Cooling component, battery module and battery pack including the same

Abstract

To provide a cooling member, a battery module and a battery pack that include the same, the cooling member preventing a cascading thermal runway.SOLUTION: A cooling member located in an upper part of a battery cell stack in which multiple battery cells are stacked includes an upper plate, a lower plate, and cooling water incorporated in an inner space between the upper plate and the lower plate. The lower plate includes a first part in which a fragile part is formed, and a second part in which the fragile part is not formed. A thickness of the first part is smaller than a thickness of the second part.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] [Cross - reference to related applications] This application claims the benefit of priority based on Korean Patent Application No. 10 - 2021 - 0096683 filed on July 22, 2021 and Korean Patent Application No. 10 - 2021 - 0165252 filed on November 26, 2021, and all the contents disclosed in the documents of the Korean patent applications are included as part of this specification.

[0002] The present invention relates to a cooling member, a battery module including the same, and a battery pack, and more specifically, to a cooling member, a battery module including the same, and a battery pack for preventing a chain thermal runaway phenomenon.

Background Art

[0003] In modern society, with the daily use of portable devices such as mobile phones, notebook computers, camcorders, and digital cameras, the development of technologies in fields related to such mobile devices has become active. In addition, rechargeable secondary batteries are used as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), plug - in hybrid electric vehicles (P - HEVs), etc. as a solution to problems such as air pollution in existing gasoline vehicles using fossil fuels. Therefore, the need for the development of secondary batteries is increasing.

[0004] Currently commercialized secondary batteries include nickel - cadmium batteries, nickel - metal hydride batteries, nickel - zinc batteries, lithium secondary batteries, etc. Among them, lithium secondary batteries are the most widely noted because of their advantages of free charge - discharge, very low self - discharge rate, and high energy density.

[0005] On the other hand, while secondary batteries used in small devices typically consist of two to three battery cells, secondary batteries used in medium- and large-sized devices such as automobiles utilize medium- and large-sized battery modules (Battery modules) in which multiple battery cells are electrically connected. Since medium- and large-sized battery modules are preferably manufactured to be as small and light as possible, prismatic batteries and pouch-type batteries, which can be stacked to a high degree of integration and have a small weight relative to their capacity, are mainly used as battery cells in medium- and large-sized battery modules. On the other hand, battery cells mounted in battery modules can generate a large amount of heat during the charging and discharging process. If their temperature rises above the appropriate temperature due to overcharging or other reasons, their performance may deteriorate, and if the temperature rise is excessive, there is a risk of explosion or fire. If a fire occurs inside a battery module, high-temperature heat, gas, or flames may be released to the outside of the battery module. At this time, the heat, gas, sparks, or flames released from one battery module may be transmitted to other battery modules located at a narrow distance within the battery pack, which can cause a continuous thermal runaway phenomenon within the battery pack.

[0006] To prevent such thermal runaway phenomena, conventional battery modules have sometimes been equipped with a water injection system that injects cooling water through nozzles or other means to suppress fires when a fire is detected inside the battery module. However, injecting cooling water from a tank located outside the battery module or battery pack involves multiple steps, such as confirming the presence or absence of a fire, deciding whether or not to inject cooling water, and transferring the cooling water, making it difficult to time the suppression of the fire appropriately.

[0007] Therefore, there is a need for new technology that can quickly suppress thermal runaway phenomena by injecting cooling water in the right place at the right time when an internal fire occurs in a battery module or battery pack. [Overview of the project] [Problems that the invention aims to solve]

[0008] The problem that the present invention aims to solve is to provide a cooling member that can supply cooling water in a timely and appropriate place when an internal fire occurs in a battery module or battery pack, and a battery module and battery pack including the same.

[0009] However, the problems that the embodiments of the present invention aim to solve are not limited to those described above, and can be broadly expanded within the scope of the technical ideas included in the present invention. [Means for solving the problem]

[0010] A cooling member located on top of a battery cell stack in which a plurality of battery cells are stacked, according to one embodiment of the present invention, includes an upper plate, a lower plate, and cooling water contained in the internal space between the upper plate and the lower plate, wherein the lower plate includes a first portion in which a weak portion is formed and a second portion in which the weak portion is not formed, and the thickness of the first portion is smaller than the thickness of the second portion.

[0011] The weak portion has a long side and a short side, and the long side can extend along the stacking direction of the battery cells.

[0012] The thickness of the first portion may be less than or equal to half the thickness of the second portion.

[0013] The thickness of the first portion may be 0.03 to 0.07 mm.

[0014] The weak portion includes a first weak portion and a second weak portion separated from the first weak portion, and the thickness of the first weak portion and the thickness of the second weak portion may be substantially the same.

[0015] The lower plate is formed by joining a first layer and a second layer having different thicknesses, such that the thickness of the first portion corresponds to the thickness of the first layer, and the thickness of the second portion corresponds to the thicknesses of the first and second layers.

[0016] One of the first layer and the second layer can include a clad metal.

[0017] At least one of the upper plate, the first layer and the second layer can include a clad metal.

[0018] The first layer and the second layer can be joined through a brazing process.

[0019] The upper plate, the first layer and the second layer can be joined through a brazing process.

[0020] The upper plate includes a bent portion, the peak of the bent portion can correspond to the first part, and the valley of the bent portion can correspond to the second part.

[0021] A battery module according to another embodiment of the present invention includes the aforementioned cooling member.

[0022] The upper plate of the cooling member can be integrated with the upper surface of a module frame that forms the outer shape of the battery module.

[0023] A cooling member according to another embodiment of the present invention is located above a battery cell stack in which a plurality of battery cells are stacked, and includes a lower plate in which a plurality of openings are formed, a main body that provides a flow path for cooling water, and a fixing member that fixes the lower plate and the main body. At least one cooling hose is attached to the main body, and the cooling hose is melted or broken at a predetermined temperature or pressure or higher.

[0024] The cooling hose can be positioned to correspond to the openings of the lower plate.

[0025] The cooling hose can have a shape that extends along the length direction of the cooling member.

[0026] The cooling hose can be manufactured from a material having a melting point of 300°C or lower.

[0027] The main body may be provided with a housing portion for housing the cooling hose.

[0028] Both ends in the length direction of the cooling hose may be respectively connected to both ends in the length direction of the housing portion.

[0029] A bank extending in the length direction of the cooling member is formed at the center of the lower plate, and the main body may be mounted at a position where the bank is not formed on the lower plate.

[0030] The fixing member may be provided in the form of a strap and may be positioned parallel to the width direction of the cooling member.

[0031] The fixing member may include an end coupling portion that couples to both ends in the width direction of the lower plate, and a central coupling portion that couples to the center in the width direction of the lower plate. <G

[0032] The end coupling portion and the central coupling portion may be formed so as to have a step with other portions of the fixing member.

[0033] The cooling member may further include an inlet port and an outlet port for injecting cooling water into the internal space, the inlet port and the outlet port are connected to an external heat exchanger, and the cooling water of the cooling member can circulate through the inlet port and the outlet port.

[0034] The main body may have a branched shape at portions corresponding to the inlet port and the outlet port respectively.

[0035] A battery pack according to another embodiment of the present invention may include the aforementioned cooling member.

[0036] The battery pack may include a battery module having an open structure.

[0037] <G The upper plate of the cooling member can be integrated with the upper surface of the pack frame that forms the outer shape of the battery pack. [Effects of the Invention]

[0038] According to the embodiment, when an internal fire occurs in the battery module or battery pack, the cooling member can open a portion of it and inject cooling water in the appropriate place at the appropriate time, thereby quickly suppressing the internal fire in the battery module or battery pack and preventing a continuous thermal runaway phenomenon.

[0039] The effects of the present invention are not limited to those mentioned above, and any other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims. [Brief explanation of the drawing]

[0040] [Figure 1] This is a perspective view showing a cooling component according to one embodiment of the present invention. [Figure 2] This is a diagram showing the upper plate included in the cooling component shown in Figure 1. [Figure 3] This is a diagram showing the lower plate included in the cooling component of Figure 1. [Figure 4] This drawing shows a modified example of the lower plate included in the cooling member shown in Figure 1. [Figure 5] This is a diagram showing an example of the AA cross-section in Figure 3. [Figure 6] This drawing shows an example of a cooling member according to one embodiment of the present invention, provided for a battery cell stack. [Figure 7] This is an enlarged view of area B in Figure 6, illustrating the changes in the lower plate during battery cell ignition. [Figure 8] This is a cross-sectional view showing an example of a cooling member according to one embodiment of the present invention. [Figure 9] This drawing shows another example of the AA cross-section in Figure 3. [Figure 10] This drawing shows another example of a cooling member according to one embodiment of the present invention, provided for a battery cell stack. [Figure 11]This is an enlarged view of region C in Figure 10, illustrating the changes in the lower plate during battery cell ignition. [Figure 12] This is a cross-sectional view showing another example of a cooling member according to one embodiment of the present invention. [Figure 13] This is a cross-sectional view showing a cooling member according to another embodiment of the present invention. [Figure 14] This is an exploded perspective view showing a battery pack according to an embodiment of the present invention. [Figure 15] Figure 14 is a perspective view of the battery module included in the battery pack. [Figure 16] This is a perspective view showing a cooling member according to another embodiment of the present invention. [Figure 17] Figure 16 is a top view showing the cooling element. [Figure 18] Figure 16 is a top view of the lower plate included in the cooling member. [Figure 19] Figure 16 is a top view of the main body included in the cooling component. [Figure 20] Figure 16 is a diagram showing the connection between the lower plate, the main body, and the cooling hose included in the cooling component. [Figure 21] Figure 17 shows the cooling component cut along line AA, illustrating the flow of cooling water into and out of the main body and cooling hose. [Figure 22] Figure 17 shows a cross-section of the cooling component, illustrating the injection of cooling water through the cooling hose when the battery cell ignites. [Modes for carrying out the invention]

[0041] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings, so that they can be easily implemented by a person with ordinary skill in the art to which the present invention pertains. The present invention can be realized in a variety of other forms besides those described below, and the scope of the present invention is not limited to the embodiments described herein.

[0042] To clearly explain the present invention, unnecessary explanatory parts have been omitted, and the same or similar reference numerals have been used throughout the specification for identical or similar components.

[0043] Furthermore, the dimensions and thicknesses of each component shown in the drawings have been arbitrarily enlarged or reduced for the sake of explanation, and it is obvious that the content of the present invention is not limited to what is shown in the drawings. In the following drawings, the thickness of each layer is shown enlarged in order to clearly represent multiple layers and regions. And in the following drawings, the thickness of some layers and regions is shown in an exaggerated manner for the sake of explanation.

[0044] Furthermore, when describing a layer, membrane, region, or plate as being "above" another part, this must be interpreted to include not only cases where the layer, membrane, region, or plate is "directly above" the other part, but also cases where there is another part in between. Conversely, when describing a layer, membrane, region, or plate as being "directly above" another part, it may mean that there is no other part in between. Also, being "above" a reference part means being located above or below the reference part, and does not necessarily mean being located "up" in the opposite direction of gravity. On the other hand, just as descriptions of being "above" another part can be understood by referring to the above points, descriptions of being "below" another part can also be understood by referring to the above points.

[0045] Furthermore, since the upper / lower surfaces of a particular component may be determined differently depending on which direction is used as the reference, throughout this specification, "upper surface" or "lower surface" is defined as meaning two surfaces facing each other on the z-axis of the component in question.

[0046] Furthermore, when a specification states that a certain part "includes" a certain component, unless otherwise stated, this means that other components are not excluded and that other components may be included.

[0047] Furthermore, throughout the specification, "on a plane" refers to the view of the subject from above, and "on a cross-section" refers to the view of a cross-section obtained by cutting the subject perpendicularly, viewed from the side.

[0048] The following describes a cooling component according to one embodiment of the present invention.

[0049] Figure 1 is a perspective view showing a cooling member according to one embodiment of the present invention. Figure 2 is a drawing showing the upper plate included in the cooling member of Figure 1. Figure 3 is a drawing showing the lower plate included in the cooling member of Figure 1. Figure 4 is a drawing showing a modified example of the lower plate included in the cooling member of Figure 1.

[0050] Referring to Figure 1, the cooling member 500 of this embodiment may be provided to lower the internal temperature of a battery module or battery pack, including battery cells. The cooling member 500 may be a water-cooled cooling member 500 into which a refrigerant or cooling water is injected. By providing the cooling member 500 in a water-cooled manner, the cooling efficiency of the cooling member 500 can be maintained uniformly, and the battery cells in the battery module or battery pack can be cooled uniformly.

[0051] The cooling water used in the cooling member 500 can be one of the known types or a mixture thereof, and any known type can be used as long as it can dissipate the heat of the battery cells by moving along the flow path inside the cooling member 500. However, as will be described later, since the cooling water of the cooling member 500 can be sprayed toward the battery cells, it is preferable that the cooling water does not contain flammable substances so as not to amplify the flame or explosion of the battery cells. Alternatively, even if some flammable additives must be included to improve the function of the cooling water, the amount of additive may be such that it can prevent secondary explosions toward the pouch-type battery cells and also be used as an antifreeze to prevent the cooling water from freezing. More specifically, the cooling water may include water. Here, in addition to water, the cooling water may also include an antifreeze to lower the freezing point of the water. Furthermore, the antifreeze included in the cooling water may be an electrically insulating antifreeze having electrical insulating properties.

[0052] The cooling member 500 may be positioned on one surface of the battery cell stack to dissipate heat from the battery cells. The cooling member 500 may be positioned parallel to the stacking direction of the battery cell stack so as to be close to multiple battery cells in the battery cell stack. Specifically, the cooling member 500 may be located on top of the battery cell stack (in the +z axis direction in Figure 14).

[0053] The size of the cooling member 500 can be adjusted to match the size of the battery cell stack to which the cooling member 500 is applied. For example, the cooling member 500 may be provided to correspond to one battery cell stack, in which case the length of the cooling member 500 may be adjusted to match the length of the battery cell stack or to be larger or smaller with a small margin, and the width of the cooling member 500 may be adjusted to match the width of the battery cell stack or to be larger or smaller with a small margin. As another example, the cooling member 500 may be provided to correspond to multiple battery cell stacks, in which case the length and width of the cooling member 500 may be adjusted to match the length and width of the multiple battery cell stacks or to be larger or smaller with a small margin. Here, the cooling member 500 can be located inside the battery module, but it can also be located outside the battery module, inside the battery pack 1000 (see Figure 14).

[0054] The cooling member 500 may include an upper plate 510 and a lower plate 520 that form the outer shape of the cooling member 500, and an inlet / outlet port 530 for injecting cooling water into the interior of the cooling member 500.

[0055] The cooling member 500 can be formed by joining the peripheries of the upper plate 510 and the lower plate 520. A sealed portion 540, formed by joining the peripheries of the upper plate 510 and the lower plate 520, can be located at the periphery of the cooling member 500. Cooling water can be contained within or circulated between the upper plate 510 and the lower plate 520 joined by the cooling member 500.

[0056] Cooling water can be supplied through adjacent inlet ports 530 and discharged from outlet ports 530. The inlet ports 530 and outlet ports 530 can be positioned parallel to one end of the cooling member 500. This may simplify the design regarding the inflow and outflow of cooling water supplied from outside the battery module or battery pack. It may also minimize the temperature difference between the area around the inlet ports 530 and the area around the outlet ports 530. Specifically, the cooling water flowing into the inlet ports 530 can have the lowest temperature, and the cooling water discharged from the outlet ports 530 can have the highest temperature. Therefore, when the inlet / outlet ports 530 are arranged adjacent to each other, heat exchange between them can minimize the temperature deviation of the overall cooling water flowing through the internal space of the cooling member. Thus, by arranging the inlet / outlet ports 530 side by side, the cooling member 500 can have a uniform heat dissipation performance overall. The inlet ports 530 or outlet ports 530 may also be made of aluminum. The inlet port 530 or outlet port 530 may be joined to the upper plate 510 or lower plate 520 by welding, such as brazing.

[0057] A flow path forming groove 550 may be formed in the cooling member 500. By providing the cooling member 500 with a flow path forming groove 550, the flow of cooling water supplied to the cooling member 500 can be determined. Multiple flow path forming grooves 550 may be formed, and the multiple flow path forming grooves 550 may be located along a straight line parallel to the longitudinal direction of the cooling member 500. The flow path forming groove 550 may be formed continuously along the longitudinal direction of the cooling member 500 in the center of the cooling member 500, except for a predetermined section, so that the flow of cooling water can be formed in a U shape. The flow of cooling water injected through the inlet port 530 of the cooling member 500 can be restricted by the flow path forming groove 550. As the cooling water flows along a U shape, the cooling water injected through the inlet port 530 can be discharged from an outlet port 530 located adjacent to the inlet port 530. Specifically, the U-shaped flow path through which the cooling water flows may include a first flow path extending from the inlet port 530 along a straight line parallel to the longitudinal direction of the cooling member 500, a second flow path extending from the end of the first flow path along a curve that rotates clockwise or counterclockwise, and a third flow path extending from the end of the second flow path toward the outlet port 530 along a straight line parallel to the longitudinal direction of the cooling member 500.

[0058] Deformation prevention grooves 560 may be formed in the cooling member 500. By providing the cooling member 500 with deformation prevention grooves 560, deformation of the shape of the cooling member 500 due to cooling water can be prevented. For example, when cooling water is injected into the cooling member 500, the injected cooling water can be concentrated in half the space of the cooling member 500 by a flow channel forming groove 550 that crosses the center. Before the cooling water moves to the remaining half space through the U-shaped flow channel, a large pressure may act on this space, which may cause at least a part of the cooling member 500 to expand or the cooling member 500 to break. When deformation prevention grooves 560 are formed in the flow channel of the cooling member 500, deformation can be minimized even if a large pressure acts on a specific section due to the temporary concentration of cooling water. The deformation prevention grooves 560 may be partially and spaced apart in the U-shaped flow channel through which the cooling water flows in the cooling member 500. The deformation prevention groove 560 can be located between the flow path forming groove 550 and the sealing portion 540 in the width direction of the cooling member 500. The specific position of the deformation prevention groove 560 can be appropriately set so as not to excessively obstruct the cooling water flowing in through the inlet port 530, while still being able to accommodate the flow rate and velocity of the cooling water. Here, the width direction of the cooling member 500 may be parallel to the short side of the cooling member 500. Also, here, the length direction of the cooling member 500 may be parallel to the long side of the cooling member 500.

[0059] Furthermore, protrusions may be formed around the cooling member 500, extending from one side of the cooling member 500 and continuously positioned along the length of the cooling member 500. As illustrated in Figure 14, which will be described later, the protrusions may be positioned in contact with or close to the electrode leads or busbars connected to the electrode leads of each battery cell stack. Since the electrode leads or busbars that provide electrical connections in a battery module or battery pack are prone to generating heat, the aforementioned protrusions can more effectively prevent temperature rise in the battery cells by promoting heat dissipation from the electrode leads or busbars.

[0060] Referring to Figure 2, the upper plate 510 may be provided in a plate shape. The central portion of the upper plate 510 may be recessed or indented to have a step with the peripheral portion. The upper plate 510 may have a recessed shape with respect to its widthwise cross-section. This may be so that the upper plate 510 forms an internal space through the step to accommodate cooling water. Here, the widthwise direction of the upper plate 510 may be parallel to the short side of the upper plate 510. However, the upper plate 510 may also be formed differently from that shown in Figure 2, and if the lower plate 520 includes a weak portion 522, etc., to provide a space for storing cooling water, the upper plate 510 may be provided to have an overall flat shape.

[0061] Referring to Figure 3, the lower plate 520 of the cooling member 500 can have a shape that is generally similar to that of the upper plate 510. The lower plate 520 may be provided in a plate shape. The lower plate 520 may be formed so that its central portion is recessed or indented, creating a step between the central portion and the peripheral portion. The lower plate 520 can form an internal space for containing cooling water by having a recessed shape based on the cross-section in the width direction. However, the lower plate 520 does not necessarily have to be provided in an indented shape; it can also be provided in an overall flat shape depending on the shape of the upper plate 510 or the volume of cooling water contained within. Here, the width direction of the lower plate 520 may be parallel to the short side of the lower plate 520.

[0062] Furthermore, the lower plate 520 may have a weak portion 522, which will be described later, and for that reason, one surface of the lower plate 520 may have a partially recessed groove. If the groove is located toward the inside of the cooling member 500, that is, if it is formed on the upper surface of the lower plate 520, cooling water can be contained in the groove.

[0063] When the cooling member 500 is provided on top of the battery cell, the lower plate 520 may be the part of the cooling member 500 that is closest to the battery cell. Therefore, it is preferable that the lower plate 520 be made of a material with high thermal conductivity so as to promote heat dissipation from the battery cell. In addition, to improve the overall heat dissipation performance of the cooling member 500, the upper plate 510 of the cooling member 500 may also be made of a material with high thermal conductivity. The upper plate 510 and lower plate 520 that form the outer shape of the cooling member 500 may be made of a highly rigid metal, specific examples of which include aluminum, gold, silver, copper, platinum, or alloys containing these.

[0064] On the other hand, as mentioned above, if a battery cell ignites, it is effective to inject a liquid such as cooling water into the battery module or battery pack to effectively suppress the fire. Since equipping the battery module or battery pack with a liquid tank inside could increase its volume, conventionally, a separate water tank was provided outside the battery module and battery pack, and cooling water or other liquids were injected into the battery module or battery pack only when a fire in a battery cell was detected via a sensor, through a nozzle extended from the water tank.

[0065] However, water tanks located outside battery modules and battery packs have the problem of not only being large in volume but also requiring separate management by the user. Furthermore, conventional water injection systems require a separate control unit or communication unit to determine whether or not to inject cooling water, and errors in these operations are unacceptable. Even when operating normally, multiple decision-making processes are required, resulting in a long processing time. Even after the decision to inject cooling water has been made, if the path from the water tank to the battery cells inside the battery module or battery pack is somewhat long, it is difficult to quickly supply cooling water from the water tank to the battery cells. As a result, conventional water injection systems have difficulty stopping rapidly progressing, continuous thermal runaway phenomena.

[0066] Therefore, the lower plate 520 of the cooling member 500 of this embodiment, which has a portion vulnerable to heat or temperature and can be partially opened in the event of a battery cell fire, will be described in more detail below.

[0067] Referring to Figures 3 and 4, the lower plate 520 of this embodiment may include a weak portion 522. A "weak portion" may refer to a portion of the lower plate 520 that is more easily fractured by heat or pressure than other portions. The weak portion 522 may be a portion that is relatively thinner than other portions of the lower plate 520. Specifically, the lower plate 520 may have a first portion called the weak portion 522 and a second portion in which the weak portion 522 is not formed, where the thickness of the second portion may be greater than the thickness of the first portion. The thickness of the first portion may be half or less of the thickness of the second portion. By having a slightly smaller thickness than other portions, the weak portion 522 can be relatively easily broken by heat or pressure.

[0068] The vulnerable portion 522 may be formed to extend along the stacking direction of the battery cells. The length direction (y-axis) of the vulnerable portion 522 is the direction in which the length (long side) extends, and may be parallel to the stacking direction of the battery cells 110. The width direction (x-axis) of the vulnerable portion 522 may be perpendicular to the stacking direction of the battery cells 110. Since it is impossible to predict which of the battery cells 110 will ignite, it is preferable that the vulnerable portion 522 be formed to correspond to all battery cells located below the cooling member 500. The vulnerable portion 522 may be formed over the entire length of the cooling member 500. Here, one vulnerable portion 522 may be provided on a straight line parallel to the stacking direction of the battery cells, as shown in Figure 3, or two or more may be provided along a straight line parallel to the stacking direction of the battery cells, as shown in Figure 4.

[0069] The vulnerable sections 522 can be located consecutively along the width direction (x-axis). Here, the width of each vulnerable section 522 can be designed to differ according to the designer's intentions. For example, a vulnerable section 522 can have a wide width. As another example, a vulnerable section 522 can have a relatively narrow width. Narrow vulnerable sections 522 can be formed continuously.

[0070] The vulnerable portion 522 can be positioned to correspond to the most heat-generating part of the battery cell. For example, the electrode leads of a battery cell may be a part where electron movement is concentrated and easily generates heat. To respond to overheating of the electrode leads or the resulting explosion, the vulnerable portion 522 may be positioned above the electrode leads of the battery cell.

[0071] Figure 5 is a diagram showing an example of the AA cross-section in Figure 3.

[0072] Referring to Figure 5, the cross-section of the weak portion 522 can have a variety of shapes. Here, the cross-section of the weak portion 522 may be obtained by cutting the cooling member 500 with respect to the xz plane, as shown in Figure 3.

[0073] The weak portion 522 is a part of the lower plate 520 with a different thickness. A part of the lower plate 520 can have a rectangular cross-sectional shape as shown in Figure 5(a) because the first part where the weak portion 522 is formed and the second part where the weak portion 522 is not formed are connected perpendicularly to each other. Furthermore, if an incline is formed on the connecting surface between the first and second parts, a part of the lower plate 520 can have a triangular cross-sectional shape as shown in Figure 5(b) or a trapezoidal cross-sectional shape as shown in Figure 5(d). If the connecting surface between the first and second parts is formed to have curvature, a part of the lower plate 520 can also have a rounded cross-section as shown in Figure 5(c). On the other hand, the cross-sectional shape of the lower plate 520 due to the formation of the weak portion 522 is not limited by the examples given above and can be varied in various ways considering ease of design, etc. Considering that the weak portion 522 should be fractured by heat or temperature, it is preferable that the weak portion 522 includes as many thin parts as possible, so other shapes in Figure 5 are preferable to the shape in Figure 5(b). However, the temperature and pressure at which fracture occurs can be influenced by factors such as thickness, material properties, and shape, and the shape in Figure 5(b) is not necessarily preferable to the other shapes in Figure 5.

[0074] Figure 6 is a diagram showing an example of a cooling member according to one embodiment of the present invention provided to a battery cell stack. Figure 7 is an enlarged view of area B in Figure 6, and is a diagram for explaining the changes in the lower plate when the battery cell ignites. Figure 8 is a cross-sectional view showing an example of a cooling member according to one embodiment of the present invention. On the other hand, it should be noted in advance that the upper plate 510 is omitted in Figure 8.

[0075] Referring to Figures 6 and 7, a battery cell stack 120 in which battery cells 110 are stacked in one direction is housed inside a module frame or pack frame, and the cooling member 500 can be placed on top of the battery cell stack 120.

[0076] The cooling member 500 includes an upper plate 510 and a lower plate 520, and cooling water can be contained in the space between the upper plate 510 and the lower plate 520. The lower plate 520 of the cooling member 500 is positioned toward the battery cell stack 120, and the weak portion 522 formed on the lower plate 520 may be formed to be elongated along the stacking direction of the battery cells 110 so that it can correspond to the battery cells 110 of the battery cell stack 120. Figures 6 and 7 show a cross-section of the location where the weak portion 522 is formed, and the upper surface of the lower plate 520 where the weak portion 522 is not formed may be hidden by the cooling water and not visible. Therefore, the upper surface of the second portion of the lower plate 520 is shown by a dotted line in Figures 6 and 7.

[0077] If a fire occurs in the first battery cell 110a due to overcharging or other reasons, the heat, gas, sparks, and flames generated from the first battery cell 110a may cause the first portion of the vulnerable part 522 located at the top of the first battery cell 110a to rupture. With the first portion opened, the cooling water contained in the internal space of the cooling member 500 can be injected into the first battery cell 110a where the fire has occurred. In this way, when a thermal runaway phenomenon occurs in the first battery cell 110a, the vulnerable part 522 opens a portion of itself, immediately injecting cooling water into the first battery cell 110a. Compared to conventional water injection systems, this allows for rapid suppression of the fire in the first battery cell 110a and enables early suppression of the thermal runaway phenomenon.

[0078] At this time, as shown on the right side of Figure 7, the heat or pressure generated from the battery cell 110 locally heats or pressurizes the vulnerable portion 522, causing the first portion to open. Therefore, only the first portion of the vulnerable portion 522 is open, while the other portions of the vulnerable portion 522 remain closed. When the vulnerable portion 522 remains closed except for the first portion, the cooling water inside the cooling member 500 can concentrate and flow out to the first portion. Therefore, compared to conventional water injection systems, the cooling water is concentrated in the first battery cell 110a, maximizing the efficiency of water injection fire suppression.

[0079] On the other hand, if an excessive amount of cooling water is injected into a battery module or battery pack, fire suppression in the first battery cell 110a can be achieved quickly, but the injection of cooling water into other battery cells 110 may damage several normally functioning battery cells 110. Therefore, the amount of cooling water injected must be pre-designed to an appropriate level.

[0080] The amount of cooling water can be preset to a level sufficient to suppress fires occurring in several battery cells 110. Here, the number of battery cells 110 on which the amount of cooling water is calculated is the number of battery cells 110 to which thermal runaway is normally transmitted during internal ignition, and can be specifically 4 to 6, or one to two fewer or larger numbers. Furthermore, since the cooling water sprayed toward the first battery cell 110a vaporizes into water vapor and evaporates during the fire suppression process, the cooling water can not remain in the battery module or battery pack, preventing damage to normal battery cells 110 due to residual moisture. On the other hand, since the amount of cooling water contained in the cooling member 500 can be pre-calculated and designed to match the energy released by the battery cells 110, the cooling member 500 of this embodiment can be applied in a variety of ways, regardless of the type or capacity of the battery cells 110, such as cylindrical, rectangular, or pouch type.

[0081] In this case, the cooling water for the cooling element 500 may or may not be circulated by being drawn in from the outside. To give a specific example, the cooling element 500 may be connected to an external tank, and the cooling water drawn in from the tank may circulate within the cooling element 500 through the inlet / outlet port 530 and be discharged back into the tank. This allows the temperature of the cooling water to be properly maintained, thereby improving the heat dissipation performance of the cooling element 500.

[0082] As another specific example, the cooling water inside the cooling element 500 may not be additionally inflowed. The cooling water may be injected before the cooling element 500 is installed in the battery module or battery pack, and may not be additionally injected or discharged during use of the battery module or battery pack. If the cooling element 500 is not continuously connected to an external tank and is built into the battery pack or battery module, the overall structure can be simplified by omitting the external tank, resulting in efficient use of space and potentially saving the cost and time of maintaining / managing the external tank. In such cases, the inlet / outlet ports 530 may also be excluded from the cooling element 500 for design simplification. Since the cooling element 500 contains water with a high specific heat, heat transfer between battery cells 110 within the battery module can be effectively prevented even without circulation. Furthermore, if an internal fire occurs in the battery module or battery pack, only a predetermined amount of cooling water can be ejected to the battery cells 110, thus minimizing problems caused by cooling water remaining in the battery module or battery pack.

[0083] Thus, if the cooling water of the cooling member 500 does not flow into an external tank, the amount of cooling water introduced into the battery module or battery pack when the first battery cell 110a ignites internally may be limited to the total amount of cooling water contained within the cooling member 500. Furthermore, if the cooling member 500 has internal partitions or grooves that restrict the movement of cooling water inside the cooling member 500, the amount of cooling water introduced into the first battery cell 110a may be limited to the amount of cooling water contained between the vulnerable part 522 and the upper plate 510.

[0084] Furthermore, this is also true even if the cooling element 500 has a system connected to an external tank. Specifically, the control system including the cooling element 500 can sense a thermal transition or thermal runaway phenomenon, and if a thermal runaway phenomenon is detected, it can limit the amount of cooling water supplied to the first battery cell 110a to within the volume range of the cooling element 500 by controlling the inflow or circulation of additional cooling water.

[0085] In this embodiment, the vulnerable part 522 allows for the rapid suppression of a fire and prevention of continuous thermal runaway by injecting cooling water into the battery pack or battery module at the appropriate time and location in the event of internal ignition.

[0086] The vulnerable portion 522 in this embodiment can be formed in a variety of ways.

[0087] For example, the weak portion 522 can be formed by partially etching the lower plate 520. The weak portion 522 can also be formed using a notching process. However, the equipment used in the etching process can be difficult to control to a precise level, and the dimensional stability of the weak portion 522 may be significantly reduced if the thickness of the lower plate 520 is thin, or if the desired thickness of the weak portion 522 is thin. For example, if the lower plate 520 is made of aluminum, it can have a thin thickness of 4 mm, 3 mm, or 2 mm or less. The appropriate thickness of the weak portion 522 may vary depending on the material of the weak portion 522, but if the lower plate 520 is made of aluminum, it is preferable that the weak portion 522 be formed to a thickness of 0.2 to 0.5 mm. Since a thin-film thickness must be formed by removing a portion of the already sufficiently thin lower plate 520 in order for the weak portion 522 to be provided on the lower plate 520, if the equipment is not perfectly controlled, the lower plate 520 may be damaged during the process of forming the weak portion 522, which can lead to wasted process costs and time due to an increase in defective products. Therefore, if the lower plate 520 has a weak portion 522, as in this embodiment, the application of the etching process may not be desirable.

[0088] To ensure that the weak portion 522 is formed to be sufficiently thin, the lower plate 520 can be formed by joining two layers. As shown in Figure 8, the lower plate 520 can be formed by joining a first layer 524 provided as a plate-shaped member and a second layer 526 having multiple holes. For reference, the shaded area in Figure 8 represents the second layer 526, and the partially empty space between the shaded areas represents the cross-section of the holes formed in the second layer 526. The holes formed in the second layer 526 may be the parts that form the aforementioned weak portion 522. The holes can have an elongated shape. One or more holes can be formed along a straight line parallel to the long side of the lower plate 520. If multiple holes are provided along a straight line parallel to the long side of the lower plate 520, the holes may not have an elongated shape depending on their number and spacing. Also, the axial cross-section of the holes can have a variety of shapes, as shown in Figure 5. The radial cross-section of the holes can have an angular shape or a rounded shape.

[0089] A portion of the lower plate 520 can have a relatively thick thickness by including the first and second layers, while another portion of the lower plate 520 can have a relatively thin thickness by including only the first layer 524. Here, the portion having the first layer 524 can be called the first portion, and the portion having both the first layer 524 and the second layer 526 can be called the second portion. Therefore, the thickness of the first portion can correspond to the thickness of the first layer 524, and the thickness of the second portion can correspond to the thickness of both the first layer 524 and the second layer 526.

[0090] When the lower plate 520 is formed by joining two layers, the thickness of each layer can be freely adjusted, so that the weak portion 522 can be formed to be sufficiently thin. For example, if the first layer 524 and the second layer 526 are all made of aluminum, the first layer 524 may be made of an aluminum sheet having a thickness of 0.03 to 0.07 mm, or 0.04 to 0.06 mm, or 0.05 mm, and the second layer 526 may be made of an aluminum sheet having a thickness of 1.0 to 1.5 mm or more with holes formed in it. Here, if the design requires mechanical rigidity, the thickness of the first layer 524 may be designed to be sufficiently thick to the point where it will melt due to thermal runaway of the battery cell. Therefore, it may also be possible for the first layer 524 to be made to have a slightly larger value than the aforementioned thickness. When the aluminum sheet material of the second layer 526 is joined onto one surface of the first layer 524, a lower plate 520 can be formed having a weak portion 522 of sufficiently thin thickness.

[0091] Here, when the lower plate 520 is formed by joining two layers, all the weak parts 522 are formed from a single plate, and their thicknesses can be the same. When the first and second weak parts are formed in the lower plate 520, the thicknesses of the first and second weak parts can be substantially the same. Furthermore, there may be no variation in the thickness of each weak part 522 depending on its location. If a thickness variation occurs in the weak parts 522 due to location, some parts may be formed thicker than designed, and as a result, certain parts may be less likely to break due to heat or pressure. However, since all the weak parts 522 in this embodiment are formed to have a uniform thickness, the error between the design and the actual product can be minimized.

[0092] Various joining processes can be applied to the joining of the two layers that form the lower plate 520. Since cooling water is located on the upper surface of the lower plate 520, the joining of the two layers must be firmly formed.

[0093] As an example, the joint between two layers can be formed through a welding process. Examples of welding processes used for this joint include brazing or laser welding. The two layers can be fused together by applying a temperature similar to the melting point of the materials to the two layers. Through this fusion joining, the watertightness of the lower plate 520 can be achieved to the desired level.

[0094] As another example, the bond between two layers can be formed through a rolling process. A rolling process is a method of joining two layers by passing a laminate, in which two or more layers are stacked between a pair of rolls. In interlayer joining by a rolling process, the laminate is heated, and at this time, if the heating temperature is above the recrystallization temperature of the metal, it may be called hot rolling, and if it is below that temperature, it may be called cold rolling. By applying pressure and / or heat to the laminate, a wide joint surface can be formed between the two layers, thereby ensuring sufficient watertightness of the lower plate 520.

[0095] On the other hand, if the lower plate 520 is formed by joining two layers, the materials of the two layers may be different, or they may be the same or similar to each other. If the materials of the two layers are the same or similar to each other, the melting points of the two layers are the same / similar, which makes the aforementioned joining process involving heat or pressure easier to perform.

[0096] On the other hand, when joining two layers through a brazing process, the joining process may not proceed smoothly due to the physical properties or melting points of the metals. For example, if the two layers are formed of aluminum of a single property, setting the brazing temperature to 660°C, which is the melting point of aluminum, can cause deformation of the aluminum layer during the joining process. To prevent such deformation of the layers, the first layer 524 or the second layer 526 may be manufactured from a clad metal, which is a double-layered metallic material.

[0097] For example, if the layers are joined through a brazing process, the first layer 524 may be 3000 series aluminum, and the second layer 526 may be a clad metal containing 3000 series and 4000 series aluminum. By including a clad metal in the second layer 526, the brazing temperature can be set to around 600°C, thereby preventing deformation of the aluminum during the joining process.

[0098] The aforementioned joining method can also be used when joining the upper plate 510 and the lower plate 520. Therefore, if the physical properties of the upper plate 510 and the lower plate 520 are the same, the joint between the two members can be formed more precisely. For example, the upper plate 510 and the lower plate 520, or the first layer 524 and the second layer 526, may contain aluminum.

[0099] On the other hand, the above description has mainly focused on the case where the lower plate 520, which is provided with the weak portion 522, has a flat lower surface. However, the stepped portion of the lower plate 520, that is, the groove, formed by locally adjusting the thickness, may not face the inside of the cooling member 500 but may be exposed to the outside.

[0100] Figure 9 is a drawing showing another example of the AA cross section of Figure 3. Figure 10 is a drawing showing another example of a cooling member according to one embodiment of the present invention provided for a battery cell stack. Figure 11 is an enlarged view of region C in Figure 10, illustrating the changes in the lower plate when a battery cell ignites. Figure 12 is a cross-sectional view showing another example of a cooling member according to one embodiment of the present invention.

[0101] Referring to Figures 9 to 12, unlike the weak portion 522 in Figures 5 to 8 which is formed to be located close to the lower surface of the lower plate 520, the weak portion 522 can be formed to be located close to the upper surface of the lower plate 520. If the weak portion 522 is located close to the upper surface of the lower plate 520 as in Figures 9 to 12, the lower surface of the cooling member 500 can have a locally protruding shape. Therefore, the protruding lower surface of the cooling member 500 can be located close to or in contact with the battery cell, thereby promoting heat dissipation from the battery cell.

[0102] As shown in Figure 9, the cross-section of the lower plate 520 can have a rectangular, triangular, rounded, or trapezoidal shape. The cross-sectional shape in Figure 9 can be explained by referring to the contents of Figure 5, except that the vertical direction is reversed, so a detailed explanation is omitted.

[0103] Figures 10 and 11 show cross-sections of a battery cell stack when the cooling member 500 is shown on the stack, cut in the xz plane. The orientation differs from that of Figures 6 and 7, and the cross-section of the cooling member 500 is shown more specifically. While Figures 6 and 7 show the positional relationship between multiple battery cells 110 and vulnerable parts 522, Figures 10 and 11 show the positional relationship between a single battery cell 110 and a vulnerable part 522. Referring to Figures 10 and 11, one battery cell 110 can correspond to multiple vulnerable parts 522, and depending on the location where ignition occurs in the battery cell 110, the corresponding vulnerable part 522 may be opened. Therefore, when a battery cell 110 ignites, one vulnerable part 522 may be opened, or multiple vulnerable parts 522 may be opened. Here, the opening of a vulnerable part 522 includes cases where only a part of one vulnerable part is opened, and does not necessarily mean that the entire vulnerable part 522 is opened.

[0104] Figures 10 and 11 differ from Figures 6 and 7 not only in their orientation but also in the shape of the cooling member 500 having a protruding lower surface. Even with the protruding lower surface of the cooling member 500, the fact that cooling water is injected into the battery cell 110 when the vulnerable part 522 is opened during ignition of the battery cell 110 remains the same. Therefore, a detailed explanation of Figures 10 and 11 can be explained through the contents of Figures 6 and 7. Accordingly, a detailed explanation will be omitted to avoid redundancy.

[0105] On the other hand, the lower plate 520 with a protruding lower surface and the weak portion 522 formed thereon can be formed in various ways. For example, the weak portion 522 can be formed by etching the lower surface of the lower plate 520. As another example, the lower plate 520 can be formed by joining two layers.

[0106] Specifically, the lower plate 520 can be formed by joining a first layer 524, provided as a plate-shaped member, and a second layer 526 having a plurality of holes, as shown in Figure 12. In this case, the second layer 526 can form the lower surface of the lower plate 520 by being located below the first layer 524. Here, if the joining of the second layer 526 and the first layer 524 is formed in a brazing process, the first layer 524 may include 3000 series and 4000 series clad metal, and the second layer 526 may include 3000 series aluminum. In this case, the upper plate 510 may also be 3000 series aluminum, and the interlayer joining can be smoothly performed through the 4000 series aluminum formed on the upper and lower surfaces of the first layer 524, which is provided as clad metal. Alternatively, the first layer 524 may be provided as 3000 series aluminum, and the second layer 526 or the upper plate 510 may be provided as 3000 series and 4000 series clad metal.

[0107] The other methods for joining the lower plate 520, and the specific details regarding the first layer 524 and the second layer 526 can be explained by referring to the explanation in Figure 8 mentioned above, except that the positions of the layers are different, so a detailed explanation will be omitted.

[0108] The following describes a cooling member according to another embodiment of the present invention.

[0109] Figure 13 is a cross-sectional view showing a cooling member according to another embodiment of the present invention.

[0110] The cooling member 500 of the embodiment described through Figure 13 may include all of the contents of Figures 1 to 12 mentioned above, in addition to those mentioned below. Therefore, in order to minimize redundant descriptions, any content that overlaps with the previously mentioned content will be omitted.

[0111] Referring to Figure 13, the cooling member 500 of this embodiment can have three layers. Specifically, the upper plate 510 of the cooling member 500 can have one layer, and the lower plate 520 can have two layers. Here, the lower plate 520 having two layers has been sufficiently explained through the above, so a detailed explanation will be omitted.

[0112] In the cooling member 500, the cooling water is contained between the upper plate 510 and the lower plate 520, so the flow rate deviation of the cooling water can be determined by the separation distance between the upper plate 510 and the lower plate 520. In the aforementioned drawings, the upper plate 510 of the cooling member 500 is shown to have an overall flat surface except for the flow path forming groove 550 and the deformation prevention groove 560. Therefore, the flow rate deviation of the cooling member 500 may depend on the thickness difference of the lower plate 520. Specifically, the flow rate per unit length may be relatively large around the first part where the weak portion 522 is formed, and relatively small around the second part where the weak portion 522 is not formed. A larger flow rate around the first part is preferable because a larger flow rate around the first part allows the cooling water to be injected more quickly due to the flow pressure when the weak portion 522 is opened.

[0113] Therefore, this embodiment provides an upper plate 510 having a bent portion 514 so as to form a flow rate deviation of the cooling water in the cooling member 500. The bent portion 514 can have a corrugated cross-sectional shape with respect to the longitudinal cross-section of the cooling member 500. Here, with respect to the cross-section, the highest point of the bent portion 514, i.e., the crest, can correspond to the first part of the lower plate 520 in which the weak portion 522 is formed. Also, the lowest point of the bent portion 514, i.e., the trough, can correspond to the second part of the lower plate 520. By having the crest of the bent portion 514 correspond to the first part, the flow rate per unit length around the first part can be increased, and when the weak portion 522 is opened, the cooling water of the cooling member 500 can be injected more quickly toward the first battery cell 110a in which the ignition phenomenon occurred.

[0114] Figure 13 shows that the valley of the bend 514 is positioned close to the second portion of the lower plate 520. However, the valley of the bend 514 can also be positioned at a distance from the second portion of the lower plate 520 so that the cooling member 500 can hold a larger amount of cooling water. However, if the distance is excessively large, the overall volume of the cooling member 500 will increase, which may increase the size of the battery module. Therefore, the cooling member 500 must be appropriately designed taking into consideration the amount of heat generated by the battery cells 110.

[0115] Furthermore, although Figure 13 shows the layers of the cooling member 500 positioned in the order of the first layer 524, the second layer 526, and the upper plate 510, it is also possible to position them in the order of the second layer 526, the first layer 524, and the upper plate 510. If the second layer 526 is positioned below the first layer 524, the lower surface of the cooling member 500 may have a protruding shape due to the second layer 526. Since the second layer 526 forming the lower surface of the cooling member 500 can be positioned close to or in contact with the battery cells, if the layers are positioned in the order of the second layer 526, the first layer 524, and the upper plate 510, the second layer 526 may have the effect of promoting heat dissipation from the battery cells.

[0116] Furthermore, in the cooling member 500 provided as shown in Figure 13, the thickness of each layer must be appropriately designed to minimize the overall volume while maintaining a strength above a predetermined range. For example, in a cooling member 500 having three layers, the upper plate 510 is referred to as the third layer and may be made of aluminum. When the third layer is made of aluminum, the upper plate 510 is preferably formed to a thickness of 1.0 to 2.0 mm, 1.3 to 1.7 mm, or 1.5 mm. The second layer 526, which is included in the lower plate 520, is preferably formed to a thickness of 1.0 to 1.5 mm, 1.2 to 1.4 mm, or 1.3 mm. The first layer 524 must be formed thin enough to have the characteristics of a weak portion 522, and specifically can have a thickness of 0.03 to 0.07 mm, or 0.04 to 0.06 mm.

[0117] In the cooling member 500 having three layers, various processes can be applied to bond the layers together. Since cooling water is located inside the cooling member 500, the bonds between the three layers must be firmly formed.

[0118] For example, the bond between three layers can be formed through a welding process.

[0119] As another example, the bonding of the three layers can be formed through a rolling process. However, if a rolling process is applied that involves applying pressure through rollers, the formation of the upper plate 510 may be somewhat limited.

[0120] On the other hand, if the lower plate 520 is formed by bonding three layers, the materials of the three layers may be different, or they may be the same or similar to each other. Since the melting point or strength may differ depending on the material, the material must be selected according to the manufacturing method, or the manufacturing method must be selected according to the material.

[0121] For example, in a structure like that shown in Figure 13, where the layers are joined through brazing, the first layer 524 may be 3000 series aluminum, the second layer 526 may be clad metal containing 3000 series and 4000 series aluminum, and the third layer, which is the top plate 510, may be 3000 series aluminum.

[0122] As another example, in a structure like that shown in Figure 13, the positions of the first layer 524 and the second layer 526 can be interchanged. In this case, if the layers are joined through brazing, the material of the second layer 526 and the top plate 510 that are joined to the first layer 524 may be limited by the physical properties of the first layer 524. As a specific example, the first layer 524 may contain 3000 series aluminum, and the second layer 526 and the top plate 510 may contain clad metal including 3000 series / 4000 series aluminum. As yet another specific example, the first layer 524 may contain 3000 series / 4000 series clad metal, and the second layer 526 and the top plate 510 may contain 3000 series aluminum.

[0123] The following describes the battery pack including the cooling components mentioned above.

[0124] The battery pack 1000 of the embodiment described through Figures 14 and 15 may include all of the contents of Figures 1 to 13 mentioned above, in addition to what is referred to below. Therefore, in order to minimize redundancy, the contents relating to the cooling member 500 mentioned above will be omitted.

[0125] Figure 14 is an exploded perspective view showing a battery pack according to another embodiment of the present invention. Figure 15 is a perspective view of a battery module included in the battery pack according to Figure 14.

[0126] Referring to Figure 14, a battery pack 1000 according to one embodiment of the present invention may include at least one battery module 100, a pack frame 200 housing the battery module 100, a resin layer 300 formed on the inner surface of the pack frame 200, an end plate 400 closing the open surface of the pack frame 200, and a cooling member 500 disposed between the pack frame 200 and the battery cell stack 120. However, the components included in the battery pack 1000 are not limited thereto, and the battery pack 1000 may be provided with some of the aforementioned components omitted by design, or with other components not mentioned added.

[0127] Referring to Figures 14 and 15, the battery module 100 provided in this embodiment can have a module-less structure in which the module frame is omitted.

[0128] Conventional battery packs typically have a double-assembly structure where a battery module is formed by assembling a stack of battery cells and many connected components, and multiple battery modules are then housed back into the battery pack. In this case, since the battery module includes a module frame that forms its outer surface, conventional battery cells are double-protected by the module frame of the battery module and the pack frame of the battery pack. However, such a double-assembly structure not only increases the manufacturing cost and process of the battery pack, but also has the disadvantage of reduced reassembly capability if some battery cells become defective. Furthermore, if cooling components are located outside the battery module, there is a problem in that the heat transfer path between the battery cells and the cooling components becomes somewhat more complex.

[0129] Therefore, the battery module 100 of this embodiment can be provided in the form of a "cell block" with the module frame omitted, and the battery cell stack 120 included in the cell block can be directly coupled to the pack frame 200 of the battery pack 1000. This simplifies the structure of the battery pack 1000, provides advantages in terms of manufacturing cost and manufacturing process, and has the effect of achieving a lighter battery pack.

[0130] In the following, a battery module 100 without a module frame may be referred to as a "cell block" to distinguish it from a battery module with a module frame. However, the term "battery module 100" is a general term for any battery cell stack 120 that has been segmented into predetermined units for modularization, regardless of whether or not it has a module frame, and the term "battery module 100" should be interpreted as including all ordinary battery modules with module frames and cell blocks.

[0131] Referring to Figure 15, the battery module 100 of this embodiment may include a battery cell stack 120 in which a plurality of battery cells 110 are stacked in one direction, side plates 130 located at both ends of the stacking direction of the battery cell stack 120, holding straps 140 that surround the side plates 130 and the battery cell stack 120 to fix their shape, and a busbar frame 150 that covers the front and rear surfaces of the battery cell stack 120.

[0132] On the other hand, although Figure 15 shows a battery module 100 provided in the form of a cell block, the contents of such drawings do not preclude the application of a sealed battery module 100 having a module frame to the battery pack 1000 of this embodiment.

[0133] Each battery cell 110 may include an electrode assembly, a cell case, and electrode leads protruding from the electrode assembly. The battery cell 110 may be supplied in a pouch or prismatic form that maximizes the number of cells stacked per unit area. For example, a battery cell 110 supplied in a pouch may be manufactured by housing an electrode assembly, including a positive electrode, a negative electrode, and a separator membrane, in a laminate sheet cell case, and then heat-sealing the cell case. On the other hand, while Figures 14 and 15 show the positive and negative electrode leads of the battery cell 110 protruding in opposite directions, this is not necessarily the case, and the electrode leads of the battery cell 110 may protrude in the same direction.

[0134] The battery cell stack 120 may be a stack of electrically connected battery cells 110 stacked in one direction. The direction in which the multiple battery cells 110 are stacked (hereinafter referred to as the "stack direction") may be the y-axis direction (or the -y-axis direction, and hereafter the expression "axis direction" may be interpreted to include all + / - directions) as shown in Figures 14 and 15.

[0135] On the other hand, because the battery cells 110 are arranged along one direction, the electrode leads of the battery cells 110 can be located on one surface of the battery cell stack 120, or on one surface and the other surface facing that surface. Thus, the surface on the battery cell stack 120 where the electrode leads are located can be referred to as the front surface or the rear surface of the battery cell stack 120, and in Figures 14 and 15, the front surface and the rear surface of the battery cell stack 120 are shown as two surfaces facing each other on the x-axis.

[0136] Furthermore, the surface on which the outermost battery cell 110 is located in the battery cell stack 120 can be referred to as the side surface of the battery cell stack 120, and in Figures 14 and 15, the side surfaces of the battery cell stack 120 are shown as two surfaces facing each other on the y-axis.

[0137] The side plates 130 may be provided to maintain the overall shape of the battery cell stack 120. The side plates 130 are plate-shaped members that can complement the rigidity of the cell block in place of a module frame. The side plates 130 may be positioned at both ends of the battery cell stack 120 in the stacking direction and can contact the outermost battery cells 110 on both sides of the battery cell stack 120.

[0138] The side plate 130 can be manufactured from a variety of materials and provided through a variety of manufacturing methods. For example, the side plate 130 may be made of a plastic material manufactured by injection molding. As another example, the side plate 130 may be made of a plate spring material. As yet another example, the side plate 130 may be made of an elastic material whose shape can be partially deformed in response to volume changes of the battery cell stack 120 due to swelling.

[0139] The holding strap 140 may be for fixing the position and shape of the side plates 130 at both ends of the battery cell stack 120. The holding strap 140 may be a member having length and width. Specifically, the battery cell stack 120 can be positioned between two side plates 130 that are in contact with the outermost battery cell 110, and the holding strap 140 can connect the two side plates 130 across the battery cell stack 120. This allows the holding strap 140 to prevent the distance between the two side plates 130 from increasing beyond a certain range, thereby maintaining the overall shape of the cell block within a certain range.

[0140] The holding strap 140 may have locking portions at both ends in its longitudinal direction for stable connection with the side plate 130. The locking portions may be formed by bending both ends of the holding strap 140 in its longitudinal direction. On the other hand, locking grooves may be formed in the side plate 130 at positions corresponding to the locking portions, and the holding strap 140 and the side plate 130 can be stably connected through the connection between the locking portions and the locking grooves.

[0141] The holding strap 140 can be provided through a variety of materials or manufacturing methods. For example, the holding strap 140 may be made of an elastic material, which allows for volume changes of the battery cell stack 120 due to swelling to remain within a certain range.

[0142] On the other hand, the holding strap 140 is for fixing the relative position between the side plate 130 and the battery cell stack 120, and once its purpose as a “fixing member” is achieved, it may be provided in a form different from that shown. For example, the fixing member may be provided in the form of a long bolt that can cross between the two side plates 130, i.e., a long bolt. The side plate 130 is provided with a groove into which the long bolt can be inserted, and the long bolt can fix the relative position of the two side plates 130 by simultaneously connecting the two side plates 130 through the groove. The long bolt may be provided at the periphery of the side plate 130, preferably near the apex of the side plate 130. Depending on the design, the holding strap 140 may be replaced by the long bolt described above, but it is also possible for both the holding strap 140 and the long bolt to be provided in the cell block.

[0143] The busbar frame 150 may be positioned on one surface of the battery cell stack 120, covering one surface of the battery cell stack 120 and guiding the connection between the battery cell stack 120 and external equipment. The busbar frame 150 may be positioned on the front or rear surface of the battery cell stack 120. Two busbar frames 150 may be provided, one positioned on the front and one on the rear surface of the battery cell stack 120. Busbars may be mounted on the busbar frame 150, so that the electrode leads of the battery cell stack 120 are connected to the busbars, thereby electrically connecting the battery cell stack 120 to external equipment.

[0144] The busbar frame 150 may include an electrically insulating material. The busbar frame 150 can restrict the busbars from contacting other parts of the battery cell 110 other than the portion connected to the electrode leads, thereby preventing electrical short circuits.

[0145] The pack frame 200 may be for protecting the battery module 100 and the electrical components connected thereto from external physical shocks. The pack frame 200 can house the battery module 100 and the electrical components connected thereto within its internal space. Here, the pack frame 200 includes internal and external surfaces, and the internal space of the pack frame 200 may be defined by the internal surface.

[0146] There may be multiple battery modules 100 housed within the pack frame 200. Multiple battery modules 100 may be referred to as a "module assembly." Module assemblies may be arranged in rows and columns within the pack frame 200. Here, "row" may mean a set of battery modules 100 arranged in one direction, and "column" may mean a set of battery modules 100 arranged in a direction perpendicular to the aforementioned direction. For example, as shown in Figure 1, the battery modules 100 can be arranged along the stacking direction of the battery cell stack to form a single row or column and thus form a module assembly.

[0147] The pack frame 200 may be provided in a hollow form that is open along one direction. For example, if multiple battery modules 100 are positioned consecutively along the stacking direction of the battery cells 110 as shown in Figure 1, the pack frame 200 may have a hollow form that is open along the aforementioned stacking direction.

[0148] The structure of the pack frame 200 can be diverse. As an example, as shown in Figure 1, the pack frame 200 may include a lower frame 210 and an upper frame 220. Here, the lower frame 210 may be provided in a plate shape, and the upper frame 220 may be provided in a U shape. At least one battery module 100 may be placed on the plate-shaped lower frame 210, and the U-shaped upper frame 220 may be provided so as to surround the top surface and two surfaces along the x-axis of the module assembly.

[0149] The pack frame 200 may include portions with high thermal conductivity to rapidly dissipate heat generated in its internal space to the outside. For example, at least a portion of the pack frame 200 may be made of a metal with high thermal conductivity, such as aluminum, gold, silver, copper, platinum, or alloys containing these. The pack frame 200 may also be partially electrically insulating, and insulating films may be provided or insulating coatings may be applied to locations where insulation is required. The portions of the pack frame 200 to which insulating films or insulating coatings are applied may also be referred to as insulating portions.

[0150] A resin layer 300 may be provided between the battery module 100 and the inner surface of the pack frame 200. The resin layer 300 may be provided between the bottom surface of the battery module 100 and the lower frame 210. The resin layer 300 may be provided between the top surface of the battery module 100 and the upper frame 220. Specifically, the resin layer 300 may be provided between the cooling member 500 (described later) and the upper frame 220.

[0151] The resin layer 300 may be formed by injecting resin between the battery cell laminate 120 and one of the inner surfaces of the pack frame 200. However, this is not necessarily the case, and the resin layer 300 may be a plate-shaped component.

[0152] The resin layer 300 can be manufactured from a variety of materials, and the function of the resin layer 300 can vary depending on the material. For example, the resin layer 300 can be formed from an insulating material, which can prevent electron transfer between the battery module 100 and the pack frame 200. As another example, the resin layer 300 can be formed from a thermally conductive material. A resin layer 300 made from a thermally conductive material can transfer heat generated in the battery cell 110 to the pack frame 200, thereby allowing heat to be released / transferred to the outside. As yet another example, the resin layer 300 can contain an adhesive material, which can fix the battery module 100 and the pack frame 200 together. Specifically, the resin layer 300 may be provided to include at least one of silicon-based materials, urethane-based materials, and acrylic-based materials.

[0153] The end plates 400 may be intended to protect the battery module 100 and its connected electrical components from external physical shocks by sealing the open sides of the pack frame 200. Each edge of the end plate 400 may be joined to the corresponding edge of the pack frame 200 by means of welding or other methods. Two end plates 400 are provided to seal the two open sides of the pack frame 200 and may be manufactured from a metallic material of a predetermined strength.

[0154] The end plate 400 has an opening 410 for exposing the inlet / outlet ports 530 of the cooling member 500, which will be described later, and a connector 420 for LV (Low voltage) connection or HV (High voltage) connection with external equipment may be attached.

[0155] The cooling element 500 may be used to cool the inside of the battery pack 1000 by releasing the heat generated from the battery cell 110. Refer to the above description for details regarding the cooling element 500.

[0156] On the other hand, while Figure 14 shows the cooling member 500 being provided outside the battery module 100, this is not necessarily the case, and the cooling member 500 can also be placed inside the battery module 100. In this case, the battery module 100 may be a closed structure with a module frame, or it may be an open structure such as a cell block.

[0157] Furthermore, although the aforementioned drawings show the cooling member 500 as having an independent structure, the cooling member 500 can also be provided integrated with the battery pack 1000 or battery module 100. For example, if the cooling member 500 is provided integrated with the battery pack 1000, the upper plate 510 of the cooling member 500 can be replaced by the upper surface of the pack frame 200, and the cooling member 500 can be formed by connecting the upper surface of the pack frame 200 and the lower plate 520 of the cooling member 500. As another example, if the cooling member 500 is provided integrated with the battery module 100, the upper plate 510 of the cooling member 500 can be replaced by the upper surface of the frame of the battery module 100, and the cooling member 500 can be formed by connecting the upper surface of the frame of the battery module 100 and the lower plate 520 of the cooling member 500. When the cooling member 500 is integrated with the battery pack 1000 or battery module 100 in this way, effects such as weight reduction, cost reduction, or simplification of the internal structure of the battery pack 1000 or battery module 100 through the omission of some components can be achieved.

[0158] Furthermore, although the battery module 100 of this embodiment was described as including a water-cooled cooling member 500, this description does not preclude the battery module 100 from including an air-cooled cooling member. Therefore, it should be made clear that the battery module 100 of this embodiment can include both air-cooled and water-cooled cooling members 500 simultaneously.

[0159] Cooling members according to the present invention and other embodiments will be described below.

[0160] Figure 16 is a perspective view showing a cooling member according to another embodiment of the present invention. Figure 17 is a top view showing a cooling member according to another embodiment of the present invention. Figure 18 is a top view of the lower plate included in the cooling member of Figure 16. Figure 19 is a top view of the main body included in the cooling member of Figure 16. Figure 20 is a diagram showing the connection between the lower plate, main body and cooling hose included in the cooling member of Figure 16. Figure 21 shows the cooling member of Figure 17 cut along line AA, illustrating the inflow and outflow of cooling water into the main body and cooling hose. Figure 22 shows the AA cross-section of the cooling member of Figure 17, illustrating the injection of cooling water through the cooling hose when a battery cell ignites.

[0161] Referring to Figures 16 and 17, the cooling member 600 of this embodiment may be provided to lower the internal temperature of a battery module or battery pack, including battery cells. The cooling member 600 may be a water-cooled cooling member 600 into which a refrigerant or cooling water is injected. By providing the cooling member 600 in a water-cooled manner, the cooling efficiency of the cooling member 600 is maintained uniformly, and the battery cells in the battery module or battery pack can be cooled uniformly. In this case, the cooling water used in the cooling member 600 may be one of the known or a mixture thereof, and any known cooling water may be used as long as it can dissipate the heat of the battery cells by moving along the flow path inside the cooling member 600.

[0162] The cooling member 600 may be positioned on one surface of the battery cell stack to dissipate heat from the battery cells. The cooling member 600 may be positioned parallel to the stacking direction of the battery cell stack so as to be close to multiple battery cells in the battery cell stack. Specifically, the cooling member 600 may be located on top of the battery cell stack.

[0163] The size of the cooling member 600 can be adjusted to match the size of the battery cell stack to which the cooling member 600 is applied. For example, the cooling member 600 may be provided to correspond to one battery cell stack, in which case the length of the cooling member 600 may be adjusted to match the length of the battery cell stack or to be larger or smaller with a margin, and the width of the cooling member 600 may be adjusted to match the width of the battery cell stack or to be larger or smaller with a margin. As another example, the cooling member 600 may be provided to correspond to multiple battery cell stacks, in which case the length and width of the cooling member 600 may be adjusted to match the length and width of the multiple battery cell stacks or to be larger or smaller with a margin. Here, the cooling member 600 can be located inside the battery module, but it can also be located outside the battery module and inside the battery pack.

[0164] The cooling member 600 may include a lower plate 620, an inlet / outlet port 630 for injecting cooling water into the cooling member 600, a main body 640 mounted on the upper surface of the lower plate 620 and containing the cooling water, a cooling hose 650, and a fixing member 660 for securing these. Referring to Figure 20, the cooling member 600 can be manufactured by mounting the main body 640 on the upper surface of the lower plate 620, attaching the cooling hose 650 to the housing portion 648 of the main body 640, and fixing the fixing member 660 to secure the lower plate 620, the main body 640, and the cooling hose 650.

[0165] The cooling member 600 of this embodiment ensures watertightness through the aforementioned structure, simplifies the manufacturing process, and allows for the timely and appropriate supply of cooling water when a battery cell ignites.

[0166] If a battery cell catches fire, it is effective to inject a liquid such as cooling water into the battery module or battery pack to effectively suppress the fire. However, equipping the battery module or battery pack with a liquid tank inside could increase its volume. Therefore, conventionally, a separate water tank was installed outside the battery module and battery pack, and cooling water was injected into the battery module or battery pack only when a fire in a battery cell was detected via a sensor, using a nozzle extended from the water tank.

[0167] However, water tanks located outside battery modules and battery packs have the problem of not only being large in volume but also requiring separate management by the user. Furthermore, conventional water injection systems require a separate control unit or communication unit to determine whether or not to inject cooling water, and errors in these operations are unacceptable. Even when operating normally, multiple decision-making processes are required, resulting in a long time. Even after the decision to inject cooling water has been made, if the path from the water tank to the battery cells inside the battery module or battery pack is somewhat long, it is difficult to quickly supply cooling water from the water tank to the battery cells. As a result, conventional water injection systems have difficulty stopping the rapidly progressing, continuous thermal runaway phenomenon. Therefore, in this embodiment, an opening can be formed in the lower plate 620 of the cooling member 600, and a cooling hose 650 can be arranged to correspond to the opening, so that cooling water can be immediately supplied to the fire location in the event of internal ignition of the battery module or battery pack.

[0168] To achieve an effect similar to that described above, an opening can be formed on the lower surface of a conventional cooling member, and then the opening can be sealed by filling or inserting a material that melts or breaks at a predetermined temperature or pressure or higher. However, in conventional structures where the cooling water of the cooling member 600 is in direct contact with the lower plate 620, the cooling water may leak out through the gap between the opening in the lower plate 620 and the material that seals it, which can significantly reduce the watertightness of the cooling member 600. Furthermore, manufacturing the lower plate 620 to include two materials with different physical properties involves a complex manufacturing process, which increases manufacturing time and costs. Therefore, in the cooling member 600 of this embodiment, the reduction in watertightness due to the opening 622 of the lower plate 620 can be minimized by isolating the cooling water in the main body 640 and the cooling hose 650. In addition, by applying the main body 640 and the cooling hose 650 to the cooling member 600, the manufacturing process of the cooling member 600 can be simplified, and manufacturing time and costs can be reduced.

[0169] Referring to Figure 18, the lower plate 620 may be provided in a plate shape. The main body 640 and cooling hose 650, through which cooling water flows, may be attached to the lower plate 620. It is preferable that the lower plate 620 be provided in a plate shape to support the main body 640 and the like.

[0170] The lower plate 620 may include at least one opening 622. The opening 622 may be for injecting internal cooling water into the battery cell in the event of internal ignition of the battery cell, using the heat or pressure generated by the ignition. Multiple openings 622 may be provided along a straight line parallel to the short or long side of the lower plate 620, and the cooling member 600 can inject cooling water in response to a fire occurring at an unspecified location within the battery module or battery pack by having multiple openings 622. Refer to Figure 22, which will be described later, for further details.

[0171] A projection 624 may be formed around the lower plate 620, extending from one side of the lower plate 620 and continuously positioned along one edge of the lower plate 620. The projection 624 may be in contact with or positioned in close proximity to the electrode leads or busbars connected to the electrode leads of each battery cell stack. Since the electrode leads or busbars that provide electrical connections in the battery module or battery pack are prone to generating heat, the aforementioned projection can more effectively prevent temperature rise in the battery cells by promoting heat dissipation from the electrode leads or busbars.

[0172] A ridge 626 may be formed on the lower plate 620. The ridge 626 may extend along the length direction of the cooling member 600 at the center of the width direction of the cooling member 600, except for a predetermined section. The ridge 626 allows the main body 640 to be mounted in the correct position and the fixing member 660 to be stably fixed. Here, the width direction of the cooling member 600 may be parallel to the short side of the cooling member 600. Also, here, the length direction of the cooling member 600 may be parallel to the long side of the cooling member 600.

[0173] The lower plate 620 may be the part of the cooling member 600 that is closest to the battery cell. The lower plate 620 may be made of a material with high thermal conductivity so as to promote heat dissipation from the battery cell. The lower plate 620 of the cooling member 600 may be made of a highly rigid metal, specific examples of which include aluminum, gold, silver, copper, platinum, or alloys containing these.

[0174] Cooling water can be supplied through adjacent inlet ports 632 and discharged from outlet ports 634. The inlet ports 632 and outlet ports 634 can be positioned parallel to each other on one end side of the cooling member 600. This may simplify the design regarding the inflow and outflow of cooling water supplied from outside the battery module or battery pack. It may also minimize the temperature difference between the area around the inlet ports 632 and the area around the outlet ports 634. Specifically, the cooling water flowing into the inlet ports 632 can have the lowest temperature, and the cooling water discharged from the outlet ports 634 can have the highest temperature. Therefore, when the inlet / outlet ports 630 are arranged adjacent to each other, heat exchange between them can minimize the overall temperature deviation of the cooling water flowing through the internal space of the cooling member. Thus, by arranging the inlet / outlet ports 630 side by side, the cooling member 600 can have an overall uniform heat dissipation performance.

[0175] Referring to Figures 19 to 21, the main body 640 can provide a flow path for cooling water to dissipate heat from the battery cells. Cooling water injected through the inlet port 632 is contained within the main body 640, and the cooling water contained within the main body 640 can be discharged through the outlet port 634. The cooling member 600 can be maintained at a relatively constant temperature by the inflow and outflow of cooling water into the main body 640. The cooling water within the main body 640 can be connected to an external heat exchanger connected to the inlet / outlet port 630 to maintain its temperature stability and be designed to circulate continuously.

[0176] The lower plate 620, cooled by the main body 640, can promote heat dissipation from the battery cells. The main body 640 may be made of a material with high thermal conductivity, thereby allowing it to quickly absorb heat from the lower plate 620. The main body 640 may be made of a material with sufficient rigidity to withstand the pressure and weight of the cooling water contained inside. The main body 640 may be made of the same material as the lower plate 620, or a similar material. Examples of materials for the main body 640 include aluminum, gold, silver, copper, platinum, or alloys containing these.

[0177] The main body 640 can be mounted in a position where the lower plate 620 does not form a levee 626. The outer shape of the main body 640 may be similar to the outer shape of the lower plate 620, excluding the protruding portion 624.

[0178] The main body 640 can have a rectangular tubular shape and can be branched into two parts corresponding to the inlet port 632 and the outlet port 634, respectively, taking into account the position of the bank 626. This allows the main body 640 to form a U-shaped flow path. The main body 640 may include a first part 642 extending from the inlet port 632 along a straight line parallel to the longitudinal direction of the cooling member 600, a second part 644 extending from the end of the first part 642 along a curve that rotates clockwise or counterclockwise, and a third part 646 extending from the end of the second part 644 toward the outlet port 634 along a straight line parallel to the longitudinal direction of the cooling member 600. Here, the longitudinal direction of the cooling member 600 may be parallel to the long side of the cooling member 600.

[0179] The main body 640 may include a housing 648 into which a cooling hose 650 is fitted. The housing 648 may represent a housing space in the main body 640 into which the cooling hose 650 is fitted. The housing 648 is a long groove extending along the longitudinal direction of the cooling member 600, and the cross-section of the housing 648 may be a polygon such as a square or a circle. The longitudinal ends of the cooling hose 650 can be connected to both longitudinal ends of the housing 648. The longitudinal ends of the cooling hose 650 can be inserted into both longitudinal ends of the housing 648. The connection points between the longitudinal ends of the housing 648 and the longitudinal ends of the cooling hose 650 can be sealed to ensure watertightness. For example, a gasket can be provided at the connection point between the cooling hose 650 and the housing 648, and watertightness between the two members can be ensured through the gasket. As another example, both ends of the cooling hose 650 may have circumferentially extending expansion portions, which are inserted into the ends of the housing portion 648 and positioned inside the main body 640, thereby complementing the connection between the cooling hose 650 and the main body 640. As yet another example, the end of the cooling hose 650 may have a first circumferentially extending expansion portion and a second expansion portion spaced apart from the first expansion portion. The first expansion portion may be positioned inside the main body 640 and the second expansion portion outside the main body 640, and the connection between the cooling hose 650 and the main body 640 may be further complemented by the close contact between the two expansion portions and the main body 640. In this case, protrusions may be formed on the expansion portion, the first expansion portion, or the second expansion portion, which may connect more closely to one side of the main body 640 through the protrusions.

[0180] The cooling hose 650 is connected to the main unit 640 and can provide a flow path for the cooling water that enables heat dissipation from the battery cells. Cooling water flowing in from the inlet / outlet port 630 can move through the cooling hose 650. The cooling hose 650 can receive a supply of cooling water from the main unit 640, which is located close to the inlet / outlet port 630.

[0181] The cooling hoses 650 can be positioned to correspond to the openings 622 in the lower plate 620. If four rows of openings 622 are formed in the lower plate 620 along a straight line parallel to the longitudinal direction of the cooling member 600, as shown in Figure 18, then four cooling hoses 650 may be provided, corresponding to each row of openings 622. Here, “row” may refer collectively to openings 622 that are positioned consecutively along a straight line parallel to the longitudinal direction of the cooling member 600.

[0182] Referring to Figure 22, the cooling hose 650 can be melted or ruptured in the event of an internal fire, allowing internal cooling water to be injected into the battery cells. When a battery cell catches fire, a portion of the cooling hose 650 corresponding to the opening 622 is opened by melting or rupturing, allowing cooling water to be sprayed, ejected, or injected in the direction of gravity, thereby suppressing the fire in the battery cells located below the cooling member 600. On the other hand, in order to achieve this effect, the housing 648 into which the cooling hose 650 is installed must also be formed to correspond to the opening 622 in the lower plate 620.

[0183] The cooling hose 650 may be manufactured from a material that is more easily melted by heat or ruptured by pressure than the lower plate 620, which is made of metal. For example, the cooling hose 650 may be manufactured from a material having a melting point of 300°C or less. Specifically, the cooling hose 650 may be manufactured to include polyamide (PA). As another specific example, the cooling hose 650 may be manufactured to include a thermoplastic polymer resin having a melting point of 200°C or less. Examples of such thermoplastic polymer resins include high-density polyethylene (HDPE), polyethylene (PE), polypropylene (PP), and polyphenylene oxide (PPO), which have a melting point of approximately 100°C to 200°C.

[0184] On the other hand, in order to achieve the aforementioned effects, it would also be possible to construct a system in which a part of the main body 640 is ruptured to allow cooling water to be introduced, without separately manufacturing the cooling hose 650. However, since the main body 640 must be made of a material with sufficient rigidity to withstand the pressure of the cooling water flowing into it and to maintain its shape, manufacturing it from a material that is easily melted by heat or ruptured by pressure would reduce the overall durability of the cooling member 600. Therefore, as in this embodiment, it is preferable to configure the cooling hose 650, which can be easily ruptured by heat, separately from the main body 640, in order to improve the performance of the overall cooling member 650.

[0185] The fixing member 660 may be intended to complement the rigidity of the cooling member 600 by fixing the lower plate 620, the main body 640, and the cooling hose 650. The fixing member 660 can fix the position of the main body 640 and the cooling hose 650 through connection with the lower plate 620.

[0186] The fixing member 660 may be provided in the form of a lengthwise strap. The fixing member 660 may be positioned parallel to the width direction of the cooling member 600. Multiple fixing members 660 may be provided along the length direction of the cooling member 600, and the multiple fixing members 660 may be arranged at uniform intervals.

[0187] The fixing member 660 is made of a highly rigid material to maintain the shape of the cooling member 600, and may be made of metal, for example.

[0188] The fixing member 660 may be connected to both ends of the cooling member 600 in the width direction. The fixing member 660 may be connected to the center of the cooling member 600 in the width direction. The fixing member 660 may include end connection portions 662 formed at both ends of the fixing member 660 in the length direction, and a central connection portion 664 formed in the center of the fixing member 660 in the length direction. The end connection portions 662 and the central connection portion 664 may refer to portions of the cooling member 600 that are fastened through fastening members such as rivets. Fasteners into which fastening members can be inserted may be formed in the end connection portions 662 and the central connection portion 664.

[0189] The fixing member 660 can be connected to both ends of the lower plate 620 in the width direction. The fixing member 660 can be connected to the center of the lower plate 620 in the width direction. The end connection portion 662 can be connected to the protrusions 624 located at both ends of the lower plate 620 in the width direction. The central connection portion 664 can be connected to the embankment 626 located in the center of the lower plate 620 in the width direction. The end connection portion 662 and the central connection portion 664 can be formed to have a step difference from the other parts of the fixing member 660 and may have a height that is slightly lower than the other parts of the fixing member 660. When considering the shapes of the protrusions 624 and the embankment 626, the end connection portion 662 can be formed to have a larger step difference than the central connection portion 664.

[0190] Thus, when fixing members 660 are used during the manufacturing of the cooling member 600, excessive heat is not generated during the manufacturing process compared to joining methods such as welding, so that specific materials that are sensitive to temperature are not deformed during the manufacturing process. Therefore, by using fixing members 660, the cooling member 600 can be manufactured to include two or more materials with different properties, and structures of various materials and shapes, such as cooling hoses 650, can be applied to the cooling member 600, making the design of the cooling member 600 easier and more diverse.

[0191] The following describes a method for manufacturing a cooling member according to another embodiment of the present invention. The method for manufacturing the cooling member 600 described below includes all of the above-mentioned information regarding the cooling member 600, and detailed explanations of overlapping information will be omitted.

[0192] Referring again to Figure 20, a method for manufacturing a cooling member according to another embodiment of the present invention may include the steps of preparing the lower plate 620, attaching the main body 640 to the upper surface of the lower plate 620, attaching the cooling hose 650 to the main body 640, and connecting the fixing member 660 to the lower plate 620.

[0193] The step of preparing the lower plate 620 may include the step of forming an opening 622 in the lower plate 620, and depending on the embodiment, it may further include the step of attaching an inlet / outlet port 630 to the lower plate 620.

[0194] The step of attaching the main body 640 to the lower plate 620 is a process of joining the lower plate 620 and the main body 640, which can be carried out by a joining process such as welding. When a welding process is used to join the lower plate 620 and the main body 640, the more similar the materials of the lower plate 620 and the main body 640 are, the more the deformation or damage of some components due to the welding temperature can be minimized, and the size safety of the cooling member 600 can be ensured.

[0195] The step of attaching the cooling hose 650 to the main body 640 may include the steps of inserting the cooling hose 650 into the housing portion 648 of the main body 640 and connecting both ends of the cooling hose 650 to both ends of the housing portion 648. Here, the connection portion between the cooling hose 650 and the housing portion 648 can be sealed.

[0196] The step of connecting the fixing member 660 to the lower plate 620 may include the steps of connecting the end connecting portion 662 of the fixing member 660 to both ends of the lower plate 620, and connecting the central connecting portion 664 of the fixing member 660 to the center of the lower plate 620. Here, both ends of the lower plate 620 refer to the ends in the width direction, and protrusions 624 can be located at both ends of the lower plate 620. Also, the center of the lower plate 620 refers to the center in the width direction, and a ridge 626 can be located at the center of the lower plate 620.

[0197] On the other hand, although not specifically mentioned above, cooling members 600 according to other embodiments of the present invention may be installed inside a battery module or battery pack. A battery module according to yet another embodiment of the present invention includes a battery cell stack consisting of a plurality of battery cells and a module frame housing the same, wherein a cooling member 600 may be provided between the module frame and the battery cell stack.

[0198] Battery packs according to other embodiments of the present invention can be provided in a variety of forms.

[0199] As an example, a battery pack according to yet another embodiment of the present invention may include at least one of the aforementioned battery modules. The battery pack in this example may include a pack frame and at least one battery module mounted within the pack frame, and the battery module may include a battery cell stack, a module frame, and a cooling member located between the battery cell stack and the module frame.

[0200] As another example, a battery pack according to yet another embodiment of the present invention may include at least one battery module comprising a stack of battery cells and a module frame housing the same, a cooling member 600, and a pack frame housing the battery module and the cooling member 600. In this example, the cooling member 600 may be provided outside the battery module. The cooling member 600 is provided between the module frame and the pack frame of the battery module, and cooling water may be injected towards the battery module in the event of ignition inside or outside the battery module.

[0201] As another example, a battery pack according to yet another embodiment of the present invention may include a battery cell stack and a pack frame housing the same, and a cooling member 600 may be provided between the battery cell stack and the pack frame.

[0202] Here, the battery cell stack may be provided in a module-less structure that is not sealed by a module frame or the like. The battery cell stack may be provided in an open structure. In this case, the battery cell stack may be provided in a state where its external shape is maintained through fixing members such as side plates or holding straps, and such a form of battery cell stack may be referred to as a cell block.

[0203] Typically, a battery pack can be formed in a double-assembly structure where a battery module is created by assembling a stack of battery cells and many connected components, and multiple battery modules are then housed again in the battery pack. In this case, since the battery module includes a module frame that forms its outer surface, conventional battery cells are double-protected by the module frame of the battery module and the pack frame of the battery pack. However, such a double-assembly structure not only increases the manufacturing cost and process of the battery pack, but also has the disadvantage of reduced reassembly if some battery cells become defective. Furthermore, if cooling components are located outside the battery module, there is a problem in that the heat transfer path between the battery cells and the cooling components becomes somewhat complex. Therefore, the battery cell stack of this embodiment is provided in a structure that is not sealed by a module frame and can be directly coupled to the pack frame of the battery pack. This makes the structure of the battery pack simpler, gains advantages in terms of manufacturing cost and process, and can achieve the effect of reducing the weight of the battery pack. Furthermore, by providing the battery cell stack in a modular structure, the battery cell stack can be positioned closer to the cooling member 600 within the pack frame, and heat dissipation by the cooling member 600 can be achieved more easily.

[0204] For further details regarding cases in which the cooling member 600 according to other embodiments of the present invention is installed in a battery module or battery pack, please refer to the description with respect to Figures 14 and 15, and any redundant information will be omitted.

[0205] Furthermore, according to the present invention, the invention is not limited to the cooling member 500 described in Figures 1 to 15 and the cooling member 600 described in Figures 16 to 22, respectively. When these are combined, various modifications and changes are possible, including, for example, applying the cooling member 500 described in Figures 1 to 15 to the main body 640 of the cooling member 600 described in Figures 16 to 22, either identically or partially modified.

[0206] On the other hand, although not specifically mentioned above, a battery pack according to one embodiment of the present invention may additionally include a battery management system (BMS) and / or a cooling device for managing the temperature and voltage of the battery.

[0207] A battery pack according to one embodiment of the present invention can be applied to a variety of devices. For example, the device to which the battery pack is applied may be a means of transportation such as an electric bicycle, electric vehicle, or hybrid vehicle. However, the devices are not limited to those described above, and the battery pack according to this embodiment can be used in a variety of devices other than those described above, and this also falls within the scope of the present invention.

[0208] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto. Various modifications and improvements made by those skilled in the art, utilizing the basic concepts of the present invention as defined in the claims, also fall within the scope of the present invention. [Explanation of symbols]

[0209] 100: Battery Module 110: Battery cell 120: Battery cell stack 130: Side plate 140: Holding Strap 150: Busbar Frame 200: Pack Frame 300: Resin layer 400: End plate 500: Cooling component 510: Top plate 514: Bending section 520: Lower plate 522: Vulnerable parts 530: Inlet / Outlet Port 540: Sealed part 550: Flow channel forming groove 560: Deformation prevention groove 600: Cooling component 620: Lower plate 630: Inlet / Outlet Port 640: Main unit 650: Cooling hose 660: Fixing member

Claims

1. In a cooling member located on top of a battery cell stack in which multiple battery cells are stacked, Includes an upper plate, a lower plate, and cooling water contained in the internal space between the upper plate and the lower plate. The lower plate includes a first portion in which a weak portion is formed, and a second portion in which the weak portion is not formed. The thickness of the first portion is less than the thickness of the second portion, and the lower plate is formed by joining a first layer and a second layer having different thicknesses. A cooling member in which the thickness of the first portion corresponds to the thickness of the first layer, and the thickness of the second portion corresponds to the thicknesses of the first and second layers.

2. In a cooling member located on top of a battery cell stack in which multiple battery cells are stacked, Includes an upper plate, a lower plate, and cooling water contained in the internal space between the upper plate and the lower plate. The lower plate includes a first portion in which a weak portion is formed, and a second portion in which the weak portion is not formed. The thickness of the first part is less than the thickness of the second part. The upper plate includes a bent portion, A cooling member wherein the peaks of the bent portion correspond to the first portion, and the valleys of the bent portion correspond to the second portion.

3. The aforementioned weak portion has a long side and a short side, The cooling member according to claim 1, wherein the long side extends along the stacking direction of the battery cells.

4. The cooling member according to claim 1 or 2, wherein the thickness of the first portion is less than or equal to half the thickness of the second portion.

5. The cooling member according to claim 1 or 2, wherein the thickness of the first portion is 0.03 to 0.07 mm.

6. The vulnerable portion includes a first vulnerable portion and a second vulnerable portion separated from the first vulnerable portion. The cooling member according to claim 1 or 2, wherein the thickness of the first weak portion and the thickness of the second weak portion are the same.

7. The cooling member according to claim 1, wherein one of the first and second layers comprises clad metal.

8. The cooling member according to claim 1, wherein at least one of the upper plate, the first layer, and the second layer includes clad metal.

9. The cooling member according to claim 1, wherein the first layer and the second layer are joined together through a brazing process.

10. The cooling member according to claim 1, wherein the upper plate, the first layer, and the second layer are joined together through a brazing process.

11. A battery module comprising the cooling member described in claim 1 or 2.

12. The battery module according to claim 11, wherein the upper plate of the cooling member is integrated with the upper surface of the module frame that forms the outer shape of the battery module.

13. A battery pack comprising the cooling member described in claim 1 or 2.

14. The battery pack according to claim 13, wherein the battery pack includes an open-type battery module.

15. The battery pack according to claim 13, wherein the upper plate of the cooling member is integrated with the upper surface of the pack frame that forms the outer shape of the battery pack.

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