further include a partition 325 protruding from the body 321 and positioned between adjacent battery cells 310 among the plurality of battery cells 310. A plurality of partitions 325 may be provided. The partitions 325 may protrude from the left and right sides of the body 321 of the side structure 320, respectively.

[0051] According to this embodiment, the plurality of battery cells 310 can be separated from adjacent battery cells 310 by the partitions 325. This can improve thermal safety.

[0052] 3 to 7 , a side structure 320 of a battery pack according to an embodiment of the present invention may include a head 322 and a vent hole 328. The head 322 may be formed on both ends of a body 321. The head 322 may be provided on the front and rear of the body 321. The head 322 may cover a plurality of battery cells 310.

[0053] The vent holes 328 may be formed in the heads 322. The vent holes 328 may be formed in each of the front and rear heads 322. The vent holes 328 may communicate with gaps between the plurality of battery cells 310 and the base plate 100.

[0054] According to this embodiment, venting of the battery pack can be easily controlled. When a thermal event occurs in the battery cell 310, vent gas, ignitable particles, etc. are discharged downward or in the -Z-axis direction. According to this embodiment, the vent gas, ignitable particles, etc. flow through the space between the battery cell 310 and the base plate 100 and can be discharged to the outside of the battery pack through the vent hole 328.

[0055] 3 to 7, the vent hole 328 of the side structure 320 of the battery pack according to an embodiment of the present invention may be open downward and may be open to the right side.

[0056] According to this embodiment, the venting of the battery pack can be easily controlled. The downward opening of the vent hole 328 reduces the resistance acting on the flow of vent gas and ignitable particles discharged from the battery cell 310. This improves the thermal safety of the battery pack.

[0057] Fig. 8 is an exploded view showing a portion of a cell array structure 300 of a battery pack according to an embodiment of the present invention, Fig. 9 is a view showing the cell array structure 300 of the battery pack according to an embodiment of the present invention, Fig. 10 is a view showing the cell array structure 300 of the battery pack according to an embodiment of the present invention as viewed from below, and Fig. 11 is an enlarged view of portion C of Fig. 10. Referring to Figs. 8 to 11, a battery pack according to an embodiment of the present invention may include a cell array structure 300. The cell array structure 300 may include a pair of inner side walls 330, a plurality of side structures 320, a plurality of cooling units 340, and a plurality of battery cells 310.

[0058] At least some of the plurality of battery cells 310 may be attached, coupled, or fixed to an interior side wall 330. The interior side wall 330 may include wall heads at both ends in the X-axis direction. The wall heads may include slots. The head 322 of the side structure 320 may include a slot 327. The slot 327 may extend through the head 322. The slot 327 may be located above a vent hole 328.

[0059] The inner side wall 330 may be fastened, coupled, fixed, or attached to the top surface of the base plate 100. The inner side wall 330 may be located between the plurality of battery cells 310 and the outer side wall 200.

[0060] The side structure 320 may extend longitudinally along the X-axis direction. The side structure 320 may fix and support a plurality of battery cells 310. A plurality of side structures 320 may be provided.

[0061] The cooling unit 340 may extend longitudinally along the X-axis direction. The cooling unit 340 may be in contact with multiple battery cells 310. Multiple cooling units 340 may be provided. The cooling units 340 may be inserted into, coupled to, attached to, or fixed to the slots 327. Cooling liquid or cooling gas may flow through the cooling units 340.

[0062] The side structures 320, the plurality of battery cells 310, and the cooling units 340 may be arranged alternately. A pair of inner side walls 330 may be arranged on the outermost periphery of the cell array structure 300.

[0063] The cell array structure 300 may be filled with resin. The resin may bond, fix, or adhere components of the cell array structure 300 to each other. The resin may also increase the rigidity of the cell array structure 300.

[0064] According to this embodiment, the cooling efficiency of the battery pack can be improved. The cooling unit 340 contacts all of the battery cells 310. This improves the thermal safety of the battery pack.

[0065] Figure 12 is an enlarged view of portion D in Figure 10. Referring to Figures 10 to 12, vent gas g discharged from the battery cell 310 of the battery pack according to an embodiment of the present invention may flow in the +X-axis direction and the -X-axis direction through the space between the battery cell 310 and the base plate 100. In addition, the vent gas may flow in the +X-axis direction and the -X-axis direction through the vent hole 328.

[0066] Figure 13 is a diagram showing a guide pipe 700 of a battery pack according to one embodiment of the present invention, Figure 14 is a diagram showing a cell array structure 300 and guide pipe 700 of a battery pack according to one embodiment of the present invention, Figure 15 is a diagram showing the connection between the cell array structure 300 and guide pipe 700 of a battery pack according to one embodiment of the present invention, Figure 16 is a perspective view showing a partial configuration of a battery pack according to one embodiment of the present invention, Figure 17 is a diagram showing a portion of the cross-sectional configuration along E-E' of Figure 16, and Figure 18 is an enlarged view of part F of Figure 17.

[0067] 13 to 18, a battery pack according to an embodiment of the present invention may include a guide pipe 700.

[0068] The guide pipe 700 may extend longitudinally along the Y-axis direction. The guide pipe 700 may be provided on the upper surface of the base plate 100. The guide pipe 700 may be located between the head 322 and the outer side wall 200.

[0069] The guide pipe 700 may have an inlet hole 701 formed in the -X-axis direction. The inlet hole 701 may face the vent hole 328. The guide pipe 700 may also be open in the +Y-axis direction and the -Y-axis direction.

[0070] The guide pipe 700 may be located below the cooling unit 340. The guide pipe 700 may be located between the base plate 100 and the cooling unit 340.

[0071] Vent gas g discharged in the +X-axis direction through vent hole 328 can flow into guide pipe 700 through inlet hole 701. Vent gas g that has flowed into guide pipe 700 can flow in the +Y-axis direction and the −Y-axis direction along flow path 702 formed inside guide pipe 700.

[0072] According to this embodiment, the venting of the battery pack can be easily controlled. Vent gases and ignitable particles flow through the space between the battery cells 310 and the base plate 100, and are discharged to the outside of the battery pack through the vent holes 328 and the guide pipe 700.

[0073] 18 , the battery pack according to an embodiment of the present invention may further include a vent device 600 attached to the outer side wall 200. The vent device 600 may be provided on a side of the battery pack. A plurality of vent devices 600 may be provided. The vent devices 600 may also be provided in the +Y-axis direction and the −Y-axis direction of the battery pack. The vent device 600 may communicate the inside and outside of the battery pack when the internal pressure of the battery pack increases. The vent gas g flowing out from the guide pipe 700 may flow along the outer side wall 200. The vent gas g may also be discharged to the outside of the battery pack through the vent device 600.

[0074] According to this embodiment, the venting of the battery pack can be easily controlled. Vent gases and ignitable particles are discharged to the outside of the battery pack through the vent device 600.

[0075] FIG. 19 is an enlarged view of portion G in FIG. 17. Referring to FIG. 19, a vent device 600 may be provided on the rear side of the battery pack. A plurality of vent devices 600 may be provided. The vent devices 600 may also be provided in the +X-axis direction and the −X-axis direction of the battery pack. When the internal pressure of the battery pack increases, the vent devices 600 may communicate between the inside and outside of the battery pack. The vent gas g flowing out in the −X-axis direction or rearward through the vent holes 328 may flow along the outer side wall 200. The vent gas g may also be discharged to the outside of the battery pack through the vent devices 600.

[0076] According to this embodiment, the venting of the battery pack can be easily controlled. Vent gases and ignitable particles are discharged to the outside of the battery pack through the vent device 600.

[0077] 20 is a view showing a portion of a cross-sectional configuration taken along line H-H' in FIG. 16, FIG. 21 is an enlarged view of portion I in FIG. 20, and FIG. 22 is an enlarged view of portion J in FIG. 20. Referring to FIGS. 20 to 22, the height of the vent hole 328 of the battery pack according to an embodiment of the present invention may be configured to be lower than the height of the bottom rib 323. Since the vent hole 328 is formed lower than the height of the bottom rib 323, the head 322 may cover the lower end of the side surface of the battery cell 310. As a result, the battery cell 310 is not exposed through the vent hole 328.

[0078] According to the present embodiment, the side structure 320 can prevent or block the flame generated from the battery cell 310 from being exposed to the outside, thereby improving the thermal safety of the battery pack.

[0079] A vehicle according to an embodiment of the present invention may include the battery pack according to an embodiment of the present invention described above. The battery pack according to an embodiment of the present invention may be applied to vehicles such as electric vehicles and hybrid vehicles. In addition to the battery pack, a vehicle according to an embodiment of the present invention may further include various other components included in a vehicle. For example, a vehicle according to an embodiment of the present invention may further include a vehicle body, a motor, a control device such as an electronic control unit (ECU), and the like.

[0080] Meanwhile, although terms indicating directions such as up, down, left, right, front, rear, inner, and outer are used in this specification, it will be obvious to those skilled in the art that these terms are used for the convenience of explanation and may change depending on the position of the object or the position of the observer, etc.

[0081] As described above, the present invention has been described using limited embodiments and drawings, but the present invention is not limited thereto, and it goes without saying that various changes and modifications can be made by a person having ordinary skill in the art to which the present invention pertains within the technical spirit of the present invention and the equivalent scope of the claims. [Explanation of symbols]

[0082] 100 base plate 200 Exterior side wall 310 battery cells 320 Side structure

Claims

1. A base plate and an outer side wall coupled to an upper surface of the base plate; a plurality of battery cells positioned on the base plate, the plurality of battery cells forming an array; a side structure positioned on the base plate, the side structure extending longitudinally along one side of the base plate to separate the plurality of battery cells from the base plate; Including the battery pack.

2. The side structure is The battery pack according to claim 1 , further comprising a body extending long and covering sides of the plurality of battery cells.

3. The body is The battery pack according to claim 2 , further comprising a curved portion formed along a side surface of the battery cell.

4. The side structure is a plurality of bottom ribs projecting from the body; a plurality of top ribs projecting from the body and positioned above the plurality of bottom ribs; further comprising The plurality of battery cells The battery pack of claim 2 , attached between a plurality of the bottom ribs and a plurality of the top ribs.

5. The side structure is The battery pack according to claim 4 , further comprising a partition protruding from the body, the partition being located between adjacent battery cells among the plurality of battery cells.

6. The side structure is a head formed at one end of the body to cover the plurality of battery cells; vent holes formed in the head, the vent holes communicating with gaps between the plurality of battery cells and the base plate; 5. The battery pack of claim 4, comprising:

7. The battery pack according to claim 6 , wherein the vent hole is open downward.

8. The battery pack according to claim 6 , wherein the height of the vent hole is configured to be lower than the height of the bottom rib.

9. 7. The battery pack of claim 6, further comprising a guide pipe provided on the upper surface of the base plate and positioned between the head and the outer side wall, the guide pipe having an inlet hole facing the vent hole.

10. the head further includes a slot positioned over the vent hole; The battery pack according to claim 6 , further comprising a cooling unit attached to the slot.

11. The battery pack of claim 1 , further comprising a vent device attached to the exterior side wall.

12. A motor vehicle comprising a battery pack according to any one of claims 1 to 11.

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