Cooling member, battery module including same, and battery pack

Abstract

According to one embodiment of the present invention, a cooling member located at an upper portion of a battery cell stack in which a plurality of battery cells are stacked includes an upper plate, a lower plate, and coolant contained in an internal space between the upper plate and the lower plate, the lower plate includes a first portion having a weak portion formed therein and a second portion having no weak portion formed therein, and a thickness of the first portion is smaller than a thickness of the second portion.

Description

[Technical Field]

[0001] [Cross-reference to related application(s)] 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 contents disclosed in the documents of said Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to a cooling member, a battery module and a battery pack including the same, and more particularly to a cooling member for preventing a chain reaction of thermal runaway phenomena, and a battery module and a battery pack including the same. [Background technology]

[0003] In modern society, as the use of portable devices such as mobile phones, laptops, camcorders, and digital cameras has become commonplace, the development of technologies related to these mobile devices has become active.In addition, rechargeable secondary batteries are being used as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (P-HEVs), etc. as a solution to air pollution caused by existing gasoline-powered vehicles that use fossil fuels, and there is an increasing need for the development of secondary batteries.

[0004] Currently commercially available secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium secondary batteries. Of these, lithium secondary batteries are attracting the most attention due to their advantages of being freely chargeable and dischargeable, having a very low self-discharge rate, and having a high energy density.

[0005] Meanwhile, secondary batteries used in small devices typically use two to three battery cells, while secondary batteries used in medium- to large-sized devices such as automobiles typically use medium- to large-sized battery modules in which multiple battery cells are electrically connected. Since medium- to large-sized battery modules are preferably manufactured to be as small in size and weight as possible, prismatic and pouch-shaped batteries, which can be stacked with a high degree of integration and are light in weight relative to their capacity, are primarily used as battery cells for medium- to large-sized battery modules. Meanwhile, battery cells installed in a battery module may generate a large amount of heat during charging and discharging, and if their temperature rises above the appropriate temperature due to overcharging or other reasons, their performance may be reduced, and if the temperature rises excessively, there is a risk of explosion or fire. If a fire occurs inside a battery module, high-temperature heat, gas, or flame may be emitted outside the battery module. At this time, the heat, gas, spark, or flame emitted from one battery module may be transferred to other adjacent battery modules at close intervals within the battery pack, which may cause continuous thermal runaway within the battery pack.

[0006] To prevent such thermal runaway, conventional battery modules have been fitted with a water injection system that extinguishes a fire by injecting cooling water through a nozzle when a fire is detected within the battery module. However, injecting cooling water from a tank located outside the battery module or battery pack requires multiple steps, such as checking for the presence of a fire, deciding whether to inject cooling water, and delivering the cooling water, making it difficult to time the fire to be extinguished.

[0007] Therefore, there is a need for a new technology that can quickly suppress the thermal runaway phenomenon by injecting cooling water at the right time and place when a fire occurs inside a battery module or a battery pack. Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a cooling member that can inject cooling water at an appropriate time and place when an internal fire occurs in a battery module or a battery pack, and a battery module and a battery pack including the cooling member.

[0009] However, the problems to be solved by the embodiments of the present invention are not limited to the above problems, and can be variously expanded within the scope of the technical ideas included in the present invention. [Means for solving the problem]

[0010] According to one embodiment of the present invention, a cooling member located on an upper portion of a battery cell stack in which a plurality of battery cells are stacked includes an upper plate, a lower plate, and coolant contained in an internal space between the upper plate and the lower plate, the lower plate including a first portion having a fragile portion formed therein and a second portion having no fragile portion formed therein, and the thickness of the first portion is smaller than the thickness of the second portion.

[0011] The fragile 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 between 0.03 and 0.07 mm.

[0014] The weakened portion may include a first weakened portion and a second weakened portion spaced apart from the first weakened portion, and the thickness of the first weakened portion may be substantially the same as the thickness of the second weakened portion.

[0015] The lower plate may be formed by bonding a first layer and a second layer having different thicknesses, and the thickness of the first portion may correspond to the thickness of the first layer, and the thickness of the second portion may correspond to the thicknesses of the first layer and the second layer.

[0016] One of the first and second layers may include a clad metal.

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

[0018] The first and second layers may be joined through a brazing process.

[0019] The top plate, the first layer and the second layer may be joined together through a brazing process.

[0020] The upper plate may include a bent portion, a peak of the bent portion corresponding to the first portion, and a valley of the bent portion corresponding to the second portion.

[0021] A battery module according to still another embodiment of the present invention includes the above-described cooling member.

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

[0023] According to another embodiment of the present invention, a cooling member includes a lower plate positioned on top of a battery cell stack in which a plurality of battery cells are stacked and having a plurality of openings formed therein, a body providing a flow path for coolant, and a fixing member fixing the lower plate and the body, wherein at least one cooling hose is attached to the body, and the cooling hose melts or breaks when it reaches or exceeds a predetermined temperature or pressure.

[0024] The cooling hose may be positioned to correspond to the opening in the lower plate.

[0025] The cooling hose may have a shape extending along the length of the cooling member.

[0026] The cooling hose may be made of a material having a melting point below 300°C.

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

[0028] Both ends of the cooling hose in the longitudinal direction may be connected to both ends of the receiving part in the longitudinal direction, respectively.

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

[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 end joints coupled to both ends of the lower plate in a width direction, and a center joint coupled to a center of the lower plate in a width direction.

[0032] The terminal connecting portions and the central connecting portion may be formed to have a step with respect to other portions of the fixing member.

[0033] The cooling member further includes an inlet port and an outlet port for injecting cooling water into the internal space, and the inlet port and the outlet port are connected to an external heat exchanger, so that 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 with portions corresponding to the inlet port and the outlet port, respectively.

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

[0036] The battery pack may include an open-type structure battery module.

[0037] The upper plate of the cooling member may be integrated with the upper surface of a pack frame that defines the outer shape of the battery pack. [Effects of the Invention]

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

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

[0040] [Figure 1] FIG. 2 is a perspective view showing a cooling member according to an embodiment of the present invention. [Figure 2] 2 is a view showing an upper plate included in the cooling member of FIG. 1; [Figure 3] 2 is a view showing a lower plate included in the cooling member of FIG. 1; [Figure 4] 1. FIG. 4 is a view showing a modified example of a lower plate included in the cooling member of FIG. [Figure 5] 4 is a diagram showing an example of an AA cross section of FIG. 3. [Figure 6] 1 is a diagram illustrating an example of a cooling member provided in a battery cell stack according to an embodiment of the present invention. [Figure 7] 7 is an enlarged view of region B in FIG. 6, illustrating the change in the lower plate when the battery cell ignites. [Figure 8] FIG. 2 is a cross-sectional view showing an example of a cooling member according to an embodiment of the present invention. [Figure 9] 4 is a view showing another example of the AA cross section of FIG. 3. [Figure 10] 10 is a view showing another example of a cooling member provided in a battery cell stack according to an embodiment of the present invention; [Figure 11]11 is an enlarged view of region C in FIG. 10, illustrating the change in the lower plate when the battery cell ignites. [Figure 12] FIG. 10 is a cross-sectional view showing another example of a cooling member according to an embodiment of the present invention. [Figure 13] FIG. 10 is a cross-sectional view showing a cooling member according to another embodiment of the present invention. [Figure 14] 1 is an exploded perspective view showing a battery pack according to an embodiment of the present invention; [Figure 15] FIG. 15 is a perspective view of a battery module included in the battery pack shown in FIG. [Figure 16] FIG. 10 is a perspective view showing a cooling member according to another embodiment of the present invention. [Figure 17] FIG. 17 is a top view showing the cooling member of FIG. [Figure 18] 17 is a top view of a lower plate included in the cooling member of FIG. 16. FIG. [Figure 19] FIG. 17 is a top view of a main body included in the cooling member of FIG. [Figure 20] 17 is a view showing the connection of a lower plate, a main body, and a cooling hose included in the cooling member of FIG. 16; [Figure 21] 18 is a view showing the cooling member of FIG. 17 cut along line AA, and showing how cooling water flows into and out of the main body and cooling hoses. [Figure 22] 18 is a cross-sectional view of the cooling member of FIG. 17 taken along the line AA, showing the introduction of cooling water through a cooling hose when a battery cell catches fire. DETAILED DESCRIPTION OF THE INVENTION

[0041] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The present invention will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can easily understand and practice the present invention. The present invention may be embodied in various different forms other than those described below, and the scope of the present invention is not limited to the embodiments described herein.

[0042] In order to clearly explain the present invention, parts unnecessary for the explanation are omitted and the same reference numerals are used throughout the specification to refer to the same or similar components.

[0043] Furthermore, the size and thickness of each component shown in the drawings are arbitrarily enlarged or reduced for the convenience of explanation, and it is obvious that the content of the present invention is not limited to those shown in the drawings. In the following drawings, the thickness of each layer is enlarged to clearly show multiple layers and regions. In the following drawings, the thickness of some layers and regions is exaggerated for the convenience of explanation.

[0044] Furthermore, when a layer, film, region, plate, etc. is described as being "above" another part, this should be interpreted as including not only the case where the layer, film, region, plate, etc. is "directly above" the other part, but also the case where there is another part between them. Conversely, when a layer, film, region, plate, etc. is described as being "directly above" another part, it can mean that there is no other part between them. Furthermore, being "above" a reference part means being located above or below the reference part, and does not necessarily mean being "above" in the opposite direction of gravity. Meanwhile, just as something described as being "above" another part, something described as being "below" another part can also be understood with reference to the above content.

[0045] Furthermore, since the upper and 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 to mean the two surfaces of the component that face each other on the z-axis.

[0046] Furthermore, throughout the specification, when a part is said to "comprise" a certain element, this does not mean that it excludes other elements and may further include other elements, unless specifically stated to the contrary.

[0047] Also, throughout the specification, "on a plane" means when the subject part is viewed from above, and "on a cross section" means when the subject part is cut vertically and viewed from the side.

[0048] A cooling member according to an embodiment of the present invention will now be described.

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

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

[0051] The coolant used in the cooling member 500 may be one of known types or a mixture thereof. Any known type may be used as long as it can dissipate heat from the battery cells by moving along a flow path inside the cooling member 500. However, as described below, since the coolant of the cooling member 500 may be sprayed toward the battery cells, it is preferable that the coolant does not contain flammable materials to prevent the battery cells from becoming flammable. Even if a flammable additive is required to improve the functionality of the coolant, the amount of additive may be sufficient to prevent secondary explosions of the pouch-type battery cells and to act as an antifreeze to prevent the coolant from freezing. More specifically, the coolant may contain water. Here, the coolant may contain an antifreeze to lower the freezing point of water in addition to water. The antifreeze contained in the coolant may be an electrically insulating antifreeze.

[0052] The cooling member 500 may be disposed on one side of the battery cell stack to dissipate heat from the battery cells. The cooling member 500 may be disposed parallel to the stacking direction of the battery cell stack so as to be positioned close to the battery cells of 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 FIG. 14 ).

[0053] The size of the cooling member 500 may be adjusted to the size of the battery cell stack to which the cooling member 500 is applied. As an example, the cooling member 500 may be provided to accommodate one battery cell stack, and in this case, the length of the cooling member 500 may be adjusted to the length of the battery cell stack or may be larger or smaller with a certain margin, and the width of the cooling member 500 may be adjusted to the width of the battery cell stack or may be larger or smaller with a certain margin. As another example, the cooling member 500 may be provided to accommodate a plurality of battery cell stacks, and in this case, the length and width of the cooling member 500 may be adjusted to the length and width of the plurality of battery cell stacks or may be larger or smaller with a certain margin. Here, the cooling member 500 may be located inside the battery module, but it may also be located outside the battery module inside the battery pack 1000 (see FIG. 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 that injects cooling water into the cooling member 500.

[0055] The cooling member 500 may be formed by joining the peripheries of an upper plate 510 and a lower plate 520. A sealing part 540 formed by joining the peripheries of the upper plate 510 and the lower plate 520 may be located at the periphery of the cooling member 500. Cooling water may be contained or circulated between the joined upper plate 510 and lower plate 520 of the cooling member 500.

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

[0057] The cooling member 500 may have a flow path forming groove 550. The presence of the flow path forming groove 550 in the cooling member 500 may determine the flow of coolant provided to the cooling member 500. A plurality of flow path forming grooves 550 may be formed, and the plurality of flow path forming grooves 550 may be positioned along a straight line parallel to the length of the cooling member 500. The flow path forming groove 550 may be formed continuously along the length of the cooling member 500 at the center of the cooling member 500 except for a predetermined section, so that the flow of coolant may be formed in a U-shape. The flow of coolant injected through the inlet port 530 of the cooling member 500 may be restricted by the flow path forming groove 550. As the coolant flows along the U-shape, the coolant injected through the inlet port 530 may be discharged from the outlet port 530 positioned next 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 length 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 length of the cooling member 500.

[0058] The cooling member 500 may have deformation prevention grooves 560 formed therein. The provision of the deformation prevention grooves 560 in the cooling member 500 may prevent deformation of the cooling member 500 due to the coolant. For example, when coolant is injected into the cooling member 500, the injected coolant can be concentrated in one-half of the space of the cooling member 500 due to the flow path forming groove 550 crossing the center. Before the coolant moves through the U-shaped flow path to the remaining one-half of the space, a large pressure may act on the space, which may cause at least a portion of the cooling member 500 to expand or the cooling member 500 to be damaged. When the deformation prevention grooves 560 are formed in the flow path of the cooling member 500, deformation caused by a large pressure acting on a specific section due to temporary concentration of the coolant can be minimized. The deformation prevention grooves 560 may be arranged at intervals in a portion of the U-shaped flow path through which the coolant flows in the cooling member 500. The deformation prevention groove 560 may 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 may be appropriately set so as to accommodate the flow rate and flow velocity of the cooling water without excessively obstructing the cooling water flowing in through the inlet port 530. Here, the width direction of the cooling member 500 may be a direction parallel to the short sides of the cooling member 500. Also, here, the length direction of the cooling member 500 may be a direction parallel to the long sides of the cooling member 500.

[0059] In addition, a protrusion may be formed around the periphery of the cooling member 500, extending from one side of the cooling member 500 and positioned continuously along the length of the cooling member 500. As illustrated in Fig. 14 below, the protrusion may be disposed in contact with or adjacent to an electrode lead of each battery cell stack or a bus bar connected to the electrode lead. Since the electrode leads or bus bars that provide electrical connection in a battery module or battery pack are prone to heat generation, if the protrusion promotes heat dissipation from the electrode leads or bus bars, an increase in temperature of the battery cells can be more effectively prevented.

[0060] Referring to FIG. 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 form a step with the peripheral portion. The upper plate 510 may have a concave shape based on a cross section in the width direction. This may be such that the upper plate 510 has an internal space formed through the step to accommodate cooling water. Here, the width direction of the upper plate 510 may be parallel to the short side of the upper plate 510. However, the upper plate 510 may be formed in a different shape from that shown in FIG. 2. For example, if the lower plate 520 includes a weakened portion 522 or the like to provide a space for containing cooling water, the upper plate 510 may be provided to have an overall flat shape.

[0061] Referring to FIG. 3, the lower plate 520 of the cooling member 500 may have an overall similar shape to the upper plate 510. The lower plate 520 may be provided in a plate-like shape. The central portion of the lower plate 520 may be recessed or indented to form a step with respect to the peripheral portion. The lower plate 520 may have a recessed shape based on the cross section in the width direction, thereby forming an internal space for accommodating cooling water. However, the lower plate 520 does not necessarily have to be indented, and may be provided in an overall flat shape depending on the shape of the upper plate 510 or the volume of cooling water to be contained. Here, the width direction of the lower plate 520 may be parallel to the short side of the lower plate 520.

[0062] In addition, the lower plate 520 may have a weakened portion 522, which will be described later, and therefore one surface of the lower plate 520 may have a partially recessed groove. If the groove is positioned 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 may 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 located closest to the battery cell. Therefore, the lower plate 520 is preferably made of a material with high thermal conductivity 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 the 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 metals.

[0064] Meanwhile, as mentioned above, in order to effectively suppress a fire in a battery cell, it is effective to inject a liquid such as cooling water into the battery module or battery pack. Since providing a liquid tank inside the battery module or battery pack can cause a problem of increasing the volume of the battery module and battery pack, in the past, a separate water tank was provided outside the battery module or battery pack, and cooling water or the like was injected into the battery module or battery pack through a nozzle extended from the water tank only when a battery cell fire was confirmed by a sensor.

[0065] However, water tanks installed outside the battery module and battery pack are not only large in volume, but also require 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 these units must operate without errors. Even after the decision to inject cooling water is 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, making it difficult for conventional water injection systems to prevent rapid and continuous thermal runaway.

[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 when a battery cell catches fire, will be described in more detail below.

[0067] 3 and 4, the lower plate 520 of this embodiment may include a weakened portion 522. The term "weakened portion" may refer to a portion that is more easily broken by heat or pressure than other portions of the lower plate 520. The weakened portion 522 may be a portion having a thickness that is relatively smaller than other portions of the lower plate 520. Specifically, the lower plate 520 may have a first portion referred to as the weakened portion 522 and a second portion where the weakened portion 522 is not formed, and here the thickness of the second portion may be greater than the thickness of the first portion. The thickness of the first portion may be less than half the thickness of the second portion. By having a thickness that is slightly smaller than other portions, the weakened portion 522 may be broken relatively easily by heat or pressure.

[0068] The weak portion 522 may be formed long and extend along the stacking direction of the battery cells. The length direction (y-axis) of the weak 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 weak portion 522 may be perpendicular to the stacking direction of the battery cells 110. Because it is unpredictable which battery cell 110 will ignite, it is preferable that the weak portion 522 be formed to correspond to all battery cells located under the cooling member 500. The weak portion 522 may be formed along the entire length of the cooling member 500. Here, one weak portion 522 may be provided on a straight line parallel to the stacking direction of the battery cells as shown in FIG. 3, or two or more weak portions 522 may be provided on a straight line parallel to the stacking direction of the battery cells as shown in FIG. 4.

[0069] The weakened portions 522 may be positioned consecutively in the width direction (x-axis). Here, the width of the weakened portions 522 may be designed to vary depending on the designer's intention. For example, the weakened portions 522 may have a wide width. As another example, the weakened portions 522 may have a relatively narrow width. The weak portions 522 with a narrow width may be formed consecutively.

[0070] The fragile portion 522 may be located to correspond to the portion of the battery cell that is most susceptible to heat generation. For example, the electrode lead of the battery cell may be a portion where electron movement is concentrated and heat is easily generated. The fragile portion 522 may be located on top of the electrode lead of the battery cell to respond to heat generation or resulting explosion of the electrode lead.

[0071] FIG. 5 is a diagram showing an example of the AA cross section of FIG.

[0072] 5, the cross section of the weakened portion 522 may have various shapes. Here, the cross section of the weakened portion 522 may be obtained by cutting the cooling member 500 based on the xz plane as shown in FIG.

[0073] The weakened portion 522 is a portion of the lower plate 520 whose thickness varies. A first portion having the weakened portion 522 and a second portion not having the weakened portion 522 are perpendicularly connected to each other, so that the portion of the lower plate 520 may have a rectangular cross-sectional shape as shown in FIG. 5(a). Furthermore, if a slope is formed on the connecting surface between the first and second portions, the portion of the lower plate 520 may have a triangular cross-sectional shape as shown in FIG. 5(b) or a trapezoidal cross-sectional shape as shown in FIG. 5(d). If the connecting surface between the first and second portions is curved, the portion of the lower plate 520 may have a rounded cross-sectional shape as shown in FIG. 5(c). Meanwhile, the cross-sectional shape of the lower plate 520 formed by the weakened portion 522 is not limited to the above-described examples and may be variously modified in consideration of ease of design, etc. Considering that the weakened portion 522 should be broken by heat or temperature, it is preferable that the weakened portion 522 include as many thin portions as possible. Therefore, the shape other than that shown in FIG. 5(b) is preferable to the shape shown in FIG. 5(b). However, the temperature and pressure at which the film breaks can be affected by factors such as thickness, physical properties, and shape, and the shape of FIG. 5(b) is not necessarily more preferable than the other shapes of FIG.

[0074] Figure 6 is a view showing an example of a cooling member according to an embodiment of the present invention provided in a battery cell stack. Figure 7 is an enlarged view of region B in Figure 6, illustrating the change in the lower plate when a battery cell ignites. Figure 8 is a cross-sectional view showing an example of a cooling member according to an embodiment of the present invention. It should be noted that the upper plate 510 is omitted from Figure 8.

[0075] 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 a pack frame, and a cooling member 500 may be disposed on the battery cell stack 120.

[0076] The cooling member 500 includes an upper plate 510 and a lower plate 520, and cooling water may be stored 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 weakened portions 522 formed on the lower plate 520 may be elongated along the stacking direction of the battery cells 110 so as to correspond to the battery cells 110 of the battery cell stack 120. Figures 6 and 7 show a cross section at a position where the weakened portions 522 are formed, and the upper surface of the lower plate 520 where the weakened portions 522 are not formed may be hidden by the cooling water and may not be 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 breaks out in the first battery cell 110a due to overcharging or other reasons, a first portion of the fragile portion 522 located above the first battery cell 110a may be broken by heat, gas, sparks, flames, etc. generated from the first battery cell 110a. When the first portion is opened, the coolant contained in the internal space of the cooling member 500 may be injected toward the first battery cell 110a where the fire has broken out. In this way, when a thermal runaway phenomenon occurs in the first battery cell 110a, the fragile portion 522 opens a portion thereof to immediately inject coolant into the first battery cell 110a, thereby quickly extinguishing the fire in the first battery cell 110a and achieving early suppression of the thermal runaway phenomenon compared to conventional water injection systems.

[0078] 7, heat or pressure generated from the battery cell 110 locally heats or pressurizes the vulnerable portion 522, thereby opening the first portion, so that only the first portion of the vulnerable portion 522 is opened, and the remaining portions of the vulnerable portion 522 remain closed. If the remaining portions of the vulnerable portion 522 other than the first portion remain closed, the cooling water inside the cooling member 500 may flow out concentratedly to the first portion. Therefore, compared to conventional water injection systems, the cooling water is injected concentratedly into the first battery cell 110a, maximizing the efficiency of water injection fire extinguishing.

[0079] Meanwhile, if an excessive amount of coolant is injected into a battery module or battery pack, the fire in the first battery cell 110a may be quickly extinguished, but the coolant may be injected into other battery cells 110, damaging several battery cells 110 that were operating normally. Therefore, the amount of coolant to be injected needs to be designed in advance to an appropriate level.

[0080] The amount of cooling water may be preset to a level sufficient to extinguish a fire occurring in several battery cells 110. Here, the number of battery cells 110 used as the basis for calculating the amount of cooling water is the number of battery cells 110 to which thermal runaway would normally be transmitted in the event of an internal fire, and may be, specifically, 4 to 6, or a number greater or less than 1 to 2. In addition, since the cooling water sprayed toward the first battery cell 110a evaporates as water vapor during the fire extinguishing process, the cooling water does not remain in the battery module or battery pack, preventing damage to healthy battery cells 110 due to residual moisture. Meanwhile, the amount of cooling water contained in the cooling member 500 may be calculated and designed in advance to match the energy released by the battery cells 110. Therefore, the cooling member 500 of this embodiment may be variously applied regardless of the type or capacity of the battery cells 110, such as cylindrical, prismatic, or pouch-shaped.

[0081] In this case, the cooling water of the cooling member 500 may or may not be circulated by being introduced from the outside. For example, the cooling member 500 may be connected to an external tank, and the cooling water introduced from the tank may circulate through the cooling member 500 through the inlet / outlet port 530 and be discharged from the tank again. This allows the temperature of the cooling water to be maintained appropriately, thereby improving the heat dissipation performance of the cooling member 500.

[0082] As another specific example, the cooling water inside the cooling member 500 may not be additionally introduced. The cooling water may be injected before the cooling member 500 is attached to 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 member 500 is not permanently connected to an external tank and is built into the battery pack or battery module, the overall structure may be simplified by omitting the external tank, which is efficient in space utilization and may reduce the cost and time required to maintain / manage the external tank. In such a case, the inlet / outlet port 530 may be omitted from the cooling member 500 to simplify the design. Because the cooling member 500 contains water with a high specific heat, heat transfer between the battery cells 110 in the battery module may 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 may be sprayed onto the battery cells 110, thereby minimizing problems caused by cooling water remaining in the battery module or battery pack.

[0083] In this way, if the cooling water in the cooling member 500 does not flow into the external tank, when the first battery cell 110a internally catches fire, the amount of cooling water injected into the battery module or battery pack may be limited to the entire amount of cooling water contained in the cooling member 500. Furthermore, if the cooling member 500 has a partition or groove therein to restrict the movement of cooling water inside the cooling member 500, the amount of cooling water injected into the first battery cell 110a may be limited to the amount of cooling water contained between the fragile portion 522 and the upper plate 510.

[0084] This also applies if the cooling member 500 has a system connected to an external tank. Specifically, the control system including the cooling member 500 can detect a heat transfer or thermal runaway phenomenon, and when a thermal runaway phenomenon is detected, can limit the amount of coolant supplied to the first battery cell 110a within the volume range of the cooling member 500 by controlling the inflow or circulation of additional coolant.

[0085] In this way, the fragile portion 522 according to this embodiment can quickly extinguish the fire and prevent continuous thermal runaway by injecting cooling water at the right time and place when a fire occurs inside the battery pack or battery module.

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

[0087] For example, the weakened portion 522 may be formed by partially etching the lower plate 520. The weakened portion 522 may be formed using a notching process. However, the equipment used in the etching process may be difficult to control precisely, and if the thickness of the lower plate 520 is thin or if the desired thickness of the weakened portion 522 is thin, the dimensional stability of the weakened portion 522 may be significantly reduced. For example, if the lower plate 520 is made of aluminum, the lower plate 520 may have a thickness of 4 mm, 3 mm, or 2 mm or less. The appropriate thickness of the weakened portion 522 may vary depending on the material of the weakened portion 522. However, if the lower plate 520 is made of aluminum, the weakened portion 522 is preferably formed to a thickness of 0.2 to 0.5 mm. In order to provide the weakened portion 522 in the lower plate 520, a thin film-level thickness must be formed by removing a portion of the already sufficiently thin lower plate 520. Therefore, if the equipment is not perfectly controlled, the lower plate 520 may be damaged during the formation of the weakened portion 522, resulting in an increase in defective products and wasted process time and costs. Therefore, when the lower plate 520 has the weak portion 522 as in this embodiment, the application of the etching process may not be preferable.

[0088] To ensure that the weakened portion 522 is formed with a sufficiently thin thickness, the lower plate 520 may be formed by bonding two layers. As shown in FIG. 8, the lower plate 520 may be formed by bonding a first layer 524, which is a plate-shaped member, and a second layer 526, which has a plurality of holes. For reference, the shaded portion in FIG. 8 represents the second layer 526, and the partially empty space between the shaded portions represents the cross section of a hole formed in the second layer 526. The hole formed in the second layer 526 may be a portion for forming the weakened portion 522 described above. The hole may have an elongated shape. One or more holes may be formed along a straight line parallel to the long side of the lower plate 520. When multiple holes are formed along a straight line parallel to the long side of the lower plate 520, the holes may not have an elongated shape depending on the number and spacing of the holes. In addition, the axial cross section of the hole may have various shapes, as shown in FIG. 5. The radial cross section of the hole may have an angular shape or a rounded shape.

[0089] A portion of lower plate 520 may have a relatively large thickness by including first layer 524 and second layer 526, while another portion of lower plate 520 may have a relatively small thickness by including only first layer 524. Here, the portion having first layer 524 may be referred to as the first portion, and the portion having both first layer 524 and second layer 526 may be referred to as the second portion. Thus, the thickness of the first portion may correspond to the thickness of first layer 524, and the thickness of the second portion may correspond to the thickness of first layer 524 and second layer 526.

[0090] When the lower plate 520 is formed by bonding two layers, the thickness of each layer can be freely adjusted, allowing the weakened portion 522 to be formed 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 formed of an aluminum plate having a thickness of 0.03 to 0.07 mm, 0.04 to 0.06 mm, or 0.05 mm, and the second layer 526 may be formed of an aluminum plate having a thickness of 1.0 to 1.5 mm or more with holes formed therein. Here, if a design requires mechanical rigidity, the thickness of the first layer 524 may be designed to be thick enough to melt due to thermal runaway of the battery cell. Therefore, the first layer 524 may be formed to have a thickness slightly greater than the aforementioned thickness. When the aluminum plate of the second layer 526 is bonded to one side of the first layer 524, a lower plate 520 having a sufficiently thin weakened portion 522 may be formed.

[0091] Here, when the lower plate 520 is formed by bonding two layers, all of the weakened portions 522 are formed from a single plate, and therefore may have the same thickness. When the first and second weakened portions are formed in the lower plate 520, the thicknesses of the first and second weakened portions may be substantially the same. Furthermore, the thickness of each weakened portion 522 may not vary depending on its position. If thickness variation occurs in the weakened portions 522 depending on their position, some portions may be formed thicker than designed, making them less likely to break under heat or pressure. However, because all of the weakened portions 522 in this embodiment are formed to have a uniform thickness, it is possible to minimize errors between the design and the actual product.

[0092] Various bonding processes may be used to bond the two layers that form the lower plate 520. Since cooling water is located on the upper surface of the lower plate 520, the bond between the two layers must be firm.

[0093] For example, the two layers may be bonded together through a welding process. Examples of welding processes used for this bonding include brazing and laser welding. The two layers may be fused together by applying a temperature similar to the melting point of the material to the two layers. Through this fusion bonding, the watertightness of the lower plate 520 may be achieved to a desired level.

[0094] As another example, the bond between the two layers may be formed through a rolling process. A rolling process is a method of joining two or more layers by passing a laminate of two or more layers between a pair of rolls. In the interlayer joining by rolling, the laminate is heated. If the heating temperature is equal to or higher than the recrystallization temperature of the metal, this is called hot rolling, and if the heating temperature is lower than this temperature, this is called cold rolling. By applying pressure and / or heat to the laminate, a wide bonding surface between the two layers may be formed, thereby ensuring sufficient watertightness of the lower plate 520.

[0095] On the other hand, when the lower plate 520 is formed by bonding two layers, the materials of the two layers may be different or the same or similar. If the materials of the two layers are the same or similar, the melting points of the two layers are the same / similar, which makes it easier to perform the bonding process using heat or pressure.

[0096] However, when joining two layers through a brazing process, the joining process may not proceed smoothly depending on the physical properties or melting point of the metal. For example, if the two layers are made of a single piece of aluminum, setting the brazing process temperature at 660°C, the melting point of aluminum, may cause deformation of the aluminum layer during the joining process. To prevent such deformation, the first layer 524 or the second layer 526 may be made of a clad metal, which is a double-layered metal material.

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

[0098] The above-described 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 joining between the two members can be more dense. 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] Meanwhile, the above description has focused on the case where the lower surface of the lower plate 520 having the weakened portion 522 is flat. However, the stepped portion, i.e., the groove, of the lower plate 520 formed by locally adjusting the thickness may be exposed to the outside rather than facing the inside of the cooling member 500.

[0100] Figure 9 is a view showing another example of the AA cross section of Figure 3. Figure 10 is a view showing another example of a cooling member according to an embodiment of the present invention provided in a battery cell stack. Figure 11 is an enlarged view of region C in Figure 10, illustrating the change 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 an embodiment of the present invention.

[0101] 9 to 12, unlike the weakened portions 522 of FIGS. 5 to 8, which are formed to be located close to the lower surface of the lower plate 520, the weakened portions 522 may be formed to be located close to the upper surface of the lower plate 520. When the weakened portions 522 are located close to the upper surface of the lower plate 520 as in FIGS. 9 to 12, the lower surface of the cooling member 500 may have a locally protruding shape. Therefore, the protruding lower surface of the cooling member 500 may be located close to or in contact with the battery cells, thereby facilitating heat dissipation from the battery cells.

[0102] 9, the cross section of the lower plate 520 may have a rectangular, triangular, rounded, or trapezoidal cross section. The cross section of FIG. 9 can be described with reference to FIG. 5 except that the top and bottom directions are reversed, and therefore detailed description thereof will be omitted.

[0103] FIGS. 10 and 11 are cross-sectional views of a cooling member 500 on a battery cell stack, taken along the x-z plane. The cross-sectional view is different from that of FIGS. 6 and 7, and more specifically illustrates the cross-section of the cooling member 500. While FIGS. 6 and 7 illustrate the positional relationship between multiple battery cells 110 and the weak portions 522, FIGS. 10 and 11 illustrate the positional relationship between one battery cell 110 and the weak portion 522. Referring to FIGS. 10 and 11, one battery cell 110 may correspond to multiple weak portions 522, and depending on the location of the battery cell 110 where ignition occurs, the corresponding weak portion 522 may open. Therefore, when a battery cell 110 ignites, one or more of the weak portions 522 may open. Here, the opening of the weak portion 522 includes the case where only a portion of one weak portion is opened, and does not necessarily mean that the entire weak portion 522 is opened.

[0104] 10 and 11 differ from Figures 6 and 7 in that the bottom surface of the cooling member 500 has a protruding shape. Even if the bottom surface of the cooling member 500 has a protruding shape, when the battery cell 110 ignites, the weak portion 522 opens, allowing coolant to enter the battery cell 110. Therefore, a detailed description of Figures 10 and 11 can be given based on the content of Figures 6 and 7. Therefore, a detailed description will be omitted to avoid duplication.

[0105] Meanwhile, the lower plate 520 having a protruding lower surface and the weakened portion 522 formed thereon may be formed in various ways. For example, the weakened portion 522 may be formed by etching the lower surface of the lower plate 520. As another example, the lower plate 520 may be formed by bonding two layers together.

[0106] Specifically, the lower plate 520 may be formed by joining a first layer 524, which is provided as a plate-shaped member, and a second layer 526, which has a plurality of holes, as shown in FIG. 12. The second layer 526 may be positioned below the first layer 524 to form the lower surface of the lower plate 520. When the second layer 526 and the first layer 524 are joined by a brazing process, the first layer 524 may include a 3000-series or 4000-series clad metal, and the second layer 526 may include a 3000-series aluminum. The upper plate 510 may also be made of 3000-series aluminum, and the interlayer bonding may be facilitated through the 4000-series aluminum formed on the upper and lower surfaces of the first layer 524, which is provided as a clad metal. Alternatively, the first layer 524 may be made of 3000-series aluminum, and the second layer 526 or the upper plate 510 may be made of a 3000-series or 4000-series clad metal.

[0107] The bonding method of the lower plate 520 and the first and second layers 524 and 526 can be described in detail with reference to the description of FIG. 8, except for the positions of the layers, and therefore detailed description thereof will be omitted.

[0108] Hereinafter, a cooling member according to another embodiment of the present invention will be described.

[0109] FIG. 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 with reference to Fig. 13 may include all of the above-described contents of Figs. 1 to 12 except as noted below. Therefore, to minimize repetition, the same contents as those described above will be omitted.

[0111] 13, the cooling member 500 of this embodiment may have three layers. Specifically, the upper plate 510 of the cooling member 500 may have one layer, and the lower plate 520 may have two layers. Here, the lower plate 520 having two layers has been fully described above, so a detailed description will be omitted.

[0112] In the cooling member 500, the cooling water is contained between the upper plate 510 and the lower plate 520, and therefore the deviation in the flow rate of the cooling water may be determined by the distance between the upper plate 510 and the lower plate 520. In the above-described drawings, the upper plate 510 of the cooling member 500 is shown to have an overall flat surface except for the flow path forming grooves 550 and the deformation prevention grooves 560. Therefore, the deviation in the flow rate of the cooling water may depend on the difference in thickness of the lower plate 520. Specifically, the flow rate per unit length may be relatively high around the first portion where the fragile portions 522 are formed, and the flow rate per unit length may be relatively low around the second portion where the fragile portions 522 are not formed. If the flow rate around the first portion is higher, the cooling water may be injected more quickly due to flow pressure when the fragile portions 522 are opened, and therefore a larger flow rate around the first portion is preferable.

[0113] Therefore, in this embodiment, an upper plate 510 having a bent portion 514 may be provided to form a flow rate deviation of the coolant in the cooling member 500. The bent portion 514 may have a corrugated cross-sectional shape based on a cross section in the longitudinal direction of the cooling member 500. Here, based on the cross section, the highest point, i.e., a crest, of the bent portion 514 may correspond to a first portion of the lower plate 520 where the weak portion 522 is formed. Furthermore, the lowest point, i.e., a trough, of the bent portion 514 may correspond to a second portion of the lower plate 520. By having the crest of the bent portion 514 correspond to the first portion, the flow rate per unit length around the first portion may increase, and when the weak portion 522 is opened, the coolant in the cooling member 500 may be more quickly injected toward the first battery cell 110a where the ignition occurred.

[0114] 13 shows that the valley of the bent portion 514 is positioned close to the second portion of the lower plate 520, but the valley of the bent portion 514 may be positioned away from the second portion of the lower plate 520 so that the cooling member 500 can hold a larger amount of coolant. However, if the distance is too large, the overall volume of the cooling member 500 increases, which may result in an increase in the size of the battery module. Therefore, the cooling member 500 should be appropriately designed taking into account the amount of heat generated by the battery cells 110, etc.

[0115] 13 shows the layers of the cooling member 500 being arranged in the order of first layer 524, second layer 526, and upper plate 510, but they may also be arranged in the order of second layer 526, first layer 524, and upper plate 510. If the second layer 526 is arranged below the first layer 524, the second layer 526 may cause the lower surface of the cooling member 500 to have a protruding shape. The second layer 526, which forms the lower surface of the cooling member 500, may be located close to or in contact with the battery cells. Therefore, if the second layer 526, first layer 524, and upper plate 510 are arranged in this order, the second layer 526 may have the effect of promoting heat dissipation from the battery cells.

[0116] In addition, in the cooling member 500 provided as shown in FIG. 13, the thickness of each layer must be appropriately designed to minimize the overall volume while maintaining strength within 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. If 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. In addition, the second layer 526 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 the fragile portion 522, and may have a thickness of 0.03 to 0.07 mm or 0.04 to 0.06 mm.

[0117] Various processes can be applied to the interlayer bonding of the three-layer cooling member 500. Since cooling water is present inside the cooling member 500, the bonding between the three layers must be firm.

[0118] As an example, the bond between the three layers may be formed through a welding process.

[0119] As another example, the bonding of the three layers may be formed through a rolling process, but when a rolling process that applies pressure through rollers is applied, the formation of the top plate 510 may be somewhat limited.

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

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

[0122] 13, the positions of the first layer 524 and the second layer 526 may be interchangeable. In this case, if the layers are joined by brazing, the materials of the second layer 526 and the top plate 510 bonded to the first layer 524 may be limited depending on the physical properties of the first layer 524. As a specific example, the first layer 524 may include 3000-series aluminum, and the second layer 526 and the top plate 510 may include a clad metal containing 3000-series / 4000-series aluminum. As another specific example, the first layer 524 may include a 3000-series / 4000-series clad metal, and the second layer 526 and the top plate 510 may include 3000-series aluminum.

[0123] A battery pack including the above-described cooling member will now be described.

[0124] The battery pack 1000 of the embodiment described with reference to Figures 14 and 15 may include all of the above-mentioned contents of Figures 1 to 13 in addition to those mentioned below. Therefore, to minimize redundant description, the above-mentioned contents related to the cooling member 500 will be omitted.

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

[0126] 14, a battery pack 1000 according to an embodiment of the present invention may include at least one battery module 100, a pack frame 200 that houses the battery module 100, a resin layer 300 formed on the inner surface of the pack frame 200, an end plate 400 that closes the open side 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 above-mentioned components omitted or with other components not mentioned added, depending on the design.

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

[0128] Typically, conventional battery packs have a double-assembly structure in which a battery module is formed by assembling a battery cell stack and various components connected thereto, and multiple battery modules are then housed in the battery pack. Since the battery module includes a module frame that forms its outer surface, the conventional battery cells are doubly protected by the module frame of the battery module and the pack frame of the battery pack. However, this double-assembly structure not only increases the manufacturing cost and manufacturing process of the battery pack, but also reduces reassembly if some battery cells are defective. Furthermore, if a cooling element is present outside the battery module, the heat transfer path between the battery cells and the cooling element becomes somewhat complicated.

[0129] Therefore, the battery module 100 of this embodiment may be provided in the form of a "cell block" in which the module frame is omitted, and the battery cell stack 120 included in the cell block may 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 achieves the effect of reducing the weight of the battery pack.

[0130] Hereinafter, 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 battery module 100 is a general term for a battery module having a battery cell stack 120 segmented into predetermined units for modularization, regardless of whether or not it has a module frame, and the battery module 100 should be interpreted as including all ordinary battery modules and cell blocks that have a module frame.

[0131] Referring to FIG. 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 battery cell stack 120 in the stacking direction, holding straps 140 that surround the side plates 130 and the battery cell stack 120 to fix their shape, and bus bar frames 150 that cover the front and rear of the battery cell stack 120.

[0132] Meanwhile, although FIG. 15 shows a battery module 100 provided in the form of a cell block, the content of this drawing does not exclude the application of a sealed structure 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 cells 110 may be provided in a pouch or prismatic shape to maximize the number of cells stacked per unit area. For example, a pouch-type battery cell 110 may be manufactured by placing an electrode assembly including a positive electrode, a negative electrode, and a separator in a cell case made of a laminate sheet and then heat-sealing the sealing portion of the cell case. While FIGS. 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; the electrode leads of the battery cell 110 may also protrude in the same direction.

[0134] The battery cell stack 120 may be formed by stacking a plurality of electrically connected battery cells 110 in one direction. The direction in which the plurality of battery cells 110 are stacked (hereinafter referred to as the "stacking direction") may be the y-axis direction (or the -y-axis direction, and hereinafter the term "axis direction" may be interpreted as including both the + / - directions) as shown in Figures 14 and 15.

[0135] Meanwhile, since the battery cells 110 are arranged in one direction, the electrode leads of the battery cells 110 may be located on one side of the battery cell stack 120, or on one side and the other side facing the one side. In this manner, the side of the battery cell stack 120 on which the electrode leads are located may be referred to as the front or rear side of the battery cell stack 120, and in Figures 14 and 15, the front and rear sides of the battery cell stack 120 are shown as two sides facing each other on the x-axis.

[0136] In addition, the surface of the battery cell stack 120 on which the outermost battery cell 110 is located may 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 supplement the rigidity of the cell blocks in place of a module frame. The side plates 130 may be disposed on both ends of the battery cell stack 120 in the stacking direction, and may be in contact with the outermost battery cells 110 on both sides of the battery cell stack 120.

[0138] The side plate 130 may be made of various materials and provided through various manufacturing methods. For example, the side plate 130 may be made of a plastic material manufactured by injection molding. For another example, the side plate 130 may be made of a leaf spring material. For still another example, the side plate 130 may be made of an elastic material that allows its shape to be partially deformed in response to a volume change of the battery cell stack 120 due to swelling.

[0139] The holding straps 140 may be used to fix the position and shape of the side plates 130 on both ends of the battery cell stack 120. The holding straps 140 may be members having a length and a width. Specifically, the battery cell stack 120 may be positioned between the two side plates 130 that contact the outermost battery cells 110, and the holding straps 140 may connect the two side plates 130 across the battery cell stack 120. In this way, the holding straps 140 may 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 the length direction for stable connection with the side plate 130. The locking portions may be formed by bending both ends in the length direction of the holding strap 140. Meanwhile, 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 may be stably connected through connection between the locking portions and the locking grooves.

[0141] The holding straps 140 may be made of various materials or manufactured using various methods. For example, the holding straps 140 may be made of an elastic material, which allows the volumetric change of the battery cell stack 120 due to swelling to be within a certain range.

[0142] Meanwhile, the holding straps 140 are used to secure the relative positions between the side plates 130 and the battery cell stack 120, and may be provided in a form different from that shown in the drawings as long as their purpose as a "securing member" is achieved. For example, the securing member may be provided in the form of a long bolt that can cross between two side plates 130. The side plates 130 may have grooves into which the long bolts can be inserted, and the long bolts can be fastened to the two side plates 130 simultaneously through the grooves to secure the relative positions of the two side plates 130. The long bolts may be provided on the periphery of the side plates 130, preferably near the apex of the side plates 130. Depending on the design, the holding straps 140 may be substituted for the long bolts described above, or both the holding straps 140 and the long bolts may be provided on the cell block.

[0143] The bus bar frame 150 may be positioned on one side of the battery cell stack 120 to cover that side and guide the connection of the battery cell stack 120 to an external device. The bus bar frame 150 may be positioned on the front or rear side of the battery cell stack 120. Two bus bar frames 150 may be provided, one positioned on the front side and one on the rear side of the battery cell stack 120. Bus bars may be attached to the bus bar frames 150, and thus, electrode leads of the battery cell stack 120 may be connected to the bus bars, thereby electrically connecting the battery cell stack 120 to an external device.

[0144] The bus bar frame 150 may include an electrically insulating material. The bus bar frame 150 may limit contact between the bus bar and other parts of the battery cell 110 other than the part connected to the electrode lead, thereby preventing an electrical short circuit.

[0145] The pack frame 200 may be configured to protect the battery module 100 and the electrical components connected thereto from external physical impacts. The pack frame 200 may accommodate the battery module 100 and the electrical components connected thereto in an internal space of the pack frame 200. Here, the pack frame 200 includes an internal surface and an external surface, and the internal space of the pack frame 200 may be defined by the internal surface.

[0146] A plurality of battery modules 100 may be accommodated within the pack frame 200. A plurality of battery modules 100 may be referred to as a "module assembly." The module assemblies may be arranged in rows and columns within the pack frame 200. Here, a "row" refers to a set of battery modules 100 arranged in one direction, and a "column" refers to a set of battery modules 100 arranged in a direction perpendicular to the one direction. For example, the battery modules 100 may be arranged in a row or column along the stacking direction of the battery cell stack, as shown in FIG. 1, to form a module assembly.

[0147] The pack frame 200 may be provided in a hollow shape that is open in one direction. For example, as shown in FIG. 1, a plurality of battery modules 100 may be positioned consecutively in the stacking direction of the battery cells 110, and the pack frame 200 may have a hollow shape that is open in the stacking direction.

[0148] The structure of the pack frame 200 may vary. For example, as shown in FIG. 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 disposed on the plate-shaped lower frame 210, and the U-shaped upper frame 220 may be provided to surround the top surface of the module assembly and two sides on the x-axis.

[0149] The pack frame 200 may include a portion with high thermal conductivity to quickly release heat generated in the 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 an alloy containing these. In addition, the pack frame 200 may be partially electrically insulating, and an insulating film may be provided or an insulating coating may be applied to a location where insulation is required. The portion of the pack frame 200 to which the insulating film or insulating coating is applied may also be referred to as an insulating portion.

[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 a cooling member 500 (described later) and the upper frame 220.

[0151] The resin layer 300 may be formed by injecting a resin between the battery cell stack 120 and one side of the inner surface of the pack frame 200. However, this is not necessarily limited to this, and the resin layer 300 may be a member provided in a plate shape.

[0152] The resin layer 300 may be made of various materials, and the function of the resin layer 300 may vary depending on the material. For example, the resin layer 300 may be made of an insulating material, and the insulating resin layer 300 may prevent electron transfer between the battery module 100 and the pack frame 200. As another example, the resin layer 300 may be made of a thermally conductive material. The resin layer 300 made of a thermally conductive material may transfer heat generated in the battery cells 110 to the pack frame 200, thereby dissipating / transferring the heat to the outside. As another example, the resin layer 300 may include an adhesive material, which may fix the battery module 100 and the pack frame 200 to each other. As a specific example, the resin layer 300 may be provided to include at least one of a silicone-based material, a urethane-based material, and an acrylic-based material.

[0153] The end plates 400 may serve to protect the battery modules 100 and the electrical components connected thereto from external physical impacts by sealing the open sides of the pack frame 200. Each edge of the end plate 400 may be joined to a corresponding edge of the pack frame 200 by a method such as welding. Two end plates 400 are provided to seal the two open sides of the pack frame 200, and may be made of a metal material having a predetermined strength.

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

[0155] The cooling member 500 may cool the inside of the battery pack 1000 by dissipating heat generated from the battery cells 110. For the description of the cooling member 500, please refer to the above contents.

[0156] 14 shows the cooling member 500 provided outside the battery module 100, this is not necessarily limited thereto, and the cooling member 500 may be disposed inside the battery module 100. In this case, the battery module 100 may have a closed structure having a module frame, or an open structure such as a cell block.

[0157] Furthermore, although the above-described drawings show the cooling member 500 as having an independent structure, the cooling member 500 may be provided integrally with the battery pack 1000 or the battery module 100. For example, when the cooling member 500 is provided integrally with the battery pack 1000, the upper plate 510 of the cooling member 500 may replace the upper surface of the pack frame 200, and the upper surface of the pack frame 200 may be coupled to the lower plate 520 of the cooling member 500 to form the cooling member 500. As another example, when the cooling member 500 is provided integrally with the battery module 100, the upper plate 510 of the cooling member 500 may replace the upper surface of the frame of the battery module 100, and the upper surface of the frame of the battery module 100 may be coupled to the lower plate 520 of the cooling member 500 to form the cooling member 500. When the cooling member 500 is integrated with the battery pack 1000 or the battery module 100 in this manner, effects such as weight reduction, cost reduction, or simplification of the internal structure of the battery pack 1000 or the battery module 100 can be achieved by omitting some components.

[0158] Furthermore, although the battery module 100 of this embodiment has been described as including the water-cooled cooling member 500, this description does not exclude the possibility that the battery module 100 may also include an air-cooled cooling member. Therefore, it should be made clear that the battery module 100 of this embodiment may also include both the air-cooled and water-cooled cooling members 500 at the same time.

[0159] Hereinafter, a cooling member according to still another embodiment of the present invention will be described.

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

[0161] 16 and 17, the cooling member 600 of this embodiment may be provided to reduce 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 coolant is injected. By providing the cooling member 600 as a water-cooled type, the cooling efficiency of the cooling member 600 can be uniformly maintained, and the battery cells in the battery module or battery pack can be uniformly cooled. In this case, the coolant used in the cooling member 600 may be one of known types or a mixture thereof, and any known type may be used as long as it can dissipate heat from the battery cells by moving along a flow path inside the cooling member 600.

[0162] The cooling member 600 may be disposed on one side of the battery cell stack to dissipate heat from the battery cells. The cooling member 600 may be disposed parallel to the stacking direction of the battery cell stack so as to be positioned close to the plurality of battery cells of 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 may be adjusted to the size of the battery cell stack to which the cooling member 600 is applied. As an example, the cooling member 600 may be provided to accommodate one battery cell stack, and in this case, the length of the cooling member 600 may be adjusted to the length of the battery cell stack or may be larger or smaller with a certain margin, and the width of the cooling member 600 may be adjusted to the width of the battery cell stack or may be larger or smaller with a certain margin. As another example, the cooling member 600 may be provided to accommodate a plurality of battery cell stacks, and in this case, the length and width of the cooling member 600 may be adjusted to the length and width of the plurality of battery cell stacks or may be larger or smaller with a certain margin. Here, the cooling member 600 may be located inside the battery module, but it may also be located outside the battery module inside the battery pack.

[0164] Cooling member 600 may include a lower plate 620, inlet / outlet ports 630 for injecting cooling water into cooling member 600, a body 640 attached to the upper surface of lower plate 620 and containing the cooling water, cooling hoses 650, and a fixing member 660 for fixing them in place. Referring to Fig. 20, cooling member 600 may be manufactured by attaching body 640 to the upper surface of lower plate 620, attaching cooling hoses 650 to receiving portions 648 of body 640, and fixing member 660 to fix lower plate 620, body 640, and cooling hoses 650 together.

[0165] The cooling member 600 of this embodiment ensures watertightness through the above-described structure, simplifies the manufacturing process, and can supply cooling water at the right time and place when a battery cell catches fire.

[0166] In order to effectively suppress a fire in a battery cell, it is effective to inject a liquid such as cooling water into the battery module or battery pack. Since providing a liquid tank inside the battery module or battery pack can increase the volume of the battery module and battery pack, in the past, a separate water tank was provided outside the battery module or battery pack, and cooling water was injected into the battery module or battery pack through a nozzle extended from the water tank only when a battery cell fire was confirmed by a sensor.

[0167] However, water tanks installed outside the battery module and battery pack are not only bulky, but also require 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. Errors must be avoided during these operations, and even if the system is operating normally, multiple decision processes must be performed, resulting in significant time consumption. Even after the decision to inject cooling water is 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 for the water to be quickly delivered from the water tank to the battery cells, making it difficult for conventional water injection systems to prevent rapid, continuous thermal runaway. Therefore, in the present embodiment, an opening may be formed in the lower plate 620 of the cooling member 600, and a cooling hose 650 may be positioned corresponding to the opening so that cooling water can be quickly delivered to the location of the fire in the event of an internal fire in the battery module or battery pack.

[0168] To achieve a similar effect, an opening can be formed in the underside of a conventional cooling member and then sealed by filling or inserting a material that melts or breaks at a predetermined temperature or pressure. However, in a conventional structure in which the cooling water of the cooling member 600 directly contacts the lower plate 620, the cooling water can leak through a gap between the opening in the lower plate 620 and the material sealing it, significantly reducing the watertightness of the cooling member 600. Furthermore, manufacturing the lower plate 620 to include two materials with different physical properties requires complex manufacturing processes, which increases manufacturing time and costs. Therefore, in the cooling member 600 of this embodiment, the cooling water is isolated between the main body 640 and the cooling hose 650, minimizing the reduction in watertightness due to the opening 622 in the lower plate 620. Furthermore, by incorporating the main body 640 and the cooling hose 650 into the cooling member 600, the manufacturing process of the cooling member 600 can be simplified, reducing manufacturing time and costs.

[0169] 18, the lower plate 620 may be provided in a plate shape. A main body 640 through which cooling water flows and a cooling hose 650 may be attached to the lower plate 620. The lower plate 620 is preferably provided in a plate shape to support the main body 640, etc.

[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 due to heat or pressure generated by the ignition in the event of an internal fire in the battery cell. A plurality of 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 may include a plurality of openings 622, thereby allowing cooling water to be injected in response to a fire occurring at an unspecified position within the battery module or battery pack. In this regard, please refer to FIG. 22, which will be described later.

[0171] A protrusion 624 may be formed around the periphery of 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 protrusion 624 may be disposed in contact with or adjacent to an electrode lead of each battery cell stack or a bus bar connected to the electrode lead. Because the electrode leads or bus bars that provide electrical connection in a battery module or battery pack are prone to heat generation, if the protrusion promotes heat dissipation from the electrode leads or bus bars, an increase in temperature of the battery cells may be more effectively prevented.

[0172] The lower plate 620 may have a bank 626 formed thereon. The bank 626 may extend along the length of the cooling member 600 at the center of the width of the cooling member 600 except for a predetermined section. The bank 626 may allow the main body 640 to be properly mounted and the fixing member 660 to be stably fixed. Here, the width direction of the cooling member 600 may be parallel to the short sides of the cooling member 600. Also, here, the length direction of the cooling member 600 may be parallel to the long sides 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 cells. The lower plate 620 may be made of a material with high thermal conductivity to promote heat dissipation from the battery cells. The lower plate 620 of the cooling member 600 may be made of a metal with high rigidity, specific examples of which include aluminum, gold, silver, copper, platinum, or alloys containing these metals.

[0174] Coolant may be supplied through the inlet ports 632 arranged side by side and discharged from the outlet port 634. The inlet port 632 and the outlet port 634 may be arranged parallel to one end of the cooling member 600. This may simplify the design for the inflow and outflow of coolant supplied from the outside of the battery module or battery pack. This may also minimize the temperature difference between the area around the inlet port 632 and the area around the outlet port 634. Specifically, the coolant flowing into the inlet port 632 may have the lowest temperature, and the coolant discharged from the outlet port 634 may have the highest temperature. Therefore, when the inlet / outlet ports 630 are arranged adjacent to each other, heat exchange occurs between them, minimizing the temperature difference of the entire coolant flowing within the interior space of the cooling member. Therefore, by arranging the inlet / outlet ports 630 side by side, the cooling member 600 may have uniform heat dissipation performance overall.

[0175] 19 to 21, the main body 640 may provide a coolant flow path for dissipating heat from the battery cells. Coolant is injected into the main body 640 through an inlet port 632 and may be discharged from the main body 640 through an outlet port 634. The inflow and outflow of coolant into the main body 640 allows the cooling member 600 to be maintained at a relatively constant temperature. The coolant in the main body 640 may be designed to circulate continuously through an external heat exchanger connected to the inlet / outlet port 630 to maintain the temperature constant.

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

[0177] The body 640 may be attached to the lower plate 620 at a position where the bank 626 is not formed. The outer shape of the body 640 may be similar to the outer shape of the lower plate 620 except for the protrusion 624.

[0178] The main body 640 may have a rectangular tubular shape and may be branched into two portions 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 portion 642 extending from the inlet port 632 along a straight line parallel to the length of the cooling member 600, a second portion 644 extending from an end of the first portion 642 along a curve that rotates clockwise or counterclockwise, and a third portion 646 extending from an end of the second portion 644 toward the outlet port 634 along a straight line parallel to the length of the cooling member 600. Here, the length 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 receiving portion 648 to which the cooling hose 650 is attached. The receiving portion 648 may refer to a receiving space in the main body 640 to which the cooling hose 650 is attached. The receiving portion 648 is a long groove extending along the length of the cooling member 600, and the cross section of the receiving portion 648 may be a polygon such as a square or a circle. The cooling hose 650 may be connected to both ends of the receiving portion 648 in the length direction. The cooling hose 650 may be inserted into both ends of the receiving portion 648 in the length direction. The connection portions between the cooling hose 650 and the receiving portion 648 in the length direction and the cooling hose 650 may be sealed to ensure watertightness. For example, a gasket may be provided at the connection portion between the cooling hose 650 and the receiving portion 648, and watertightness between the two components may be ensured through the gasket. As another example, both ends of the cooling hose 650 may be formed with circumferentially extending extensions at the ends of the cooling hose 650, and the extensions may be inserted into the ends of the receiving portions 648 and positioned inside the main body 640 to complement the connection between the cooling hose 650 and the main body 640. As another example, the end of the cooling hose 650 may be formed with a first circumferentially extending extension and a second circumferentially extending extension spaced apart from the first extension. The first extension may be positioned inside the main body 640, and the second extension may be positioned outside the main body 640, and the two extensions may be closely attached to the main body 640 to further complement the connection between the cooling hose 650 and the main body 640. In this case, a protrusion may be formed on the extension, the first extension, or the second extension, and the protrusion may allow for closer attachment to one side of the main body 640.

[0180] The cooling hose 650 is connected to the main body 640 and can provide a flow path for the coolant that dissipates heat from the battery cells. The coolant flowing in from the inlet / outlet port 630 can flow through the cooling hose 650. The cooling hose 650 can receive the coolant from the main body 640 located near the inlet / outlet port 630.

[0181] The cooling hoses 650 may be positioned to correspond to the openings 622 of the lower plate 620. When four rows of openings 622 are formed in the lower plate 620 along a straight line parallel to the length direction of the cooling member 600 as shown in Fig. 18, four cooling hoses 650 may be provided to correspond to each row of the openings 622. Here, the term "row" may collectively refer to openings 622 positioned consecutively along a straight line parallel to the length direction of the cooling member 600.

[0182] 22, in the event of an internal fire, cooling hose 650 melts or breaks, allowing internal cooling water to be injected toward the battery cell. When a battery cell catches fire, a portion of cooling hose 650 corresponding to opening 622 melts or breaks and opens, allowing cooling water to be sprayed, spurted, or injected in the direction of gravity, thereby extinguishing the fire in the battery cell located below cooling member 600. Meanwhile, to achieve this effect, receiving portion 648 to which cooling hose 650 is attached must also be formed to correspond to opening 622 of lower plate 620.

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

[0184] Meanwhile, to achieve the above-described effect, it may be possible to configure the cooling water to be introduced by breaking a portion of the main body 640, without separately manufacturing the cooling hose 650. However, in order for the main body 640 to withstand the pressure of the cooling water flowing inside and to maintain its shape, the main body 640 must be made of a material with sufficient rigidity. Therefore, manufacturing the main body 640 from a material that is easily melted by heat or broken by pressure may reduce the overall durability of the cooling member 600. Therefore, configuring the cooling hose 650, which can be easily broken by heat, separately from the main body 640, as in this embodiment, is preferable for improving the performance of the entire cooling member 650.

[0185] The fixing member 660 may be used to supplement the rigidity of the cooling member 600 by fixing the lower plate 620 to the main body 640 and the cooling hose 650. The fixing member 660 may fix the positions of the main body 640 and the cooling hose 650 by being coupled to the lower plate 620.

[0186] The fixing member 660 may be provided in the form of a strap having a length. The fixing member 660 may be positioned parallel to the width direction of the cooling member 600. A plurality of fixing members 660 may be provided along the length direction of the cooling member 600, and the plurality of 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 attached to both ends of the cooling member 600 in the width direction. The fixing member 660 may be attached to the center of the cooling member 600 in the width direction. The fixing member 660 may include end connecting portions 662 formed at both ends of the fixing member 660 in the length direction, and a center connecting portion 664 formed at the center of the fixing member 660 in the length direction. The end connecting portions 662 and the center connecting portion 664 may refer to portions of the cooling member 600 that are fastened together using fastening members such as rivets. The end connecting portions 662 and the center connecting portion 664 may be formed with fasteners into which fastening members can be inserted.

[0189] The fixing member 660 may be connected to both ends of the lower plate 620 in the width direction. The fixing member 660 may be connected to the center of the lower plate 620 in the width direction. The end connecting portions 662 may be connected to the protrusions 624 located at both ends of the lower plate 620 in the width direction. The center connecting portion 664 may be connected to the bank 626 located at the center of the lower plate 620 in the width direction. The end connecting portions 662 and the center connecting portion 664 may be formed to have a step with other portions of the fixing member 660, and may have a slightly lower height than other portions of the fixing member 660. When considering the shapes of the protrusions 624 and the bank 626, the end connecting portion 662 may be formed to have a larger step than the center connecting portion 664.

[0190] In this way, when using fixing member 660 in manufacturing cooling member 600, excessive heat is not generated during the manufacturing process compared to joining methods such as a welding process, and therefore specific materials that are vulnerable to temperature are not deformed during the manufacturing process. Therefore, by using fixing member 660, cooling member 600 can be manufactured to include two or more materials with different properties, and various materials and shapes, such as cooling hose 650, can be applied to cooling member 600, making the design of cooling member 600 easier and more diverse.

[0191] Hereinafter, a method for manufacturing a cooling member according to another embodiment of the present invention will be described. The method for manufacturing a cooling member 600 described below includes all of the above-described contents related to the cooling member 600, and detailed description of overlapping contents will be omitted.

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

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

[0194] The step of attaching the body 640 to the lower plate 620 is a process of joining the lower plate 620 and the body 640, and may be performed by a joining process such as welding. When a welding process is used to join the lower plate 620 and the body 640, the more similar the materials of the lower plate 620 and the body 640 are, the more likely it is that deformation or damage to some components due to welding temperatures will be minimized, and the dimensional stability of the cooling member 600 will 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 receiving portion 648 of the main body 640 and connecting both ends of the cooling hose 650 to both ends of the receiving portion 648. Here, the connection portion between the cooling hose 650 and the receiving portion 648 may be sealed.

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

[0197] Meanwhile, although not specifically mentioned above, the cooling member 600 according to another embodiment of the present invention may be installed in a battery module or a battery pack. A battery module according to another embodiment of the present invention includes a battery cell stack consisting of a plurality of battery cells and a module frame that houses the battery cell stack, and 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 may be provided in various forms.

[0199] For example, a battery pack according to another embodiment of the present invention may include at least one of the battery modules described above. The battery pack of this example may include a pack frame and at least one battery module mounted in the pack frame, and the battery module may include a battery cell stack, a module frame, and a cooling member positioned between the battery cell stack and the module frame.

[0200] As another example, a battery pack according to another embodiment of the present invention may include at least one battery module including a battery cell stack and a module frame accommodating the battery cell stack, a cooling member 600, and a pack frame accommodating the battery module and the cooling member 600. That is, in this example, the cooling member 600 may be provided outside the battery module. The cooling member 600 is provided between the module frame of the battery module and the pack frame, and cooling water may be injected toward the battery module in the event of a fire inside or outside the battery module.

[0201] As another example, a battery pack according to another embodiment of the present invention may include a battery cell stack and a pack frame that houses the battery cell stack, 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 outer shape is maintained through fixing members such as side plates or holding straps, and a battery cell stack of this type may be called a cell block.

[0203] Typically, a battery pack may have a double-assembly structure in which a battery module is formed by assembling a battery cell stack and various components connected thereto, and multiple battery modules are then housed in the battery pack. In this case, the battery module includes a module frame that forms its outer surface, so that conventional battery cells are doubly protected by the module frame of the battery module and the pack frame of the battery pack. However, this double-assembly structure not only increases the manufacturing cost and manufacturing process of the battery pack, but also reduces reassembly if some battery cells are defective. Furthermore, if a cooling element is present outside the battery module, the heat transfer path between the battery cells and the cooling element becomes somewhat complicated. 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 connected to the pack frame of the battery pack. This simplifies the battery pack structure, provides advantages in manufacturing cost and manufacturing process, and achieves a lightweight battery pack. Also, since the battery cell stack is provided in a moduleless 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 more easily achieved.

[0204] For a description of the case where the cooling member 600 according to another embodiment of the present invention is mounted in a battery module or a battery pack, please refer to the description of FIGS. 14 and 15, and detailed description of overlapping content will be omitted.

[0205] Furthermore, according to the present invention, the cooling member 500 described in FIGS. 1 to 15 and the cooling member 600 described in FIGS. 16 to 22 are not limited to these, and various modifications and variations are possible, including a combination of these. For example, the cooling member 500 described in FIGS. 1 to 15 may be applied to the main body 640 of the cooling member 600 described in FIGS. 16 to 22 in its entirety or with a partial modification.

[0206] Meanwhile, although not specifically mentioned above, the battery pack according to an embodiment of the present invention may additionally include a battery management system (BMS) that manages the temperature, voltage, etc. of the battery and / or a cooling device.

[0207] The battery pack according to an embodiment of the present invention may be applied to various devices. For example, the device to which the battery pack is applied may be a means of transportation such as an electric bicycle, an electric vehicle, a hybrid vehicle, etc. However, the device is not limited thereto, and the battery pack according to the present embodiment may be used in various devices other than the above examples, and this also falls within the scope of the present invention.

[0208] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention 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 material 510: Upper plate 514: Bend 520: Lower plate 522: Weak part 530: Inlet / Outlet Port 540: Sealed part 550: Flow path forming groove 560: Deformation prevention groove 600: Cooling material 620: Lower plate 630: Inlet / Outlet Port 640:Main body 650: Cooling hose 660: Fixing member

Claims

1. A cooling member located on top of a battery cell stack in which a plurality of battery cells are stacked, an upper plate, a lower plate, and cooling water contained in an internal space between the upper plate and the lower plate; the lower plate includes a first portion having a weakened portion formed therein and a second portion having no weakened portion formed therein; the thickness of the first portion is less than the thickness of the second portion; The cooling member wherein heat or pressure generated from the battery cell locally heats or pressurizes the weak portion, thereby opening the first portion and allowing the cooling water to be introduced into the battery cell.

2. The weakened portion has a long side and a short side, The cooling member according to claim 1 , wherein the long sides extend along a stacking direction of the battery cells.

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

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

5. the weakened portion includes a first weakened portion and a second weakened portion spaced apart from the first weakened portion, The cooling member according to claim 1 , wherein the first weakened portion and the second weakened portion have the same thickness.

6. the lower plate is formed by bonding a first layer and a second layer having different thicknesses; a thickness of the first portion corresponding to a thickness of the first layer; The cooling member of claim 1 , wherein the thickness of the second portion corresponds to the thickness of the first layer and the second layer.

7. The cooling member of claim 6 , wherein one of the first layer and the second layer comprises a clad metal.

8. The cooling member of claim 6 , wherein at least one of the top plate, the first layer, and the second layer comprises a clad metal.

9. The cooling element of claim 6 , wherein the first layer and the second layer are joined through a brazing process.

10. The cooling member of claim 6 , wherein the top plate, the first layer, and the second layer are joined together through a brazing process.

11. the upper plate includes a bent portion; a peak of the bent portion corresponds to the first portion, The cooling member of claim 1 , wherein a valley of the bend corresponds to the second portion.

12. A cooling member located on top of a battery cell stack in which a plurality of battery cells are stacked, a lower plate having a plurality of openings formed therein; a body that provides a flow path for cooling water; and a fixing member for fixing the lower plate and the main body together; At least one cooling hose is attached to the body; A cooling member in which the cooling hose melts or breaks when the heat or pressure generated from the battery cell reaches or exceeds a predetermined temperature or pressure, thereby injecting the cooling water into the battery cell.

13. The cooling member according to claim 12 , wherein the cooling hoses are positioned to correspond to the openings in the lower plate.

14. The cooling member according to claim 12 , wherein the cooling hose has a shape extending along the length of the cooling member.

15. The cooling element according to claim 12, wherein the cooling hose is made of a material having a melting point of 300°C or less.

16. The cooling member according to claim 12 , wherein the main body is provided with a housing for housing the cooling hose.

17. The cooling member according to claim 16 , wherein both ends of the cooling hose in the longitudinal direction are connected to both ends of the receiving part in the longitudinal direction, respectively.

18. The cooling member according to claim 12 , wherein a bank extending in the length direction of the cooling member is formed at the center of the lower plate, and the main body is attached to a position of the lower plate where the bank is not formed.

19. The cooling member according to claim 12 , wherein the fixing members are provided in the form of straps and are positioned parallel to the width direction of the cooling member.

20. The cooling member of claim 19 , wherein the fixing member includes end joints that are joined to both ends of the lower plate in the width direction, and a center joint that is joined to the center of the lower plate in the width direction.

21. The cooling member according to claim 20 , wherein the terminal joints and the central joint are formed to have a step with respect to other portions of the fixing member.

22. the cooling member further includes an inlet port and an outlet port for injecting the cooling water into the interior space; The inlet port and the outlet port are connected to an external heat exchanger; The cooling element of claim 12 , wherein the cooling water of the cooling element circulates through the inlet port and the outlet port.

23. The cooling member according to claim 22 , wherein the main body has a branched shape with portions corresponding to the inlet port and the outlet port, respectively.

24. A battery module comprising the cooling member according to claim 1 or 12.

25. The battery module according to claim 24 , wherein the upper plate of the cooling member is integrated with an upper surface of a module frame that defines the outer shape of the battery module.

26. A battery pack comprising the cooling member according to claim 1 or 12.

27. 27. The battery pack of claim 26, wherein the battery pack includes an open-type structure battery module.

28. 27. The battery pack according to claim 26, wherein the upper plate of the cooling member is integrated with the upper surface of a pack frame that forms the outer shape of the battery pack.

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