Battery pack cooling structure

Abstract

The disclosed battery pack cooling structure includes a heatsink with a plurality of cooling channels, a plurality of battery assemblies mounted vertically and / or horizontally on the heatsink, and a plurality of electrical components mounted on the front and / or rear of the heatsink, wherein at least one of the plurality of electrical components has insulating oil sealed inside, and the heat accumulated in the insulating oil is discharged to the outside through the cooling channels of the heatsink.

Description

Technical Field

[0001] The present invention relates to a cooling structure for a battery pack that can provide a high-performance battery pack by efficiently cooling not only battery cells but also electrical components with a heat sink forming the bottom surface of the battery pack.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0038147 filed on March 20, 2024, and Korean Patent Application No. 10-2024-0149590 filed on October 29, 2024, and all the contents disclosed in the documents of the Korean patent applications are incorporated herein by reference.

Background Art

[0003] Unlike primary batteries, secondary batteries can be recharged and have been extensively studied and developed in recent years due to the potential for miniaturization and increased capacity. With the increasing development of technology 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, it is necessary to effectively control the heat generated during the charge and discharge process. If the cooling of the secondary battery is not smooth, the temperature rise will cause an increase in current, and the increase in current will cause a positive feedback chain reaction that causes another temperature rise, ultimately leading to a catastrophic state of thermal runaway.

[0006] To effectively dissipate the heat generated by secondary batteries, heat sinks (also called cooling plates) with flowing coolants are widely used. Heat sinks are attached to the bottom of a group of secondary batteries, such as a battery pack containing many secondary batteries, and perform a cooling function by absorbing the heat generated inside the pack with a coolant and releasing it to the outside.

[0007] Battery packs are applied in a wide range of technological fields, and in recent years, the demand for battery packs in electric vehicles has been extremely high. To increase the driving range on a full charge and improve driving performance, battery packs for electric vehicles are gradually becoming higher capacity and more high performance. Furthermore, as the amount of current required for rapid charging of battery packs and the progression of driving cycles gradually increases, the heat generated by busbars and electrical components is also increasing. Therefore, the cooling performance of battery packs must also be improved.

[0008] The battery pack primarily cools the battery cells, but does not cool the electrical components. As a result, the high heat from the electrical components can be transferred to the battery cells via the busbars, causing the battery cells to overheat. This can lead to a decrease in battery cell performance or thermal runaway. [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] The purpose of this invention is to provide a battery pack cooling structure that enables the safer manufacture of high-performance battery packs by ensuring that the heat sink forming the bottom surface of the battery pack efficiently cools not only the battery cells but also the electrical components.

[0010] However, the technical problems that this invention aims to solve are not limited to those described above, and other problems not mentioned can be clearly understood by an ordinary person from the description of the invention below. [Means for solving the problem]

[0011] The present invention relates to a cooling structure for a battery pack, and in one example includes a heat sink with a plurality of cooling channels, a plurality of battery assemblies mounted vertically and / or horizontally on the heat sink, and a plurality of electrical components mounted on the front and / or rear of the heat sink, wherein at least one of the plurality of electrical components has insulating oil sealed inside, and the heat accumulated in the insulating oil is discharged to the outside through the cooling channels of the heat sink.

[0012] In one embodiment, the plurality of cooling channels are provided along the overall length of the heat sink.

[0013] For example, the heat sink may have cooling channels integrally formed by extrusion molding, and the plurality of cooling channels may be formed by a plurality of ribs arranged spaced apart in the width direction along the overall length direction of the heat sink.

[0014] A heat transfer material (TIM) may be interposed between the electrical component, which has insulating oil sealed inside, and the heat sink mentioned above.

[0015] Furthermore, a fin structure may be interposed between the electrical component, which has insulating oil sealed inside, and the heat sink.

[0016] The fin structure described above may be formed on the bottom surface of an electrical component in which insulating oil is sealed inside, or on the top surface of the heat sink.

[0017] Furthermore, the heat transfer material can cover the entire fin structure.

[0018] In one embodiment, an electrical component in which insulating oil is sealed inside may be a BDU (Battery Disconnection Unit).

[0019] Furthermore, insulating oil can be sealed inside the BMS (Battery Management System) connected to the BDU via a busbar.

[0020] In one embodiment, an electrical component with insulating oil sealed inside may include a relief valve.

Advantages of the Invention

[0021] According to the cooling structure of the battery pack as described above, the heat generated by the electrical component is accumulated in the insulating oil sealed inside while being discharged to the outside through the refrigerant flowing through the heat sink, before being transmitted to the battery cell. As a result, since the heat of the electrical component does not flow into the battery cell, a higher-performance battery pack can be configured.

[0022] By forming the cooling channels integrally from the front to the rear of the heat sink serving as an extruded heat sink for the bottom surface of the battery pack, efficient cooling can also be performed on the electrical components arranged on the front and / or rear surfaces of the heat sink.

[0023] However, the technical effects that can be obtained by the present invention are not limited to the above-described effects, 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

[0025] [Figure 1] It is a drawing showing a battery pack to which a cooling structure of a battery pack according to an embodiment of the present invention is applied. [Figure 2] It is an exploded perspective view of the battery pack of FIG. 1. [Figure 3] It is a drawing showing an example of an electrical component mounted on the battery pack of FIG. 1. [Figure 4]It is a cross-sectional view cut along the "A-A" line in FIG. 1. [Figure 5] It is a drawing showing an embodiment of a structure for promoting heat transfer between a heat sink and an electrical component.

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 as including all modifications, equivalents or alternatives included in the spirit and technical scope of the present invention.

[0028] In the present invention, terms such as "including" and "having" are intended to specify the presence of features, numbers, steps, operations, components, parts or combinations thereof described in the specification, and do not preclude in advance the presence or addition possibility 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, plate, etc. is described as being "on" another part, this includes not only the case where it is "directly on" another part, but also the case where there is another part in between. Conversely, when a part such as a layer, film, region, plate, etc. is described as being "under" another part, it includes not only the case where it is "directly under" another part, but also the case where there is another part in between. Also, in this application, being "disposed on" can include the case of being disposed not only on the upper part but also on the lower part.

[0030] The present invention relates to a cooling structure for a battery pack, and in one example includes a heat sink with a plurality of cooling channels, a plurality of battery assemblies mounted vertically and / or horizontally on the heat sink, and a plurality of electrical components mounted on the front and / or rear of the heat sink, wherein at least one of the plurality of electrical components has insulating oil sealed inside, and the heat accumulated in the insulating oil is discharged to the outside through the cooling channels of the heat sink.

[0031] With the battery pack cooling structure described above, heat generated by electrical components is stored in an insulating oil sealed inside before being transferred to the battery cells, while simultaneously being discharged to the outside via a coolant flowing through a heat sink. This prevents heat from electrical components from flowing into the battery cells, enabling the construction of a higher-performance battery pack.

[0032] Specific embodiments of the battery pack cooling structure according to the present invention will be described in detail below with reference to the attached drawings. For reference, the front-to-back and up-down-left-right directions used in the following description to specify relative positions are for the purpose of aiding the understanding of the invention, and unless otherwise defined, the directions shown in the drawings shall be used as the reference.

[0033] (First Embodiment) Figure 1 is a drawing showing a battery pack 10 to which a battery pack cooling structure according to one embodiment of the present invention is applied, Figure 2 is an exploded perspective view of the battery pack 10, and Figure 3 is a drawing showing an example of electrical components 300 mounted on the battery pack 10 of Figure 1.

[0034] The present invention relates to a cooling structure for a battery pack, and more particularly to a cooling structure for a battery pack that can effectively cool not only the heat generated in the battery assembly 200 but also the heat generated in the electrical components 300. The cooling structure for a battery pack according to the present invention will be described in detail with reference to Figures 1 to 3.

[0035] The battery pack 10 includes a heat sink 100 that functions as the bottom plate of a battery housing that accommodates at least one, and in most cases more than one, battery assemblies 200. A battery assembly 200 refers to a collection of multiple battery cells in which multiple battery cells are structurally and electrically coupled. Depending on the structure that connects the multiple battery cells, the battery assembly 200 may be expressed in various terms such as a battery module, battery block, or battery unit. The present invention does not particularly limit the structure of the collection of multiple battery cells mounted on the heat sink 100. The heat sink 100 includes a plurality of cooling channels 112. The plurality of cooling channels 112 provided in the heat sink 100 can be formed in various ways. For example, the heat sink 100 can be divided into a brazed heat sink and an extruded heat sink depending on its structure or manufacturing method. A brazed heat sink is a structure in which two plate materials are brazed together to form channels, and while it offers a high degree of freedom in channel design, it has the disadvantage of being unfavorable in terms of structural rigidity due to the deterioration of the material properties. In contrast, extruded heat sinks, which are manufactured as a continuous body by extrusion molding, have an advantage in terms of structural rigidity, but they can only realize straight flow channels, resulting in many ports, which can mean that connecting pipes occupy space.

[0036] The battery pack cooling structure according to the present invention is applicable to heat sinks 100 of various specifications, however, it is preferable that the multiple cooling channels 112 are provided along the overall length of the heat sink 100. Specifically, it is preferable that the multiple cooling channels 112 are formed over the area occupied by the entire battery assembly 200 and electrical components 300 housed or mounted within the battery pack 10.

[0037] Multiple battery assemblies 200 are mounted vertically and / or horizontally on the heatsink 100. At least one or more electrical components 300 are mounted on the heatsink 100. In relation to the battery assemblies 200, at least one or more electrical components 300 may be positioned along one edge of the heatsink 100, adjacent to the outermost battery assembly 200. The edge of the heatsink 100 on which the electrical components 300 are mounted may be the front or rear of the battery pack 10. The electrical components 300 refer to components, modules, or devices that control and monitor the charging and discharging of the entire battery assembly 200, thereby ensuring that the battery pack 10 functions fully.

[0038] The electrical components 300 of the battery pack 10 include the BDU310 (Battery Disconnection Unit) and the BMS320 (Battery Management System). The BDU310 is a module that combines relays, current sensors, precharge resistors, fuses, etc. It is an important module that connects the battery and inverter to distribute high voltage and high current, and prevents accidents by performing emergency shutdowns in the event of abnormalities. The BMS320 is a system installed to manage battery performance and lifespan in an optimal state. It measures and understands the battery's current, voltage, temperature, etc., through sensors and controls the battery so that it can perform at its best.

[0039] When a coolant (e.g., cooling water) flows through multiple cooling channels 112 provided in the heat sink 100, the coolant cools the battery assembly 200 and electrical components 300 on the heat sink 100, preventing overheating. The battery assembly 200 generates a lot of heat during charging and discharging, and overheating of the battery cells can cause serious accidents such as thermal runaway and heat transfer. Therefore, the battery pack 10 focuses primarily on cooling the battery assembly 200. In contrast, the cooling of the electrical components 300 is not considered separately. As a result, as the performance and capacity of the battery pack 10 increase, the high heat from the electrical components 300 is transferred to the battery assembly 200 via the busbar 312, which can cause the battery assembly 200 to overheat.

[0040] To resolve the problem of overheating of electrical components 300 adversely affecting the battery assembly 200, the cooling structure of the battery pack 10 according to the present invention is such that at least one of the multiple electrical components 300 has insulating oil 330 sealed inside, and the heat accumulated in the insulating oil 330 is discharged to the outside through the cooling channel 112 of the heat sink 100. The insulating oil 330 refers to an oil used for the purpose of electrical insulation, and generally a highly refined, low-viscosity petroleum-based lubricant is used. While its main purpose is electrical insulation, it can also prevent the intrusion of moisture and play a cooling role by dissipating the generated heat.

[0041] Because the insulating oil 330 has a much higher heat transfer coefficient and heat capacity than air, it can play a role in heat dissipation and cooling, thereby effectively accumulating heat generated inside the electrical component 300 in the insulating oil 330. The heat accumulated in the insulating oil 330 is transferred to the heat sink 100, which is in contact with the surface of the electrical component 300, in the form of heat conduction. The heat transferred to the heat sink 100 is then transferred to the coolant and finally discharged to the outside of the battery pack 10.

[0042] Referring to Figures 1 and 2, the heat sink 100 shown as an example is an extruded heat sink. In the illustrated heat sink 100, cooling channels 112 are integrally formed by extrusion molding, and the multiple cooling channels 112 are formed by a plurality of ribs 110 arranged along the overall length L of the heat sink 100 and spaced apart in the width W.

[0043] The open surfaces of the heat sink 100 are closed with multiple end plugs 120 so that the coolant can circulate along the multiple cooling channels 112. The open surfaces of the heat sink 100 are the surfaces located at both ends in the longitudinal direction L, and due to the characteristics of the extruded product, both ends of the heat sink 100 in the longitudinal direction L are open. For the sake of explanation, the two open surfaces will be referred to as the first surface and the second surface, respectively. Here, the longitudinal direction L is the extrusion molding direction of the heat sink 100, that is, the direction in which the multiple ribs 110 extend, and the width direction W corresponds to the direction perpendicular to the longitudinal direction L on a plane in which the multiple cooling channels 112 are spaced apart.

[0044] The end plug 120 includes an inlet plug 122, an outlet plug 124, and a return plug 126. On the first front surface in the drawing, the central inlet plug 122 is connected, with a pair of outlet plugs 124 on either side. The inlet plug 122 has an inlet port 123, and the outlet plug 124 has an outlet port 125. The return plug 126 is connected to the second rear surface in the drawing. When the inlet plug 122 is closed, the cooling channel 112 forms an inlet channel, and when the outlet plug 124 is closed, the cooling channel 112 forms an outlet channel. The return plug 126 forms a return channel connecting the inlet channel to the outlet channel. With this flow path configuration, the refrigerant introduced into the inlet flow path through the central inlet port 123 hits the return plug 126, branches to the left and right, and enters the outlet flow path. The refrigerant that has flowed through the outlet flow path is discharged through the outlet port 125. However, this configuration of the cooling flow path 112 of the heat sink 100 is just one example shown in the drawing, and it goes without saying that the heat sink 100 can have cooling flow path 112 of various different forms and structures.

[0045] "130," which is not shown in the drawing, is a plate member that surrounds the heat sink 100 on all four sides, and the plate member 130 forms the space inside the pack in which the battery assembly 200 and electrical components 300 are installed. A lid, which is not shown, forms the cover of the battery pack 10, thereby protecting the inside of the battery pack 10 from the outside.

[0046] Figure 4 is a cross-sectional view taken along the line "AA" in Figure 1. Referring to Figure 4, a heat transfer material 400 (TIM) is interposed between the electrical component 300, which has insulating oil 330 sealed inside, and the heat sink 100. Such a heat transfer material 400 may also be interposed between the battery assembly 200 and the heat sink 100. Referring to Figure 2, the heat transfer material 400 may be applied to the heat sink 100 to an appropriate thickness, and the battery assembly 200 and the electrical component 300 may be mounted on the applied heat transfer material 400. The heat transfer material 400 may be a curable material, such as a thermal resin, that hardens over time to form an adhesive state so that the battery assembly 200 and the electrical component 300 can be fixed to the heat sink 100.

[0047] As described above, the electrical component 300 in which insulating oil 330 is sealed inside may be a BDU 310 (Battery Disconnection Unit). The BDU 310 is connected to the battery assembly 200 by a busbar 312 and, because it handles high voltage and high current, belongs to the category of electrical components 300 that generate a lot of heat. Since the BDU 310 and the battery assembly 200 are connected by a busbar 312, the high heat generated in the BDU 310 can flow to the battery assembly 200 through the thermally conductive busbar 312. Therefore, by sealing insulating oil 330 inside the BDU 310 and effectively dissipating the heat to the heatsink 100, the amount of heat transferred to the battery assembly 200 can be reduced.

[0048] Furthermore, depending on the embodiment, the BMS320 (Battery Management System) may also be connected to the BDU310 by a busbar 312. In this case, it may be preferable to seal insulating oil 330 inside the BMS320 to prevent overheating.

[0049] Referring to Figure 4, an electrical component 300, which has insulating oil 330 sealed inside, may be equipped with a relief valve 340. The relief valve 340 is a safety device that, when the internal pressure of the electrical component 300 rises above a set value, opens the valve to relieve the internal pressure. If the heat generated in the electrical component 300 rises abnormally, the insulating oil 330 may boil locally, causing the internal pressure of the electrical component 300 to rise rapidly. To cope with such an emergency, the electrical component 300 may be equipped with a relief valve 340, and the operation of the relief valve 340 can prevent damage to the electrical component 300 and the complete leakage of insulating oil 330.

[0050] (Second Embodiment) Figure 5 is a diagram illustrating one embodiment of a structure that facilitates heat transfer between the heat sink 100 and the electrical component 300. Referring to Figure 5, a fin structure 500 is interposed between the electrical component 300, which has insulating oil 330 sealed inside, and the heat sink 100. The fin structure 500 expands the heat transfer area, thereby allowing heat from the electrical component 300, which has insulating oil 330 sealed inside, to be transferred to the heat sink 100 more quickly. In other words, the fin structure 500 facilitates the cooling of the electrical component 300 and more effectively suppresses the transfer of heat from the electrical component 300 to the battery assembly 200.

[0051] The fin structure 500 can be formed on the bottom surface of the electrical component 300, which has insulating oil 330 sealed inside, or on the top surface of the heat sink 100. Figure 5 shows one embodiment in which the fin structure 500 is integrally formed on the top surface of the heat sink 100. When the fin structure 500 is formed on the heat sink 100, if the heat sink 100 is an extruded heat sink, the fin structure 500 can be formed along the longitudinal direction L of the heat sink 100, in the same direction as the formation of the ribs 110. Therefore, since the fin structure 500 on an extruded heat sink can be formed along the entire longitudinal direction of the heat sink 100, the fin structure 500 can be interposed not only on the electrical component 300 but also on the bottom surface of the battery assembly 200, thereby promoting the cooling of the battery assembly 200 as well.

[0052] The fin structure 500 and the heat transfer material 400 can be applied together. The heat transfer material 400 may cover the entire fin structure 500 so that the heat dissipation functions of the fin structure 500 and the heat transfer material 400 are fully utilized. That is, it may be preferable that the fin structure 500 is covered with the heat transfer material 400, thereby eliminating spaces that hinder heat transfer, such as air layers, in the heat transfer path between the electrical component 300 and the heat sink 100.

[0053] The present invention has been described in more detail above with reference to the drawings and embodiments. However, the configurations described in the drawings or embodiments described herein are merely one embodiment of the present invention and do not represent the entire technical concept of the present invention. Therefore, at the time of filing, there may be a variety of equivalents and modifications that can substitute for them. [Explanation of Symbols]

[0054] 10: Battery pack 100: Heatsink 110: Rib 112: Cooling channel 120: End plug 122: Inlet Plug 123: Inlet Port 124: Outlet plug 125: Outlet Port 126: Return plug 130: Plate component 200: Battery Assembly 300: Electrical components 310: BDU 312: Bus bar 320: BMS 330: Insulating oil 340: Relief valve 400: Heat transfer material 500: Fin structure

Claims

1. A heatsink including multiple cooling channels, Multiple battery assemblies mounted vertically and / or horizontally on the heatsink, Multiple electrical components mounted on the aforementioned heatsink, Includes, A cooling structure for a battery pack, wherein at least one of the aforementioned multiple electrical components has insulating oil sealed inside it, and the heat accumulated in the insulating oil is discharged to the outside through a cooling channel of the heat sink.

2. The aforementioned plurality of cooling channels are The cooling structure for the battery pack according to claim 1, provided along the overall length direction of the heat sink.

3. The heat sink has a cooling channel integrally formed by extrusion molding. The cooling structure for a battery pack according to claim 2, wherein the plurality of cooling channels are formed by a plurality of ribs arranged spaced apart in the width direction along the overall length direction of the heat sink.

4. The cooling structure for a battery pack according to claim 1, wherein a heat transfer material (TIM) is interposed between an electrical component, which has insulating oil sealed inside, and the heat sink.

5. The cooling structure for a battery pack according to claim 4, wherein a fin structure is interposed between the electrical component, which has insulating oil sealed inside, and the heat sink.

6. The fin structure is The cooling structure for a battery pack according to claim 5, which is formed on the bottom surface of an electrical component in which insulating oil is sealed inside, or on the top surface of the heat sink.

7. The heat transfer material is A cooling structure for a battery pack according to claim 5, which covers the entire fin structure.

8. The cooling structure for a battery pack according to claim 1, wherein the electrical component with insulating oil sealed inside is a BDU (Battery Disconnection Unit).

9. The battery pack cooling structure according to claim 8, wherein insulating oil is also sealed inside the BMS (Battery Management System) connected to the BDU by a busbar.

10. The cooling structure for a battery pack according to claim 1, wherein the electrical component, which has insulating oil sealed inside, is equipped with a relief valve.

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