Battery pack

Abstract

A battery pack is provided, comprising a pack body and a cooling device provided outside the pack body, in a vertical coordinate system defined as a first, second, and third direction perpendicular to each other, wherein the pack body comprises a plurality of battery cells stacked in the first direction, a lower case configured to house the plurality of battery cells and including a first cooling channel capable of cooling the plurality of battery cells, and an upper case that together with the lower case defines an internal space in which the plurality of battery cells are housed, the cooling device provided on the upper case and including a second cooling channel capable of contacting the upper case and cooling the plurality of battery cells, and the upper case comprising two or more recesses capable of housing the cooling device and a venting channel provided between the recesses and configured to discharge gas generated from the plurality of battery cells.

Description

Technical Field

[0001] The present invention relates to a battery pack, and more specifically, to a battery pack that can smoothly discharge gas without significantly sacrificing the cooling performance of battery cells when a thermal event occurs, and can safely protect battery cells even when the cooling fluid leaks.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0043390 filed on April 3, 2023, and all the contents disclosed in the literature of the Korean patent application are included as part of this specification.

Background Art

[0003] Unlike primary batteries, secondary batteries can be charged and discharged multiple times. Secondary batteries are widely used as an energy source for various wireless devices such as handsets, notebook computers, and wireless vacuum cleaners. In recent years, due to the improvement of energy density and economies of scale, the manufacturing cost per unit capacity of secondary batteries has decreased epochally, and as the cruising range of battery electric vehicles (BEVs) has increased to the same level as fuel vehicles, the main use of secondary batteries has shifted from mobile devices to mobility.

[0004] On the other hand, in recent years, the demand for large-capacity battery packs applied to electric vehicles and the like has been increasing. A large-capacity battery pack mounted on a vehicle may cause a thermal event due to a temperature rise in some battery cells during the charging and discharging of electricity of a large number of battery cells. At this time, the high-temperature gas, flame, and spark discharged from the battery cells may move to other adjacent battery cells, which may cause thermal runaway or secondary gas explosion of other battery cells.

[0005] Therefore, there has been a continuous demand for a solution to prevent the propagation of thermal events from some battery cells among a large number of battery cells to other adjacent battery cells. [Overview of the project] [Problems that the invention aims to solve]

[0006] The technical problem that this invention aims to solve is to provide a battery pack that can smoothly discharge gas without significantly sacrificing the cooling performance of the battery cells when a thermal event occurs, and that can safely protect the battery cells even if the cooling fluid leaks. [Means for solving the problem]

[0007] To achieve the above technical objectives, the present invention provides a battery pack comprising a pack body and a cooling device provided outside the pack body in a vertical coordinate system defined as a first, second, and third direction perpendicular to each other, wherein the pack body comprises a plurality of battery cells stacked in the first direction, a lower case configured to house the plurality of battery cells and including a first cooling channel capable of cooling the plurality of battery cells, and an upper case that together with the lower case defines an internal space in which the plurality of battery cells are housed, the cooling device provided on the upper case and including a second cooling channel capable of contacting the upper case and cooling the plurality of battery cells, and the upper case comprises two or more recesses capable of housing the cooling device and a venting channel provided between the recesses and configured to discharge gas generated from the plurality of battery cells.

[0008] In some embodiments, the second cooling channel may extend in the first direction, and the recess may be positioned to overlap with the cell leads of the plurality of battery cells stacked in the first direction.

[0009] In some embodiments, each of the plurality of battery cells includes a first cell lead and a second cell lead positioned at both ends in the second direction, one of the two or more recesses may be positioned to overlap the first cell lead arranged in the first direction in the third direction, and the other of the two or more recesses may be positioned to overlap the second cell lead arranged in the first direction in the third direction.

[0010] In some embodiments, the venting channel may be configured to extend in the first direction between the first cell leads and the second cell leads, which are respectively arranged in the first direction.

[0011] In some embodiments, the battery pack may be configured such that the flow direction of the cooling fluid passing through the second cooling channel and the flow direction of the gas flowing through the venting channel are opposite to each other.

[0012] In some embodiments, the upper case is made of aluminum or an aluminum alloy, and the surface facing the plurality of battery cells may be treated with a fire-resistant surface treatment.

[0013] In some embodiments, the battery pack may be configured such that an inlet port is provided at the inlet of the second cooling channel, and an outlet port is provided at the outlet of the second cooling channel, and the inlet port and the outlet port extend away from the pack body and are connected to an external conduit.

[0014] In some embodiments, the venting passage may be provided by a venting channel formed between two or more recesses and configured to communicate fluidly with a venting device provided in the lower case.

[0015] In some embodiments, the thickness of the upper case in the third direction at the recess, the thickness of the upper case in the third direction at the venting channel, and the thickness of the upper case between the recess and the venting channel may be substantially the same as each other.

[0016] In some embodiments, the upper case may have a substantially constant thickness over its entire surface area.

[0017] In some embodiments, the cooling device may be coupled to the upper case by brazing.

[0018] Another aspect of the present invention provides a battery pack comprising: a plurality of battery cells stacked in the first direction in a vertical coordinate system defined as a first, second, and third direction perpendicular to each other; a lower case configured to house the plurality of battery cells and including a first cooling channel capable of cooling the plurality of battery cells; and an upper case that together with the lower case defines an internal space in which the plurality of battery cells are housed, wherein the upper case has an uneven shape with a certain thickness, has a venting channel configured to discharge gas generated from the plurality of battery cells on one surface of the upper case, and includes a plurality of recesses on the other surface of the upper case.

[0019] In some embodiments, the battery pack may further include a cooling device having cooling channels that are housed within the plurality of recesses and capable of cooling the plurality of battery cells.

[0020] In some embodiments, the battery pack may include additional cooling channels within the lower case that can cool the plurality of battery cells.

[0021] In some embodiments, the recess and the venting channel may have complementary shapes. [Effects of the Invention]

[0022] The battery pack according to an embodiment of the present invention has an effect that it can smoothly discharge gas without significantly sacrificing the cooling performance of the battery cells when a thermal event occurs, and the battery cells can be safely protected even when the cooling fluid leaks.

[0023] The effects obtainable from the exemplary embodiments of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly derived and understood by those having ordinary knowledge in the technical field to which the exemplary embodiments of the present disclosure belong from the following description. That is, unintended effects associated with implementing the exemplary embodiments of the present disclosure can also be derived by those having ordinary knowledge in the technical field from the exemplary embodiments of the present disclosure.

Brief Description of the Drawings

[0024] [Figure 1] It is a perspective view of a battery pack according to an exemplary embodiment of the present invention. [Figure 2] It is a perspective view showing some elements of a battery pack according to an exemplary embodiment. [Figure 3] It is an exploded perspective view showing the upper case of FIG. 1 and the main part of the cooling device. [Figure 4] It is a perspective view of a battery pack according to an embodiment of the present invention. [Figure 5] It is a partial cross-sectional perspective view showing a cross-section obtained by cutting the battery pack of FIG. 4 along the line A - A'. [Figure 6] It is a partial cross-sectional view showing a cross-section obtained by cutting the battery pack of FIG. 4 along the line A - A'. [Figure 7] It is a partially enlarged view of part B of FIG. 4. [Figure 8] It is a cross-sectional view of a cooling device according to an exemplary embodiment of the present invention. [Figure 9] It is a cross-sectional view of a cooling device according to an exemplary additional embodiment of the present invention.

Modes for Carrying Out the Invention

[0025] Preferred embodiments of the concept of the present invention will be described in detail below with reference to the attached drawings. However, embodiments of the concept of the present invention may be modified into various different forms, and the scope of the concept of the present invention should not be construed as being limited by the embodiments described above. It is preferable that embodiments of the concept of the present invention be construed as being provided to more fully explain the concept of the present invention to a person of average knowledge in the art. The same reference numerals mean the same element throughout. Furthermore, the various elements and areas in the drawings are depicted schematically. Therefore, the concept of the present invention is not limited by the relative sizes or spacings depicted in the attached drawings.

[0026] Terms such as "first," "second," etc., may be used to describe a variety of components, but the components are not limited by these terms. The terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the concept of the present invention, the first component may be named the second component, and conversely, the second component may be named the first component.

[0027] The terms used in this application are used solely to describe specific embodiments and are not intended to limit the concepts of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, expressions such as “includes” or “has” are intended to specify the existence of features, quantities, steps, operations, components, parts, or combinations thereof described in the specification, and are understood not to pre-exist to exclude the existence or possibility of adding one or more other features, quantities, steps, operations, components, parts, or combinations thereof.

[0028] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as those commonly understood by those of ordinary skill in the art to which the concepts of this invention pertain. Furthermore, terms defined in commonly used dictionaries may be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and should not be interpreted in an overly formal sense unless explicitly defined herein.

[0029] Where a particular embodiment can be otherwise realized, a specific sequence of steps may be performed in a different order than that described. For example, two steps described consecutively may be performed substantially simultaneously, or in the reverse order of the description.

[0030] In the accompanying drawings, deformation of the shown shapes may be expected, for example, due to manufacturing techniques and / or tolerances. Therefore, embodiments of the present invention should not be construed as being limited to specific shapes of the regions shown herein, and may include, for example, changes in shape resulting from the manufacturing process. All terms used herein, "and / or," include each of the components mentioned and all combinations of one or more of them. The term "substrate" as used herein may mean the substrate itself or a laminated structure including a substrate and a predetermined layer or film formed on its surface. The term "surface of the substrate" as used herein may mean the exposed surface of the substrate itself or an outer surface of a predetermined layer or film formed on the substrate.

[0031] (First Embodiment) Figure 1 is a perspective view of a battery pack 100 according to an exemplary embodiment of the present invention.

[0032] Figure 2 is a perspective view showing some elements of a battery pack 100 according to an exemplary embodiment.

[0033] Referring to Figures 1 and 2, the battery pack 100 may include a pack body 101 and a cooling device 180 provided outside the pack body 101. The pack body 101 may also include a lower case 110, a plurality of battery cells 120, a center beam 130, a plurality of venting devices 140, a pack gasket 160, and an upper case 170. The battery pack 100 is the final form of a battery system to be installed in mobility devices and the like.

[0034] The pack case 101c, which corresponds to the housing of the pack body 101, may include the lower case 110 and the upper case 170.

[0035] The lower case 110 may provide internal space 119 for mounting multiple battery cells 120. In some embodiments, the lower case 110 may include a plate portion 110P and a side wall 110S. Two directions substantially parallel to the plate portion 110P are defined as the first direction (e.g., the X-axis direction) and the second direction (e.g., the Y-axis direction), and a direction substantially perpendicular to the plate portion 110P of the lower case 110 is defined as the third direction (e.g., the Z-axis direction).

[0036] In Figure 1, the battery pack 100 is shown to be defined in a vertical coordinate system defined as a first direction along the X-axis, a second direction along the Y-axis, and a third direction along the Z-axis, all of which are perpendicular to each other. However, the first, second, and third directions only need to be perpendicular to each other and are not particularly limited.

[0037] Multiple battery cells 120 may be arranged on a plate portion 110P of the lower case 110. The plate portion 110P can support multiple battery cells 120. The plate portion 110P may include substantially parallel upper and lower surfaces. The upper surface of the plate portion 110P may face the multiple battery cells 120. The lower surface of the plate portion 110P is the opposite surface of the upper surface of the plate portion 110P. In some embodiments, the battery cells 120 may be packaged in the form of a battery module and placed inside the lower case 110. A typical technician can understand that the battery cells 120 may be placed on the lower case 110 either after being packaged in various forms of frames or independently.

[0038] The side wall 110S can horizontally surround multiple battery cells 120. The side wall 110S can protect multiple battery cells 120 from the side. The side wall 110S may include a first side wall 111, a second side wall 112, a third side wall 113, and a fourth side wall 114. The first to fourth side walls 111, 112, 113, and 114 may be fixed to each other by methods such as friction stir welding or spot welding, and are not particularly limited.

[0039] The first side wall 111 and the second side wall 112 may be substantially perpendicular to the second direction (e.g., the Y-axis direction). The third side wall 113 and the fourth side wall 114 may each be substantially perpendicular to the first direction (e.g., the X-axis direction). In some embodiments, the first side wall 111 and the second side wall 112 may cover the sides of the plate portion 110P. In some embodiments, the third side wall 113 and the fourth side wall 114 may be positioned on the plate portion 110P.

[0040] In some embodiments, the first to fourth side walls 111, 112, 113, and 114 may be provided by an extrusion process. According to exemplary embodiments, the first to fourth side walls 111, 112, 113, and 114 may include internal voids, thereby reducing the weight of the side wall 110S. According to exemplary embodiments, the voids in the first to fourth side walls 111, 112, 113, and 114 may be either gas venting paths or coolant channels.

[0041] A first cooling channel 115 (see Figure 5) may be provided in the plate portion 110P that forms the bottom of the lower case 110. The first cooling channel 115 may be configured to carry a cooling fluid to remove heat generated from the battery cell 120. The cooling fluid may be, for example, water or air.

[0042] The technical idea of ​​the present invention will be described below with reference to embodiments in which multiple battery cells 120 constitute a battery assembly without a module frame. However, this is a non-limiting example and does not limit the technical idea of ​​the present invention in any sense. Based on what is described herein, ordinary articulators of the art will readily arrive at battery packs employing multiple battery assemblies including a module frame, as well as embodiments in which the battery cells are directly mounted within the pack case.

[0043] The center beam 130 can isolate the elements mounted on the lower case 110 from each other. This allows the center beam 130 to protect the multiple battery cells 120 while simultaneously preventing unnecessary short circuits between them.

[0044] The center beam 130 is obtained by extending in the first direction (e.g., the X-axis direction) between the third side wall 113 and the fourth side wall 114. In some embodiments, the center beam 130 may be in contact with the third side wall 113 and the fourth side wall 114. In some embodiments, the center beam 130 may isolate a plurality of battery cells 120 from each other in the second direction (e.g., the Y-axis direction). The center beam 130 may be interposed between a plurality of battery cells 120.

[0045] The arrangement of the center beam 130 and the plurality of battery cells 120 disclosed in Figure 1 is a non-limiting example and does not limit the technical idea of ​​the present invention in any sense. Based on what has been described herein, ordinary articulators of the art can easily arrive at battery packs including a variety of arrangements and numbers of center beams and battery assemblies.

[0046] Multiple venting devices 140 may be connected to the fourth side wall 114. The fourth side wall 114 may include multiple exhaust holes connected to the multiple venting devices 140. The multiple exhaust holes may be configured to provide a path for exhausting gases and heat from inside the battery pack 100.

[0047] Multiple venting devices 140 may be configured to slow down thermal propagation by releasing high-temperature gas from inside the battery pack 100 to the outside when at least one of the multiple battery cells 120 is in a thermal runway state.

[0048] Here, thermal runaway of multiple battery cells 120 is a state in which the temperature change of multiple battery cells 120 further accelerates that temperature change, resulting in an uncontrollable positive feedback loop. Multiple battery cells 120 in a thermal runaway state exhibit a rapid temperature increase and may emit large amounts of high-pressure gas and combustion residue. This will be explained in more detail later.

[0049] Multiple first embedded guides 151 may be positioned on the side wall 110S. Multiple first embedded guides 151 may be positioned on the corners 110C of the upper surface of the side wall 110S. Multiple first embedded guides 151 may be coupled to the corners 110C of the upper surface of the side wall 110S. Multiple first embedded guides 151 may be partially embedded in the side wall 110S. Multiple first embedded guides 151 may partially protrude from the side wall 110S.

[0050] Multiple second embedding guides 153 may be positioned on the side wall 110S. Multiple second embedding guides 153 may be positioned on the upper surface of the side wall 110S. Multiple second embedding guides 153 may be interposed between the corners 110C of the side wall 110S. Multiple second embedding guides 153 may be interposed between multiple first embedding guides 151. Multiple second embedding guides 153 may be coupled to the upper surface of the side wall 110S. Multiple second embedding guides 153 may be partially embedded in the side wall 110S. Multiple second embedding guides 153 may partially protrude from the side wall 110S.

[0051] Each of the multiple first embedding guides 151 and second embedding guides 153 may contain a metallic material. Each of the multiple first embedding guides 151 and second embedding guides 153 may contain, for example, aluminum. Each of the multiple first embedding guides 151 and second embedding guides 153 may also contain, for example, steel such as carbon steel, nickel steel, chromium steel, nickel-chromium steel, and manganese steel.

[0052] The battery pack 100 may further include electrical components. In some embodiments, the electrical components may be mounted on the lower case 110. In some embodiments, the electrical components may be located between the fourth side wall 114, on which the venting device 140 is installed, and the plurality of battery cells 120. In some embodiments, the electrical components may include any electronic elements necessary to power the battery pack.

[0053] In some embodiments, the electrical components may include, for example, a battery management system (BMS). The BMS may be configured to perform monitoring, balancing, and control of the battery pack. In some embodiments, monitoring of the battery pack 100 may include measuring the voltage and current of specific nodes within a plurality of battery cells 120, and measuring the temperature of a set location within the battery pack 100. In some embodiments, the battery pack 100 may include measuring instruments for measuring the aforementioned voltage, current, and temperature.

[0054] Balancing the battery pack 100 is an operation to reduce deviations between multiple battery cells 120. Control of the battery pack 100 includes preventing overcharging, over-discharging, and overcurrent. Through monitoring, balancing, and control, the battery pack 100 can operate under optimal conditions, thereby preventing or reducing shortening of the lifespan of each of the multiple battery cells 120.

[0055] In some embodiments, the electrical components may further include a cooling device, a power relay assembly (PRA), a safety plug, and the like. The cooling device may include a cooling fan. The cooling fan can prevent each of the multiple battery cells 120 from overheating by circulating air inside the battery pack 100. The PRA may be configured to supply or cut off power from the high-voltage battery to an external load (e.g., the vehicle's motor). The PRA can protect the multiple battery cells 120 and the external load (e.g., the vehicle's motor) by cutting off the power supply to the external load (e.g., the vehicle's motor) in situations where abnormal voltages occur, such as a voltage surge.

[0056] The battery pack 100 may further include a plurality of busbars configured to electrically connect a plurality of battery cells 120. The plurality of battery cells 120 may be connected in series and / or parallel by the plurality of busbars. This may configure the battery pack 100 to output a high voltage to an external load (e.g., a vehicle motor).

[0057] The pack gasket 160 may contain a material that is elastic in response to applied pressure. The pack gasket 160 may contain rubber synthesized from a material such as EPDM (ethylene-propylene diene monomer). When the lower case 110 and the upper case 170 are joined, the pack gasket 160 may be interposed between the lower case 110 and the upper case 170. The lower case 110 and the upper case 170 may pressurize the pack gasket 160 so that it deforms slightly. This allows the battery pack 100 to be sealed and external fluids to be isolated from the internal space of the battery pack 100.

[0058] Figure 3 is an exploded perspective view showing the main parts of the upper case 170 and cooling device 180 in Figure 1.

[0059] Referring to Figure 3, the upper case 170 includes two or more recesses 172 that are recessed in a third direction (e.g., the Z-axis direction). In some embodiments, the recesses 172 may extend in the first direction (e.g., the X-axis direction), which is the direction in which the battery cells 120 are stacked. In some embodiments, the recesses 172 may be configured to at least partially house the cooling device 180.

[0060] In some embodiments, the upper case 170 may have a generally constant thickness over its entire surface area. Here, "generally" constant thickness means that the thickness at the thinnest point is at least 50% of the thickness at the thickest point.

[0061] In some embodiments, the upper case 170 may have a substantially constant thickness over its entire surface area. Here, "substantially" constant thickness means that the thickness deviation of the upper case 170 due to its position is within 500 micrometers.

[0062] The upper case 170 may include at least one venting channel portion 174 extending in the first direction (for example, the X-axis direction). The venting channel portion 174 may be a structure that is formed complementary to the upper case 170, which generally has a constant thickness, by forming the recess 172. The venting channel portion 174 appears flat from the viewpoint shown in Figure 3, which is viewed from the top side of the upper case 170, but when viewed from the bottom side, the two recesses 172 have a convex shape, and the area between these recesses 172 has a relatively concave shape.

[0063] The cooling device 180 is configured to be housed in the recess 172 of the upper case 170. The cooling device 180 includes a second cooling channel 184 through which a cooling fluid flows. The second cooling channel 184 may extend in the first direction (for example, the X-axis direction).

[0064] The second cooling channel 184 is configured such that a cooling fluid (e.g., water or air) supplied from the outside flows in one direction, and may extend, for example, in the first direction (e.g., the X-axis direction). In some embodiments, the second cooling channel 184 may be a conduit. In some embodiments, the second cooling channel 184 may be a fluid passage in the form of a conduit formed together by the upper surface of the recess 172 and the cooling device 180.

[0065] The second cooling channel 184 may be configured to make physical surface contact with the bottom surface of the recess 172 for efficient heat transfer with the upper case 170. In some embodiments, the dimension of the second cooling channel 184 in the second direction (e.g., the Y-axis direction) may be about 2 to 25 times the dimension in the third direction (e.g., the Z-axis direction). In some embodiments, the dimension of the second cooling channel 184 in the second direction (e.g., the Y-axis direction) may be about 2 to 25 times, 3 to 24 times, 4 to 23 times, 5 to 22 times, 6 to 21 times, 7 to 20 times, 8 to 19 times, 9 to 18 times, 10 to 17 times, 11 to 16 times, 12 to 15 times, 13 to 14 times, or within a range between any two of these values.

[0066] Since the cooling device 180 is located outside the pack body 101, even if the cooling fluid leaks, it will not adversely affect the battery cells 120 located inside the pack body 101, which is sealed by the upper case 170. Therefore, the safety of the battery pack 100 can be improved.

[0067] Figure 4 is a perspective view of a battery pack 100 according to one embodiment of the present invention.

[0068] The battery pack 100 in Figure 4 may be a configuration in which the upper case 170 and cooling device 180 of the battery pack 100 shown in Figure 1 are assembled on the lower case 110.

[0069] Referring to Figure 4, the cooling device 180 is housed in the recess 172 (see Figure 3) of the upper case 170. The bottom surface of the cooling device 180 may come into contact with the surface of the recess 172.

[0070] The venting channel portion 174 of the upper case 170 may be located between the two cooling devices 180. The venting channel portion 174 may face the battery cell 120 housed in the lower case 110. Furthermore, the venting channel portion 174 may have a space between it and the battery cell 120 corresponding to the height of the venting channel portion 174. This will be explained in more detail later.

[0071] The battery pack 100 includes a plurality of venting devices 140. The plurality of venting devices 140 may be configured to communicate fluidly with the venting channel 174. When a thermal event occurs in the battery cell 120, the gas generated from the battery cell 120 may be guided to flow through the venting channel 174 in a second direction (e.g., the Y-axis direction). The gas can then be discharged to the outside of the battery pack 100 through the venting devices 140. In some embodiments, the battery pack 100 may be further provided with guide structures between the venting channel 174 and the venting devices 140 to guide the flow of the gas.

[0072] In some embodiments, the cooling device 180 may be connected to the upper case 170 by brazing. In some embodiments, the cooling device 180 may be connected to the upper case 170 by welding or screw coupling.

[0073] In some embodiments, the upper case 170 may be made of aluminum (Al) or an Al alloy. In some embodiments, the upper case 170 may further include a refractory surface treatment layer on its lower surface. The refractory surface treatment layer may be a layer produced by refractory surface treatment of the lower surface of the upper case 170 made of Al or an Al alloy. The refractory surface treatment may be, for example, anodizing or a refractory layer coating, but the present invention is not limited thereto.

[0074] In some embodiments, the cooling device 180 may include an inlet port 182 on the inlet side where the cooling fluid flows into the second cooling channel 184, and an outlet port 183 on the outlet side where the cooling fluid flows out of the second cooling channel 184. The inlet port 182 and the outlet port 183 may each extend separately from the pack body 101. Furthermore, the inlet port 182 and the outlet port 183 may each be connected to an external conduit to establish fluid communication.

[0075] Figure 5 is a partial cross-sectional perspective view showing a cross-section of the battery pack 100 in Figure 4, cut along the line A-A'. Figure 6 is a partial cross-sectional view showing a cross-section of the battery pack 100 in Figure 4, cut along the line A-A'.

[0076] Referring to Figures 5 and 6, multiple battery cells 120 are stacked in a first direction (for example, the X-axis direction) within the lower case 110, and the upper case 170 is connected to the lower case 110. A cooling device 180 is provided in the recess 172 of the upper case 170.

[0077] A first cooling channel 115 is provided inside the lower case 110, and a second cooling channel 184 is provided in the cooling device 180. The upper case 170 includes a venting channel 174 that can discharge gas generated from the battery cell 120.

[0078] The venting channel portion 174 has a certain space between it and the battery cells 120 arranged in a first direction (for example, the X-axis direction), and this space acts as a venting channel 174c through which gas generated from the battery cells 120 flows to be discharged to the outside. In other words, the venting channel portion 174 defines a venting channel 174c configured to discharge the gas.

[0079] The gas generated from the battery cell 120 is guided in a first direction (for example, the X-axis direction) via the venting channel 174c, and then discharged to the outside via the venting device 140 (see Figure 4).

[0080] In some embodiments, the direction in which the cooling fluid flows within the second cooling channel 184 may be opposite to the direction in which the gas flows within the venting channel 174. In other embodiments, the direction in which the cooling fluid flows within the second cooling channel 184 may be the same as the direction in which the gas flows within the venting channel 174.

[0081] The first cooling channel 115, the second cooling channel 184, and the venting channel portion 174 may extend in a first direction (for example, in the X-axis direction). The venting channel portion 174 may be positioned between the two second cooling channels 184.

[0082] In some embodiments, the plurality of battery cells 120 include first cell leads 121 and second cell leads 122 positioned at both ends in the second direction (e.g., the Y-axis direction). Since the plurality of battery cells 120 are stacked in the first direction (e.g., the X-axis direction), the first cell leads 121 and the second cell leads 122 may also be arranged in the first direction (e.g., the X-axis direction).

[0083] In some embodiments, the recess 172 may be located closer to the cell leads 121 and 122 of the battery cell 120 than the venting channel portion 174. In some embodiments, the recess 172 may be positioned to overlap the cell leads 121 and 122 in a third direction (e.g., the Z-axis direction).

[0084] In some embodiments, the venting channel portion 174 defining the venting flow path 174c may be located on the center of the battery cell 120 and extend in a first direction (e.g., the X-axis direction). Thus, one of the recesses 172 located on either side of the venting channel portion 174 may be located closer to the first cell lead 121 than the venting channel portion 174, and the other may be located closer to the second cell lead 122 than the venting channel portion 174. In some embodiments, one of the recesses 172 may be arranged to overlap the first cell lead 121 in a third direction (e.g., the Z-axis direction), and the other may be arranged to overlap the second cell lead 122 in a third direction (e.g., the Z-axis direction).

[0085] During charging and discharging of the battery pack 100, the area where the temperature mainly rises is near the cell leads 121 and 122. Conventionally, cooling channels were provided even near the center of the battery cell 120, where the temperature rise is not significant and the need for cooling is relatively low. Furthermore, since the cooling channels are provided at the bottom and lid of the battery pack, there was insufficient ventilation for exhausting gas generated from the battery cell 120 due to thermal events. As a result, the function of mitigating the pressure rise inside the battery cell 120 and blocking heat propagation when a thermal event occurs in the battery cell 120 was inadequate.

[0086] In this invention, near the center of the battery cell 120, instead of a cooling channel, a channel is provided to discharge gas generated from the battery cell 120, thereby sufficiently mitigating heat propagation and pressure rise within the battery cell 120 when a thermal event occurs. Furthermore, by providing the cooling channels for the battery cell 120 mainly near the cell leads 121 and 122 and outside the pack body 101, it is possible that even if the cooling fluid leaks, it will not adversely affect the battery cell 120.

[0087] In some embodiments, the upper case 170 may have a substantially constant thickness over its entire area. As shown in Figure 6, the thickness of the upper case 170 in a third direction (e.g., the Z-axis direction) at the recess 172 may be substantially the same as the thickness of the upper case 170 in a third direction (e.g., the Z-axis direction) at the venting channel portion 174. In some embodiments, the thickness of the upper case 170 between the recess 172 and the venting channel portion 174 may be the same as the thickness of the upper case 170 in a third direction (e.g., the Z-axis direction) at the recess 172 and / or the thickness of the upper case 170 in a third direction (e.g., the Z-axis direction) at the venting channel portion 174.

[0088] Figure 7 is a magnified view of section B of Figure 4.

[0089] Referring to Figure 7, the inlet of the second cooling channel 184 includes an inlet port 182, and the inlet port 182 can be connected to an external conduit 20 at a distance from the pack body 101. In the same manner, the outlet of the second cooling channel 184 includes an outlet port (not shown), and the outlet port can be connected to an external conduit (not shown) at a distance from the pack body 101.

[0090] As shown in Figure 7, the cooling device 180 is configured separately from the pack body 101, so that even if the cooling fluid leaks, it may not adversely affect the battery cells 120 located inside the pack body 101.

[0091] (Second Embodiment) Figure 8 is a cross-sectional view of a cooling device 180 according to an exemplary embodiment of the present invention.

[0092] Referring to Figure 8, the cooling device 180 may include a flat plate portion 181 extending perpendicularly in a third direction (e.g., the Z-axis direction) to form a second cooling channel 184, and a fixing portion 187 that contacts the upper case 170 to fix the cooling device to the upper case 170. The fixing portion 187 may be fixed in the recess 172, for example, by brazing.

[0093] The fixed portion 187 and the flat portion 181 together with the upper case 170 can form the second cooling channel 184. That is, the bottom of the second cooling channel 184 can be defined by the upper surface of the bottom of the recess 172 of the upper case 170. The flat portion 181 can be bent and extended and then connected to the fixed portion 187.

[0094] In the embodiment shown in Figure 8, the cooling fluid passing through the second cooling channel 184 comes into direct contact with the upper surface of the upper case 170, resulting in excellent cooling efficiency.

[0095] In some embodiments, the cooling device 180 may further include a wing portion 188 that extends from the fixed portion 187 and contacts the upper case 170. The wing portion 188 can rapidly diffuse the heat transferred from the fixed portion 187 horizontally (i.e., in a first and / or second direction) and dissipate it to the outside, thereby contributing to the smooth cooling of the battery cell 120.

[0096] (Third embodiment) Figure 9 is a cross-sectional view of a cooling device 180, which is an exemplary additional embodiment of the present invention.

[0097] Referring to Figure 9, the cooling device 180 may include a flat plate portion 181 extending perpendicularly in a third direction (e.g., the Z-axis direction) to form a second cooling channel 184, and a conduit portion 189 that defines the second cooling channel 184 together with the flat plate portion 181. The bottom of the conduit portion 189 may be fixed in the recess 172, for example, by brazing.

[0098] In the embodiment shown in Figure 9, the flat plate portion 181 and the conduit portion 189 are shown to both define the second cooling channel 184. However, in other embodiments, the conduit portion alone may define the second cooling channel 184, and the conduit portion may simply be attached to the flat plate portion 181. In either case, the bottom surface of the conduit portion 189 is further interposed between the second cooling channel 184 and the bottom surface of the upper recess 172, so the heat transfer efficiency may be slightly lower compared to the embodiment shown in Figure 8. However, since the second cooling channel 184 is defined by a single structure, concerns about leakage of the cooling fluid may be reduced.

[0099] In some embodiments, the cooling device 180 may further include a wing portion 188 that extends from the flat plate portion 181 and contacts the upper case 170. The wing portion 188 can rapidly diffuse the heat transferred from the flat plate portion 181 horizontally (i.e., in a first and / or second direction) and discharge it to the outside, thereby contributing to the smooth cooling of the battery cell 120.

[0100] As described above, embodiments of the present invention have been described in detail, but a person with ordinary skill in the art to which the present invention pertains can modify and implement the present invention in various ways without departing from the spirit and scope of the invention as defined in the appended claims. Accordingly, any future modifications of embodiments of the present invention will not depart from the art of the present invention. [Explanation of symbols]

[0101] 20 External conduits 100 Battery Packs 101 pack main unit 101c Pack Case 110 Lower case 110C Corner 110P Plate Section 110S side wall 111 First side wall 112 Second side wall 113 Third side wall 114 Fourth side wall 115 First cooling channel 119 Interior space 120 battery cells 121 First Cell Lead 122 Cell Lead No. 2 130 Center Beam 140 Venting device 151 First Embedding Guide 153 Second Embedding Guide 160 Pack Gaskets 170 Top Case 172 recess 174 Venting channel section 174c Venting channel 180 Cooling device 181 Flat plate part 182 Entrance Port 183 Exit Port 184 Second cooling channel 187 Fixed part 188 Wings 189 Conduit section

Claims

1. In a vertical coordinate system defined as a first direction, a second direction, and a third direction that are perpendicular to each other, The pack itself, A cooling device provided on the outside of the pack body, A battery pack including, The pack body comprises a plurality of battery cells stacked in the first direction, A lower case configured to house the plurality of battery cells and including a first cooling channel for cooling the plurality of battery cells, Includes an upper case that defines an internal space in which the plurality of battery cells are housed together with the lower case, The cooling device includes a second cooling channel provided on the upper case and in contact with the upper case to cool the plurality of battery cells. The upper case has two or more recesses for housing the cooling device, A battery pack comprising a venting channel provided between the recesses and configured to discharge gas generated from the plurality of battery cells.

2. The second cooling channel extends in the first direction, The battery pack according to claim 1, wherein the recess is arranged to overlap with the cell leads of the plurality of battery cells stacked in the first direction.

3. Each of the plurality of battery cells includes a first cell lead and a second cell lead positioned at both ends in the second direction, One of the two or more recesses is arranged to overlap the first cell lead arranged in the first direction with the third direction, The battery pack according to claim 2, wherein one of the two or more recesses is arranged to overlap in the third direction with the second cell leads arranged in the first direction.

4. The battery pack according to claim 3, wherein the venting channel is configured to extend in the first direction between the first cell lead and the second cell lead, which are respectively arranged in the first direction.

5. The battery pack according to claim 4, configured such that the flow direction of the cooling fluid passing through the second cooling channel and the flow direction of the gas flowing through the venting channel are opposite to each other.

6. The battery pack according to any one of claims 1 to 5, wherein the upper case is made of aluminum or an aluminum alloy, and the surface facing the plurality of battery cells is treated with a fire-resistant surface treatment.

7. An inlet port is provided at the inlet of the second cooling channel, An outlet port is provided at the outlet of the second cooling channel. The battery pack according to any one of claims 1 to 5, wherein the inlet port and the outlet port are configured to extend away from the pack body and be connected to an external conduit.

8. The battery pack according to any one of claims 1 to 5, wherein the venting channel is defined by a venting channel formed between the two or more recesses and is configured to communicate fluidly with a venting device provided in the lower case.

9. The battery pack according to claim 8, wherein the thickness of the upper case in the third direction at the recess, the thickness of the upper case in the third direction at the venting channel, and the thickness of the upper case between the recess and the venting channel are substantially the same.

10. The battery pack according to claim 8, wherein the upper case has a substantially constant thickness over its entire surface area.

11. The battery pack according to any one of claims 1 to 5, wherein the cooling device is coupled to the upper case by brazing.

12. In a vertical coordinate system defined as a first direction, a second direction, and a third direction that are perpendicular to each other, A plurality of battery cells stacked in the first direction, A lower case configured to house the plurality of battery cells and including a first cooling channel for cooling the plurality of battery cells, An upper case that defines the internal space in which the plurality of battery cells are housed together with the lower case, A battery pack including, A battery pack comprising an upper case having a constant thickness and an uneven shape, a venting channel configured to discharge gas generated from the plurality of battery cells on one surface of the upper case, and a plurality of recesses on the other surface of the upper case.

13. The battery pack according to claim 12, further comprising a cooling device housed in the plurality of recesses and having cooling channels for cooling the plurality of battery cells.

14. The battery pack according to claim 12 or 13, further comprising an additional cooling channel within the lower case for cooling the plurality of battery cells.

15. The battery pack according to claim 12 or 13, wherein the venting channel portion defining the venting flow path and the recess have complementary shapes.

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