Battery pack

Abstract

The technical concept of the present invention provides a battery pack comprising a base frame, a cell block including a plurality of battery cells on the base frame, a cooling structure provided on the cell block and having a first cooling channel, and a heat transfer structure that thermally connects the cell block to the cooling structure and includes a plurality of thermal conductive pads attached to the cell block and a plurality of thermal conductive rails attached to the cooling structure, wherein the plurality of thermal conductive rails are arranged in a first direction on the cell block and two adjacent thermal conductive rails overlap in a second direction.

Description

Technical Field

[0001] The present invention relates to a battery pack.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0046509 filed on April 5, 2024, and all the contents disclosed in the document of the Korean patent application are incorporated herein by reference.

Background Art

[0003] Unlike primary batteries, secondary batteries can be charged and discharged multiple times. Secondary batteries are widely used as an energy source for various cordless devices such as handsets, notebook computers, and cordless cleaners. In recent years, due to improvements in energy density and economies of scale, the manufacturing cost per unit capacity of secondary batteries has been significantly reduced, and as the driving range of battery electric vehicles (BEVs) has increased to a level comparable to that of fuel vehicles, the main application of secondary batteries has shifted from mobile devices to mobility.

[0004] As secondary batteries are used in mobility, the requirements for the safety of secondary batteries are increasing. When an accident such as a fire occurs in a secondary battery used for mobility, it may endanger the life of the driver, so research on technologies to improve the safety of secondary batteries is essential.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The technical problem to be achieved by the present invention is to provide a battery pack.

Means for Solving the Problems

[0006] To solve the above-mentioned problems, the technical concept of the present invention provides a battery pack comprising a base frame, a cell block including a plurality of battery cells on the base frame, a cooling structure provided on the cell block and having a first cooling channel, and a heat transfer structure that thermally connects the cell block to the cooling structure and includes a plurality of thermal conductive pads attached to the cell block and a plurality of thermal conductive rails attached to the cooling structure, wherein the plurality of thermal conductive rails are arranged in a first direction on the cell block and two adjacent thermal conductive rails overlap in a second direction.

[0007] In an exemplary embodiment, the system further includes a first thermally conductive adhesive layer for attaching each of the multiple thermally conductive rails to a cooling structure.

[0008] In an exemplary embodiment, the base frame includes a second cooling channel and further includes a second thermally conductive adhesive layer for attaching each of the plurality of battery cells to the base frame.

[0009] In an exemplary embodiment, a plurality of thermal conductive pads are each attached to a corresponding one of a plurality of battery cells, and a plurality of thermal conductive rails are each integrated with a corresponding one of the plurality of thermal conductive pads.

[0010] In an exemplary embodiment, each of the thermal conductive rails includes a first plate and a second plate located at different levels from each other, wherein one of the two adjacent thermal conductive rails overlaps the remaining first plate of the two adjacent thermal conductive rails in a second direction.

[0011] In an exemplary embodiment, the first plate overlaps one of the plurality of battery cells in a second direction, and the second plate overlaps two of the plurality of battery cells in a second direction.

[0012] In an exemplary embodiment, the cooling structure includes a first cooling plate and a second cooling plate spaced apart with an opening in between, and each of the plurality of battery cells overlaps the opening in a second direction.

[0013] In an exemplary embodiment, the cooling structure further includes a connecting plate extending between a first cooling plate and a second cooling plate, wherein the first cooling plate includes a first channel configured to guide the cooling fluid in a first flow direction, the second cooling plate includes a second channel configured to guide the cooling fluid in a second flow direction opposite to the first flow direction, and the connecting plate includes a third channel extending between the first channel of the first cooling plate and the second channel of the second cooling plate.

[0014] In an exemplary embodiment, the invention further includes an inlet pipe configured to transmit cooling fluid to the first channel of the first cooling plate, and a first inlet channel communicating with a first channel of the first cooling plate; and an outlet pipe configured to discharge cooling fluid to the outside, and a first outlet channel communicating with a second channel of the second cooling plate.

[0015] In an exemplary embodiment, the base frame includes a second cooling channel, the inlet pipe further includes a second inlet channel communicating with the inlet of the second cooling channel of the base frame, and the outlet pipe further includes a second outlet channel communicating with the outlet of the second cooling channel of the base frame.

[0016] In exemplary embodiments, each of the battery cells is characterized by including a central portion that overlaps the opening of the cooling structure in a second direction, and an outer portion that overlaps one of the first and second cooling plates in a second direction, to which electrode leads are connected.

[0017] In an exemplary embodiment, the plurality of battery cells are arranged in a first direction, and each of the plurality of battery cells extends in a third direction perpendicular to the first and second directions.

[0018] An exemplary embodiment further includes an internal frame positioned on a base frame and on one side of the cell block, and a fixing bracket for securing the cooling structure to the internal frame.

[0019] In exemplary embodiments, the invention further includes a pack cover that covers the cell block and the cooling structure, and a compressible pad provided between the cooling structure and the pack cover.

[0020] In exemplary embodiments, the present invention further includes a pack cover that covers the cell block and the cooling structure, bolts attached to the cooling structure and inserted into holes in the pack cover, and nuts fastened to protrusions of the bolts protruding from the pack cover. [Effects of the Invention]

[0021] According to an exemplary embodiment of the present invention, the battery pack has a dual cooling structure configured to cool the battery cells by flowing a cooling fluid through a lower cooling channel in a base frame located beneath the cell assembly and a cooling channel in a cooling structure located above the cell assembly, thereby improving the cooling performance for the battery cells.

[0022] According to an exemplary embodiment of the present invention, the outer casing of the battery cell, which generates a relatively large amount of heat, is thermally coupled to the cooling structure via a heat transfer structure. This enhances cooling of the outer casing of the battery cell and reduces temperature deviations within the battery cell.

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

Brief Description of Drawings

[0024] [Figure 1] It is a cross-sectional view showing a battery pack according to an exemplary embodiment of the present invention. [Figure 2] It is a separated perspective view showing a part of a cell assembly according to an exemplary embodiment of the present invention. [Figure 3] It is a perspective view showing a part of a heat transfer structure according to an exemplary embodiment of the present invention. [Figure 4] It is a separated perspective view showing a part of a heat transfer structure according to an exemplary embodiment of the present invention. [Figure 5] It is a perspective view showing a battery pack according to an exemplary embodiment of the present invention. [Figure 6] It is a perspective view showing a part of a battery pack according to an exemplary embodiment of the present invention. [Figure 7] It is a perspective view showing a part of a cooling structure of a battery pack according to an exemplary embodiment of the present invention. [Figure 8] It is a cross-sectional view showing a part of a battery pack according to an exemplary embodiment of the present invention. [Figure 9a] It is a cross-sectional view showing a manufacturing method of a battery pack according to an exemplary embodiment of the present invention. [Figure 9b] It is a cross-sectional view showing a manufacturing method of a battery pack according to an exemplary embodiment of the present invention. [Figure 9c] It is a cross-sectional view showing a manufacturing method of a battery pack according to an exemplary embodiment of the present invention. [Figure 9d] It is a cross-sectional view showing a manufacturing method of a battery pack according to an exemplary embodiment of the present invention. [Modes for carrying out the invention]

[0025] Preferred embodiments of the present invention will now be described in detail with reference to the attached drawings. As a premise, terms and words used herein and in the claims should not be interpreted in a manner limited to their general or dictionary meanings, but rather in a manner consistent with the technical spirit of the present invention, based on the principle that inventors may appropriately define the concepts of terms in order to best describe their own invention.

[0026] Therefore, the embodiments described herein and the configurations shown in the drawings represent only one of the most preferred embodiments of the present invention and do not represent the entire technical concept of the present invention; thus, there may be a variety of equivalents and modifications that can be substituted for them at the time of filing.

[0027] Furthermore, in describing the present invention, if it is determined that a specific description of a related known configuration or function may obscure the gist of the present invention, such detailed description will be omitted.

[0028] The embodiments of the present invention are provided to give a more complete explanation to those skilled in the art; therefore, the shapes and sizes of the components in the drawings may be exaggerated, omitted, or shown schematically for the sake of clarity. Accordingly, the sizes and proportions of each component do not fully reflect the actual sizes and proportions.

[0029] (First Embodiment) Figure 1 is a cross-sectional view showing a battery pack 10 according to an exemplary embodiment of the present invention. Figure 2 is a separated perspective view showing a portion of a cell assembly 200 according to an exemplary embodiment of the present invention. Figure 3 is a perspective view showing a portion of a heat transfer structure 250 according to an exemplary embodiment of the present invention. Figure 4 is a separated perspective view showing a portion of a heat transfer structure 250 according to an exemplary embodiment of the present invention.

[0030] Referring to Figures 1 to 4, the battery pack 10 may include a pack frame 100, a cell assembly 200, a cooling structure 400, pipes 500, and a compressible pad 710.

[0031] The pack frame 100 can provide an internal space for housing the cell assembly 200. The pack frame 100 may include a base frame 110, side frames 120, a pack cover 130, and a plurality of internal frames 140.

[0032] The base frame 110 can support the cell assemblies 200. The base frame 110 may have a flat plate shape extended in a substantially first horizontal direction (e.g., the X direction) and a second horizontal direction (e.g., the Y direction). Multiple cell assemblies 200 can be provided on the base frame 110, arranged in a first horizontal direction (e.g., the X direction) and a second horizontal direction (e.g., the Y direction).

[0033] The base frame 110 may include a lower cooling channel 111 through which a cooling fluid flows. The cooling fluid, supplied from outside the battery pack 10, can be supplied to the inlet of the lower cooling channel 111, flow along the lower cooling channel 111, and discharged to the outside through the outlet of the lower cooling channel 111. Cooling of the cell assembly 200 can be performed while the cooling fluid flows along the lower cooling channel 111. The cooling fluid may include coolant and / or refrigerant.

[0034] The side frame 120 can be extended along the edge of the base frame 110 and can surround the cell assembly 200.

[0035] The pack cover 130 can be fastened onto the side frame 120 so as to cover the cell assembly 200. The pack cover 130 may have a flat plate shape that extends in a first horizontal direction (e.g., the X direction) and a second horizontal direction (e.g., the Y direction).

[0036] Multiple internal frames 140 can divide the internal space of the pack frame 100 into multiple accommodation spaces. One or more cell assemblies 200 can be placed in each of the multiple accommodation spaces of the pack frame 100 defined by the multiple internal frames 140. In an exemplary embodiment, the multiple internal frames 140 can be spaced apart from each other in a first horizontal direction (e.g., the X direction), and individual internal frames 140 can be extended in a second horizontal direction (e.g., the Y direction). One cell assembly 200 can be placed between a pair of internal frames 140.

[0037] The cell assembly 200 may include a cell block 210, a thermal barrier pad 230, and a heat transfer structure 250.

[0038] The cell block 210 can include a plurality of battery cells 220. Each battery cell 220 is the basic unit of a lithium-ion battery, i.e., a secondary battery. Each battery cell 220 can include an electrode assembly, an electrolyte, and a cell case. The electrode assembly housed in the cell case can include a positive electrode, a negative electrode, and a separator membrane interposed between the positive and negative electrodes. Depending on the assembly configuration, the electrode assembly can be either a jelly roll type or a stack type. A jelly roll type electrode assembly can include a winding structure of a positive electrode, a negative electrode, and a separator membrane interposed between them. A stack type electrode assembly can include a plurality of sequentially stacked positive electrodes, a plurality of negative electrodes, and a plurality of separator membranes interposed between them. The positive electrode can include a positive electrode current collector and a positive electrode active material. The negative electrode can include a negative electrode current collector and a negative electrode active material.

[0039] Each battery cell 220 may be a pouch-type battery cell, a cylindrical battery cell, or a prismatic battery cell. The electrode assembly of a pouch-type battery cell is housed in a pouch case containing an aluminum laminate sheet. The electrode assembly of a cylindrical battery cell is housed in a cylindrical metal can. The electrode assembly of a prismatic battery cell is housed in a prismatic metal can.

[0040] Multiple battery cells 220 provided to the cell assembly 200 can be connected in series and / or in parallel. In one example, multiple battery cells 220 can be connected in series with each other. In another example, multiple battery cells 220 may be connected in parallel with each other. For example, when defining a set of two or more battery cells 220 connected in parallel with each other as a bank, one bank consisting of two or more battery cells 220 connected in parallel with each other and another bank consisting of two or more battery cells 220 connected in parallel with each other can be connected in series.

[0041] In exemplary embodiments, a plurality of battery cells 220 provided in a cell assembly 200 may be arranged in a first horizontal direction (e.g., the X direction), and individual battery cells 220 may extend in a second horizontal direction (e.g., the Y direction). At least one of the ends of an individual battery cell 220 along the second horizontal direction (e.g., the Y direction) may be provided with an electrode lead 229. An individual battery cell 220 may have a central part and a pair of outer parts, and an electrode lead 229 may be connected to each of the pair of outer parts of an individual battery cell 220. The electrode leads 229 of adjacent battery cells 220 among the plurality of battery cells 220 may be electrically and physically connected to each other.

[0042] The thermal barrier pad 230 can be positioned between battery cells 220. The thermal barrier pad 230 may have a flat plate shape extended in substantially a second horizontal direction (e.g., the Y direction) and a vertical direction (e.g., the Z direction). At least one of the two sides of the thermal barrier pad 230 can be in contact with a battery cell 220. The thermal barrier pad 230 can be attached to the corresponding battery cell 220 by an adhesive member 291 such as double-sided tape or adhesive. The cell assembly 200 may include a plurality of thermal barrier pads 230. At least one battery cell 220 can be positioned between two adjacent thermal barrier pads 230. The thermal barrier pad 230 can be positioned between battery cells 220 to prevent or suppress thermal propagation between the battery cells 220. The thermal barrier pad 230 can also be configured to elastically deform in response to external forces and to support the corresponding battery cell 220. As the thickness of the battery cell 220 increases along the first horizontal direction (e.g., the X direction) due to the swelling of the battery cell 220, the thermal barrier pad 230 can elastically deform to absorb or disperse the force acting on the corresponding battery cell 220 due to the swelling. In exemplary embodiments, the thermal barrier pad 230 may include polyurethane, silicone, or a combination thereof.

[0043] The heat transfer structure 250 can thermally connect the cell block 210 to the cooling structure 400. The heat transfer structure 250 can be attached to each of the multiple battery cells 220 and can be attached to the cooling structure 400. The heat transfer structure 250 can provide a heat transfer path for thermally connecting each of the multiple battery cells 220 to the cooling structure 400. The heat transfer structure 250 may include a material with good thermal conductivity, such as copper, silver, gold, aluminum, tungsten, or a combination thereof. The thermal conductivity of the material of the heat transfer structure 250 may be greater than the thermal conductivity of the material of the thermal barrier pad 230.

[0044] The heat transfer structure 250 may include a plurality of heat-conductive pads 251 attached to the cell block 210 and a plurality of heat-conductive rails 253 provided on the cell block 210.

[0045] Multiple thermal conductive pads 251 can each be attached to one or more corresponding battery cells 220 from among multiple battery cells 220. Each thermal conductive pad 251 may have a flat plate shape extended in a substantially second horizontal direction (e.g., the Y direction) and a vertical direction (e.g., the Z direction). At least one of the two sides of each thermal conductive pad 251 can be in contact with a battery cell 220. Each thermal conductive pad 251 can be attached to an adjacent battery cell 220 by an adhesive member 291.

[0046] In the cell assembly 200, a plurality of battery cells 220 can be arranged in a first horizontal direction (e.g., the X direction), and the thermal conductive pads 251 and thermal barrier pads 230 can be arranged alternately and repeatedly in the first horizontal direction (e.g., the X direction). In an exemplary embodiment, one side of each battery cell 220 can be attached to the thermal conductive pad 251 by an adhesive member 291, and the other side of each battery cell 220 can be attached to the thermal barrier pad 230 by an adhesive member 291.

[0047] The cell assembly 200 can be thermally and physically bonded to the base frame 110 by a lower thermal conductive adhesive layer 310. The lower thermal conductive adhesive layer 310 can be in direct contact with each of the multiple battery cells 220 and each of the multiple thermal conductive pads 251. The lower thermal conductive adhesive layer 310 may contain a thermal resin and / or a thermal interface material.

[0048] Multiple thermal conductive rails 253 are provided on a cell block 210 and can be arranged in a first horizontal direction (e.g., the X direction). Two adjacent thermal conductive rails 253 can be in contact with each other. Each of the multiple thermal conductive rails 253 can be integrated with a corresponding thermal conductive pad 251 from among multiple thermal conductive pads 251. The integrated thermal conductive rails 253 and thermal conductive pads 251 can constitute a heat transfer fin 259. The heat transfer structure 250 can consist of multiple heat transfer fins 259 aligned in a first horizontal direction (e.g., the X direction).

[0049] The multiple thermal conductive rails 253 cover a portion of the upper surface of the cell block 210, but do not have to cover other portions of the upper surface of the cell block 210. In exemplary embodiments, the multiple thermal conductive rails 253 cover a pair of outer casings of individual battery cells 220 to which electrode leads 229 are connected, but do not have to cover the central part of individual battery cells 220. In exemplary embodiments, the multiple thermal conductive rails 253 may include a first group of thermal conductive rails 253 and a second group of thermal conductive rails 253 spaced apart in a second horizontal direction (e.g., the Y direction). The first group of thermal conductive rails 253 may be arranged in a first horizontal direction (e.g., the X direction), and the second group of thermal conductive rails 253 may be arranged in a first horizontal direction (e.g., the X direction). The first group of thermal conductive rails 253 may cover one outer casing of each of the multiple battery cells 220, and the second group of thermal conductive rails 253 may cover the other outer casing of each of the multiple battery cells 220. Between the first group of thermal conductive rails 253 and the second group of thermal conductive rails 253, an opening can be provided that overlaps the center of each of the multiple battery cells 220 in a vertical direction (e.g., the Z direction).

[0050] Each thermal conductive rail 253 may have a stepped or staircase structure. Each thermal conductive rail 253 may include a first plate 2531 at a first vertical level and a second plate 2533 at a second vertical level different from the first vertical level, where the vertical level can refer to a position along the vertical direction (e.g., the Z direction). The distance along the vertical direction (e.g., the Z direction) between the first plate 2531 and the cooling structure 400 may be greater than the distance along the vertical direction (e.g., the Z direction) between the second plate 2533 and the cooling structure 400.

[0051] In exemplary embodiments, the length of the second plate 2533 of an individual thermal conductive rail 253 along the first horizontal direction (e.g., the X direction) may be greater than the length of the first plate 2531 of an individual thermal conductive rail 253 along the first horizontal direction (e.g., the X direction). The first plate 2531 of an individual thermal conductive rail 253 may overlap perpendicularly (e.g., the Z direction) with one of a plurality of battery cells 220. The second plate 2533 of an individual thermal conductive rail 253 may overlap perpendicularly (e.g., the Z direction) with two of a plurality of battery cells 220.

[0052] Of the multiple thermal conductive rails 253, two adjacent thermal conductive rails 253 in the first horizontal direction (e.g., X direction) can overlap in the vertical direction (e.g., Z direction). A portion of one of the two thermal conductive rails 253 can overlap perpendicularly (e.g., Z direction) with a portion of the other thermal conductive rail 253. A second plate 2533 of one of the two thermal conductive rails 253 can overlap perpendicularly (e.g., Z direction) with the remaining first plate 2531 of the two thermal conductive rails 253. The bottom surface of the second plate 2533 of one of the two thermal conductive rails 253 can contact the top surface of the remaining first plate 2531 of the two thermal conductive rails 253. In this case, each battery cell 220 can overlap perpendicularly (for example, in the Z direction) with one of the two thermal conductive rails 253, specifically with the second plate 2533 and the other of the two thermal conductive rails 253, specifically with the first plate 2531.

[0053] According to an exemplary embodiment of the present invention, in the heat transfer structure 250, the plurality of heat transfer fins 259 are arranged to have an overlapping structure in which they overlap each other, thereby improving the rigidity of the cell assembly 200 including the heat transfer structure 250.

[0054] The cooling structure 400 can be placed on the cell assembly 200. The cooling structure 400 can cover a plurality of battery cells 220 and a heat transfer structure 250. The cooling structure 400 may include cooling channels 401 configured for the flow of a cooling fluid. Cooling fluid supplied from outside the battery pack 10 can be supplied to the inlet of the cooling channel 401, flow along the cooling channel 401, and discharged to the outside through the outlet of the cooling channel 401. Cooling can be performed on the cell assembly 200 while the cooling fluid is flowing along the cooling channel 401.

[0055] The cell assembly 200 can be thermally and physically bonded to the cooling structure 400 by an upper thermal conductive adhesive layer 330. The upper thermal conductive adhesive layer 330 can be interposed between the multiple thermal conductive rails 253 and the cooling structure 400. The upper thermal conductive adhesive layer 330 can thermally and physically bond the multiple thermal conductive rails 253 to the cooling structure 400. The upper thermal conductive adhesive layer 330 may contain a thermal resin and / or a thermal interface material.

[0056] The pipe 500 can be mounted on the pack frame 100 and configured to transmit cooling fluid. For example, the pipe 500 can be mounted on the side frame 120. The pipe 500 may include a first channel 501 communicating with a cooling channel 401 of the cooling structure 400 and a second channel 503 communicating with a lower cooling channel 111 of the base frame 110. In an exemplary embodiment, the first channel 501 of the pipe 500 may be an inlet channel configured to transmit cooling fluid supplied from an external cooling fluid supply to the inlet of the cooling channel 401 of the cooling structure 400, and the second channel 503 of the pipe 500 may be an inlet channel configured to transmit cooling fluid supplied from an external cooling fluid supply to the inlet of the lower cooling channel 111 of the base frame 110. In an exemplary embodiment, the first channel 501 of the pipe 500 may be an outlet channel configured to transmit the cooling fluid discharged from the outlet of the cooling channel 401 to the cooling fluid supply unit, and the second channel 503 of the pipe 500 may be an outlet channel configured to transmit the cooling fluid discharged from the outlet of the lower cooling channel 111 to the cooling fluid supply unit.

[0057] The compressible pad 710 can be provided between the cooling structure 400 and the pack cover 130. The compressible pad 710 can be attached to the cooling structure 400 and / or the pack cover 130. The compressible pad 710 can be configured to elastically deform in response to external forces. For example, the compressible pad 710 may include polyurethane, silicone, or a combination thereof. The compressible pad 710 can improve the durability of the battery pack 10 by reducing vibration of the pack cover 130.

[0058] Figure 5 is a perspective view showing a battery pack 10A according to an exemplary embodiment of the present invention. Figure 6 is a perspective view showing a part of the battery pack 10A according to an exemplary embodiment of the present invention. Figure 7 is a perspective view showing a part of the cooling structure 400A of the battery pack 10A according to an exemplary embodiment of the present invention.

[0059] Referring to Figures 5 to 7, the cooling structure 400A of the battery pack 10A may include a first cooling plate 410, a second cooling plate 420, and a connecting plate 430. The first cooling plate 410 and the second cooling plate 420 may each be extended in a first horizontal direction (e.g., the X direction). In an exemplary embodiment, the first cooling plate 410 and the second cooling plate 420 may be extended in a first horizontal direction (e.g., the X direction) to cover two or more cell assemblies 200 arranged in a first horizontal direction (e.g., the X direction). The first cooling plate 410 and the second cooling plate 420 may be separated in a second horizontal direction (e.g., the Y direction) with an opening 450 in between. The connecting plate 430 may be extended between the end of the first cooling plate 410 and the end of the second cooling plate 420.

[0060] The first cooling plate 410 may include a first channel configured to guide the cooling fluid CF in a first flow direction. The second cooling plate 420 may include a second channel configured to guide the cooling fluid CF in a second flow direction opposite to the first flow direction. The connecting plate 430 may include a third channel extending between the first channel of the first cooling plate 410 and the second channel of the second cooling plate 420. The first channel of the first cooling plate 410 may communicate with the second channel of the second cooling plate 420 via the third channel of the connecting plate 430.

[0061] The battery pack 10A may include a fixing bracket for fixing the cooling structure 400A to the pack frame 100. The battery pack 10A may include a first fixing bracket 610 for fixing a first cooling plate 410 to the pack frame 100, and a second fixing bracket 620 for fixing a second cooling plate 420 to the pack frame 100. The first fixing bracket 610 can be joined to the first cooling plate 410 by welding and can be fastened to the corresponding internal frame 140 by fastening members such as bolts. The second fixing bracket 620 can be joined to the second cooling plate 420 by welding and can be fastened to the corresponding internal frame 140 by fastening members such as bolts.

[0062] The battery pack 10A may include an inlet pipe 510 into which a cooling fluid CF supplied from an external source is introduced, and an outlet pipe 530 for discharging the cooling fluid CF to the outside.

[0063] The inlet pipe 510 may include a first portion 511 having a first inlet channel communicating with the inlet of a first channel of a first cooling plate 410, and a second portion 515 having a second inlet channel communicating with the inlet of a lower cooling channel 111 of a base frame 110. Cooling fluid CF supplied from an external source can be transmitted to the first channel of the first cooling plate 410 via the first inlet channel of the inlet pipe 510, and can be transmitted to the lower cooling channel 111 of the base frame 110 via the second inlet channel of the inlet pipe 510. Within the inlet pipe 510, the first inlet channel and the second inlet channel can communicate with each other, and the cooling fluid supplied to the inlet of the inlet pipe 510 can be separated between the first inlet channel and the second inlet channel.

[0064] The outlet pipe 530 may include a first portion 531 having a first outlet channel communicating with the outlet of the second channel of the second cooling plate 420, and a second portion 535 having a second outlet channel communicating with the outlet of the lower cooling channel 111 of the base frame 110. The first outlet channel of the outlet pipe 530 can transmit the cooling fluid CF discharged from the second channel of the second cooling plate 420 to the outside. The second outlet channel of the outlet pipe 530 can transmit the cooling fluid CF discharged from the lower cooling channel 111 of the base frame 110 to the outside. The first outlet channel and the second outlet channel can communicate with each other within the outlet pipe 530, and the cooling fluids discharged from the second channel of the second cooling plate 420 and the lower cooling channel 111 of the base frame 110 can be combined within the outlet pipe 530.

[0065] The first inlet channel of the inlet pipe 510, the first channel of the first cooling plate 410, the third channel of the connecting plate 430, the second channel of the second cooling plate 420, and the first outlet channel of the outlet pipe 530 can be sequentially connected to form a first flow path for the cooling fluid CF. The second inlet channel of the inlet pipe 510, the lower cooling channel 111 of the base frame 110, and the second outlet channel of the outlet pipe 530 can be sequentially connected to form a second flow path for the cooling fluid CF.

[0066] According to an exemplary embodiment of the present invention, the battery pack 10A has a dual cooling structure configured to cool the battery cells 220 by flowing a cooling fluid CF through the lower cooling channel 111 of the base frame 110 located below the cell assembly 200 and the cooling channel 401 of the cooling structure 400A located above the cell assembly 200, thereby improving the cooling performance for the battery cells 220.

[0067] In an exemplary embodiment, the first cooling plate 410 can cover one outer casing of each of the plurality of battery cells 220, and the second cooling plate 420 can cover the other outer casing of each of the plurality of battery cells 220. The opening 450 provided between the first cooling plate 410 and the second cooling plate 420 can overlap perpendicularly (e.g., in the Z direction) to the center of each of the plurality of battery cells 220. In this case, a pair of outer casings of the individual battery cells 220 to which the electrode leads 229 are connected can overlap perpendicularly (e.g., in the Z direction) to the first cooling plate 410 and the second cooling plate 420, respectively, and the center of the individual battery cell 220 can overlap perpendicularly (e.g., in the Z direction) to the opening 450 of the cooling structure 400A.

[0068] In an exemplary embodiment, the opening 450 of the cooling structure 400A may be provided as a venting passage through which hot gases generated in the multiple battery cells 220 flow and as a passage through which radio signals to components such as a Battery Management System (BMS) are transmitted. Because the cooling structure 400A has the opening 450, when a thermal event such as a thermal runaway occurs, the hot gases generated in the battery cells 220 can be vented upward through the opening 450 of the cooling plate.

[0069] Generally, heat generation in individual battery cells 220 is greater in the outer casing of the battery cell 220 where the electrode leads 229 are connected than in the center of the battery cell 220. According to an exemplary embodiment, the outer casing of the battery cell 220, which generates relatively more heat, is thermally coupled to the cooling structure 400A via the heat transfer structure 250, thereby enhancing the cooling of the outer casing of the battery cell 220 and reducing temperature deviations within the battery cell 220.

[0070] (Second Embodiment) Figure 8 is a cross-sectional view showing a portion of a battery pack according to an exemplary embodiment of the present invention.

[0071] Referring to Figure 8, the battery pack may include a bolt 731 attached to the cooling structure 400 and a nut 735 fastened to the bolt 731.

[0072] The bolt 731 can be joined to the cooling structure 400. For example, the bolt 731 can be joined to the cooling structure 400 by a joint 733 formed by welding. For example, the bolt 731 is a projection stud and can be joined to the cooling structure 400 by projection welding. The bolt 731 can be inserted into a hole in the pack cover 130 and may include a projection that protrudes outward from the pack cover 130. A nut 735 can be fitted onto the projection of the bolt 731 located outside the pack cover 130. The inner surface of the nut 735 may have threads that engage with the threads provided on the outer surface of the projection of the bolt 731. By fitting the nut 735 onto the projection of the bolt 731, the cooling structure 400 can be fixed to the pack cover 130. In an exemplary embodiment, the cooling structure 400 can be secured to the pack cover 130 by bolts 731 and nuts 735, and a compression pad (710 in Figure 1) can be provided between the cooling structure 400 and the pack cover 130. Since the pack cover 130 is secured to the cooling structure 400 by bolts 731 and nuts 735, vibration of the pack cover 130 can be reduced, and the durability of the battery pack can be improved.

[0073] (Third embodiment) Figures 9a to 9d are cross-sectional views showing a method for manufacturing a battery pack according to an exemplary embodiment of the present invention.

[0074] Referring to Figure 9a, the cell assembly 200 is mounted in the mounting area of ​​the base frame 110. The cell assembly 200 may include a plurality of battery cells 220, a plurality of thermal barrier pads 230, and a heat transfer structure 250. The cell assembly 200 can be attached to the base frame 110 by a lower thermal conductive adhesive layer 310 applied to the base frame 110.

[0075] Referring to Figure 9b, an upper thermal conductive adhesive layer 330 is formed on multiple thermal conductive rails 253 of the heat transfer structure 250.

[0076] Referring to Figure 9c, after forming an upper thermal conductive adhesive layer 330 on the multiple thermal conductive rails 253 of the heat transfer structure 250, the cooling structure 400 is placed on the cell assembly 200. The cooling structure 400 can be attached to the multiple thermal conductive rails 253 of the heat transfer structure 250 by the upper thermal conductive adhesive layer 330.

[0077] Referring to Figure 9d, after the cooling structure 400 is placed on the cell assembly 200, the compressible pad 710 is placed on the cooling structure 400. The compressible pad 710 can be attached to the cooling structure 400 by an adhesive member.

[0078] Referring to Figure 1, after the compressible pad 710 is placed on the cooling structure 400, the pack cover 130 is fastened to the side frame 120.

[0079] According to an exemplary embodiment of the present invention, the battery pack has a dual cooling structure configured to cool the battery cells 220 by flowing a cooling fluid through a lower cooling channel 111 of a base frame 110 located beneath the cell assembly 200 and a cooling channel 401 of a cooling structure 400 located above the cell assembly 200, thereby improving the cooling performance for the battery cells 220.

[0080] According to an exemplary embodiment of the present invention, the outer casing of the battery cell 220, which generates a relatively large amount of heat, is thermally coupled to the cooling structure 400 via the heat transfer structure 250. This enhances the cooling of the outer casing of the battery cell 220 and reduces temperature deviations within the battery cell 220.

[0081] The present invention has been described in more detail above with reference to the drawings and embodiments. However, the configurations described in the drawings or embodiments described herein are merely one embodiment of the present invention and do not represent the entire technical concept of the present invention. Therefore, there may be a variety of equivalents and modifications that can be substituted for them at the time of filing.

Claims

1. Base frame and A cell block including a plurality of battery cells arranged on the base frame in a first direction horizontal to the base frame, A cooling structure provided on the cell block and having a first cooling channel, A heat transfer structure is included, which thermally connects the cell block to the cooling structure and includes a plurality of heat conductive pads attached to the cell block and a plurality of heat conductive rails attached to the cooling structure. The plurality of thermally conductive rails are arranged on the cell block in the first direction, Of the plurality of thermal conductive rails, two adjacent thermal conductive rails overlap in a second direction perpendicular to the first direction. Battery pack.

2. The battery pack according to claim 1, further comprising a first thermal conductive adhesive layer for attaching each of the plurality of thermal conductive rails to the cooling structure.

3. The base frame includes a second cooling channel, The system further includes a second thermally conductive adhesive layer for attaching each of the plurality of battery cells to the base frame. The battery pack according to claim 1.

4. Each of the aforementioned heat-conducting pads is attached to a corresponding one of the aforementioned battery cells. Each of the aforementioned plurality of thermal conductive rails is integrated with a corresponding one of the plurality of thermal conductive pads. The battery pack according to claim 1.

5. The plurality of heat-conducting rails each include a first plate and a second plate located at different levels from each other. The second plate of any two adjacent thermal conductive rails among the plurality of thermal conductive rails overlaps the remaining first plate of the two adjacent thermal conductive rails in the second direction. The battery pack according to claim 1.

6. The first plate overlaps one of the plurality of battery cells in the second direction, The second plate overlaps two of the plurality of battery cells in the second direction, The battery pack according to claim 5.

7. The cooling structure includes a first cooling plate and a second cooling plate separated by an opening in between, Each of the plurality of battery cells overlaps the opening in the second direction, The battery pack according to claim 1.

8. The cooling structure further includes a connecting plate extending between the first cooling plate and the second cooling plate, The first cooling plate includes a first channel configured to guide the cooling fluid in a first flow direction, The second cooling plate includes a second channel configured to guide the cooling fluid in a second flow direction opposite to the first flow direction, The connecting plate includes a third channel extending between the first channel of the first cooling plate and the second channel of the second cooling plate. The battery pack according to claim 7.

9. An inlet pipe is configured to transmit the cooling fluid to the first channel of the first cooling plate, and includes a first inlet channel communicating with the first channel of the first cooling plate, The present invention further includes an outlet pipe configured to discharge the cooling fluid to the outside, which includes a first outlet channel communicating with the second channel of the second cooling plate, The battery pack according to claim 8.

10. The base frame includes a second cooling channel, The inlet pipe further includes a second inlet channel that communicates with the inlet of the second cooling channel of the base frame, The outlet pipe further includes a second outlet channel that communicates with the outlet of the second cooling channel of the base frame. The battery pack according to claim 9.

11. Each of the aforementioned plurality of battery cells is: The opening of the cooling structure has a central part that overlaps in the second direction, The first cooling plate and the second cooling plate include an outer casing that overlaps in the second direction and to which electrode leads are connected, The battery pack according to claim 7.

12. The plurality of battery cells are arranged in the first direction, Each of the plurality of battery cells extends in a third direction perpendicular to the first and second directions. The battery pack according to claim 11.

13. An internal frame, which is placed on the base frame and positioned on one side of the cell block, The cooling structure further includes a fixing bracket for fixing the cooling structure to the internal frame, The battery pack according to claim 1.

14. A pack cover covering the cell block and the cooling structure, The cooling structure and the pack cover are further comprising a compressible pad provided between them, The battery pack according to claim 1.

15. A pack cover covering the cell block and the cooling structure, A bolt attached to the cooling structure and inserted into the hole in the pack cover, The pack cover further includes a nut fastened to the protruding portion of the bolt that protrudes from the pack cover, The battery pack according to claim 1.

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