Battery pack cooling structure

Abstract

Disclosed herein is a battery pack cooling structure including: a heat sink including a plurality of cooling flow paths; the plurality of battery assemblies are longitudinally and / or transversely mounted on the radiator; and a plurality of electrical components mounted on a front surface and / or a rear surface of the heat sink, in which an interior of at least one of the plurality of electrical components is sealed with insulating oil, and heat accumulated in the insulating oil is discharged to the outside through a cooling flow path of the heat sink.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a battery pack cooling structure that constitutes a heat sink of a bottom surface of a battery pack to enable efficient cooling of battery cells and electrical components, thereby providing a battery pack with high performance.

[0002] This application claims the benefit of 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, the disclosures of which are incorporated herein by reference. BACKGROUND

[0003] Unlike primary batteries, secondary batteries are rechargeable, and have been widely researched and developed in recent years due to their potential for miniaturization and large capacity. Due to the development of technology and the increasing demand for mobile devices and the increasing use of electric vehicles and energy storage systems in response to environmental protection, the demand for secondary batteries as an energy source is rapidly growing.

[0004] Secondary batteries are classified into button-type battery cells, cylindrical battery cells, square battery cells, and pouch-type battery cells according to the shape of the battery case. In a secondary battery, an electrode assembly installed inside the battery case is a chargeable and dischargeable power source composed of a laminated structure of an electrode and a separator.

[0005] Since secondary batteries need to be used for a long time, it is necessary to efficiently control the heat generated during charging and discharging. If the cooling of the secondary battery is not smoothly performed, the temperature rise causes an increase in current, and the increase in current causes a further increase in temperature, causing a continuously enhanced chain reaction, eventually leading to a catastrophic situation of thermal runaway.

[0006] In order to efficiently dissipate the heat generated by the secondary battery, a heat sink (also referred to as a cooling plate) through which a coolant flows is widely used. The heat sink is installed on the bottom surface of a large group of secondary batteries (for example, a battery pack having a plurality of secondary batteries), and performs a cooling function by absorbing the heat generated inside the battery pack with a coolant and dissipating it to the outside.

[0007] Battery packs are applied to a wide range of technologies, and in recent years, electric vehicles have a high demand for battery packs. In order to increase the driving distance per charge and improve driving performance, the capacity and performance of battery packs for electric vehicles are becoming higher and higher. In addition, the current required for fast charging and driving cycles of the battery pack is becoming larger, which increases the heat generation of the busbars and electrical components. Therefore, the cooling performance of the battery pack should also be improved.

[0008] The battery pack mainly cools the battery cells, and the electrical components are not cooled. Accordingly, high heat of the electrical components is transferred to the battery cells through the bus bars, causing the battery cells to heat up, which can cause performance degradation or thermal runaway of the battery cells. SUMMARY

[0009] TECHNICAL PROBLEM An object of the disclosure is to provide a battery pack cooling structure capable of achieving efficient cooling of battery cells and electrical components through a heat sink constituting a bottom surface of a battery pack to make a high-performance battery pack safer.

[0010] However, the technical problems that the disclosure attempts to solve are not limited to the above-mentioned problems, and other problems not mentioned will be obvious to those of ordinary skill in the art according to the description of the disclosure set forth below.

[0011] TECHNICAL SOLUTION The disclosure relates to a battery pack cooling structure, in one example, including a heat sink including a plurality of cooling flow paths, a plurality of battery components installed longitudinally and / or transversely on the heat sink, and a plurality of electrical components installed on the heat sink, wherein an inside of at least one of the plurality of electrical components is sealed with insulating oil, and heat accumulated in the insulating oil is discharged to the outside through the cooling flow paths of the heat sink.

[0012] In one exemplary embodiment, the plurality of cooling flow paths are provided along an entire length direction of the heat sink.

[0013] For example, the heat sink is integrally formed with the cooling flow paths by extrusion molding, and the plurality of cooling flow paths are formed along the entire length direction of the heat sink by a plurality of ribs spaced apart in a width direction.

[0014] A thermal interface material (TIM) can be interposed between the heat sink and the electrical component having the insulating oil sealed inside.

[0015] In addition, a heat dissipation fin can be interposed between the electrical component having the insulating oil sealed inside and the heat sink.

[0016] The heat dissipation fin can be formed on a bottom surface of the electrical component having the insulating oil sealed inside, or on an upper surface of the heat sink.

[0017] In addition, the thermal interface material can cover the entire heat dissipation fin.

[0018] In one exemplary embodiment, the electrical component having the insulating oil sealed inside can be a BDU (Battery Disconnect Unit).

[0019] In addition, the inside of a BMS (Battery Management System) connected to the BDU through the bus bar can also be sealed with the insulating oil.

[0020] In one exemplary embodiment, the electrical component having the insulating oil sealed inside can be equipped with a pressure relief valve.

[0021] Advantageous Effects According to the battery pack cooling structure as described above, the heat generated from the electrical component is accumulated in the insulating oil sealed inside before being transferred to the battery cell, and is discharged to the outside through the coolant flowing through the heat sink. Therefore, the heat generated from the electrical component is prevented from entering the battery cell, thereby improving the performance of the battery pack.

[0022] Further, by manufacturing the heat sink constituting the bottom surface of the battery pack as an extrusion-molded heat sink such that the cooling flow path is integrally formed from the front to the rear, efficient cooling can also be achieved for the electrical component disposed on the front and / or the rear of the heat sink.

[0023] However, the technical effects obtainable with the present disclosure are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those of ordinary skill in the art from the description of the present disclosure set forth below. BRIEF DESCRIPTION OF DRAWINGS

[0024] The following drawings attached to the present specification illustrate preferred embodiments of the present disclosure and serve to further explain the technical idea of the present disclosure, and the present disclosure should not be construed as being limited to what is shown in these drawings.

[0025] Figure 1 is a diagram of a battery pack having a battery pack cooling structure according to one embodiment of the present disclosure.

[0026] Figure 2 is Figure 1 an exploded perspective view of the battery pack of

[0027] Figure 3 is a diagram showing an example of an electrical component installed in the battery pack of Figure 1

[0028] Figure 4 is a cross-sectional view taken along line “A-A” of Figure 1

[0029] Figure 5 is a diagram showing one embodiment of a structure that facilitates heat transfer between the heat sink and the electrical component. DETAILED DESCRIPTION

[0030] The present disclosure is subject to various modifications and can have many embodiments, and some of these embodiments are described in detail below.

[0031] ​​However, this is not intended to limit this disclosure to any particular embodiment, and should be understood to include all modifications, equivalents, or substitutions that fall within the scope of the ideas and techniques of this disclosure.

[0032] In this disclosure, the terms “comprising” or “having” are intended to indicate the presence of the described features, quantities, steps, actions, components, parts or combinations thereof, and are not intended to exclude the possibility of the presence or addition of one or more other features, quantities, steps, actions, components, parts or combinations thereof.

[0033] Furthermore, when this disclosure describes layers, films, regions, plates, etc., as being "located" on top of another part, this includes not only the case where they are "directly" located "above" another part, but also the case where another part exists between them. Conversely, when layers, films, regions, plates, etc., are described as being "below" another, this includes not only the case where they are "directly" located "below" another, but also the case where another part exists between them. Moreover, in this application, when a part is disposed "on top" of another part, this includes not only being disposed on the upper part, but also being disposed on the lower part.

[0034] This disclosure relates to a battery pack cooling structure. In one example, the battery pack cooling structure includes: a radiator including multiple cooling flow paths; multiple battery assemblies mounted longitudinally and / or laterally on the radiator; and multiple electrical components mounted on the front and / or rear of the radiator, wherein at least one of the multiple electrical components is internally sealed with insulating oil, and heat accumulated in the insulating oil is dissipated to the outside through the cooling flow paths of the radiator.

[0035] According to the battery pack cooling structure described above, the heat generated by the electrical components accumulates in the insulating oil sealed inside before being transferred to the individual battery cells, and is then dissipated to the outside by the coolant flowing through the radiator. Therefore, a battery pack with higher performance can be constructed by preventing heat from the electrical components from entering the individual battery cells. Detailed Implementation

[0036] In the following, specific embodiments of the battery pack cooling structure according to the present disclosure will be described in detail with reference to the accompanying drawings. For reference, the directions indicating relative positions such as front-back, up-down, and left-right are used in the following description for the purposes of understanding the present disclosure, and unless otherwise defined, refer to the directions shown in the accompanying drawings.

[0037] [First Embodiment] Figure 1 This is a diagram of a battery pack 10 having a battery pack cooling structure according to an embodiment of the present disclosure. Figure 2 This is an exploded perspective view of battery pack 10, and Figure 3 It is installed inFigure 1 A diagram showing an example of electrical components 300 in the battery pack 10.

[0038] This disclosure relates to a battery pack cooling structure, and more specifically to a battery pack cooling structure capable of efficiently cooling heat generated by the battery assembly 200 and heat generated by the electrical components 300. Referring now to... Figures 1 to 3 The battery pack cooling structure according to this disclosure will be described in detail.

[0039] The battery pack 10 includes a heat sink 100 serving as a base plate for the battery housing, which houses at least one battery assembly 200, and in most cases, multiple battery assemblies 200. A battery assembly 200 refers to an assembly of multiple battery cells structurally and electrically combined. Depending on the structure combining the multiple battery cells, the battery assembly 200 can be referred to by various terms, such as battery module, battery block, battery cell, etc. This disclosure does not specifically limit the structure of the assembly of multiple battery cells mounted on the heat sink 100. The heat sink 100 includes multiple cooling flow paths 112. The multiple cooling flow paths 112 disposed in the heat sink 100 can be formed in various ways. For example, depending on the structure or manufacturing method of the heat sink 100, the heat sink 100 can be classified as a brazed heat sink and an extruded heat sink. A brazed heat sink is a structure in which two plates are brazed together to form a flow channel, which has a high degree of freedom in flow path design, but suffers from poor structural rigidity due to material degradation. On the other hand, extruded heat sinks, which are manufactured as continuous bodies through extrusion molding, have high structural rigidity, but can only achieve a straight flow path, resulting in a large number of ports, and the pipes used for connection occupy space.

[0040] The battery pack cooling structure according to this disclosure can be applied to radiators 100 of various sizes, but preferably, multiple cooling flow paths 112 are provided along the overall length of the radiator 100. Specifically, multiple cooling flow paths 112 are preferably formed in the entire area occupied by the battery assembly 200 and electrical components 300 housed or installed in the battery pack 10.

[0041] Multiple battery modules 200 are mounted longitudinally and / or laterally on the top of the radiator 100. Furthermore, at least one electrical component 300 is mounted on the top of the radiator 100. In the relative arrangement with respect to the battery modules 200, at least one electrical component 300 may be positioned along the side of the radiator 100 adjacent to the outermost battery module 200. The side of the radiator 100 on which the electrical component 300 is mounted may be the front or rear surface of the battery pack 10. The electrical component 300 refers to a component, module, or device that controls and monitors the charging and discharging of the entire battery pack 200 to ensure the battery pack 10 operates fully and normally.

[0042] Examples of the electrical components 300 of the battery pack 10 include a battery disconnect unit (BDU 310), a battery management system (BMS 320), etc. The BDU 310 is a module that combines a relay, a current sensor, a pre-charge resistor, a fuse, etc., and is an important module connected between a battery and an inverter to distribute high voltage and high current, and prevents accidents by performing an emergency shutdown in an abnormal situation. The BMS 320 is a system installed to best manage the performance and lifespan of a battery, and measures the current, voltage, temperature, etc. of the battery through a sensor, and identifies them in advance to control the battery so that the battery can be optimally operated.

[0043] When a coolant (for example, cooling water) flows through the plurality of cooling flow paths 112 provided in the heat sink 100, the coolant cools the battery assembly 200 and the electrical components 300 on the heat sink 100 so that they do not overheat. The battery pack 10 focuses on cooling the battery assembly 200 because the battery assembly 200 generates high heat during charging and discharging, and overheating of the battery cells can cause a serious accident, for example, thermal runaway or thermal propagation. In contrast, cooling of the electrical components 300 is not separately considered, which can cause the battery pack 10 to heat because the battery pack 10 becomes higher in performance and higher in capacity, resulting in the temperature of the battery assembly 200 increasing due to the high heat of the electrical components 300 being transferred to the battery assembly 200 through the bus bar 312.

[0044] To solve the problem that overheating of the electrical components 300 adversely affects the battery assembly 200, the cooling structure of the battery pack 10 according to the present disclosure is such that the inside of at least one of the plurality of electrical components 300 is sealed with insulating oil 330, and heat accumulated in the insulating oil 330 is discharged to the outside through the cooling flow path 112 of the heat sink 100. The insulating oil 330 refers to oil for electrical insulation purposes, and is typically highly refined low-viscosity petroleum-based lubricating oil. While its main purpose is electrical insulation, it can also serve as a coolant that prevents moisture from entering and dissipates generated heat.

[0045] The insulating oil 330 has a very high heat transfer rate and heat capacity compared to air, so it can play a role in heat dissipation cooling, and heat generated inside the electrical components 300 is efficiently accumulated in the insulating oil 330. The heat accumulated in the insulating oil 330 is transferred to the heat sink 100 in contact with the surface of the electrical components 300 in the form of heat conduction, and the heat transferred to the heat sink 100 is transferred to the coolant and finally discharged to the outside of the battery pack 10.

[0046] Referring to Figure 1 and Figure 2The heat sink 100 exemplarily shown corresponds to an extrusion-molded heat sink. The heat sink 100 shown is extrusion-molded and integrally formed with a plurality of cooling flow paths 112 formed in parallel along the entire length direction L of the heat sink 100 by a plurality of ribs 110 spaced apart in the width direction W.

[0047] The open surfaces of the heat sink 100 are closed by a plurality of end plugs 120 to circulate the coolant along the plurality of cooling flow paths 112. The open surfaces of the heat sink 100 are surfaces at both ends in the length direction L, and both ends in the length direction L of the heat sink 100 are open due to the extrusion feature of the heat sink 100. For ease of description, the two open surfaces will be referred to as a first surface and a second surface, respectively. Here, the length direction L corresponds to the extrusion molding direction of the heat sink 100, i.e., the direction in which the plurality of ribs 110 extend, and the width direction W corresponds to the direction orthogonal to the length direction L in the plane in which the plurality of cooling flow paths 112 are spaced apart.

[0048] The end plugs 120 include an inlet plug 122, an outlet plug 124, and a return plug 126. On the first surface located on the front side of the drawing, the inlet plug 122 is joined at the middle, and a pair of outlet plugs 124 is joined on both sides thereof. The inlet plug 122 is provided with an inlet 123, and the outlet plug 124 is provided with an outlet 125. Then, the return plug 126 is joined to the second surface located on the rear side of the drawing. The cooling flow paths 112 closed by the inlet plug 122 form inlet flow paths, and the cooling flow paths 112 closed by the outlet plug 124 form outlet flow paths. The return plug 126 forms a return path connecting the inlet flow paths with the outlet flow paths. By forming such flow paths, the coolant introduced into the inlet flow paths through the inlet 123 in the middle meets the return plug 126 and branches left and right to enter the outlet flow paths, and the coolant flowing through the outlet flow paths is discharged through the outlet 125. However, this configuration of the coolant flow paths 112 of the heat sink 100 is only one example shown in the drawing, and the heat sink 100 can have various other shapes and structures of coolant flow paths 112.

[0049] "130" not shown in the drawing is a plate member that surrounds all sides of the heat sink 100, and the plate member 130 forms a space in which the battery assembly 200 and the electrical components 300 are mounted in the battery pack. In addition, a cover portion not shown forms a cover for the battery pack 10, thereby protecting the inside of the battery pack 10 from the outside.

[0050] Figure 4 is a cross-sectional view taken along the line "A-A" of Figure 1 Referring to Figure 4, a thermal interface material 400 (TIM) is interposed between the electrical component 300 internally sealed with the insulating oil 330 and the heat sink 100. The thermal interface material 400 can also be interposed between the battery assembly 200 and the heat sink 100. Referring to Figure 2 , the thermal interface material 400 can be coated on the heat sink 100 with a suitable thickness, and the battery assembly 200 and the electrical component 300 can be mounted on the coated thermal interface material 400. The thermal interface material 400 can be a hardenable material such as a thermal resin, which cures over time to form an adhesive state, thereby fixing the battery assembly 200 and the electrical component 300 to the heat sink 100.

[0051] As described above, the electrical component 300 internally sealed with the insulating oil 330 can be a BDU 310 (Battery Disconnection Unit). The BDU 310 is connected with the battery assembly 200 through a bus bar 312, and is a high heat output component since it handles high voltage and high current. Since the BDU 310 and the battery assembly 200 are connected through the bus bar 312, high heat generated in the BDU 310 can be transferred to the battery assembly 200 through the thermally conductive bus bar 312. Therefore, it is possible to reduce the heat transferred to the battery assembly 200 by sealing the insulating oil 330 inside the BDU 310 to efficiently dissipate heat to the heat sink 100.

[0052] Further, according to an embodiment, a battery management system (BMS) 320 can also be connected with the BDU 310 through the bus bar 312. In this case, it can be desirable to seal the insulating oil 330 inside the BMS 320 to prevent overheating.

[0053] Further, referring to Figure 4 , the electrical component 300 internally sealed with the insulating oil 330 can include a pressure relief valve 340. The pressure relief valve 340 is a safety device that opens to release internal pressure when the pressure inside the electrical component 300 rises above a set value. If the heat generated by the electrical component 300 abnormally rises, the insulating oil 330 can partially boil, which can cause the pressure inside the electrical component 300 to rapidly rise. To cope with such an emergency, the electrical component 300 can be provided with the pressure relief valve 340, and the operation of the pressure relief valve 340 can prevent the electrical component 300 from being damaged and prevent all of the insulating oil 330 from leaking.

[0054] [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 5The heat sink fin 500 is interposed between the electrical component 300, in which the insulating oil 330 is internally sealed, and the heat sink 100. The heat sink fin 500 expands the heat transfer area, thereby allowing heat to be more quickly transferred from the electrical component 300, in which the insulating oil 330 is sealed, to the heat sink 100. In other words, the heat sink fin 500 facilitates cooling of the electrical component 300 and more efficiently suppresses the spread of heat from the electrical component 300 to the battery assembly 200.

[0055] The heat sink fin 500 can be formed on a bottom surface of the electrical component 300, in which the insulating oil 330 is internally sealed, or on an upper surface of the heat sink 100. Figure 5 An embodiment in which the heat sink fin 500 is integrally formed on the upper surface of the heat sink 100 is illustrated. When the heat sink fin 500 is formed on the heat sink 100, if the heat sink 100 is an extrusion-molded heat sink, the heat sink fin 500 can be formed in the length direction L of the heat sink 100, in the same direction in which the ribs 110 are formed. Accordingly, the heat sink fin 500 on the extrusion-molded heat sink can be formed in the entire length direction of the heat sink 100, so that the bottom surface of the electrical component 300 as well as the bottom surface of the battery assembly 200 can be provided with the heat sink fin 500, thereby facilitating cooling of the battery assembly 200.

[0056] The heat sink fin 500 and the thermal interface material 400 can be applied together. In order to fully utilize the heat dissipation capacity of the heat sink fin 500 and the thermal interface material 400, the thermal interface material 400 can cover the entire heat sink fin 500. That is, preferably, the heat sink fin 500 can be covered with the thermal interface material 400, thereby eliminating a space that hinders heat transfer, such as an air layer, in a heat transfer path between the electrical component 300 and the heat sink 100.

[0057] The present disclosure has been described above in greater detail with reference to the accompanying drawings and embodiments. However, it should be understood that the configuration shown in the drawings or embodiments described herein is only one embodiment of the present disclosure, and does not represent all technical ideas of the present disclosure, and various equivalents and modifications that can replace them at the time of filing the present disclosure can exist.

[0058] [REFERENCE NUMERALS] 10: battery pack 100: heat sink 110: rib 112: cooling flow path 120: end plug 122: inlet plug 123: inlet 124: outlet plug 125: outlet 126: return plug 130: plate member 200: battery assembly 300: electrical component 310: BDU 312: bus bar 320: BMS 330: insulating oil 340: pressure relief valve 400: thermal interface material 500: heat sink fin

Claims

1. A battery pack cooling structure, comprising: A radiator includes multiple cooling flow paths; Multiple battery assemblies are mounted longitudinally and / or laterally on the heat sink; as well as Multiple electrical components are mounted on the radiator. At least one of the plurality of electrical components is internally sealed with insulating oil, and the heat accumulated in the insulating oil is discharged to the outside through the cooling flow path of the radiator.

2. The battery pack cooling structure according to claim 1, wherein, The plurality of cooling flow paths are arranged along the overall length of the radiator.

3. The battery pack cooling structure according to claim 2, wherein: The radiator is integrally formed with a cooling flow path through extrusion molding, and The plurality of cooling flow paths are formed along the overall length of the radiator by multiple ribs spaced apart in the width direction.

4. The battery pack cooling structure according to claim 1, wherein, Thermal interface material, or TIM, is placed between the heat sink and the electrical components that are internally sealed with insulating oil.

5. The battery pack cooling structure according to claim 4, wherein, The electrical components, which are internally sealed with insulating oil, are fitted with heat dissipation fins between themselves and the radiator.

6. The battery pack cooling structure according to claim 5, wherein, The heat dissipation fins are formed on the bottom surface of the electrical component, which is internally sealed with insulating oil, or on the upper surface of the radiator.

7. The battery pack cooling structure according to claim 5, wherein, The thermal interface material covers the entire heat dissipation fin.

8. The battery pack cooling structure according to claim 1, wherein, Electrical components sealed with insulating oil are called BDUs, or battery disconnect units.

9. The battery pack cooling structure according to claim 8, wherein, The BMS, or battery management system, which is connected to the BDU via a busbar, is also sealed with insulating oil.

10. The battery pack cooling structure according to claim 1, wherein, Electrical components that are internally sealed with insulating oil are equipped with pressure relief valves.

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