Pack case having improved heat dissipation structure

Abstract

The disclosed invention relates to a pack case having a space for accommodating a plurality of battery modules, wherein in one example, a plurality of recessed 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 recessed structures form a space for accommodating thermal resin.

Description

Technology 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 a pack case. Background Technology

[0002] Unlike primary batteries, secondary batteries are rechargeable and are currently the subject of extensive research and development due to their potential for miniaturization and high capacity. The demand for secondary batteries as an energy source is increasing rapidly due to the growing technological development and demand for mobile devices, as well as the rise of electric vehicles and energy storage systems driven by the contemporary need for environmental protection.

[0003] Rechargeable batteries are classified into coin batteries, cylindrical batteries, prismatic batteries, and pouch batteries according to the shape of the battery case. In rechargeable batteries, the electrode assembly mounted inside the battery case is a power generation device capable of charging and discharging, consisting of a laminated structure of electrodes and separators.

[0004] Since secondary batteries require continuous use over long periods, it is necessary to effectively control the heat generated during the charging and discharging process. If the cooling of the secondary battery is not performed smoothly, a positive feedback chain reaction occurs where the temperature rise causes an increase in current, and this increase in current again causes a temperature rise, eventually leading to a catastrophic state of thermal runaway.

[0005] In addition, when secondary batteries are grouped in the form of modules or packs, a thermal propagation phenomenon occurs in which surrounding secondary batteries are continuously overheated due to thermal runaway in one secondary battery. 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 consequently, dust accumulates on the high-voltage terminal of an adjacent battery module, and the thermal propagation phenomenon is triggered by heat transfer from the gas and flames.

[0006] As a design to prevent or delay heat propagation in which high heat from a battery cell or module experiencing thermal runaway is transferred to an adjacent battery cell or module, an insulation design using insulating material to prevent or delay heat transfer from the battery module experiencing thermal runaway to an adjacent battery module, and a heat dissipation design that reduces heat transfer to an adjacent battery module by rapidly releasing heat from the battery module experiencing thermal runaway to the outside of the battery pack in the early stages are applied.

[0007] The suppression and delay of heat propagation are treated as critical issues, particularly in electric vehicles where they are directly linked to human casualties, and related regulations are becoming increasingly stringent. Specifically, regulations require a sufficient time delay before heat propagation occurs, ensuring sufficient time for emergency evacuation and safety measures to be taken after a thermal runaway event. Therefore, there is a pressing need for more effective measures to suppress or delay the occurrence of heat propagation within battery packs. Prior art literature

[0008] Korean Patent Publication No. 10-2021-0092566 (Published July 26, 2021) The problem to be solved

[0009] The purpose of the present invention is to provide a pack case capable of suppressing and delaying heat propagation by rapidly transferring heat generated in a battery module that has undergone thermal runaway to the pack case in the form of conductive heat transfer from the perspective of thermal dissipation design, and thereby rapidly releasing it to the outside as convective heat transfer from the pack case.

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

[0011] The present invention relates to a pack case having a space for accommodating a plurality of battery modules, wherein in one example, a plurality of recessed 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 recessed structures form a space for accommodating thermal resin.

[0012] In one embodiment of the present invention, the intaglio structure may form a grid structure that is uniformly arranged longitudinally and transversely with respect to the upper surface of the base plate.

[0013] The above-described engraved 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 intaglio structure may form a curved surface including a hemispherical or semi-elliptical surface.

[0015] Alternatively, the above-mentioned intaglio structure can form a honeycomb structure.

[0016] Meanwhile, the present invention provides a battery pack comprising 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 the upper surface of the base plate.

[0017] In the battery pack of the present invention, the conductive heat transfer area of ​​the base plate to the lower frame of the battery module is increased compared to a planar contact through the thermal resin filled within the intaglio structure.

[0018] In addition, the battery pack of the present invention may include a partition member in which the pack case partitions the plurality of battery modules from one another, and the base plate may have a slot formed through the area in contact with the partition member.

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

[0020] In addition, a plurality of slots may be formed spaced apart along the bulkhead member. Effects of the invention

[0021] The pack case of the present invention, having the above-described configuration, has an intaglio structure formed on the upper surface of the base plate that provides an expanded heat transfer area for the thermal resin. The heat transfer area expanded by the intaglio structure increases the amount of heat conducted from the battery module to the base plate, and thereby, the heat from the battery module where thermal runaway has occurred is quickly transferred to the base plate and dissipated to the outside of the battery pack, so as a result, it contributes to the suppression or delay of heat propagation.

[0022] In addition, a slot formed through the base plate along a bulkhead member forming a boundary between battery modules physically eliminates a portion of the heat conduction path between battery modules, thereby reducing and delaying excessive heat transfer caused by a battery module experiencing thermal runaway, as well as further promoting heat dissipation from the base plate.

[0023] However, the technical effects obtainable through the present invention are not limited to those described above, and other unmentioned effects will be clearly understood by a person skilled in the art from the description of the invention below. Brief explanation of the drawing

[0024] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings. FIG. 1 is a drawing illustrating a pack case according to the present invention. FIG. 2 is a cross-sectional view taken along the line "AA" of FIG. 1. FIG. 3 is a drawing illustrating another embodiment of an intaglio structure provided on a base plate. FIG. 4 is a drawing illustrating a battery pack according to the present invention. FIG. 5 is a cross-sectional view showing the contact surface between the battery module and the base plate. FIG. 6 is a diagram illustrating the conductive heat transfer path in the battery pack of FIG. 5. FIG. 7 is a drawing illustrating another embodiment of a pack case. FIG. 8 is a diagram illustrating the conductive heat transfer path in the battery pack of FIG. 7. Specific details for implementing the invention

[0025] The present invention is capable of various modifications and may have various embodiments, and specific embodiments are to be described in detail below.

[0026] However, this is not intended to limit the invention to specific embodiments, and it should be understood that it includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0027] In the present invention, terms such as "comprising" or "having" are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not excluding in advance the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0028] Furthermore, 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 cases where it is "immediately above" the other part, but also cases 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, this includes not only cases where it is "immediately below" the other part, but also cases where there is another part in between. Additionally, in the present application, being "placed on" may include cases where it is placed on the lower part as well as on the upper part.

[0030] The present invention relates to a pack case having a space for accommodating a plurality of battery modules, wherein in one example, a plurality of recessed 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 recessed structures form a space for accommodating thermal resin.

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

[0032] Accordingly, the pack case of the present invention can rapidly transfer heat generated in a battery module that has undergone thermal runaway to the pack case in the form of conductive heat transfer by increasing the heat transfer surface area of ​​the thermal resin from the perspective of heat dissipation design, and as a result, a large amount of heat is transferred to the pack case early, and as the amount of heat released to the outside as convective heat transfer increases, heat propagation within the battery pack can be effectively suppressed or delayed.

[0034] Hereinafter, specific embodiments of the pack case (100) according to the present invention will be described in detail with reference to the attached drawings. For reference, the directions of front, back, up, down, left, and right used to specify relative positions in the following description are intended to aid in understanding the invention, and unless otherwise specifically defined, the directions shown in the drawings are used as the reference.

[0036] [First embodiment]

[0037] FIG. 1 is a drawing illustrating a pack case (100) according to the present invention, and FIG. 2 is a cross-sectional view taken along the line "AA" of FIG. 1.

[0038] Referring to FIGS. 1 and 2, the illustrated pack case (100) comprises a base plate (110) forming a bottom surface, a side plate (120) surrounding the outer edge of the base plate (110), a partition member (130) arranged longitudinally and / or transversely to partition a receiving space defined by the side plate (120), and a lid (160) closing the upper surface of the receiving space. Additionally, the base plate (110) is provided with a cooling channel (114) in which a cooling fluid is stored or flows. However, although FIG. 2 illustrates that the cooling channel (114) is provided in the base plate (110), it is also possible to attach a separate cooling plate (not shown) to the base plate (110).

[0039] Looking at the upper surface of the base plate (110) illustrated in FIGS. 1 and 2, a plurality of intaglio structures (112) are formed in each area that contacts the lower surface of each battery module (200). The plurality of intaglio structures (112) can form a grid structure that is uniformly arranged horizontally and vertically on the upper surface of the base plate (110), and each individual intaglio structure (112) forms a concave space.

[0040] A plurality of intaglio structures (112) can be formed by applying any one of known processing techniques such as press processing, mechanical cutting, plasma processing, electrolytic processing, etching, or casting. Additionally, a raised structure may protrude into the interior of the base plate (110) in correspondence with the plurality of intaglio structures (112), but since this may have a negative effect on the flow of the cooling fluid flowing through the cooling channel (114), it may be desirable for the inner surface of the base plate (110) that forms part of the cooling channel (114) to have a flat surface.

[0041] In the present invention, a plurality of engraved structures (112) formed on the upper surface of the base plate (110) form a space for accommodating thermal resin (300). A plurality of battery modules (200) are housed in a pack case (100) to form a battery pack (10), and conductive heat transfer is achieved when the base plate (110), which forms the bottom surface of the pack case (100), and the lower frame (222) of the module case (220) come into contact with each other. Furthermore, to promote conductive heat transfer, a thermal resin (300) with excellent thermal conductivity is interposed on the contact surface between the base plate (110) and the module case (220).

[0042] When a thermal runaway occurs in any battery module (200) within the battery pack (10), a large amount of heat is propagated to an adjacent battery module (200) along the base plate (110) where conductive heat transfer occurs actively. On the other hand, the base plate (110) is often equipped with a heat dissipation means such as a cooling channel (114). Therefore, before the heat of the battery module (200) spreads by convective heat transfer to a side other than the base plate (110) inside the pack case (100), it may be advantageous to increase the amount of heat dissipated to the outside of the battery pack (10) by conducting the heat of the battery module (200) where the thermal runaway occurred to the base plate (110) as soon as possible, thereby increasing the amount of heat dissipated outside the battery pack (10), which may be advantageous for suppressing or delaying heat propagation.

[0043] From the perspective of heat dissipation, the engraved structures (112) provided in a plurality on the upper surface of the base plate (110) provide an expanded heat transfer area for the thermal resin (300). FIG. 2 is a cross-sectional view taken along the line "AA" of FIG. 1, and as shown in the drawing, the thermal resin (300) filled in the concave engraved structures (112) has the effect of increasing the heat transfer area from the battery module (200) to the base plate (110) compared to a flat contact surface.

[0044] Through the heat transfer area expanded by the engraved structure (112), the amount of heat conducted from the battery module (200) to the base plate (110) increases proportionally, and thereby the heat from the battery module (200) where thermal runaway has occurred is quickly transferred to the base plate (110) and has the opportunity to be dissipated outside the battery pack (10). Accordingly, the plurality of engraved structures (112) formed on the upper surface of the base plate (110) contribute to the suppression or delay of heat propagation through the thermal resin (300).

[0045] In the exemplary embodiment of FIG. 2, the intaglio structure (112) forms a curved surface including a hemispherical or semi-elliptical surface. This is based on the consideration that a curved surface is a surface shape advantageous for expanding the heat transfer area. Alternatively, as shown in FIG. 3, the intaglio structure (112) may form a honeycomb structure. Although the honeycomb structure may be somewhat inferior to the case 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 intaglio structure (112).

[0047] [Second embodiment]

[0048] FIG. 4 is a drawing illustrating a battery pack (10) according to the present invention. Although FIG. 4 illustrates one battery module (200) as an example, one battery module (200) is mounted in each individual receiving space partitioned by a partition member (130).

[0049] The battery module (200) includes a plurality of battery cells (210) and a module case (220) that accommodates the plurality of battery cells (210). In addition, the battery module (200) may further include components such as an insulating material for insulating between the battery cells (210), and a busbar frame assembly (BFA) for electrical connection and external output between the plurality of battery cells (210); however, since these components are not directly related to the heat dissipation design of the pack case (100) according to the present invention, a description thereof is omitted.

[0050] The illustrated pack case (100) includes a base plate (110) forming the bottom surface, a side plate (120) surrounding the outer edge of the base plate (110), a partition member (130) arranged longitudinally and / or transversely to partition a receiving space limited by the side plate (120), and a lid (160) closing the upper surface of the receiving space. Additionally, the base plate (110) is provided with a cooling channel (114) in which a cooling fluid is stored or flows. However, although FIGS. 2 and FIGS. 5 show that the cooling channel (114) is provided in the base plate (110), it is also possible to configure the cooling channel (114) as a structure in which a separate cooling plate (not shown) is joined to the base plate (110).

[0051] Here, the bulkhead member (130) may be distinguished into a longitudinal center beam (140) that crosses the center of the pack case (100) and divides the internal receiving space left and right according to the arrangement direction relative to the base plate (110), and a transverse cross beam (150) that intersects the center beam (140) to form a grid shape.

[0052] FIG. 5 is a cross-sectional view illustrating 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). Accordingly, the thermal resin (300) is filled into all the recessed structures (112) on the upper surface of the base plate (100).

[0053] As described in the first embodiment, the engraved structure (112) provided on the base plate (110) provides an expanded heat transfer area for the thermal resin (300), and due to the expansion of the heat transfer area achieved in the base plate (110), the amount of heat conducted from the battery module (200) to the base plate (110) increases proportionally. FIG. 6 is a diagram illustrating the conductive heat transfer path in the battery pack (10) of FIG. 5. Assuming that the illustrated battery module (200) has undergone 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, with a larger amount as the heat transfer area is increased by the engraved structure (112). A large amount of the heat transferred to the base plate (110) is released outside the battery pack (10) through the base plate (110) and the cooling fluid, thereby reducing the amount of heat conducted to other surrounding battery modules (200) using the base plate (110) as a heat conduction medium. This improvement in heat dissipation performance contributes to suppressing and delaying heat propagation within the battery pack (10).

[0054] FIG. 7 is a drawing illustrating another embodiment of the pack case (100). The embodiment of the pack case (100) illustrated in FIG. 7 includes a partition member (130) that partitions a plurality of battery modules (200) from one another, while the base plate (110) has a slot (116) formed through the area in contact with the partition member (130). The slot (116) formed through the base plate (110) is a structure for limiting conductive heat transfer occurring across the bottom surface of the partition member (130).

[0055] The partition member (130) forming the center beam (140) and / or cross beam (150) forms a boundary between battery modules (200), and conductive heat transfer propagating across the partition member (130) to adjacent battery modules (200) is limited by a slot (116) formed through the base plate (110). That is, as shown in FIG. 8, a portion of the heat conduction path between battery modules (200) through the base plate (110) is physically eliminated by the slot (116) penetrating the base plate (110), thereby reducing and delaying excessive heat transfer caused by a battery module (200) in which thermal runaway has occurred. For reference, if a cooling channel (114) is provided in the base plate (110), the slot (116) structure needs to be formed to avoid the cooling channel (114).

[0056] In another aspect, the through slot (116) of the base plate (110) also serves to promote heat dissipation by convective heat transfer. In other words, conductive heat transfer propagating across the bulkhead member (130) to the adjacent battery module (200) is restricted and delayed by the through slot (116) formed in the base plate (110), thereby providing an opportunity for more heat dissipation to occur in the base plate (110) as a counterbalance.

[0057] In one embodiment, it may be preferable that the slot (116), which is positioned parallel to the partition member (130), is not exposed outside the partition member (130). To reliably limit conductive heat transfer, the slot (116) is formed by penetrating the base plate (110), and the slot (116) formed through it affects the airtightness of the pack case (100). Therefore, the airtightness of the pack case (100) can be ensured by designing the size of the slot (116) so that the partition member (130) completely surrounds the slot (116) to close the slot (116) formed through the base plate (110).

[0058] Additionally, a plurality of slots (116) may be formed spaced apart along the partition member (130). Conductive heat transfer occurs in the area between the spaced-apart slots (116). If a plurality of slots (116) are spaced apart, preferably evenly spaced, the heat conducted to adjacent battery modules (200) is not locally concentrated, which can be advantageous in preventing another thermal runaway.

[0060] The present invention has been described in more detail above through 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 technical concepts of the present invention; therefore, it should be understood that various equivalents and modifications that can replace them may exist at the time of filing this application. Explanation of the symbols

[0061] 10: Battery Pack 100: Pack Case 110: Base plate 112: Engraved structure 114: Cooling Channel 116: Slot 120: Side plate 130: Bulkhead member 140: Center beam 150: Cross beam 160: Lead 200: Battery Module 210: Battery cell 220: Module case 222: Lower frame 300: Thermal resin

Claims

Claim 1 A pack case having a space for accommodating a plurality of battery modules, wherein a plurality of recessed structures are formed on the upper surface of a base plate that contacts and supports the bottom surface of the battery modules, and the plurality of recessed structures form a space for accommodating thermal resin, and the recessed structures increase the heat transfer area from the battery modules to the thermal resin filled therein compared to a flat surface, and the recessed structures form a curved surface including a hemispherical surface and a semi-elliptical surface. Claim 2 A pack case according to claim 1, wherein the engraved structure forms a grid structure uniformly arranged longitudinally and transversely with respect to the upper surface of the base plate. Claim 3 delete Claim 4 delete Claim 5 delete Claim 6 A battery pack comprising: a battery module including a plurality of battery cells and a module case accommodating the plurality of battery cells; a pack case according to claim 1 or 2; 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 intaglio structures formed on the upper surface of the base plate. Claim 7 A battery pack according to claim 6, wherein the conductive heat transfer area of ​​the base plate to the lower frame of the battery module is increased compared to a planar contact through the thermal resin filled within the engraved structure. Claim 8 In claim 6, the battery pack comprises, wherein the pack case includes a partition member that partitions the plurality of battery modules from one another, and the base plate has a slot formed through the area in contact with the partition member. Claim 9 In claim 8, the above slot is a battery pack that is not exposed outside the above bulkhead member. Claim 10 In claim 8, the battery pack, wherein the slots are spaced apart along the partition member.

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