Battery pack and method for manufacturing same

Abstract

The technical concept of the present invention provides a battery pack comprising: a battery pack case; and a battery assembly in the pack case, in which the battery assembly includes: a heat diffusion film attached to a bottom plate of the pack case; a battery cell block including a plurality of battery cells stacked in the first direction; and a thermally conductive resin layer for attaching the battery cell block to the thermal diffusion film.

Description

Technical Field

[0001] The present disclosure relates to a battery pack and a method for manufacturing the same.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0150503, filed on November 3, 2023, and Korean Patent Application No. 10-2024-0145615, filed on October 23, 2024, and the entire contents of the aforementioned Korean Patent Applications 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 energy sources for various types of wireless devices, such as mobile phones, laptops, and cordless vacuum cleaners. Recently, due to the improvement of energy density and economies of scale, the manufacturing cost per unit capacity of secondary batteries has been significantly reduced, and the cruising range of battery electric vehicles (BEVs) has increased to the same level as fuel vehicles, and the main use of secondary batteries has shifted from mobile devices to vehicles (mobility).

[0004] Since secondary batteries are used in vehicles, the safety requirements for secondary batteries are constantly increasing. When an accident such as a fire occurs in a secondary battery used in a vehicle, the driver's life may be in danger, so research on technologies to enhance the safety of secondary batteries is crucial. Summary of the Invention

[0005] Technical issues

[0006] The present disclosure provides a battery pack and a method for manufacturing the same.

[0007] Technical Solution

[0008] One aspect of the present disclosure provides a battery pack, including: a battery pack case; and a battery assembly located in the battery pack case, wherein the battery assembly includes: a heat diffusion film attached to a bottom plate of the battery pack case; a battery cell block including a plurality of battery cells; and a thermally conductive resin layer configured to attach the battery cell block to the heat diffusion film.

[0009] In an exemplary embodiment, the base plate may include cooling channels configured to flow a cooling fluid therethrough.

[0010] In exemplary embodiments, the thermally conductive resin layer may be in direct contact with the plurality of battery cells.

[0011] In exemplary embodiments, the thermally conductive resin layer may not be in contact with the base plate.

[0012] In exemplary embodiments, the thermally conductive resin layer may include a thermosetting resin.

[0013] In an exemplary embodiment, the battery pack may further include an adhesive layer configured to attach the heat spreading film to the base plate, and an upper surface of the heat spreading film may contact the thermally conductive resin layer, and a lower surface of the heat spreading film may contact the adhesive layer.

[0014] In exemplary embodiments, the adhesive strength between the heat spreading film and the bottom plate may be lower than the adhesive strength between the heat spreading film and the battery cell block.

[0015] In an exemplary embodiment, the bottom plate may include a groove for receiving the adhesive layer.

[0016] In an exemplary embodiment, a plurality of battery cells may be arranged in a first direction, and the battery assembly may further include a fastening frame configured to be connected to one end portion of the battery cell block in the first direction and fastened to the pack case.

[0017] In an exemplary embodiment, the battery pack may further include a gas exhaust plate covering the battery cell block and including a gas exhaust portion configured to exhaust gas.

[0018] In an exemplary embodiment, the plurality of battery cells may be arranged in a first direction and extend in a second direction perpendicular to the first direction, and the battery assembly may further include a bus bar electrically connected to at least one of the plurality of battery cells.

[0019] In exemplary embodiments, the heat diffusion film may include a plurality of unit films, and each of the plurality of unit films of the heat diffusion film may provide a space for accommodating a corresponding battery cell among the plurality of battery cells.

[0020] In an exemplary embodiment, the thermally conductive resin layer may include: a first sub-thermal conductive resin layer configured to attach a first region of the battery cell block to the thermal diffusion film; and a second sub-thermal conductive resin layer configured to attach a second region of the battery cell block to the thermal diffusion film. The thermal conductivity of the first sub-thermal conductive resin layer may be higher than the thermal conductivity of the second sub-thermal conductive resin layer, and the adhesive strength of the first sub-thermal conductive resin layer may be lower than the adhesive strength of the second sub-thermal conductive resin layer.

[0021] In an exemplary embodiment, each of the plurality of battery cells may include a first outer portion, a second outer portion, and a middle portion between the first outer portion and the second outer portion, the first sub-thermal conductive resin layer may contact the first outer portion and the second outer portion of each of the plurality of battery cells, and the second sub-thermal conductive resin layer may contact the middle portion of each of the plurality of battery cells.

[0022] One aspect of the present disclosure provides a method for manufacturing a battery pack, comprising: applying a thermally conductive resin on an upper surface of a heat diffusion film; forming a battery assembly by attaching a battery cell block including a plurality of battery cells to the upper surface of the heat diffusion film, wherein the battery assembly includes the battery cell block, the heat diffusion film, and the thermally conductive resin; applying an adhesive layer to a bottom plate of a battery pack case; and attaching the heat diffusion film to the bottom plate using the adhesive layer.

[0023] In an exemplary embodiment, forming the battery assembly may include attaching a battery cell block to an upper surface of a heat diffusion film and applying heat to a thermally conductive resin to cure the thermally conductive resin.

[0024] In an exemplary embodiment, the heat diffusion film may cover a lower surface of the battery cell block facing the upper surface of the base plate, the thermally conductive resin may be in direct contact with the plurality of battery cells and not in contact with the base plate, the heat diffusion film may be attached to the base plate by an adhesive layer locally applied to the upper surface of the base plate, and the bonding strength between the heat diffusion film and the base plate may be lower than the bonding strength between the heat diffusion film and the battery cell block.

[0025] In an exemplary embodiment, the manufacturing method may further include: separating the battery assembly from the base plate; and attaching a new battery assembly to the base plate.

[0026] In an exemplary embodiment, in a battery cell block, a plurality of battery cells may be arranged in a first direction, the battery assembly may further include a fastening frame disposed at one end portion in the first direction of the battery cell block and configured to be fastened to a battery pack housing, the manufacturing method may further include fastening the fastening frame to the battery pack housing using a fastening member after attaching the battery assembly to the base plate, and the step of separating the battery assembly from the base plate may include releasing the fastening of the fastening frame from the battery pack housing.

[0027] Beneficial effects

[0028] According to an exemplary embodiment of the present disclosure, the battery assembly can have a module-free (cell-to-pack) structure that is directly assembled with the battery pack housing. The battery cells can be thermally bonded to the bottom plate of the battery pack housing equipped with a cooling function using a thermally conductive resin layer and a heat diffusion film to effectively control the heat generation of the battery cells, thereby improving the safety and reliability of the battery pack.

[0029] According to an exemplary embodiment of the present disclosure, the battery cell block is attached to the base plate via a heat diffusion film, so the battery assembly as a module-less unit can be separated from the battery pack housing without damaging the battery cells. In a battery pack, replacement work can be performed in a module-less unit to reduce costs.

[0030] The effects that can be achieved by the exemplary embodiments of the present disclosure are not limited to the effects described above, and those skilled in the art to which the exemplary embodiments of the present disclosure pertain will clearly derive and understand other effects not described herein based on the following description. In other words, those skilled in the art can deduce from the exemplary embodiments of the present disclosure unexpected effects that can be achieved when implementing the exemplary embodiments of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a perspective view of a battery assembly according to an exemplary embodiment of the present disclosure.

[0032] Figure 2 is a cross-sectional view of a battery assembly according to an exemplary embodiment of the present disclosure.

[0033] Figure 3 is a cross-sectional view of a battery pack according to an exemplary embodiment of the present disclosure.

[0034] Figure 4 is Figure 3 An enlarged view of the area indicated by "EX1".

[0035] Figures 5A to 5F is a diagram illustrating a method of manufacturing a battery pack according to an exemplary embodiment of the present disclosure.

[0036] Figure 6A and Figure 6B is a cross-sectional view illustrating a method of manufacturing a battery pack according to an exemplary embodiment of the present disclosure.

[0037] Figure 7 is a cross-sectional view of a battery assembly according to an exemplary embodiment of the present disclosure.

[0038] Figure 8 is a cross-sectional view of a battery assembly according to an exemplary embodiment of the present disclosure.

[0039] Figure 9 is a cross-sectional view of a battery pack according to an exemplary embodiment of the present disclosure.

[0040] Figure 10 is a cross-sectional view of a battery pack according to an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0041] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Before describing the embodiments of the present disclosure, the terms or expressions used in this specification and claims should not be interpreted as limited to terms or expressions generally understood or defined in commonly used dictionaries, but should be understood according to the meanings and concepts corresponding to the present disclosure based on the principle that the inventor of the present application can appropriately define terms or expressions to best interpret the present disclosure.

[0042] Therefore, the embodiments described herein and the configurations shown in the accompanying drawings are merely examples of the present disclosure and do not reflect all technical concepts of the present disclosure. Therefore, it should be understood that various equivalents and modifications have been made to replace the configurations on the filing date of the present application.

[0043] When well-known configurations or functions related to describing the present disclosure are determined to obscure the subject matter of the present disclosure due to unnecessary details, such configurations or functions are not described in detail.

[0044] Since the embodiments of the present disclosure are provided to more fully explain the present disclosure to those skilled in the art, the shapes, sizes, etc. of the components shown in the drawings may be exaggerated, omitted, or schematically illustrated for the sake of clarity. Therefore, it should not be understood that the sizes or ratios of the components completely reflect their actual sizes or ratios.

[0045] (First embodiment)

[0046] Figure 1 is a perspective view of a battery assembly 100 according to an exemplary embodiment of the present disclosure. Figure 2 is a cross-sectional view of a battery assembly 100 according to an exemplary embodiment of the present disclosure.

[0047] Reference Figure 1 and Figure 2 , the battery assembly 100 may include a battery cell block 110 , a heat diffusion film 121 , a thermally conductive resin layer 125 , a fastening frame 130 , and a vent plate 150 .

[0048] The battery cell block 110 may include a plurality of battery cells 111. Each battery cell 111 is a basic unit of a lithium-ion battery (i.e., a secondary battery). Each battery cell 111 may include an electrode assembly, an electrolyte, and a battery cell shell. The electrode assembly in the battery cell shell may include a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode. Depending on the form of assembly, the electrode assembly may be a wound electrode assembly or a stacked electrode assembly. The wound electrode assembly may include a structure in which the positive electrode, the negative electrode, and the separator located between the positive electrode and the negative electrode are wound together. The stacked electrode assembly may include a plurality of positive electrodes and a plurality of negative electrodes stacked in sequence and a plurality of separators located therebetween. The positive electrode may include a positive electrode current collector and a positive electrode active material. The negative electrode may include a negative electrode current collector and a negative electrode active material.

[0049] The plurality of battery cells 111 may be connected in series and / or in parallel. For example, the plurality of battery cells 111 may be connected in series with one another. For example, the plurality of battery cells 111 may be connected in parallel with one another. For example, when a set of two or more battery cells 111 connected in parallel is defined as a group, one group including the two or more battery cells 111 connected in parallel and another group including the two or more battery cells 111 connected in parallel may be connected in series.

[0050] Each battery cell 111 can 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 made of aluminum laminate. 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.

[0051] In an exemplary embodiment, the battery cell block 110 may include a plurality of battery cells 111 stacked on each other in a first horizontal direction (e.g., X-axis direction). In the battery cell block 110, adjacent battery cells 111 among the plurality of battery cells 111 may be fixed to each other by an adhesive member such as a tape. For example, each of the plurality of battery cells 111 may be a soft-pack type battery cell having a length in the first horizontal direction (e.g., X-axis direction) less than its length in the second horizontal direction (e.g., Y-axis direction). Each battery cell 111 may extend in the second horizontal direction (e.g., Y-axis direction), and the electrode lead 1111 (see Figure 10 ) may be provided on at least one of both end portions of each battery cell 111 in the second horizontal direction (eg, the Y-axis direction).

[0052] The battery cell block 110 may include a pad 113 attached to the side of a portion of the plurality of battery cells 111. Each pad 113 may be attached to the corresponding battery cell 111 by an adhesive member such as a tape. The pad 113 may be disposed between adjacent battery cells 111 in a first horizontal direction (e.g., X-axis direction) among the plurality of battery cells 111. Adjacent battery cells 111 may be spaced apart from each other in the first horizontal direction (e.g., X-axis direction) with the pad 113 located therebetween. The pad 113 may be disposed between the battery cells 111 and configured to support the battery cells 111. In an exemplary embodiment, the pad 113 may be configured to thermally isolate adjacent battery cells 111.

[0053] When viewed in plan, the battery cell block 110 may have a rectangular shape. The battery cell block 110 may include an upper surface and a lower surface that are opposite to each other in a vertical direction (e.g., the Z-axis direction), two side surfaces (i.e., a first side surface and a second side surface) that are opposite to each other in a first horizontal direction (e.g., the X-axis direction), and a front surface and a rear surface that are opposite to each other in a second horizontal direction (e.g., the Y-axis direction). The upper surface of the battery cell block 110 may include the upper surfaces of the plurality of battery cells 111, and the lower surface of the battery cell block 110 may include the lower surfaces of the plurality of battery cells 111.

[0054] The bus bar frame 143 (see FIG. 1 ) supports the electrode leads 1111 of the plurality of battery cells 111 and the bus bars 145. Figure 10 ) may be located on the front and rear surfaces of the battery cell block 110, respectively. Each of the bus bar frames 143 on the front and rear surfaces of the battery cell block 110 may include a slit into which the electrode lead 1111 is inserted. In addition, each of the bus bar frames 143 on the front and rear surfaces of the battery cell block 110 may support at least one bus bar 145 connected to at least one electrode lead 1111. Insulating covers 141, each covering the bus bar frames 143, may be located on both ends of the battery assembly 100 in the second horizontal direction (e.g., the Y-axis direction).

[0055] Each bus bar 145 may be connected to an end portion of a corresponding battery cell 111 in the plurality of battery cells 111 in the second horizontal direction (e.g., the Y-axis direction). The bus bar 145 may be electrically and physically connected to at least one of the electrode leads 1111 of the plurality of battery cells 111. The bus bar 145 may be coupled to at least one of the electrode leads 1111 of the plurality of battery cells 111 by welding. The bus bar 145 may include a terminal bus bar for electrically connecting a battery cell block 110 of a battery assembly 100 to a battery cell block 110 of another battery assembly 100 or an external electrical device. In an exemplary embodiment, the bus bar 145 may include an intermediate bus bar connected to the electrode leads 1111 of different battery cells 111 to electrically connect different battery cells 111.

[0056] The heat diffusion film 121 may be attached to the lower surface of the battery cell block 110. The heat diffusion film 121 may be configured to separate the battery cell block 110 and the Figure 5E The battery pack case 501 on which the battery assembly 100 is mounted is thermally bonded.

[0057] The heat diffusion film 121 may cover the lower surface of the battery cell block 110 and have a substantially uniform thickness. For example, the thickness of the heat diffusion film 121 may range from several micrometers to several hundred micrometers (μm). In exemplary embodiments, the thickness of the heat diffusion film 121 may be approximately 5 μm to approximately 30 μm, approximately 10 μm to approximately 25 μm, or approximately 15 μm to approximately 20 μm.

[0058] The heat diffusion film 121 may have high thermal conductivity and be a non-conductive body. In an exemplary embodiment, the thermal conductivity of the heat diffusion film 121 may be 500 W / (m·K) or more, 600 W / (m·K) or more, 700 W / (m·K) or more, 800 W / (m·K) or more, 900 W / (m·K) or more, 1000 W / (m·K) or more, 1100 W / (m·K) or more, 1200 W / (m·K) or more, 1300 W / (m·K) or more, 1400 W / (m·K) or more, 1500 W / (m·K) or more, 1600 W / (m·K) or more, 1700 W / (m·K) or more, 1800 W / (m·K) or more, 1900 W / (m·K) or more, or 2000 W / (m·K) or more. In an exemplary embodiment, the thermal conductivity of the heat diffusion film 121 may be in the range of about 1500 W / (m·K) to about 2300 W / (m·K), about 1600 W / (m·K) to about 2200 W / (m·K), about 1700 W / (m·K) to about 2100 W / (m·K), or about 1800 W / (m·K) to about 2000 W / (m·K). The thermal conductivity of the heat diffusion film 121 may be higher than that of the thermally conductive resin layer 125.

[0059] The thermally conductive resin layer 125 may be interposed between the thermal diffusion film 121 and the lower surface of the battery cell block 110, and may attach the battery cell block 110 to the thermal diffusion film 121. The thermally conductive resin layer 125 may completely or partially fill the space between the thermal diffusion film 121 and the lower surface of the battery cell block 110. The thermally conductive resin layer 125 may thermally bond the thermal diffusion film 121 to the battery cell block 110. For example, the thermally conductive resin layer 125 may include a resin layer and a thermally conductive filler contained in the resin layer.

[0060] The thermally conductive resin layer 125 may be in contact with the lower surface of the battery cell block 110. The thermally conductive resin layer 125 may be in direct contact with the lower surfaces of the plurality of battery cells 111 and extend along the lower surfaces of the plurality of battery cells 111.

[0061] In an exemplary embodiment, the thermally conductive resin layer 125 may include a thermosetting resin. In this case, the thermally conductive resin layer 125 may be formed by coating the thermosetting resin on the upper surface of the heat diffusion film 121, placing the battery cell block 110 on the heat diffusion film 121, and applying heat to the thermosetting resin to cure the thermosetting resin.

[0062] The fastening frame 130 may be attached to each of the outermost battery cells 111 in the first horizontal direction (e.g., the X-axis direction) among the plurality of battery cells 111. The fastening frame 130 may be fastened to the battery pack housing 501 by fastening members 551, such as bolts. For example, the battery assembly 100 may be installed in the battery pack housing 501 by a side mounting method through the fastening frame 130.

[0063] The fastening frame 130 may include a first fastening frame 131 and a second fastening frame 135 spaced apart from each other, with the battery cell block 110 positioned therebetween. The first fastening frame 131 may be connected to one end of the battery cell block 110 in a first horizontal direction (e.g., the X-axis direction), and the second fastening frame 135 may be connected to the other end of the battery cell block 110 in the first horizontal direction (e.g., the X-axis direction). The first fastening frame 131 may include a first fixing plate 1311 attached to one end of the battery cell block 110 in the first horizontal direction (e.g., the X-axis direction) via an adhesive member such as tape, and a first flange 1313 fastened to the battery pack housing 501 via a fastening member 551. The first fixing plate 1311 may have a flat plate shape that covers one side of the battery cell block 110, and the first flange 1313 may be connected to the lower portion of the first fixing plate 1311. The second fastening frame 135 may include a second fixing plate 1351 attached to the other end portion of the battery cell block 110 in a first horizontal direction (e.g., X-axis direction) by an adhesive member such as an adhesive tape, and a second flange 1353 fastened to the battery pack case 501 by a fastening member 551. The second fixing plate 1351 may have a flat plate shape covering one side surface of the battery cell block 110, and the second flange 1353 may be connected to an upper portion of the second fixing plate 1351.

[0064] The exhaust plate 150 may be disposed on the battery cell block 110 and cover the upper surface of the battery cell block 110. The exhaust plate 150 may include a plurality of exhaust portions 1531 configured to exhaust gas. The exhaust plate 150 may include a support frame 151 having a plurality of openings 1511 and a cover plate 153 attached to the support frame 151. The cover plate 153 may cover the upper surface of the plurality of battery cells 111. The cover plate 153 may include a heat-resistant sheet, a fire-proof sheet, or a combination thereof. The cover plate 153 may include exhaust portions 1531 each configured to exhaust gas to one of the electrical regions corresponding to the plurality of openings 1511 of the support frame 151. The exhaust portion 1531 may be a cutout or cutout line formed in the cover plate 153. The high-temperature gas generated from the plurality of battery cells 111 may be discharged to the external space above the battery assembly 100 through the exhaust portion 1531 of the cover plate 153.

[0065] (Second embodiment)

[0066] Figure 3 is a cross-sectional view of a battery pack 500 according to an exemplary embodiment of the present disclosure. Figure 4 is Figure 3 An enlarged view of the area indicated by "EX1".

[0067] Reference Figure 1 、 Figure 2 、 Figure 3 and Figure 4 , the battery pack 500 may include Figure 5E The battery pack housing 501 and the battery assembly 100 installed in the battery pack housing 501. The battery pack 500 may include one or more battery assemblies 100 in the battery pack housing 501. In an exemplary embodiment, a plurality of battery assemblies 100 may be accommodated in an accommodation space provided by the battery pack housing 501 and arranged in a first horizontal direction (e.g., an X-axis direction) and / or a second horizontal direction (e.g., a Y-axis direction) in the accommodation space of the battery pack housing 501.

[0068] The battery pack housing 501 may include Figure 5E The battery pack housing 501 includes a bottom plate 510 and side walls 520 connected to the edges of the bottom plate 510. The side walls 520 may extend along the edges of the bottom plate 510 and surround the accommodation space of the battery pack housing 501. The battery pack housing 501 may further include a battery pack cover connected to the side walls 520 of the battery pack housing 501 to cover the accommodation space. The accommodation space of the battery pack housing 501 may be a sealed space.

[0069] The bottom plate 510 may have a flat plate shape extending in a first horizontal direction (eg, X-axis direction) and a second horizontal direction (eg, Y-axis direction) and may support one or more battery assemblies 100 .

[0070] The bottom plate 510 may include a cooling channel 511 configured to allow a cooling fluid to flow through and configured to cool the battery assembly 100. A cooling fluid from outside the battery pack 500 may be supplied to the inlet of the cooling channel 511, flow along the cooling channel 511, and be discharged to the outside through the outlet of the cooling channel 511. When the cooling fluid flows along the cooling channel 511, the plurality of battery cells 111 of the battery assembly 100 may be cooled. The cooling fluid may include a coolant and / or a refrigerant. In an exemplary embodiment, the bottom plate 510 may be formed by an extrusion process.

[0071] The battery assembly 100 can be attached to the base plate 510 via an adhesive layer 561 between the lower surface of the heat diffusion film 121 and the upper surface of the base plate 510. For example, when the battery assembly 100 is assembled with the battery pack housing 501, the adhesive layer 561 can be applied to the upper surface of the base plate 510, and then the battery assembly 100 can be attached to the upper surface of the base plate 510 using the adhesive layer 561. The bottom surface of the heat diffusion film 121 can be attached to the upper surface of the base plate 510 via the adhesive layer 561. When the battery assembly 100 is attached to the base plate 510, the thermally conductive resin layer 125 can be spaced apart from the base plate 510, and the thermal diffusion film 121 is located between the thermally conductive resin layer 125 and the base plate 510 and may not be in direct contact with the base plate 510. The adhesive layer 561 may include a resin layer and a heat dissipation filler contained in the resin layer.

[0072] In an exemplary embodiment, the adhesive layer 561 may be partially applied to the upper surface of the base plate 510. In an exemplary embodiment, the adhesive layer 561 may be applied in dots to multiple areas of the upper surface of the base plate 510. In an exemplary embodiment, the total contact area between the adhesive layer 561 and the thermal diffusion film 121 may be smaller than the total contact area between the thermally conductive resin layer 125 and the thermal diffusion film 121. In an exemplary embodiment, the thickness of the adhesive layer 561 may be smaller than the thickness of the thermally conductive resin layer 125.

[0073] In an exemplary embodiment, the adhesive layer 561 between the heat diffusion film 121 and the bottom plate 510 may have a lower adhesive strength than the thermally conductive resin layer 125 between the heat diffusion film 121 and the battery cell block 110. The type of adhesive layer 561, the coating area of ​​the adhesive layer 561, and the like may be adjusted so that the adhesive strength between the heat diffusion film 121 and the bottom plate 510 is lower than the adhesive strength between the thermally conductive resin layer 125 and the battery cell block 110. By setting the adhesive strength between the heat diffusion film 121 and the bottom plate 510 to be lower than the adhesive strength between the thermally conductive resin layer 125 and the battery cell block 110, the heat diffusion film 121 can be easily removed from the battery cell block 501 together with the battery cell block 110 when the battery assembly 100 is separated from the pack case 501 or disassembled to replace the battery assembly 100 with another one.

[0074] The battery assembly 100 can be fixed to the bottom plate 510 by fastening members 551, such as bolts. The battery assembly 100 can be fastened to the bottom plate 510 by fastening the first fastening frame 131 and the second fastening frame 135 of the battery assembly 100 to the bottom plate 510 by the fastening members 551. The fastening members 551 can be fastened to the bottom plate 510 without interfering with the cooling channel 511 of the bottom plate 510.

[0075] In an exemplary embodiment, the second fastening frame 135 of one of the battery assemblies 100 adjacent in a first horizontal direction (e.g., the X-axis direction) may be fastened to the first fastening frame 131 of another of the adjacent battery assemblies 100. More specifically, the second flange 1353 of the second fastening frame 135 of one of the adjacent battery assemblies 100 may be seated on the first flange 1313 of the first fastening frame 131 of another of the adjacent battery assemblies 100 and fastened to the first flange 1313 of the first fastening frame 131 of the other of the adjacent battery assemblies 100 by the fastening members 551. The adjacent battery assemblies 100 may be fastened to each other by fastening the second fastening frame 135 of one of the adjacent battery assemblies 100 to the first fastening frame 131 of the other of the adjacent battery assemblies 100.

[0076] (Third embodiment)

[0077] Figures 5A to 5F is a diagram illustrating a method for manufacturing a battery pack 500 according to an exemplary embodiment of the present disclosure. Figures 1 to 4 and Figures 5A to 5F , a method of assembling the battery assembly 100 to the pack case 501 will be described.

[0078] Reference Figure 5A, a heat diffusion film 121 is prepared, and a thermal conductive resin 125 a is applied onto the heat diffusion film 121 .

[0079] Reference Figure 5B and Figure 5C , a structure 101 including a battery cell block 110 is prepared and attached to a heat diffusion film 121. The structure 101 may include the battery cell block 110, first and second fastening frames 131 and 135, and a vent plate 150. The structure 101 may be temporarily bonded to the heat diffusion film 121 by a thermally conductive resin 125a.

[0080] Reference Figure 5D Heat 310 may be applied to the thermally conductive resin 125a to cure the thermally conductive resin 125a. As the thermally conductive resin 125a cures, the battery cell block 110 may be securely attached to the thermal diffusion film 121. The thermally conductive resin 125a may be cured to form a thermally conductive resin layer 125. The battery cell block 110, the first and second fastening frames 131 and 135, the vent plate 150, the thermally conductive resin layer 125, and the thermal diffusion film 121 may collectively form the battery assembly 100.

[0081] Reference Figure 5E , the adhesive layer 561 is applied to the mounting area of ​​the upper surface of the base plate 510. The adhesive layer 561 may be partially applied to one mounting area of ​​the upper surface of the base plate 510. Figure 5E The adhesive layer 561 is shown as being applied to the bottom plate 510 , but in some embodiments, the adhesive layer 561 may be applied to the bottom surface of the heat spreading film 121 .

[0082] Reference Figure 5F , the battery assembly 100 is attached to one mounting area of ​​the upper surface of the base plate 510. The battery assembly 100 may be attached to the base plate 510 by an adhesive layer 561 coated on the upper surface of the base plate 510.

[0083] Then, the adhesive layer 561 may be applied to the remaining mounting area of ​​the upper surface of the bottom plate 510 , and the battery assembly 100 may be attached to the remaining mounting area of ​​the upper surface of the bottom plate 510 .

[0084] Next, the battery assembly 100 may be fastened to the bottom plate 510 by the fastening members 551. The first fastening frame 131 and the second fastening frame 135 of each battery assembly 100 may be fastened to the bottom plate 510 by the fastening members 551. The second fastening frame 135 of one of the battery assemblies 100 adjacent in the first horizontal direction (e.g., the X-axis direction) may be fastened to the first fastening frame 131 of another of the adjacent battery assemblies 100. The adjacent battery assemblies 100 may be coupled to each other by fastening the second fastening frame 135 of one of the adjacent battery assemblies 100 to the first fastening frame 131 of another of the adjacent battery assemblies 100.

[0085] Figure 6A and Figure 6B is a cross-sectional view illustrating a method of manufacturing the battery pack 500 according to an exemplary embodiment of the present disclosure.

[0086] In the following, reference will be made to Figures 1 to 4 、 Figure 6A and Figure 6B A method of replacing the battery assembly 100 in the battery pack 500 with another one is described.

[0087] Reference Figure 6A , replacing the battery assembly 100 with another one may include separating the defective battery assembly 100 from the battery pack case 501. Separating the battery assembly 100 from the battery pack case 501 may include releasing the fastening of the defective battery assembly 100 from the battery pack case 501. In order to release the fastening of the defective battery assembly 100 from the bottom plate 510, the fastening member 551 may be separated from the first fastening frame 131 and the second fastening frame 135 of the defective battery assembly 100.

[0088] Reference Figure 6B Separating the battery assembly 100 from the battery pack housing 501 may include lifting the battery assembly 100 upward to separate the heat diffusion film 121 from the bottom plate 510. For example, after the lifting mechanism is attached to the defective battery assembly 100, the battery assembly 100 may be lifted by the lifting mechanism to separate the defective battery assembly 100 from the battery pack housing 501.

[0089] In an exemplary embodiment, the adhesive strength of the adhesive layer 561 between the heat diffusion film 121 and the bottom plate 510 may be set to be lower than the adhesive strength of the thermally conductive resin layer 125 between the heat diffusion film 121 and the battery cell block 110. In this case, when the defective battery assembly 100 is lifted to be separated from the bottom plate 510, the heat diffusion film 121 may be easily separated from the bottom plate 510 together with the battery cell block 110.

[0090] After the defective battery assembly 100 is separated from the battery pack housing 501, a new battery assembly 100 can be assembled, with the mounting area of ​​the bottom plate 510 exposed due to the removal of the defective battery assembly 100. The new battery assembly 100 can be assembled in the same manner as described above with reference to FIG. Figures 5A to 5F The method of assembling the battery assembly 100 is described in substantially the same manner as that used to assemble the battery pack housing 501 .

[0091] According to an exemplary embodiment of the present disclosure, the battery assembly 100 may have a cell-to-pack structure that is directly assembled with the battery pack case 501 of the battery pack 500. The battery cells 111 are thermally bonded to the bottom plate 510 of the battery pack case 501 equipped with a cooling function through the thermally conductive resin layer 125 and the heat diffusion film 121 without an intermediate frame, thereby effectively controlling the heat generation of the battery cells 111, thereby improving the safety and reliability of the battery pack 500.

[0092] In the case of a conventional battery pack (particularly a battery pack in which a module-less unit of a battery cell is fastened to a battery pack case), the battery cell is directly attached to the battery pack case via a resin layer. In this case, when the battery cell is separated from the battery pack case, the battery cell may be damaged, for example, the battery cell may be torn, and therefore replacement work is not allowed to be performed on a module-less unit basis, for example, replacing a module-less unit with another module-less unit, and replacement work can only be performed on a battery pack basis.

[0093] According to an exemplary embodiment of the present disclosure, the battery cell block 110 is attached to the base plate 510 via the heat diffusion film 121, so the battery assembly 100 corresponding to the module-less unit can be separated from the pack case 501 without damaging the battery cell 111. In the battery pack 500, replacement work can be performed in the module-less unit to reduce costs.

[0094] (Fourth embodiment)

[0095] Figure 7 is a cross-sectional view of a battery assembly 100A according to an exemplary embodiment of the present disclosure. Figure 1 and Figure 2 The differences of the battery assembly 100 are described Figure 7 Battery assembly 100A.

[0096] Reference Figure 7, in the battery assembly 100A, the heat diffusion film 121A may include a plurality of unit films 122. The plurality of unit films 122 may be separated from each other. The plurality of unit films 122 may be arranged in a first horizontal direction (e.g., X-axis direction). Each of the plurality of unit films 122 may overlap with a corresponding battery cell 111 in a vertical direction (e.g., Z-axis direction) among a plurality of battery cells 111 and be attached to the corresponding battery cell 111 by a thermally conductive resin layer 125. When the battery assembly 100A is separated or disassembled from the battery pack housing 501, only a portion of the plurality of battery cells 111 may be removed. During the period in which only the battery cell 111 to be removed is replaced with another, the unit film 122 that overlaps with the battery cell 111 to be removed among the plurality of unit films 122 may also be removed.

[0097] (Fifth embodiment)

[0098] Figure 8 is a cross-sectional view of a battery assembly 100B according to an exemplary embodiment of the present disclosure. Figure 1 and Figure 2 The differences of the battery assembly 100 are described Figure 8 battery assembly 100B.

[0099] Reference Figure 8 In the battery assembly 100B, the heat diffusion film 121B may include a plurality of unit films 123. The plurality of unit films 123 may be separated from each other. The plurality of unit films 123 may be arranged in a first horizontal direction (e.g., the X-axis direction). Two adjacent unit films 123 in the first horizontal direction (e.g., the X-axis direction) may contact each other. Each of the plurality of unit films 123 may accommodate a corresponding battery cell 111 among the plurality of battery cells 111. Each unit film 123 may have a curved shape to provide a space for accommodating a corresponding battery cell 111 among the plurality of battery cells 111. When viewed in a cross-sectional view, each unit film 123 may have a U-shape. For example, each unit film 123 may include a bottom facing the bottom surface of the corresponding battery cell 111 and a pair of side cover portions spaced apart from each other, with the corresponding battery cell 111 interposed therebetween. One of the pair of side cover portions may contact one side of each corresponding battery cell 111, and the other side cover portion may contact the other side of each corresponding battery cell 111.

[0100] (Sixth embodiment)

[0101] Figure 9 is a cross-sectional view of a battery pack 500 according to an exemplary embodiment of the present disclosure. Figure 3 and Figure 4 The differences of the battery pack 500 are described Figure 9Battery pack 500A.

[0102] Reference Figure 9 In the battery pack 500A, the bottom plate 510 may include a groove 519 for accommodating the adhesive layer 561. The groove 519 of the bottom plate 510 may limit the coating range of the adhesive layer 561. When viewed in a plan view, the groove 519 of the bottom plate 510 may have a rectangular or circular shape. The adhesive layer 561 may completely or partially fill the groove 519 of the bottom plate 510. A portion of the adhesive layer 561 may overflow from the groove 519 of the bottom plate 510 and be coated on the surface of the bottom plate 510 near the groove 519 of the bottom plate 510. The bottom plate 510 may be provided with a plurality of grooves 519 spaced apart from each other, and the adhesive layer 561 may be provided in each of the plurality of grooves 519 of the bottom plate 510.

[0103] (Seventh embodiment)

[0104] Figure 10 is a cross-sectional view of a battery pack 500B according to an exemplary embodiment of the present disclosure. Figure 3 and Figure 4 The differences of the battery pack 500 are described Figure 10 Battery pack 500B.

[0105] Reference Figure 10 In the battery pack 500B, the thermally conductive resin layer 125A may include multiple sub-thermal conductive resin layers having different material compositions, different thermal conductivities, and / or different adhesive strengths. The multiple sub-thermal conductive resin layers of the thermally conductive resin layer 125A may be attached to different areas of the battery cell block 110. The multiple sub-thermal conductive resin layers may each include a heat dissipation filler, and the amount of the heat dissipation filler in the multiple sub-thermal conductive resin layers may differ from one another. For example, the heat dissipation filler may include aluminum oxide, boron nitride, aluminum nitride, zinc oxide, magnesium oxide, or a combination of the foregoing materials.

[0106] In an exemplary embodiment, the thermally conductive resin layer 125A may include a first sub-thermal conductive resin layer 1251 that contacts a first region of the battery cell block 110 and a second sub-thermal conductive resin layer 1253 that contacts a second region of the battery cell block 110. The first sub-thermal conductive resin layer 1251 may attach the first region of the battery cell block 110 to the heat diffusion film 121, and the second sub-thermal conductive resin layer 1253 may attach the second region of the battery cell block 110 to the heat diffusion film 121. The first sub-thermal conductive resin layer 1251 may attach portions of the plurality of battery cells 111 located in the first region of the battery cell block 110 to the heat diffusion film 121, and the second sub-thermal conductive resin layer 1253 may attach portions of the plurality of battery cells 111 located in the second region of the battery cell block 110 to the heat diffusion film 121.

[0107] The first thermally conductive resin layer 1251 may have a first thermal conductivity and a first adhesive strength, and the second thermally conductive resin layer 1253 may have a second thermal conductivity and a second adhesive strength. The first thermally conductive resin layer 1251 may have a higher first thermal conductivity than the second thermally conductive resin layer 1253. The first adhesive strength of the first thermally conductive resin layer 1251 may be lower than the second adhesive strength of the second thermally conductive resin layer 1253. The first thermally conductive resin layer 1251, which has a higher thermal conductivity, may be attached to a portion of the battery cell block 110 that generates a greater amount of heat, thereby enhancing cooling of the battery cell block 110. The second thermally conductive resin layer 1253, which has a lower thermal conductivity, may be attached to a portion of the battery cell block 110 that generates less heat. Because the first thermally conductive resin layer 1251 is attached to a portion of the battery cell block 110 that generates a greater amount of heat, and the second thermally conductive resin layer 1253 is attached to a portion of the battery cell block 110 that generates less heat, temperature deviations within the battery cell block 110 can be reduced. The second sub-thermal conductive resin layer 1253 having higher adhesive strength may be attached to a portion of the battery cell block 110 that is more susceptible to vibration, thereby enhancing structural safety of the battery cell block 110 .

[0108] In an exemplary embodiment, the first thermally conductive resin layer 1251 may have a first thermal conductivity between about 3 W / (m·K) and about 10 W / (m·K), between about 4 W / (m·K) and about 9 W / (m·K), between about 5 W / (m·K) and about 8 W / (m·K), or between about 6 W / (m·K) and about 7 W / (m·K). In an exemplary embodiment, the second thermally conductive resin layer 1253 may have a second thermal conductivity between about 20% and about 80%, between about 30% and about 70%, or between about 40% and about 60% of the first thermally conductive resin layer 1251.

[0109] In an exemplary embodiment, the second adhesive strength of the second thermally conductive resin layer 1253 may be between about 1 MPa and about 5 MPa, between about 1.5 MPa and about 4.5 MPa, between about 2 MPa and about 4 MPa, or between about 2.5 MPa and about 3.5 MPa. In an exemplary embodiment, the first adhesive strength of the first thermally conductive resin layer 1251 may be between about 10% and about 90%, between about 20% and about 80%, between about 30% and about 70%, or between about 40% and about 60% of the second adhesive strength of the second thermally conductive resin layer 1253.

[0110] In an exemplary embodiment, each of the plurality of battery cells 111 may include a first portion closer to the electrode lead 1111 and a second portion farther from the electrode lead 1111. The first portion of the plurality of battery cells 111 may be located in the first region of the battery cell block 110, and the second portion of the plurality of battery cells 111 may be located in the second region of the battery cell block 110. A first sub-thermal conductive resin layer 1251 may contact the first portion of the plurality of battery cells 111, and a second sub-thermal conductive resin layer 1253 may contact the second portion of the plurality of battery cells 111. During operation of the battery cells 111, a greater amount of heat is generated in the first portion of the battery cells 111 closer to the electrode lead 1111, and a lesser amount of heat is generated in the second portion of the battery cells 111 farther from the electrode lead 1111. The first sub-thermal conductive resin layer 1251, which has a higher thermal conductivity, may be attached to the first portion of each of the plurality of battery cells 111 to enhance cooling of the plurality of battery cells 111. The second sub-thermal conductive resin layer 1253 having lower thermal conductivity can be attached to the second portion of each of the plurality of battery cells 111. Because the first sub-thermal conductive resin layer 1251 is attached to the first portion of each of the plurality of battery cells 111, and the second sub-thermal conductive resin layer 1253 is attached to the second portion of each of the plurality of battery cells 111, the temperature deviation in each of the plurality of battery cells 111 can be reduced. The first portion of each battery cell 111 is supported by the bus bar frame 143 and the insulating cover 141, so its structural safety is higher, and the second portion of each battery cell 111 is farther away from the bus bar frame 143 and the insulating cover 141, so its structural safety is lower. The second sub-thermal conductive resin layer 1253 having higher adhesive strength can attach the second portion of each of the plurality of battery cells 111 to the heat diffusion film 121, thereby enhancing the structural safety of the plurality of battery cells 111.

[0111] In an exemplary embodiment, each of the plurality of battery cells 111 may include a first outer portion connected to an electrode lead 1111, a second outer portion connected to another electrode lead 1111, and an intermediate portion between the first and second outer portions. The battery cells 111 may extend in a second horizontal direction (e.g., the Y-axis direction), and the intermediate portion of the battery cells 111 may be located between the first and second outer portions of the battery cells 111 in the second horizontal direction (e.g., the Y-axis direction). The first and second outer portions of each battery cell 111 may be located in the first region of the battery cell block 110, and the intermediate portion thereof may be located in the second region of the battery cell block 110.

[0112] The first sub-thermal conductive resin layer 1251 may be in contact with the first and second outer portions of each of the plurality of battery cells 111, and the second sub-thermal conductive resin layer 1253 may be in contact with the middle portion of each of the plurality of battery cells 111. During operation of the battery cells 111, a greater amount of heat is generated in the first and second outer portions of the battery cells 111 because the first and second outer portions are closer to the electrode leads 1111, and a lesser amount of heat is generated in the middle portion of the battery cells 111 because the middle portion is farther away from the electrode leads 1111. The first sub-thermal conductive resin layer 1251, which has a higher thermal conductivity, may be attached to the first and second outer portions of each of the plurality of battery cells 111 to enhance cooling of the plurality of battery cells 111. The second sub-thermal conductive resin layer 1253, which has a lower thermal conductivity, may be attached to the middle portion of each of the plurality of battery cells 111. Because the first sub-thermal conductive resin layer 1251 is attached to the first and second outer portions of each of the plurality of battery cells 111, and the second sub-thermal conductive resin layer 1253 is attached to the second portion of each of the plurality of battery cells 111, temperature deviations in each of the plurality of battery cells 111 can be reduced. By adjusting the size of the middle portion of the battery cell 111 that contacts the second sub-thermal conductive resin layer 1253, temperature deviations between regions of the battery cell 111 can be more effectively controlled. For example, the length of the middle portion of the battery cell 111 that contacts the second sub-thermal conductive resin layer 1253 in the second horizontal direction (e.g., the Y-axis direction) can be between approximately 10% and approximately 70%, between approximately 20% and approximately 60%, or between approximately 30% and approximately 50% of the length of the battery cell 111 in the second horizontal direction (e.g., the Y-axis direction).

[0113] The first and second outer portions of the battery cells 111 are supported by the busbar frame 143 and the insulating cover 141, thus providing a higher level of structural safety. The middle portion of the battery cells 111 is located farther from the busbar frame 143 and the insulating cover 141, thus providing a lower level of structural safety. The second sub-thermal conductive resin layer 1253, which has a higher adhesive strength, allows the middle portion of each of the battery cells 111 to be attached to the heat diffusion film 121, thereby enhancing the structural safety of the battery cells 111.

[0114] In the battery pack 500B according to the exemplary embodiment, the portion of each battery cell 111 that generates a greater amount of heat can be attached to the heat diffusion film 121 via a thermally conductive resin layer having higher thermal conductivity, and the portion of each battery cell 111 that is more susceptible to vibration can be attached to the heat diffusion film 121 via a thermally conductive resin layer having higher adhesive strength. Therefore, the temperature uniformity and structural safety of the battery cells 111 can be improved compared to when the battery cells 111 are attached to the heat diffusion film 121 via a single adhesive layer.

[0115] The present disclosure has been described in more detail above with reference to the accompanying drawings, embodiments, etc. However, the configurations shown in the drawings or embodiments described in the present disclosure are merely embodiments of the present disclosure and do not reflect all technical concepts of the present disclosure. Therefore, it should be understood that various equivalents and modifications have been made to replace the configurations as of the filing date of the present application.

Claims

1. A battery pack comprising: Battery pack housing; as well as A battery assembly, located in the battery pack housing, Wherein, the battery assembly includes: a heat diffusion film attached to the bottom plate of the battery pack housing; a battery cell block comprising a plurality of battery cells; and A thermally conductive resin layer is configured to attach the battery cell block to the heat diffusion film.

2. The battery pack according to claim 1, wherein: The base plate includes cooling channels configured to flow a cooling fluid therethrough.

3. The battery pack according to claim 1, wherein: The thermally conductive resin layer is in direct contact with the plurality of battery cells.

4. The battery pack according to claim 3, wherein: The thermally conductive resin layer does not contact the bottom plate.

5. The battery pack according to claim 1, wherein The thermally conductive resin layer includes a thermosetting resin.

6. The battery pack according to claim 1 , further comprising an adhesive layer configured to attach the heat spreading film to the base plate, in, An upper surface of the heat diffusion film contacts the thermally conductive resin layer, and a lower surface of the heat diffusion film contacts the adhesive layer.

7. The battery pack according to claim 6, wherein: The adhesive strength between the heat diffusion film and the bottom plate is lower than the adhesive strength between the heat diffusion film and the battery cell block.

8. The battery pack according to claim 6, wherein: The bottom plate includes a groove for accommodating the adhesive layer.

9. The battery pack according to claim 1, wherein: The plurality of battery cells are arranged in a first direction, and The battery assembly further includes a fastening frame configured to be connected to one end portion of the battery cell block in the first direction and fastened to the pack case. 10 . The battery pack according to claim 1 , further comprising a gas exhaust plate covering the battery cell block and including a gas exhaust portion configured to exhaust gas.

11. The battery pack according to claim 1, wherein: The plurality of battery cells are arranged in a first direction, Each of the plurality of battery cells extends in a second direction perpendicular to the first direction, and The battery assembly further includes a bus bar electrically connected to at least one of the plurality of battery cells.

12. The battery pack according to claim 1, wherein: The heat diffusion film includes a plurality of unit films. Each of the plurality of unit films of the heat diffusion film provides a space for accommodating a corresponding battery cell among the plurality of battery cells.

13. The battery pack according to claim 1, wherein The thermally conductive resin layer comprises: a first sub-thermal conductive resin layer configured to attach a first region of the battery cell block to the heat diffusion film; and a second sub-thermal conductive resin layer configured to attach a second region of the battery cell block to the heat diffusion film; wherein the thermal conductivity of the first sub-thermal conductive resin layer is higher than the thermal conductivity of the second sub-thermal conductive resin layer, and The first sub-thermal conductive resin layer has an adhesive strength lower than that of the second sub-thermal conductive resin layer.

14. The battery pack according to claim 13, wherein: Each of the plurality of battery cells includes a first outer portion, a second outer portion, and a middle portion between the first outer portion and the second outer portion. wherein the first sub-thermal conductive resin layer is in contact with the first outer portion and the second outer portion of each of the plurality of battery cells, and The second sub-thermal conductive resin layer is in contact with the middle portion of each of the plurality of battery cells.

15. A method for manufacturing a battery pack, comprising: coating a thermally conductive resin on the upper surface of the thermal diffusion film; forming a battery assembly by attaching a battery cell block including a plurality of battery cells to the upper surface of the heat diffusion film, wherein the battery assembly includes the battery cell block, the heat diffusion film, and the thermally conductive resin; applying an adhesive layer to a bottom plate of a battery pack housing; as well as The heat spreading film is attached to the base plate using the adhesive layer.

16. The manufacturing method according to claim 15, wherein: The step of forming a battery assembly includes attaching the battery cell block to the upper surface of the heat diffusion film and applying heat to the thermally conductive resin to cure the thermally conductive resin.

17. The manufacturing method according to claim 16, wherein: The thermal diffusion film covers the lower surface of the battery cell block facing the upper surface of the bottom plate, The thermally conductive resin is in direct contact with the plurality of battery cells and is not in contact with the bottom plate. The heat diffusion film is attached to the base plate by an adhesive layer partially applied to the upper surface of the base plate, and The adhesive strength between the heat diffusion film and the bottom plate is lower than the adhesive strength between the heat diffusion film and the battery cell block.

18. The manufacturing method according to claim 15, further comprising: separating the battery assembly from the base plate; as well as Attach the new battery assembly to the base plate.

19. The manufacturing method according to claim 18, wherein: In the battery cell block, the plurality of battery cells are arranged in a first direction, The battery assembly further includes a fastening frame provided at one end portion of the battery cell block in the first direction and configured to be fastened to the battery pack case. The manufacturing method further includes fastening the fastening frame to the battery pack case using a fastening member after attaching the battery assembly to the base plate, and The step of separating the battery assembly from the base plate includes releasing the fastening frame from the battery pack case.

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