Pack 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 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 contents disclosed in the documents of said Korean patent application are incorporated herein by reference. [Background technology]

[0003] Unlike primary batteries, secondary batteries are rechargeable and have been the subject of much research and development in recent years due to their potential for miniaturization and large capacity. Demand for secondary batteries as an energy source is rapidly increasing due to the increasing technological development and demand for mobile devices, as well as the emergence of electric vehicles and energy storage systems in response to modern demands for environmental protection.

[0004] Secondary batteries are classified into coin-type batteries, cylindrical batteries, prismatic batteries, and pouch-type batteries depending on the shape of the battery case. The electrode assembly installed inside the battery case of a secondary battery is a power generating element that can be charged and discharged and is made up of 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 charging and discharging process.If the secondary battery is not cooled smoothly, a positive feedback chain reaction will occur in which a rise in temperature causes an increase in current, and the increase in current causes another rise in temperature, resulting in a catastrophic state of thermal runaway.

[0006] Furthermore, when secondary batteries are grouped together in the form of a module or pack, thermal runaway in one secondary battery can cause other surrounding secondary batteries to continuously overheat, resulting in a thermal propagation phenomenon. That is, when thermal runaway occurs in a battery module within a battery pack, a large amount of conductive dust, gas, and flames are emitted from the high-voltage terminal of the battery module, causing dust to accumulate at the high-voltage terminals of other adjacent battery modules, and the heat transfer caused by the gas and flames triggers a thermal propagation phenomenon.

[0007] As a design to prevent or delay the heat transfer of high heat from a battery cell or module where thermal runaway has occurred to an adjacent battery cell or module, a heat insulation design that uses a heat insulating material to prevent or delay the heat transfer from a battery module where thermal runaway has occurred to an adjacent battery module, and a heat dissipation design that quickly releases the heat from a battery module where thermal runaway has occurred to the outside of the battery pack in an early stage, thereby reducing the heat transfer to an adjacent battery module, are applied.

[0008] The suppression and delay of heat propagation is particularly important in electric vehicles, which can directly lead to fatal accidents, and related regulations are being strengthened daily. Specifically, they require a sufficient time delay for the heat propagation phenomenon to dissipate so that there is enough time to take emergency evacuation and safety measures after a thermal runaway occurs. Therefore, a more effective method for suppressing or delaying the occurrence of heat propagation in battery packs is needed. Summary of the Invention [Problem to be solved by the invention]

[0009] An object of the present invention is to provide a pack case that, from the perspective of heat dissipation design, allows heat generated from a battery module that has experienced thermal runaway to be quickly transferred to the pack case in the form of conductive heat transfer in order to suppress and delay heat propagation, thereby enabling heat to be quickly released to the outside as convective heat transfer in the pack case.

[0010] However, the technical problems that the present invention aims to solve are not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention described below. [Means for solving the problem]

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

[0012] In one embodiment of the present invention, the recessed structures may form a lattice structure that is uniformly arranged in the vertical and horizontal directions on the upper surface of the base plate.

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

[0014] In an exemplary embodiment, the recessed structure may have a curved surface, including a hemisphere, a semi-ellipsoid, or the like.

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

[0016] Meanwhile, the present invention provides a battery pack including: a battery module including a plurality of battery cells and a module case accommodating the plurality of battery cells; a pack case having the above configuration; and a 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 into a plurality of recessed structures formed on an upper surface of the base plate.

[0017] In the battery pack of the present invention, the heat transfer area of ​​the base plate to the lower frame of the battery module is increased compared to flat contact via the thermal resin filled in the recessed structure.

[0018] The battery pack of the present invention may include a plurality of the battery modules, the pack case may include a partition member that separates the plurality of battery modules from each other, and the base plate may have a slot formed therethrough in an area that contacts the partition member.

[0019] In one embodiment, it is preferable that the slot is not exposed to the outside of the partition member.

[0020] A plurality of the slots may be formed along the partition member at intervals. [Effects of the Invention]

[0021] In the pack case of the present invention having the above-described configuration, the recessed structure formed on the upper surface of the base plate provides an expanded heat transfer area for the thermal resin, and the expanded heat transfer area due to the recessed structure increases the amount of heat conducted from the battery module to the base plate. As a result, heat from the battery module in the event of thermal runaway is quickly transferred to the base plate and dissipated to the outside of the battery pack, thereby contributing to suppressing or delaying heat propagation.

[0022] In addition, the slots formed through the base plate along the partition members that form the boundaries between the battery modules physically remove part of the heat conduction path between the battery modules, thereby not only reducing and delaying excessive heat transfer caused by a battery module experiencing thermal runaway, but also further promoting the heat dissipation effect in the base plate.

[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, together with the detailed description of the invention described below, serve to further understand the technical concept of the present invention, and therefore the present invention should not be interpreted as being limited solely to the matters depicted in such drawings. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a view showing a pack case according to the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along line "AA" in FIG. [Figure 3] 10 is a view showing another embodiment of an intaglio structure provided on a base plate; [Figure 4] 1 is a view showing a battery pack according to the present invention; [Figure 5] 4 is a cross-sectional view showing a contact surface between a battery module and a base plate. FIG. [Figure 6] 6 is a diagram showing conductive heat transfer paths in the battery pack of FIG. 5. [Figure 7] 10 is a view showing another embodiment of the pack case. [Figure 8] 8 is a diagram showing conductive heat transfer paths in the battery pack of FIG. 7. DETAILED DESCRIPTION OF THE INVENTION

[0026] Because the present invention is susceptible 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 invention to any particular embodiment, but rather to be understood as including all modifications, equivalents, or alternatives falling within the spirit and scope of the invention.

[0028] In the present invention, terms such as "comprise" and "have" are intended to specify the presence of features, numbers, steps, operations, components, parts or combinations thereof described in the specification, and may be understood as not precluding the presence or additional possibility of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0029] Furthermore, in the present invention, when a layer, film, region, plate, or other portion is described as being "on" another portion, this includes not only the case where it is "directly on" the other portion, but also the case where there is another portion therebetween. Conversely, when a layer, film, region, plate, or other portion is described as being "under" the other portion, this includes not only the case where it is "directly under" the other portion, but also the case where there is another portion therebetween. Furthermore, in this application, being "located on" can include not only the case where it is located at the top, but also the case where it is located at the bottom.

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

[0031] Here, the recessed structure increases the heat transfer area from the battery module to the thermal resin filled therein, compared to a flat surface.

[0032] As a result, from the perspective of heat dissipation design, the pack case of the present invention can quickly transfer heat generated in a battery module that has experienced thermal runaway to the pack case in the form of conductive heat transfer due to the increased heat transfer area for the thermal resin.As a result, a large amount of heat is transferred to the pack case early, and the amount of heat released to the outside as convective heat transfer increases, thereby effectively suppressing or delaying heat propagation within the battery pack.

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

[0034] (First embodiment) FIG. 1 is a view showing a pack case 100 according to the present invention, and FIG. 2 is a cross-sectional view taken along line "AA" in FIG.

[0035] 1 and 2, the illustrated pack case 100 includes a base plate 110 forming the bottom surface, side plates 120 surrounding the outer periphery of the base plate 110, partition members 130 arranged vertically and / or horizontally to define an accommodation space defined by the side plate 120, and a lid 160 closing the top of the accommodation space. The base plate 110 is provided with cooling channels 114 through which a cooling fluid is stored or flows. Although FIG. 2 shows the base plate 110 as having the cooling channels 114, a separate cooling plate (not shown) may also be attached to the base plate 110.

[0036] 1 and 2, a plurality of recessed structures 112 are formed in each region that contacts the bottom surface of each battery module 200. The recessed structures 112 may form a lattice structure that is uniformly arranged vertically and horizontally on the upper surface of the base plate 110, and each recessed structure 112 forms a concave space.

[0037] The plurality of engraved structures 112 can be formed by applying any one of known processing techniques such as press processing, mechanical cutting, plasma processing, electrolytic processing, etching, casting, etc. The plurality of engraved structures 112 can also have embossed structures protruding from the interior of the base plate 110, but this can adversely affect the flow of cooling fluid through the cooling channels 114. Therefore, it is preferable that the inner surface of the base plate 110, which forms part of the cooling channels 114, be flat.

[0038] In the present invention, a plurality of recessed structures 112 formed on the upper surface of the base plate 110 form spaces for accommodating thermal resin 300. A plurality of battery modules 200 are accommodated in the pack case 100 to complete the battery pack 10, and conductive heat transfer occurs when the base plate 110 forming the bottom of the pack case 100 and the lower frame 222 of the module case 220 come into contact with each other. To promote conductive heat transfer, thermal resin 300 with 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 battery module 200 in the battery pack 10, a large amount of heat is transferred to the adjacent battery module 200 along the base plate 110 where conductive heat transfer actively occurs. Meanwhile, the base plate 110 is often provided with a heat dissipation means such as a cooling channel 114. Therefore, it may be advantageous to suppress or delay heat transfer by conducting the heat of the battery module 200 in which thermal runaway has occurred to the base plate 110 as quickly as possible before the heat of the battery module 200 is diffused by convective heat transfer toward the other side of the pack case 100 other than the base plate 110.

[0040] From the viewpoint of heat dissipation, the multiple recessed structures 112 provided on the upper surface of the base plate 110 provide an expanded heat transfer area for the thermal resin 300. Figure 2 is a cross-sectional view taken along line "AA" in Figure 1, and as shown in the drawing, the thermal resin 300 filled in the recessed recessed structures 112 has the effect of providing a wider heat transfer area from the battery module 200 to the base plate 110 compared to a flat contact surface.

[0041] The amount of heat conducted from the battery module 200 to the base plate 110 increases proportionally through the heat transfer area expanded by the recessed structures 112, and as a result, heat from the battery module 200 in the event of thermal runaway is quickly transferred to the base plate 110, providing an opportunity for the heat to be dissipated to the outside of the battery pack 10. Therefore, the multiple recessed structures 112 formed on the upper surface of the base plate 110 contribute to suppressing or delaying heat transfer through the thermal resin 300.

[0042] In the exemplary embodiment of FIG. 2, the engraved structure 112 has a curved surface, including a hemispherical surface and a semi-ellipsoidal surface. This is because a curved surface is an advantageous surface form for expanding the heat transfer area. Alternatively, as shown in FIG. 3, the engraved structure 112 can have a honeycomb structure. Although the honeycomb structure may be somewhat inferior to the structure of FIG. 2 in terms of expanding the heat transfer area, it may be effective in supplementing or strengthening the support rigidity of the base plate 110, which may be weakened by the engraved structure 112.

[0043] (Second embodiment) 4 is a diagram showing a battery pack 10 according to the present invention. Although one battery module 200 is shown in FIG. 4 as an example, one battery module 200 is mounted in each of the storage spaces partitioned by the partition members 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. The battery module 200 may further include accessories such as a heat insulating material for insulating between the battery cells 210 and a busbar frame assembly (BFA) for electrical connection between the plurality of battery cells 210 and external output, but these accessories are not directly related to the heat dissipation design of the pack case 100 according to the present invention, and therefore a description thereof will be omitted.

[0045] The illustrated pack case 100 includes a base plate 110 forming the bottom surface, side plates 120 surrounding the outer periphery of the base plate 110, partition members 130 arranged vertically and / or horizontally to define an accommodation space defined by the side plate 120, and a lid 160 closing the top surface of the accommodation space. The base plate 110 is provided with cooling channels 114 through which a cooling fluid is stored or flows. Although FIGS. 2 and 5 show the cooling channels 114 provided in the base plate 110, the cooling channels 114 may also be configured as a structure in which a separate cooling plate (not shown) is joined to the base plate 110.

[0046] Here, depending on the arrangement direction relative to the base plate 110, the partition member 130 can be divided into a vertical center beam 140 that crosses the center of the pack case 100 and divides the internal storage space into left and right, and a horizontal cross beam 150 that intersects with the center beam 140 in a lattice pattern.

[0047] 5 is a cross-sectional view showing the contact surface between the battery module 200 and the base plate 110. The battery pack 10 of 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, all of the recessed structures 112 on the upper surface of the base plate 100 are filled with the thermal resin 300.

[0048] As described in the first embodiment, the recessed structure 112 provided on the base plate 110 provides an expanded heat transfer area for the thermal resin 300. The expanded heat transfer area achieved by the base plate 110 proportionally increases the amount of heat transferred from the battery module 200 to the base plate 110. FIG. 6 is a diagram showing conductive heat transfer paths in the battery pack 10 of FIG. 5. Assuming that the illustrated battery module 200 experiences thermal runaway, a large amount of heat generated by the thermal runaway is transferred to the base plate 110 in the form of conductive heat transfer due to the increased heat transfer area provided by the recessed structure 112. Much of the heat transferred to the base plate 110 is dissipated to the outside of the battery pack 10 via the base plate 110 and the cooling fluid, thereby reducing the amount of heat transferred to other nearby battery modules 200 using the base plate 110 as a heat transfer medium. This improved heat dissipation performance contributes to suppressing and delaying heat propagation within the battery pack 10.

[0049] 7 is a view showing another embodiment of a pack case 100. In the embodiment of the pack case 100 shown in Fig. 7, the pack case 100 includes a partition member 130 that separates a plurality of battery modules 200 from one another, while the base plate 110 has a slot 116 formed therethrough in an area that contacts the partition member 130. The slot 116 formed therethrough in the base plate 110 is a structure for limiting conductive heat transfer that occurs across the bottom surface of the partition member 130.

[0050] The partition members 130 forming the center beam 140 and / or the cross beams 150 form boundaries between the battery modules 200, but conductive heat transfer that crosses the partition members 130 and propagates to adjacent battery modules 200 is limited by the slots 116 that penetrate the base plate 110. That is, as shown in FIG. 8 , a portion of the heat conduction path between the battery modules 200 via the base plate 110 is physically eliminated by the slots 116 that penetrate the base plate 110, thereby reducing and delaying excessive heat transfer caused by a battery module 200 experiencing thermal runaway. For reference, if the base plate 110 is provided with cooling channels 114, the slot 116 structure needs to be formed to avoid the cooling channels 114.

[0051] In another aspect, the through slots 116 of the base plate 110 also serve to promote heat dissipation by convection. In other words, conductive heat transfer that crosses the partition member 130 and propagates to the adjacent battery module 200 is restricted and delayed by the slots 116 formed through the base plate 110, which in turn provides more opportunities for heat dissipation in the base plate 110.

[0052] In one embodiment, it is preferable that the slots 116 arranged next to the partition member 130 are not exposed to the outside of the partition member 130. To reliably limit conductive heat transfer, the slots 116 are formed through the base plate 110, but the slots 116 formed through in this manner affect the airtightness of the pack case 100. Therefore, the size of the slots 116 can be designed so that the partition member 130 completely surrounds the slots 116 so as to close the slots 116 formed through the base plate 110, thereby ensuring the airtightness of the pack case 100.

[0053] A plurality of slots 116 may be formed at intervals along the partition member 130. Conductive heat transfer occurs in the areas between the spaced-apart slots 116, but when the plurality of slots 116 are formed at intervals, preferably evenly spaced apart, it can be advantageous to prevent heat conducted to adjacent battery modules 200 from being locally concentrated and causing another thermal runaway.

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

[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, a plurality of recessed structures are formed on an upper surface of a base plate that contacts and supports a bottom surface of the battery module, and the plurality of recessed structures form spaces that accommodate thermal resin; The recessed structure is A pack case with a curved surface including a hemisphere and a semi-ellipsoid.

2. The recessed structure is The pack case according to claim 1 , wherein the pack case has a lattice structure that is uniformly arranged vertically and horizontally on the upper surface of the base plate.

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

4. a battery module including a plurality of battery cells and a module case that houses the plurality of battery cells; The pack case according to any one of claims 1 to 3; a thermal resin applied between the lower frame of the battery module and the base plate of the pack case, The battery pack, wherein the thermal resin is filled into a plurality of recessed structures formed on the upper surface of the base plate.

5. 5. The battery pack according to claim 4, wherein a heat transfer area of ​​the base plate to the lower frame of the battery module is increased compared to a flat contact through the thermal resin filled in the recessed structure.

6. A plurality of the battery modules are provided, the pack case includes partition members that separate the plurality of battery modules from one another, The battery pack according to claim 4 , wherein the base plate includes a slot formed therethrough in a region that contacts the partition member.

7. The slot is The battery pack according to claim 6 , wherein the partition member is not exposed to the outside.

8. The slot is The battery pack according to claim 6 , wherein a plurality of the partition members are formed along the partition member at intervals.

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