Packaging case with improved heat dissipation structure

Abstract

The disclosed invention relates to a pack case having a space for accommodating at least one battery module. In one example, a plurality of engraved structures are formed on the upper surface of a base plate that contacts and supports the bottom surface of the battery module, and the plurality of engraved structures form a space for accommodating thermal resin.

Description

Technical Field

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

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0026639 filed on February 28, 2023, and all the contents disclosed in the literature of the Korean patent application are included as part of this specification.

Background Art

[0003] Unlike primary batteries, secondary batteries are rechargeable and have been actively researched and developed in recent years due to the possibility of being made smaller and having a larger capacity. With the increasing technological development and demand for mobile devices, as well as the emergence of electric vehicles and energy storage systems in line with the contemporary requirements of environmental protection, the demand for secondary batteries as an energy source has been increasing even more rapidly.

[0004] Secondary batteries are classified into coin-type batteries, cylindrical batteries, prismatic batteries, and pouch-type batteries according to the shape of the battery case. The electrode assembly mounted inside the battery case in a secondary battery is a power generation element capable of charge and discharge, which has a laminated structure of electrodes and a separator.

[0005] Since secondary batteries are required to be used continuously for a long period of time, it is necessary to effectively control the heat generated during the charge and discharge process. If the cooling of the secondary battery is not performed smoothly, the temperature rise causes an increase in current, and the increase in current causes a positive feedback chain reaction that again causes a temperature rise, and as a result, it leads to a catastrophic state of thermal runaway.

[0006] In addition, when secondary batteries form a group in the form of modules or packs, a thermal propagation phenomenon occurs where the heat runaway in any one secondary battery causes the other surrounding secondary batteries to continuously overheat. That is, when thermal runaway occurs in a battery module within a battery pack, a large amount of conductive dust, gas, and flames are ejected from the high-voltage terminal of the battery module, and as a result, dust accumulates on the high-voltage terminals of other adjacent battery modules, and the thermal propagation phenomenon is triggered by heat transfer due to the gas and flames.

[0007] As a design to prevent or delay the heat propagation in which the high heat of the battery cell or module that has experienced thermal runaway is transmitted to the adjacent battery cell or module, a heat insulation design that uses a heat insulation material to prevent or delay the heat transfer from the battery module that has experienced thermal runaway to the adjacent battery module, and a heat dissipation design that rapidly releases the heat of the battery module that has experienced thermal runaway to the outside of the battery pack initially and reduces the heat transfer to the adjacent battery module are applied.

[0008] The suppression and delay of heat propagation are particularly emphasized in electric vehicles which are directly related to life-threatening accidents, and the relevant regulations are being strengthened day by day. That is, in order to ensure a time margin for taking emergency evacuation and safety measures after thermal runaway occurs, a sufficient time delay is required until the heat propagation phenomenon spreads. Therefore, the actual situation is that a more effective solution for suppressing or delaying the occurrence of heat propagation in the battery pack is needed.

Summary of the Invention

Problems to be Solved by the Invention

[0009] The object of the present invention is to provide a pack case in which the heat generated from a battery module that has experienced thermal runaway is rapidly transmitted to the pack case in the form of conductive heat transfer from the perspective of heat dissipation design for suppressing and delaying heat propagation, and thus can be rapidly released to the outside as convective heat transfer in the pack case.

[0010] However, the technical problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those of ordinary skill in the art from the description of the invention described below.

Means for Solving the Problems

[0011] The present invention relates to a pack case having a space for accommodating at least one battery module. In one example, on the upper surface of a base plate that contacts and supports the bottom surface of the battery module, a plurality of engraved structures are formed, and the plurality of engraved structures form a space for accommodating thermal resin.

[0012] In one embodiment of the present invention, the engraved structure may form a lattice structure that is uniformly arranged vertically and horizontally with respect to the upper surface of the base plate.

[0013] The engraved structure increases the heat transfer area from the battery module to the thermal resin filled therein as compared with a flat surface.

[0014] In an exemplary embodiment, the engraved structure may form a curved surface including a hemispherical surface and a semi-elliptical surface.

[0015] Alternatively, the engraved structure may form a honeycomb structure.

[0016] On the other hand, the present invention provides a battery pack including a plurality of battery cells, a battery module including a module case for accommodating the plurality of battery cells, a pack case having the above configuration, and thermal resin applied between a lower frame of the battery module and a base plate of the pack case, wherein the thermal resin is filled in a plurality of engraved structures formed on the upper surface of the base plate.

[0017] In the battery pack of the present invention, the heat transfer area of the base plate with respect to the lower frame of the battery module increases via the thermal resin filled in the intaglio structure as compared with the planar contact.

[0018] And the battery pack of the present invention includes a plurality of the battery modules, the pack case includes partition members that partition the plurality of battery modules from each other, and the base plate may be provided with slots formed therethrough in a region in contact with the partition members.

[0019] In one embodiment, it can be said that it is preferable that the slots are not exposed outside the partition members.

[0020] And a plurality of the slots may be formed at intervals along the partition members.

Effect of the Invention

[0021] The pack case of the present invention having the above-described configuration provides an extended heat transfer area for the thermal resin by the intaglio structure formed on the upper surface of the base plate, and the heat transfer area extended by the intaglio structure increases the amount of heat conducted from the battery module to the base plate. As a result, the heat of the battery module in which thermal runaway has occurred is quickly transferred to the base plate and dissipated to the outside of the battery pack. Therefore, it contributes to suppressing or delaying heat propagation.

[0022] In addition, the slots formed through the base plate along the partition members that form boundaries between the battery modules physically remove a part of the heat conduction paths between the battery modules. As a result, not only does the excessive heat transfer caused by the battery module in which thermal runaway has occurred decrease and be delayed, but also the heat dissipation effect at the base plate is further promoted.

[0023] However, the technical effects that can be obtained by the present invention are not limited to the effects described above, and other effects not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0024] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further understand the technical idea of the present invention together with the detailed description of the invention to be described later. Therefore, the present invention should not be construed as being limited only to the matters described in such drawings.

Brief Description of the Drawings

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Embodiments for Carrying Out the Invention

[0026] Since the present invention can be subjected to various modifications and can have various embodiments, specific embodiments will be described in detail below.

[0027] However, this is not intended to limit the present invention to specific embodiments, and it should be understood to include all modifications, equivalents, or alternatives included in the spirit and technical scope of the present invention.

[0028] In the present invention, terms such as "comprising" and "having" are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and are not to be construed as precluding the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0029] Also, in the present invention, when a part such as a layer, film, region, or plate is described as being "on" another part, this includes not only the case where it is directly on the other part but also the case where there is another part in between. Conversely, when a part such as a layer, film, region, or plate is described as being "under" another part, it includes not only the case where it is directly under the other part but also the case where there is another part in between. Also, in this application, being "disposed on" can include not only the upper part but also the case of being disposed on the lower part.

[0030] The present invention relates to a pack case having a space for accommodating at least one battery module. In one example, on the upper surface of a base plate that contacts and supports the bottom surface of the battery module, a plurality of engraved structures are formed, and the plurality of engraved structures form a space for accommodating thermal resin.

[0031] Here, the engraved structure increases the heat transfer area from the battery module to the thermal resin filled therein as compared with a plane.

[0032] As a result, from the perspective of heat dissipation design, the pack case of the present invention can quickly transfer the heat generated in the battery module that has caused thermal runaway to the pack case in the form of conductive heat transfer due to the increase in the heat transfer area to the thermal resin. As a result, a large amount of heat is quickly transferred to the pack case at an early stage, and the amount of heat released to the outside as convective heat transfer increases, so that the heat propagation in the battery pack can be effectively suppressed or delayed.

[0033] Hereinafter, with reference to the accompanying drawings, specific embodiments of the pack case 100 according to the present invention will be described in detail. For reference, the front-back, up-down, left-right directions specifying the relative positions used in the following description are for helping the understanding of the invention, and are based on the directions shown in the drawings unless otherwise defined.

[0034] (First Embodiment) FIG. 1 is a drawing showing the pack case 100 according to the present invention, and FIG. 2 is a cross-sectional view taken along the line “A-A” of FIG. 1.

[0035] Referring to FIGS. 1 and 2, the illustrated pack case 100 includes a base plate 110 forming a bottom surface, a side plate 120 surrounding the outer contour of the base plate 110, partition members 130 arranged vertically and / or horizontally so as to partition the accommodation space defined by the side plate 120, and a lid 160 closing the upper surface of the accommodation space. The base plate 110 is provided with cooling channels 114 in which a cooling fluid is stored or flows. However, although FIG. 2 shows that the base plate 110 is provided with the cooling channels 114, it is also possible that a separate cooling plate (not shown) is joined to the base plate 110.

[0036] Looking at the upper surface of the base plate 110 shown in FIGS. 1 and 2, a plurality of recessed structures 112 are formed in each region in contact with the bottom surface of each battery module 200. The plurality of recessed structures 112 may form a lattice structure arranged uniformly vertically and horizontally with respect to the upper surface of the base plate 110, and each individual recessed structure 112 forms a concave space.

[0037] The plurality of recessed structures 112 can be formed by applying any one of known processing techniques such as press working, mechanical cutting, plasma processing, electrolytic processing, etching, and casting. And, although a protruding structure can protrude corresponding to the inside of the base plate 110 by the plurality of recessed structures 112, since this can have an adverse effect on the flow of the cooling fluid flowing through the cooling channel 114, it can be said that the inner surface of the base plate 110 forming a part of the cooling channel 114 preferably forms a flat surface.

[0038] In the present invention, the plurality of recessed structures 112 formed on the upper surface of the base plate 110 form a space for accommodating the thermal resin 300 (Thermal Resin). Although a plurality of battery modules 200 are housed in the pack case 100 to complete the battery pack 10, the base plate 110 forming the bottom surface of the pack case 100 and the lower frame 222 of the module case 220 are in contact with each other to perform conductive heat transfer. And, in order to promote the conductive heat transfer, the thermal resin 300 having excellent thermal conductivity is interposed between the contact surfaces of the base plate 110 and the module case 220.

[0039] When thermal runaway occurs in a certain battery module 200 in the battery pack 10, a large amount of heat propagates to the adjacent battery module 200 along the base plate 110 where conductive heat transfer actively occurs. On the other hand, the base plate 110 is often provided with heat dissipation means such as a cooling channel 114. Therefore, inside the pack case 100, before the heat of the battery module 200 diffuses by convective heat transfer to the other surfaces other than the base plate 110, if possible, quickly conducting the heat of the battery module 200 in which thermal runaway has occurred to the base plate 110, It may be advantageous for suppressing or delaying heat propagation to increase the amount of heat dissipated to the outside of the battery pack 10.

[0040] From the perspective of heat dissipation, the engraved structure 112 provided in large numbers on the upper surface of the base plate 110 provides an extended heat transfer area for the thermal resin 300. FIG. 2 is a cross-sectional view taken along the line “A-A” of FIG. 1. As shown in the drawing, the thermal resin 300 filled in the concave engraved structure 112 has the effect of increasing the heat transfer area from the battery module 200 to the base plate 110 as compared with a flat contact surface.

[0041] Through the heat transfer area extended by the engraved structure 112, the amount of heat conducted from the battery module 200 to the base plate 110 will increase proportionally, so that the heat of the battery module 200 that has experienced thermal runaway is quickly transferred to the base plate 110, and an opportunity to dissipate heat to the outside of the battery pack 10 will be obtained. Therefore, the large number of engraved structures 112 formed on the upper surface of the base plate 110 will contribute to suppressing or delaying heat propagation through the thermal resin 300.

[0042] In the exemplary embodiment of FIG. 2, the engraved structure 112 forms a curved surface including a hemispherical surface and a semi-elliptical surface. This is considered in view of the fact that the curved surface is an advantageous surface form for expanding the heat transfer area. Alternatively, as shown in FIG. 3, the engraved structure 112 can also form a honeycomb structure. The honeycomb structure may be somewhat inferior to the case of FIG. 2 in terms of expanding the heat transfer area, but it can be effective in complementing or strengthening the support rigidity of the base plate 110 that may be weakened by the engraved structure 112.

[0043] (Second Embodiment) FIG. 4 is a drawing showing the battery pack 10 according to the present invention. Although one battery module 200 is exemplarily shown in FIG. 4, one battery module 200 is mounted in each individual accommodation space partitioned by the partition member 130.

[0044] The battery module 200 includes a plurality of battery cells 210 and a module case 220 that houses the plurality of battery cells 210. In addition, the battery module 200 may further include a heat insulating material for heat insulation between the battery cells 210, a busbar frame assembly (BFA) for electrical connection and external output between the plurality of battery cells 210, etc. However, since such accessories have no direct relation to the heat dissipation design of the pack case 100 according to the present invention, the description thereof is omitted.

[0045] The illustrated pack case 100 includes a base plate 110 forming a bottom surface, a side plate 120 surrounding the outer contour of the base plate 110, partition members 130 arranged vertically and / or horizontally so as to partition the accommodation space limited by the side plate 120, and a lid 160 closing the upper surface of the accommodation space. The base plate 110 is provided with cooling channels 114 in which a cooling fluid is stored or flows. However, although FIGS. 2 and 5 show that the base plate 110 is provided with the cooling channels 114, it is also possible to configure the cooling channels 114 as a structure in which a separate cooling plate (not shown) is joined to the base plate 110.

[0046] Here, the partition member 130 can be distinguished into a vertical center beam 140 that divides the internal accommodation space into left and right across the center of the pack case 100 according to the arrangement direction with respect to the base plate 110, and a horizontal cross beam 150 that intersects the center beam 140 in a lattice form.

[0047] FIG. 5 is a cross-sectional view showing the contact surface between the battery module 200 and the base plate 110. The battery pack 10 in FIG. 5 includes a thermal resin 300 applied between the lower frame 222 of the battery module 200 and the base plate 110 of the pack case 100. As a result, the thermal resin 300 is filled in all the recessed structures 112 on the upper surface of the base plate 100.

[0048] As described in the first embodiment, the engraved structure 112 provided on the base plate 110 provides an extended heat transfer area for the thermal resin 300. Due to the extension of the heat transfer area achieved by the base plate 110, the amount of heat conducted from the battery module 200 to the base plate 110 proportionally increases accordingly. FIG. 6 is a drawing showing the conductive heat transfer path in the battery pack 10 of FIG. 5. Assuming that the illustrated battery module 200 causes a thermal runaway, a large amount of heat generated by the thermal runaway is transmitted to the base plate 110 in the form of conductive heat transfer in a larger amount due to the increase in the heat transfer area by the engraved structure 112. A large amount of the heat transmitted to the base plate 110 is released to the outside of the battery pack 10 through the base plate 110 and through the cooling fluid. As a result, the amount of heat conducted to other surrounding battery modules 200 with the base plate 110 as a heat conduction medium decreases. Such an improvement in heat dissipation performance will contribute to suppressing and delaying heat propagation within the battery pack 10.

[0049] FIG. 7 is a drawing showing another embodiment of the pack case 100. The embodiment of the pack case 100 shown in FIG. 7 includes a partition member 130 in which the pack case 100 partitions a plurality of battery modules 200 from each other. On the other hand, the base plate 110 is provided with slots 116 formed therethrough in a region in contact with the partition member 130. The slots 116 formed through the base plate 110 are structures for restricting conductive heat transfer occurring across the bottom surface of the partition member 130.

[0050] The partition member 130 that forms the center beam 140 and / or the cross beam 150 forms a boundary between the battery modules 200, but the conductive heat transfer that propagates to the adjacent battery modules 200 across the partition member 130 is restricted by the slots 116 formed through the base plate 110. That is, as shown in FIG. 8, a part of the heat conduction path between the battery modules 200 through the base plate 110 is physically removed by the slots 116 penetrating the base plate 110, so that the excessive heat transfer caused by the battery module 200 in which thermal runaway has occurred is reduced and delayed. For reference, when the base plate 110 is provided with the cooling channels 114, the slot 116 structure needs to be formed avoiding the cooling channels 114.

[0051] On the other hand, the through slots 116 of the base plate 110 also play a role in promoting heat dissipation by convective heat transfer. In other words, since the conductive heat transfer that propagates to the adjacent battery modules 200 across the partition member 130 is restricted and delayed by the slots 116 formed through the base plate 110, as a countermeasure, there will be more opportunities for heat dissipation to occur on the base plate 110.

[0052] In one embodiment, it can be said that the slots 116 arranged side by side with respect to the partition member 130 are preferably not exposed outside the partition member 130. In order to reliably restrict the conductive heat transfer, the slots 116 are formed through the base plate 110, but the slots 116 formed in this way affect the airtightness of the pack case 100. Therefore, the airtightness of the pack case 100 can be ensured by designing the size of the slots 116 so that the partition member 130 completely surrounds the slots 116 so as to close the slots 116 formed through the base plate 110.

[0053] And a plurality of slots 116 can be formed at intervals along the partition member 130. Although conduction heat transfer occurs in the regions between the slots 116 spaced apart from each other, when the plurality of slots 116 are formed at intervals, preferably evenly spaced, the heat conducted to the adjacent battery modules 200 is not locally concentrated, which can advantageously act to prevent another thermal runaway from occurring.

[0054] As described above, the present invention has been described in more detail through the drawings and embodiments. However, the configurations described in the drawings or embodiments described in this specification are merely one embodiment of the present invention and do not represent all of the technical ideas of the present invention. Therefore, there may be various equivalents and modifications that can replace these at the time of this application.

Explanation of Reference Numerals

[0055] 10: Battery pack 100: Pack case 110: Base plate 112: Intaglio structure 114: Cooling channel 116: Slot 120: Side plate 130: Partition member 140: Center beam 150: Cross beam 160: Lid 200: Battery module 210: Battery cell 220: Module case 222: Lower frame 300: Thermal resin

Claims

1. A pack case having a space for accommodating at least one battery module, wherein a plurality of engraved structures are formed on the upper surface of a base plate that contact-supports the bottom surface of the battery module, and the plurality of engraved structures form a space for accommodating thermal resin. The pack case.

2. The engraved structure is The pack case according to claim 1, which forms a lattice structure arranged uniformly vertically and horizontally with respect to the upper surface of the base plate.

3. The engraved structure is The pack case according to claim 1, which increases the heat transfer area from the battery module to the thermal resin filled therein as compared with a flat surface.

4. The engraved structure is The pack case according to claim 1, which has a curved surface including a hemispherical surface and a semi-elliptical surface.

5. The engraved structure is The pack case according to claim 2, which forms a honeycomb structure.

6. A battery pack including a battery module including a plurality of battery cells and a module case for accommodating the plurality of battery cells, The pack case according to any one of claims 1 to 5, and thermal resin applied between a lower frame of the battery module and the base plate of the pack case, wherein the thermal resin is filled in a plurality of engraved structures formed on the upper surface of the base plate.

7. The battery pack according to claim 6, wherein the heat transfer area of the base plate with respect to the lower frame of the battery module is increased through the thermal resin filled in the engraved structure as compared with flat contact.

8. A plurality of the battery modules are provided, the pack case includes partition members that partition the plurality of battery modules from each other, and the base plate is provided with slots formed therethrough in a region that contacts the partition members. The battery pack according to claim 6.

9. The slot is The battery pack according to claim 8, which is not exposed outside the partition member.

10. The slot is The battery pack according to claim 8, in which a plurality of the slots are formed at intervals along the partition member.

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