Battery module with improved heat dissipation structure

Abstract

The invention relates to a battery module. One embodiment of the present invention includes a plurality of battery cells and a module case for accommodating the plurality of battery cells, in which a lower frame of the module case is formed with a plurality of intaglio structures on an outer surface thereof, and each of the plurality of intaglio structures forms a space for accommodating a thermal resin.

Description

Technical Field

[0001] The present invention relates to a battery module that improves the heat dissipation performance of a battery pack by promoting conductive heat transfer from the battery module to a battery pack housing.

[0002] The present application claims priority based on Korean Patent Application No. 10-2023-0026624 filed on February 28, 2023, the entire contents of which are incorporated herein by reference. Background Art

[0003] Unlike primary batteries, secondary batteries are rechargeable and have been widely researched and developed in recent years due to their potential in miniaturization and large capacity. The demand for secondary batteries as energy sources is rapidly increasing as technology develops and demand for mobile devices increases, as well as electric vehicles and energy storage systems emerge in response to environmental protection needs.

[0004] Secondary batteries can be divided into coin-type batteries, cylindrical batteries, square batteries and pouch-type batteries according to the shape of the battery case. In secondary batteries, the electrode assembly installed inside the battery case is a chargeable and dischargeable power generation device, which includes a stacked structure of electrodes and separators.

[0005] Since secondary batteries need to be used continuously for a long time, it is necessary to effectively control the heat generated during the charging and discharging process. If the secondary battery is not properly cooled, the increase in temperature will cause the current to increase, which will cause the temperature to increase again, which will cause a chain reaction and eventually lead to the catastrophic condition of thermal runaway.

[0006] In addition, if the secondary batteries are grouped in the form of modules or battery packs, the thermal runaway caused by one secondary battery can cause other secondary batteries nearby to continue to overheat, resulting in a heat propagation phenomenon. In other words, when a battery module in a battery pack experiences thermal runaway, a large amount of conductive dust, gas, and flames are ejected from the high-voltage terminals of the battery module, which causes dust to accumulate on the high-voltage terminals of other adjacent battery modules and triggers a heat propagation phenomenon through heat transfer from gas and flames.

[0007] A design for preventing or delaying heat transfer from a battery cell or module that has experienced thermal runaway to an adjacent battery cell or module, including an insulation design and a heat dissipation design, wherein the insulation design uses insulating materials to prevent or delay heat transfer from a battery module that has experienced thermal runaway to an adjacent battery module, and the heat dissipation design initially quickly dissipates the heat of the battery module that has experienced thermal runaway to the outside of the battery pack to reduce heat transfer to the adjacent battery modules.

[0008] Preventing and delaying thermal runaway is a critical issue, especially in electric vehicles, where thermal runaway can lead to life-threatening accidents, and laws and regulations are becoming increasingly stringent. In other words, these laws and regulations require a sufficient delay before the thermal runaway phenomenon spreads, so that there is time for emergency evacuation and safety measures. Therefore, more effective measures are needed to suppress or delay the occurrence of heat transfer in battery packs. Summary of the invention

[0009] Technical issues

[0010] The present invention aims to provide a battery module in which the heat generated by a battery module that has generated thermal runaway can be quickly transferred to a battery pack housing in the form of conductive heat transfer to suppress and delay heat propagation, thereby being quickly released to the outside in the form of convective heat transfer in the battery pack housing.

[0011] However, the technical problems to be solved by the present invention are not limited to the above problems, and those skilled in the art can clearly understand other problems not mentioned from the following description of the present invention.

[0012] Technical Solution

[0013] The present invention relates to a battery module. In one example, the battery module includes: a plurality of battery cells; and a module housing for accommodating the plurality of battery cells, wherein an outer surface of a lower frame of the module housing is formed with a plurality of engraved structures, and the plurality of engraved structures form a space for accommodating a thermal resin.

[0014] In one embodiment of the present invention, the engraved structure may form a grid structure that is evenly arranged vertically and horizontally relative to the outer surface of the lower frame.

[0015] Regarding the thermal resin to be filled in the negative-engraved structure, the negative-engraved structure can increase the heat transfer area of ​​the lower frame compared with a flat surface.

[0016] In an exemplary embodiment, the engraved structure may form a curved surface including a hemispherical surface and a semi-elliptical surface.

[0017] Alternatively, the engraved structure may form a honeycomb structure.

[0018] At the same time, the present invention provides a battery pack, which includes a plurality of battery modules having the above-mentioned configuration, a battery pack case accommodating the plurality of battery modules, and a thermal resin coated between a lower frame of the battery module and a bottom plate of the battery pack case, wherein the thermal resin is filled in a plurality of engraved structures formed on an outer surface of the lower frame of the battery pack case.

[0019] The battery pack of the present invention, wherein the area of ​​conductive heat transfer through the flow of the thermal resin filled in the engraved structure to the bottom plate is increased compared to a planar contact.

[0020] Furthermore, the battery pack of the present invention may include a pack case, wherein the pack case includes a partition wall member partitioning the plurality of battery modules from each other, and wherein the bottom plate may include a groove formed through a region in contact with the partition wall member.

[0021] In one embodiment, the groove may not be exposed outside the partition wall member.

[0022] In addition, the groove may be formed as a plurality of grooves spaced apart along the partition wall member.

[0023] Beneficial Effects

[0024] The battery module of the present invention having the above-mentioned configuration, wherein the engraved structure arranged in the lower frame of the module shell provides an enlarged heat dissipation area for the thermal resin, and the enlarged heat dissipation area provided by the engraved structure increases the heat conducted from the battery module to the base plate, so that the heat of the battery module that has thermal runaway can be quickly transferred to the base plate and dissipated to the outside of the battery pack, thereby helping to suppress or delay heat propagation.

[0025] In addition, the grooves formed through the bottom plate along the partition wall members forming the boundaries between the battery modules physically eliminate a portion of the heat conduction path between the battery modules, thereby reducing and delaying excessive heat transfer caused by the battery modules experiencing thermal runaway, while further promoting heat dissipation in the bottom plate.

[0026] However, the technical effects that can be obtained by the present invention are not limited to the above-mentioned effects, and those skilled in the art can clearly understand other effects that are not mentioned from the following description of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Since the attached drawings attached to this specification illustrate exemplary embodiments of the present invention and, together with the detailed description of the present invention described below, serve to facilitate understanding of the technical concept of the present invention, the present invention should not be restrictively interpreted based on the drawings.

[0028] Figure 1 is a diagram illustrating a battery module according to the present invention.

[0029] Figure 2 FIG. 1 is a diagram illustrating an outer surface of a lower frame of a module case.

[0030] Figure 3 It is through along Figure 2 Sectional view taken along line “AA”.

[0031] Figure 4 FIG. 1 is a diagram illustrating another embodiment of the lower frame of the module case.

[0032] Figure 5 is a diagram illustrating a battery pack according to the present invention.

[0033] Figure 6 is a cross-sectional view illustrating a contact surface of a battery module and a base plate.

[0034] Figure 7 is an example Figure 6 Diagram of the conductive heat transfer paths within a battery pack.

[0035] Figure 8 It is a diagram illustrating another embodiment of the battery pack case.

[0036] Fig. 9 is an example Figure 8 Diagram of the conductive heat transfer paths within a battery pack. DETAILED DESCRIPTION

[0037] The present invention is susceptible to various modifications and embodiments, and therefore, specific embodiments thereof will be described in detail below.

[0038] However, it should be understood that the present invention is not limited to these specific embodiments, but includes all modifications, equivalents or substitutes within the spirit and technical scope of the present invention.

[0039] The terms "comprising", "including" and "having" used herein specify the presence of features, quantities, steps, actions, parts or components, or a combination thereof described in the specification, and it should be understood that they do not preclude the possibility of the presence or addition of one or more other features, quantities, steps, actions, parts, components, or a combination thereof.

[0040] Furthermore, in the present invention, when a part of a layer, film, region, plate, etc. is disposed "on" another part, this includes not only a case where a part is "directly disposed" on another part, but also a case where another part is interposed between them. Conversely, when a part of a layer, film, region, plate, etc. is disposed "under" another part, this includes not only a case where a part is "directly disposed" under another part, but also a case where another part is interposed between them. Furthermore, in the present application, "on" may include not only a case where it is disposed on an upper part, but also a case where it is disposed on a lower part.

[0041] The present invention relates to a battery module. In one example, the battery module includes a plurality of battery cells and a module housing for accommodating the plurality of battery cells, wherein an outer surface of a lower frame of the module housing is formed with a plurality of engraved structures, and the plurality of engraved structures form a space for accommodating a thermal resin.

[0042] Here, the engraved structure increases the heat transfer area of ​​the lower frame for the thermal resin to be filled inside thereof, compared with the flat surface.

[0043] Therefore, from the perspective of heat dissipation design, the battery module of the present invention can quickly transfer the heat generated in the battery module that causes thermal runaway to the battery pack housing in the form of conductive heat transfer by increasing the heat transfer area of ​​the thermal resin. As a result, a large amount of heat is transferred to the battery pack housing at an early stage, and as the amount of heat released to the outside in the form of convection heat increases, the heat propagation within the battery pack is effectively suppressed or delayed.

[0044] Embodiments of the present invention

[0045] Hereinafter, a specific embodiment of the battery module 200 of the present invention will be described in detail with reference to the accompanying drawings. For reference, the directions of front, rear, up, down, left, and right used to indicate relative positions in the following description are for understanding the present invention, and unless otherwise specified, refer to the directions shown in the accompanying drawings.

[0046] [First embodiment]

[0047] Figure 1 is a diagram illustrating a battery module 200 according to the present invention, Figure 2 2 is a diagram illustrating an outer surface of the lower frame 222 of the module case 220 .

[0048] Reference Figure 1 and Figure 2 Generally speaking, the battery module 200 includes a plurality of battery cells 210 and a module housing 220 accommodating the plurality of battery cells 210. In addition, the battery module 200 may further include components such as an insulating material for insulation between the battery cells 210, a bus frame assembly (BFA) for electrical connection between the plurality of battery cells 210 and an external output, etc., but these components are not directly related to the heat dissipation design of the battery module 200 according to the present invention, and therefore will not be described herein.

[0049] Reference Figure 2 , which shows the lower surface of the module housing 220, a plurality of engraved structures 230 are formed on the outer surface of the lower frame 222 of the module housing 220. The plurality of engraved structures 230 may form a grid structure uniformly arranged vertically and horizontally relative to the outer surface of the lower frame 222, and each engraved structure 230 forms an inwardly concave space.

[0050] The plurality of intaglio structures 230 may be manufactured by applying any known processing techniques such as pressing, mechanical cutting, plasma processing, electrolytic processing, etching, casting, etc. Also, although the plurality of intaglio structures 230 may be manufactured such that the corresponding intaglio structures protrude into the interior of the lower frame 222, this may adversely affect the capacity of the battery module 200, so it may be desirable that the lower frame 222 has a flat inner surface.

[0051] In the present invention, a plurality of engraved structures 230 form a space for accommodating the thermal resin 300. The battery module 200 is accommodated in the battery pack case 100 to complete the battery pack 10, wherein the bottom plate 110 forming the bottom surface of the battery pack case 100 and the lower frame 222 of the module case 220 are in contact with each other to promote conductive heat transfer. In addition, in order to promote conductive heat transfer, the contact surfaces of the bottom plate 110 and the module case 220 are interposed with the thermal resin 300 having excellent thermal conductivity.

[0052] When any battery module 200 in the battery pack 10 experiences thermal runaway, the heat propagates to the adjacent battery module 200 along the bottom plate 110 where conductive heat transfer is actively occurring. At the same time, the bottom plate 110 is generally provided with a heat dissipation device such as a cooling channel 114. Therefore, before the heat of the battery module 200 diffuses to the side other than the bottom plate 110 by convection heat transfer, the heat of the battery module 200 that experiences thermal runaway is conducted to the bottom plate 110 as soon as possible inside the battery pack housing 100, which can be beneficial to suppress or delay heat propagation to increase the amount of heat dissipated to the outside of the battery pack 10.

[0053] From this heat dissipation perspective, the engraved structure 230 provided in the lower frame 222 of the module case 220 provides an expanded heat transfer area for the thermal resin 300 . Figure 3 It is through along Figure 2 As shown in the cross-sectional view taken along the line “AA” in FIG. 1 , the thermal resin 300 filled in the concave engraved structure 230 provides a larger heat transfer surface for the battery module 200 compared to a flat contact surface.

[0054] The heat transfer area enlarged by the engraved structures 230 increases the amount of heat conducted from the battery module 200 to the bottom plate 110 in proportion, so that the heat of the battery module 200 that has generated thermal runaway can be quickly transferred to the bottom plate 110 and has a chance to be dissipated to the outside of the battery pack 10. Therefore, the plurality of engraved structures 230 formed on the bottom surface of the battery module 200 help to suppress or delay heat propagation through the thermal resin 300.

[0055] exist Figure 3In the exemplary embodiment of the embodiment, the engraved structure 230 forms a curved surface including a hemispherical surface and a semi-elliptical surface. This is in view of the fact that the curved surface is a favorable surface shape for expanding the heat transfer area. Alternatively, as Figure 4 As shown, the engraved structure 230 can form a honeycomb structure. Although the honeycomb structure may be more effective than the conventional structure in terms of expanding the heat transfer area, Figure 3 The situation is slightly lower, but it can effectively compensate or strengthen the structural rigidity of the lower frame 222 which may be weakened by the engraved structure 230.

[0056] [Second embodiment]

[0057] Figure 5 is a diagram illustrating a battery pack 10 according to the present invention. A plurality of battery modules 200 as described in the first embodiment are accommodated in a battery pack housing 100. The battery pack housing 100 shown includes a bottom plate 110 forming a bottom surface, a side plate 120 surrounding the periphery of the bottom plate 110, a partition wall member 130 disposed longitudinally and / or transversely to divide a housing space defined by the side plate 120, and a cover 160 closing the upper surface of the housing space. In addition, the bottom plate 110 is provided with a cooling channel 114 through which a cooling fluid is stored or flows. However, although Figure 5 The bottom plate 110 shown in FIG. 1 is provided with the cooling channels 114 , but a separate cooling plate (not shown) may be coupled to the bottom plate 110 .

[0058] Here, according to the arrangement direction relative to the base plate 110, the partition wall member 130 can be further distinguished by a longitudinal center beam 140 that crosses the center of the battery pack housing 100 and divides the internal accommodating space from one side to the other, and a transverse cross beam 150 that forms a grid relative to the center beam 140.

[0059] Figure 6 is a cross-sectional view illustrating a contact surface of the battery module 200 and the base plate 110 . Figure 6 The battery pack 10 includes a thermal resin 300 coated between the lower frame 222 of the battery module 200 and the bottom plate 110 of the pack case 100. Therefore, a plurality of engraved structures 230 formed on the outer surface of the lower frame 222 of the module case 220 are filled with the thermal resin 300.

[0060] As described in the first embodiment, the engraved structure 230 provided in the lower frame 222 of the module case 220 provides an enlarged heat transfer area for the thermal resin 300, and the heat conducted from the battery module 200 to the base plate 110 increases proportionally by the enlargement of the heat transfer area in the module case 220. Figure 7 is an example Figure 6FIG. 1 is a diagram of a conductive heat transfer path in a battery pack 10. Assuming that the depicted battery module 200 experiences thermal runaway, a large amount of heat generated by the thermal runaway is transferred to the bottom plate 110 by conduction due to the increased heat transfer area by the engraved structure 230. A large amount of heat transferred to the bottom plate 110 is dissipated through the bottom plate 110 and to the outside of the battery pack 10 with the aid of the cooling fluid, thereby reducing the heat that is propagated to other nearby battery modules 200 using the bottom plate 110 as a heat transfer medium. This improvement in heat dissipation performance helps to suppress and delay heat propagation within the battery pack 10.

[0061] Figure 8 1 is a diagram illustrating an alternative embodiment of a battery pack case 100. Figure 8 In the embodiment of the battery pack housing 100 shown, the battery pack housing 100 includes a partition wall member 130 that separates the plurality of battery modules 200 from each other, and at the same time, the bottom plate 110 includes a through groove 112 in a region in contact with the partition wall member 130. The through groove 112 in the bottom plate 110 is intended to limit conductive heat transfer across the bottom surface of the partition wall member 130.

[0062] The partition wall members 130 forming the center beam 140 and / or the cross beam 150 form the boundary between the battery modules 200, and restrict the conductive heat transfer across the partition wall members 130 to the adjacent battery modules 200 through the grooves 112 formed through the bottom plate 110. In other words, Fig. 9 As shown, by forming the groove 112 through the bottom plate 110, a portion of the heat conduction path between the battery modules 200 through the bottom plate 110 is physically eliminated, thereby reducing and delaying excessive heat transfer caused by the battery module 200 experiencing thermal runaway. For reference, when the bottom plate 110 is provided with a cooling channel 114, the groove 112 structure needs to be formed by avoiding the cooling channel 114.

[0063] On the other hand, the through grooves 112 in the bottom plate 110 also play a role in promoting heat dissipation through convective heat transfer. In other words, the conductive heat transfer that spreads across the partition wall member 130 to the adjacent battery module 200 is limited and delayed due to the through grooves 112 in the bottom plate 110, so that the bottom plate 110 has more heat dissipation opportunities.

[0064] In one embodiment, it may be desirable that the groove 112 disposed side by side with respect to the partition wall member 130 does not extend beyond the partition wall member 130. In order to further limit the conductive heat transfer, the groove 112 is formed through the bottom plate 110, which affects the sealing of the battery pack housing 100. Therefore, the sealing of the battery pack housing 100 can be achieved by designing the groove 112 to a size that allows the partition wall member 130 to completely surround the groove 112, so that the partition wall member 130 closes the through groove 112 on the bottom plate 110.

[0065] Furthermore, the grooves 112 may be spaced apart along the partition wall member 130. Conductive heat transfer may occur in the areas between the spaced apart grooves 112, and the plurality of grooves 112 being spaced apart, preferably evenly spaced apart, may be advantageous in preventing heat conducted to the adjacent battery module 200 from being locally concentrated and causing another thermal runaway.

[0066] As described above, the present invention has been described in more detail through the drawings and embodiments. However, since the configuration described in the drawings or embodiments described herein is only one embodiment of the present invention and does not represent the overall technical concept of the present invention, it should be understood that the present invention covers various equivalents, modifications and alternatives at the time of filing this application.

[0067] [Description of Reference Signs]

[0068] 10: Battery Pack

[0069] 100: Battery pack housing

[0070] 110: Base plate

[0071] 112: Slot

[0072] 114: Cooling channel

[0073] 120: Side panels

[0074] 130: Partition wall component

[0075] 140: Center beam

[0076] 150: beam

[0077] 160: Cover

[0078] 200: Battery module

[0079] 210: Battery cells

[0080] 220: Module housing

[0081] 222: Lower frame

[0082] 230: Intaglio Structure

[0083] 300: Thermal resin

Claims

1. A battery module, comprising: Multiple battery cells; as well as a module housing accommodating the plurality of battery cells, The outer surface of the lower frame of the module housing is formed with a plurality of engraved structures, and the plurality of engraved structures form a space for accommodating thermal resin.

2. The battery module according to claim 1, wherein: The engraved structure forms a grid structure that is evenly arranged vertically and horizontally relative to the outer surface of the lower frame.

3. The battery module according to claim 1, wherein: Regarding the thermal resin to be filled in the negative structure, the negative structure increases the heat transfer area of ​​the lower frame compared to a flat surface.

4. The battery module according to claim 1, wherein: The engraved structure forms a curved surface including a hemispherical surface and a semi-elliptical surface.

5. The battery module according to claim 2, wherein: The engraved structure forms a honeycomb structure.

6. A battery pack, comprising: A plurality of battery modules according to any one of claims 1 to 5; A battery pack housing, the battery pack housing accommodating a plurality of the battery modules; as well as thermal resin, the thermal resin being coated between the lower frame of the battery module and the bottom plate of the battery pack case, The thermal resin is filled in a plurality of engraved structures formed on an outer surface of the lower frame of the battery pack case.

7. The battery pack according to claim 6, wherein: Compared with a planar contact, the area of ​​conductive heat transfer through the thermal resin filled in the engraved structure flowing to the base plate increases.

8. The battery pack according to claim 6, wherein: The battery pack case includes a partition wall member that partitions the plurality of battery modules from each other. And, the bottom plate includes a groove formed through a region contacting the partition wall member.

9. The battery pack according to claim 8, wherein: The groove is not exposed outside the partition wall member.

10. The battery pack according to claim 8, wherein: The groove is formed as a plurality of grooves spaced apart along the partition wall member.

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