Battery module with improved shock resistance and safety and battery pack including the same

Abstract

The present invention relates to a battery module having improved impact resistance and safety, and a battery pack including the same. Specifically, the present invention relates to a battery module including: a first case having a storage space; a plurality of battery cells stored upright in the storage space with their positive terminals facing upward; one or more bus bars located near the positive terminals of the battery cells; wires electrically connecting the battery cells and the bus bars; a rib structure located on an upper portion of the battery cells, the rib structure having ribs protruding upward to protect the wires and openings through which the wires pass; and a resin layer filled on the upper portion of the battery cells; and a battery pack including the battery module.

Description

[Technical field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 2022-0010180 filed on January 24, 2022, and Korean Patent Application No. 2022-0183559 filed on December 23, 2022, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to a battery module having improved impact resistance and safety and a battery pack including the same, and more particularly to a battery module having improved impact resistance and safety, which has a structure in which internal parts, including battery cells, are completely sealed to prevent loose movement and is capable of blocking venting gas and flames, and a battery pack including the same. [Background technology]

[0003] With the introduction of environmentally friendly energy policies, the battery market using lithium secondary batteries is gradually expanding. In addition, the capacity and energy density of lithium secondary batteries have been rapidly increased through technological development, and the scope of use of lithium secondary batteries in the field of green energy is expanding.

[0004] Since normal charging and discharging processes of a lithium secondary battery are heat generating processes, it is inevitable that the temperature will increase. An excessive increase in temperature of the secondary battery can cause a decrease in the performance of the battery cells.

[0005] When lithium secondary batteries overheat, there is a risk of explosion, and if the flames caused by the explosion spread to adjacent battery cells, the fire is difficult to contain until the entire battery is burned.

[0006] In addition, when a thermal runaway phenomenon occurs in a battery cell, flames, sparks, and venting gases with temperatures above the ignition point may be generated, and the flames may spread to adjacent battery cells, which may ultimately lead to the explosion of the battery cell.

[0007] Therefore, in order to reduce the temperature of flames and sparks generated in the battery cells, a structure that quickly dissipates heat from the inside of the battery module or battery pack to the outside can be designed to prevent additional damage caused by the explosion of the battery cells.

[0008] FIG. 1 is a perspective view of a battery module according to the prior art, FIG. 2 is an enlarged perspective view of a portion A in FIG. 1, and FIG. 3 is an enlarged cross-sectional view of a portion B in FIG.

[0009] As shown in Figures 1 to 3, cylindrical battery cells 30 are stored side by side in an upright state inside a first case 10 and a second case 20, and these battery cells 30 can be connected in parallel or in series via bus bars 40 and wires 50 to form a single battery module.

[0010] The first case 10 is made up of a first frame 11 to which one end of the battery cell 30 is attached, and a second frame 12 for surrounding and protecting the side surfaces of the battery cell 30.

[0011] That is, a long rod-shaped bus bar 40 is positioned on top of the multiple cylindrical battery cells 30, and the top cap and crimping portion which function as the positive and negative terminals of the battery cells 30 are electrically connected to adjacent bus bars 40 via a first wire 51 and a second wire 52 which pass through an opening 62 of the rib structure 60.

[0012] Here, the first wire 51 and the second wire 52 are formed by metal that is continuously discharged through a nozzle (not shown), and connect the terminals of the battery cells to the bus bars by wire-bonding.

[0013] When wire bonding is used, it is advantageous to form an electrical connection structure quickly and accurately. However, it is necessary to provide a space in the area where the wire 50 is located so that it does not come into contact with the second case 20, and a rib 61 extending to a certain height may be further formed to protect the wire 50 while preventing deformation of the second case 20 due to external impact, etc. Of course, when the first case 10 and the second case 20 are assembled, the upper end surface of the rib 61 and the inner surface of the second case 20 can be closely attached to each other, but it may also be designed so that a certain gap G is generated in consideration of assembly tolerance.

[0014] Although the battery module having the above-described structure is relatively easy to assemble, it is difficult to mount the battery cell 30 in a device with the positive terminal facing downwards because there is space where the positive terminal of the battery cell 30 and the rib structure are located. Furthermore, if thermal runaway occurs in a specific battery cell, it is likely that adjacent battery cells will also experience thermal runaway or catch fire in a chain reaction. Summary of the Invention [Problem to be solved by the invention]

[0015] The present invention has been made to solve the above problems, and aims to provide a battery module that is resistant to external impact and allows the battery module to be attached to a device regardless of the orientation of battery cells stored therein, and a battery pack including the same.

[0016] Another object of the present invention is to provide a battery module capable of minimizing chain fires and a battery pack including the same. [Means for solving the problem]

[0017] In order to achieve the above-mentioned object, the battery module according to the present invention is characterized by including: a first case (100) having a storage space; a plurality of battery cells (300) stored upright in the storage space with their positive terminals facing upward; one or more bus bars (400) located near the positive terminals of the battery cells (300); wires (500) electrically connecting the battery cells (300) and the bus bars (400); a rib structure (600) located on an upper portion of the battery cells (300), the rib structure (600) having a rib (610) protruding upward to protect the wires (500) and an opening (620) through which the wires (500) pass; and a resin layer (700) filled on the upper portion of the battery cells (300).

[0018] In addition, the battery module according to the present invention is characterized in that a second case (200) fixed to the first case (100) is further provided on the resin layer (700).

[0019] In the battery module according to the present invention, the upper surface of the resin layer (700) is flat.

[0020] In addition, in the battery module according to the present invention, the resin layer (700) is filled so as to be in complete contact with the upper surfaces of the battery cells (300), the bus bars (400), the wires (500), and the rib structure (600).

[0021] In the battery module according to the present invention, the height of the rib is equal to or greater than the height of the bonded wire.

[0022] In the battery module according to the present invention, the height of the resin layer is equal to or greater than the height of the ribs.

[0023] In addition, the battery module according to the present invention is characterized in that a pad (800) is located between the resin layer (700) and the second case (200).

[0024] In the battery module according to the present invention, the pad (800) includes a thermally conductive material.

[0025] In addition, in the battery module according to the present invention, the pad (800) includes a material having elasticity and compressibility.

[0026] In the battery module according to the present invention, the upper surface of the resin layer (700) and the lower surface of the pad (800) are in close contact with each other.

[0027] In the battery module according to the present invention, the upper surface of the pad (800) and the lower surface of the second case (200) are in close contact with each other.

[0028] In the battery module according to the present invention, a plurality of spaces (810) are formed in the pad (800), and the spaces (810) have a shape penetrating the pad (800).

[0029] In the battery module according to the present invention, the space (810) is located on a vertical extension of the battery cell (300).

[0030] In the battery module according to the present invention, the number of the spaces (810) is the same as the number of the battery cells (300).

[0031] The present invention is also characterized in that it is a battery pack including the above-mentioned battery module. Effect of the Invention

[0032] As described above, in the battery module according to the present invention, the resin layer is filled in the spaces in which the wires and rib structures for electrical connection are located, thereby preventing the components from moving loosely. This has the advantage that the installation direction of the battery module can be freely changed regardless of the direction of the battery cells housed therein.

[0033] In addition, the battery module according to the present invention has an advantage that the generated heat can be quickly discharged to the outside since the heat dissipation pad is located so as to be in contact with the resin layer.

[0034] Furthermore, since the battery module according to the present invention has a space in the pad, when gas or thermal runaway occurs in a specific battery cell, the movement of the gas or thermal runaway to an adjacent battery can be minimized, thereby ensuring safety. [Brief description of the drawings]

[0035] [Figure 1] FIG. 1 is a perspective view of a battery module according to the prior art. [Diagram 2] FIG. 2 is an enlarged perspective view of a portion A in FIG. [Diagram 3] FIG. 2 is an enlarged cross-sectional view of part B in FIG. [Figure 4] 1 is a perspective view of a battery module according to a first preferred embodiment of the present invention; [Diagram 5] FIG. 5 is an exploded perspective view of the battery module of FIG. [Figure 6] FIG. 5 is an enlarged cross-sectional view of part C in FIG. [Figure 7] FIG. 4 is a perspective view of a battery module according to a second preferred embodiment of the present invention. [Figure 8] FIG. 8 is an exploded perspective view of the battery module of FIG. 7. [Figure 9] FIG. 8 is an enlarged cross-sectional view of a portion D in FIG. [Figure 10] FIG. 11 is an enlarged cross-sectional view of a portion of a battery module in a third preferred embodiment of the present invention. [Figure 11]FIG. 11 is a perspective view of a pad according to a third preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings, in which a person having ordinary skill in the art to which the present invention pertains can easily carry out the present invention. However, in describing the operation principle of the preferred embodiment of the present invention in detail, detailed description of related well-known functions or configurations will be omitted if it is determined that such detailed description may unnecessarily obscure the gist of the present invention.

[0037] In addition, the same reference numerals are used throughout the drawings for parts having similar functions and actions. Throughout the specification, when a part is said to be connected to another part, this includes not only the case where the part is directly connected to another part, but also the case where the part is indirectly connected via another element between the two parts. In addition, when a part includes a certain component, it does not mean that the other component is excluded, but that the part may further include the other component, unless otherwise specified.

[0038] Furthermore, descriptions that limit or add specific elements are applicable to all inventions and are not limited to a particular invention unless otherwise specified.

[0039] Furthermore, throughout the description of the present invention and the claims, the singular includes the plural unless otherwise stated.

[0040] In addition, throughout the description of the present invention and the claims, unless otherwise stated, "or" includes "and." Therefore, "including A or B" means three cases: including A, including B, or including both A and B.

[0041] Hereinafter, a battery module having improved impact resistance and safety and a battery pack including the same according to the present invention will be described.

[0042] FIG. 4 is a perspective view of a battery module according to a first preferred embodiment of the present invention, FIG. 5 is an exploded perspective view of the battery module of FIG. 4, and FIG. 6 is an enlarged cross-sectional view of part C of FIG.

[0043] As shown in Figures 4 to 6, the battery module according to the first embodiment of the present invention includes a first case 100 having a storage space, a second case 200, a plurality of battery cells 300, one or more bus bars 400, a wire 500, a rib structure 600, and a resin layer 700.

[0044] The first case 100 may have a hexahedral shape with an open interior, and includes a first frame 110 to which one end of the battery cell 300 is attached, and a second frame 120 for surrounding and protecting the side of the battery cell 300.

[0045] The second case 200 located on the top of the first case 100 is intended to protect the housed battery cells 300 and various electrical components (not shown), and is fastened to the first case 100.

[0046] The battery cells 300 housed in the housing space of the first case 100 may be cylindrical battery cells, but are not necessarily limited to this and may also be square batteries.

[0047] The battery cells 300 are arranged upright with the top caps and crimping parts that function as positive and negative terminals facing upward, and are provided with bus bars 400 and wires 500 to connect the battery cells 300 in series or in parallel. In addition, a rib structure 600 for protecting the wires 500 is arranged near the top of the battery cells 300.

[0048] That is, as described above, a large number of long rod-shaped bus bars 400 are arranged at regular intervals near the top of the battery cells 300. In addition, near the bus bars 400, more specifically, on the top of the battery cells 300, a rib structure 600 having upwardly protruding ribs 610 and openings 620 alternately provided thereon is provided parallel to the bus bars 400.

[0049] The top cap and bus bar 400, which function as a positive terminal of the battery cell 300, and the crimping part and bus bar 400, which function as a negative terminal, are electrically connected via a first wire 510 and a second wire 520 formed by a bonding method.

[0050] Here, the wire is made of a conductive material such as gold, aluminum, or copper, and the molten conductive material is spun like a thin thread from the end of a nozzle (not shown). Since this wire bonding method is a well-known technology, detailed explanation will be omitted.

[0051] On the other hand, the height H1 of the rib is preferably equal to or greater than the height of the bonded wire so as to provide sufficient protection for the bonded wire.

[0052] Next, the resin layer 700 will be described. The resin layer 700 is formed in an upper space of the battery cell 300, more specifically, in the vicinity of the positive and negative terminals of the battery cell 300, and in a space where the bus bar 400, the wire 500, and the rib structure 600 are located, and is filled with resin.

[0053] When the resin in a fluid state is filled into the space, it comes into complete contact with the busbars 400, wires 500, and rib structures 600, including the terminals of the battery cells 300, thereby completely eliminating the space.

[0054] The filled resin hardens and flattens over time, so that the upper surface of the resin layer 700 is flattened, and the parts exposed in the space, such as the terminals of the battery cells 300 and the bus bars 400, are recessed in the resin layer 700, limiting their movement. Of course, the second case 200 is positioned on top of the resin layer 700, and then fastened to the first case 100 by known fastening means such as bolts.

[0055] Here, the resin may be a polymer composite material containing a thermally conductive polymer resin, for example, a polymer substance such as epoxy, polyimide, or polystyrene, metal particles such as Al, Ag, Cu, or Ni, ceramic particles such as AlN, Al2O3, BN, SiC, or BeO, or carbon-based fillers such as graphite, carbon nanotubes, carbon fibers, or graphene.

[0056] Conventionally, the upper space inside the battery module restricted the installation direction when the battery module was attached to a device. However, by filling the space with resin layer 700, the battery module can be attached so that the positive terminals of the battery cells 300 face downwards, and the battery module is also resistant to external impacts.

[0057] In particular, in the case of cylindrical battery cells, considering that gas venting mainly occurs at the crimping portion with the top cap, when the battery module is installed in a device such as a vehicle, damage to the driver can be minimized by installing the battery module so that the top cap is located on the side opposite to the side where the driver and passengers are located.

[0058] Meanwhile, it is preferable that the height H2 of the resin layer is equal to or slightly higher than the height H1 of the rib, because the upper surface of the resin layer 700 and the inner surface of the second case 200 are in full contact with each other, thereby minimizing the movement of the bus bar 400, the wire 500, etc.

[0059] FIG. 7 is a perspective view of a battery module according to a second preferred embodiment of the present invention, FIG. 8 is an exploded perspective view of the battery module of FIG. 7, and FIG. 9 is an enlarged cross-sectional view of part D of FIG.

[0060] Except for the additional provision of a pad, the rest is the same as in the first embodiment described above, so only the pad, which is a different configuration, will be described below.

[0061] The pad 800 is located between the resin layer 700 and the second case 200, and serves to protect various components including the battery cell 300 from external impacts and to release heat generated by the battery cell 300 etc. to the outside.

[0062] In particular, the pad 800 includes planar upper and lower surfaces, is configured to have a certain thickness, and includes a material with excellent thermal conductivity inside or outside, for example, a metal, a ceramic, a polymer composite, or a silicon.

[0063] The pad 800 completely fills the gap between the flat surface of the resin layer 700 and the bottom surface of the second case 200. That is, the second case 200, the pad 800, and the resin layer 700 are completely attached to each other. Therefore, heat can be smoothly transferred toward the upper case of the battery module, and in particular, when a heat sink (not shown) is disposed on the outer surface of the second case 200, the cooling performance of the battery module can be further improved.

[0064] In addition, when the pad 800 contains silicone or a polymer composite material as a component, it can be expected to have both elasticity and compressibility, which not only provides the function of absorbing external shock, but also allows the pad to be assembled without gaps even if tolerances occur during manufacturing.

[0065] FIG. 10 is an enlarged cross-sectional view of a portion of a battery module in the third preferred embodiment of the present invention, and FIG. 11 is a perspective view of a pad according to the third preferred embodiment of the present invention.

[0066] Except for the fact that a space 810 is formed in the pad 800, the rest is substantially the same as in the second embodiment described above. Therefore, the following description will focus on the space 810 of the pad 800, which is a different configuration.

[0067] When gas venting or thermal runaway occurs in a particular battery cell due to various reasons such as an external impact, it is necessary to prevent high-temperature and high-pressure gas, sparks, flames, etc. from transferring to adjacent battery cells.

[0068] The spaces 810 formed at regular intervals through the pad 800 can act as a kind of pocket that can contain high-temperature, high-pressure gas, sparks, or flames generated when an event occurs in the battery cell 300, and can block or delay the movement of gas, flames, etc. to adjacent battery cells.

[0069] In other words, when high-temperature, high-pressure gas generated in a particular battery cell 300 rises through the resin layer 700, the high-temperature, high-pressure gas can be trapped in the space 810 of the pad 800, which has relatively better heat resistance and physical strength than the resin layer 700, thereby protecting the adjacent battery cells 300.

[0070] In particular, when the number of spaces 810 formed is the same as the number of all battery cells 300 that constitute the battery module and is located on the vertical extension line of each battery cell 300, the safety of the battery module can be further improved.

[0071] Of course, it is preferable that the outer shape of the space 810 is circular, but this is not necessarily limited to this. If it is circular, the diameter may be smaller than the outer diameter of the cylindrical battery cell 300.

[0072] The present invention may also provide a battery pack including the above-mentioned battery module, and the above-mentioned battery module or battery pack may be included as an energy source for any one device selected from the group including a light electric vehicle (LEV), an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), an electric bike (E-Bike), and an electric scooter (E-Scooter).

[0073] Those skilled in the art will appreciate that various applications and modifications within the scope of the present invention will be possible based on the above content. [Explanation of symbols]

[0074] 10, 100 Case 1 11, 110 1st frame 12, 120 2nd frame 20, 200 Case 2 30, 300 battery cells 40, 400 busbar 50, 500 Wires 51, 510 First Wire 52, 520 Second Wire 60, 600 Rib structure 61, 610 Rib 62, 620 open mouth 700 Resin layer 800 pads 810 Space section G Gap H1 Rib Height H2 resin layer height

Claims

1. a first case having a storage space; A plurality of battery cells are stored in the storage space in an upright state with their positive terminals facing upward; one or more bus bars located near the positive terminals of the battery cells; a wire electrically connecting the battery cell and the bus bar; a rib structure located on an upper portion of the battery cell, the rib structure having a rib protruding upward to protect the wire and an opening through which the wire passes; A resin layer filled in an upper portion of the battery cell; Including, the resin layer is filled so as to be in complete contact with the upper surfaces of the battery cells, the bus bars, the wires, and the rib structure.

2. The battery module of claim 1 , further comprising a second case fixed to the first case on an upper portion of the resin layer.

3. The battery module according to claim 2 , wherein an upper surface of the resin layer is a flat surface.

4. The battery module according to claim 2 , wherein the height of the ribs is equal to or greater than the height of the bonded wires.

5. The battery module according to claim 4 , wherein the height of the resin layer is equal to or greater than the height of the ribs.

6. The battery module according to claim 2 , wherein a pad is located between the resin layer and the second case.

7. The battery module of claim 6 , wherein the pad comprises a thermally conductive material.

8. The battery module according to claim 6 , wherein the pad comprises a material having elasticity and compressibility.

9. The battery module according to claim 6 , wherein the upper surface of the resin layer and the lower surface of the pad are positioned in close contact with each other.

10. The battery module according to claim 9 , wherein an upper surface of the pad and a lower surface of the second case are positioned in close contact with each other.

11. The battery module according to claim 10 , wherein the pad has a plurality of spaces formed therein, the spaces having a shape penetrating the pad.

12. The battery module according to claim 11 , wherein the space is located on a vertical extension line of the battery cell.

13. The battery module according to claim 12 , wherein the number of the spaces is equal to the number of the battery cells.

14. A battery pack comprising a battery module described in any one of claims 1 to 13.

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