Battery pack and manufacturing method therefor

Abstract

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

Description

Battery pack and method for manufacturing the same

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

[0002] This application claims the benefit of priority to Republic of Korea Patent Application No. 10-2023-0150503, filed on November 3, 2023, and Republic of Korea Patent Application No. 10-2024-0145615, filed on October 23, 2024, all of which are incorporated herein by reference.

[0003] Unlike primary batteries, secondary batteries can be charged and discharged multiple times. They are widely used as a power source for various wireless devices, including handsets, laptops, and cordless vacuum cleaners. Recently, improved energy density and economies of scale have dramatically reduced the per-unit manufacturing cost of secondary batteries. Furthermore, as the range of battery electric vehicles (BEVs) has increased to match that of fuel-powered vehicles, the primary use of secondary batteries is shifting from mobile devices to mobility.

[0004] As secondary batteries become increasingly used in mobility, demand for their safety is increasing. Fires and other accidents involving secondary batteries used in mobility vehicles can endanger the lives of drivers, making research into technologies that enhance secondary battery safety essential.

[0005] The technical problem to be solved by the present invention is to provide a battery pack and a method for manufacturing the same.

[0006] In order to solve the above-described problem, the technical idea of ​​the present invention provides a battery pack including: a pack housing; and a battery assembly mounted on the pack housing; wherein the battery assembly includes: a heat diffusion film attached to a bottom plate of the pack housing; a cell block including a plurality of battery cells; and a heat conductive resin layer attaching the cell block to the heat diffusion film.

[0007] In exemplary embodiments, the floor plate is characterized by including cooling channels configured to allow cooling fluid to flow.

[0008] In exemplary embodiments, the thermally conductive resin layer is characterized in that it is in direct contact with the plurality of battery cells.

[0009] In exemplary embodiments, the thermally conductive resin layer is characterized in that it does not contact the bottom plate.

[0010] In exemplary embodiments, the thermally conductive resin layer is characterized by including a thermosetting resin.

[0011] In exemplary embodiments, the thermal diffusion film further comprises an adhesive layer configured to attach the thermal diffusion film to the bottom plate, wherein an upper surface of the thermal diffusion film is in contact with the thermally conductive resin layer, and a lower surface of the thermal diffusion film is in contact with the adhesive layer.

[0012] In exemplary embodiments, the adhesion between the thermal diffusion film and the bottom plate is characterized by being less than the adhesion between the thermal diffusion film and the cell block.

[0013] In exemplary embodiments, the bottom plate is characterized by including a groove for receiving the adhesive layer.

[0014] In exemplary embodiments, the plurality of battery cells are arranged in a first direction, and the battery assembly further comprises a fastening frame connected to one end of the cell block along the first direction and fastened to the pack housing.

[0015] In exemplary embodiments, the cell block is further characterized by including a venting plate covering the cell block and including a venting portion configured to discharge gas.

[0016] In exemplary embodiments, the plurality of battery cells are arranged in a first direction, each of the plurality of battery cells extending in a second direction perpendicular to the first direction, and the battery assembly further comprises a busbar electrically connected to at least one of the plurality of battery cells.

[0017] In exemplary embodiments, the thermal diffusion film comprises a plurality of unit films, and each of the plurality of unit films of the thermal diffusion film is characterized in that it provides a space for accommodating corresponding battery cells among the plurality of battery cells.

[0018] In exemplary embodiments, the thermally conductive resin layer includes a first sub-thermal conductive resin layer configured to attach a first area of ​​the cell block to the thermal diffusion film; and a second sub-thermal conductive resin layer configured to attach a second area of ​​the cell block to the thermal diffusion film; wherein a thermal conductivity of the first sub-thermal conductive resin layer is greater than a thermal conductivity of the second sub-thermal conductive resin layer, and an adhesive force of the first sub-thermal conductive resin layer is less than an adhesive force of the second sub-thermal conductive resin layer.

[0019] In exemplary embodiments, the plurality of battery cells each include a first outer portion, a second outer portion, and a central 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 central portion of each of the plurality of battery cells.

[0020] In order to solve the above-described problem, the technical idea of ​​the present invention provides a method for manufacturing a battery pack, including the steps of: applying a thermally conductive resin on the upper surface of a thermal diffusion film; attaching a cell block including a plurality of battery cells to the upper surface of the thermal diffusion film to form a battery assembly including the cell block, the thermal diffusion film, and the thermally conductive resin; applying an adhesive layer on the bottom plate of a pack housing; and attaching the thermal diffusion film to the bottom plate using the adhesive layer.

[0021] In exemplary embodiments, the step of forming the battery assembly is characterized by comprising attaching the cell block onto the upper surface of the thermal diffusion film and applying heat to the thermally conductive resin to harden the thermally conductive resin.

[0022] In exemplary embodiments, the thermal diffusion film covers a lower surface of the cell block facing the upper surface of the bottom plate, the thermally conductive resin is in direct contact with the plurality of battery cells but does not contact the bottom plate, the thermal diffusion film is attached to the bottom plate by an adhesive layer locally applied to the upper surface of the bottom plate, and the adhesive force between the thermal diffusion film and the bottom plate is characterized in that it is smaller than the adhesive force between the thermal diffusion film and the cell block.

[0023] In exemplary embodiments, the method further comprises the steps of: separating the battery assembly from the bottom plate; and attaching a new battery assembly to the bottom plate.

[0024] In exemplary embodiments, the plurality of battery cells in the cell block are arranged in a first direction, the battery assembly further includes a fastening frame provided at one end of the cell block along the first direction and fastened to the pack housing, and after the step of attaching the battery assembly to the bottom plate, the step of fastening the fastening frame to the pack housing using a fastening member is further included, and the step of separating the battery assembly from the bottom plate includes a step of releasing the fastening between the fastening frame and the pack housing.

[0025] According to exemplary embodiments of the present invention, a battery assembly may have a cell-to-pack structure that is directly assembled into a pack housing of a battery pack. The battery cells are thermally bonded to a bottom plate of the pack housing, which has a cooling function, through a thermally conductive resin layer and a thermal diffusion film, thereby effectively controlling heat generation of the battery cells, thereby improving the safety and reliability of the battery pack.

[0026] According to exemplary embodiments of the present invention, the cell blocks are attached to the bottom plate via a heat diffusion film, thereby enabling the battery assembly, corresponding to a cell-to-pack unit, to be separated from the pack housing without damaging the battery cells. This enables the replacement of individual cell-to-pack units within the battery pack, thereby reducing costs.

[0027] The effects that can be 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 skilled in the art to which the exemplary embodiments of the present disclosure pertain from the following description. In other words, unintended effects resulting from practicing the exemplary embodiments of the present disclosure can also be derived by those skilled in the art from the exemplary embodiments of the present disclosure.

[0028] FIG. 1 is a perspective view showing a battery assembly according to exemplary embodiments of the present invention.

[0029] FIG. 2 is a cross-sectional view showing a battery assembly according to exemplary embodiments of the present invention.

[0030] FIG. 3 is a cross-sectional view showing a battery pack according to exemplary embodiments of the present invention.

[0031] Figure 4 is an enlarged view showing the area indicated as “EX1” in Figure 3.

[0032] FIGS. 5A to 5F are drawings showing a method of manufacturing a battery pack according to exemplary embodiments of the present invention.

[0033] FIGS. 6A and 6B are cross-sectional views illustrating a method for manufacturing a battery pack according to exemplary embodiments of the present invention.

[0034] FIG. 7 is a cross-sectional view showing a battery assembly according to exemplary embodiments of the present invention.

[0035] FIG. 8 is a cross-sectional view showing a battery assembly according to exemplary embodiments of the present invention.

[0036] FIG. 9 is a cross-sectional view showing a battery pack according to exemplary embodiments of the present invention.

[0037] FIG. 10 is a cross-sectional view showing a battery pack according to exemplary embodiments of the present invention.

[0038] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, it should be noted that the terms and words used in this specification and claims should not be construed as limited to their conventional or dictionary meanings. Based on the principle that the inventor can appropriately define the concepts of terms to best explain his or her invention, they should be interpreted in a way that aligns with the technical spirit of the present invention.

[0039] Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0040] In addition, when describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description is omitted.

[0041] Since the embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art, the shapes and sizes of components in the drawings may be exaggerated, omitted, or schematically illustrated for clearer explanation. Accordingly, the sizes and proportions of each component do not fully reflect the actual sizes or proportions.

[0042]

[0043] (Example 1)

[0044] Fig. 1 is a perspective view illustrating a battery assembly (100) according to exemplary embodiments of the present invention. Fig. 2 is a cross-sectional view illustrating a battery assembly (100) according to exemplary embodiments of the present invention.

[0045] Referring to FIGS. 1 and 2, the battery assembly (100) may include a cell block (110), a thermal diffusion film (121), a thermally conductive resin layer (125), a fastening frame (130), and a venting plate (150).

[0046] A 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 cell case. The electrode assembly built into the cell case may include a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode. The electrode assembly may be either a jelly-roll type or a stack type depending on the assembly form. A jelly-roll type electrode assembly may include a winding structure of a positive electrode, a negative electrode, and a separator interposed therebetween. A stack type electrode assembly may include a plurality of sequentially stacked positive electrodes, a plurality of negative electrodes, and a plurality of separators interposed 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 an negative electrode active material.

[0047] A plurality of battery cells (111) may be connected in series and / or in parallel. For example, a plurality of battery cells (111) may be connected in series with each other. For example, a plurality of battery cells (111) may also be connected in parallel with each other. For example, when a set of two or more battery cells (111) connected in parallel with each other is defined as a bank, one bank composed of two or more battery cells (111) connected in parallel with each other and another bank composed of two or more battery cells (111) connected in parallel with each other may be connected in series.

[0048] Each battery cell (111) may correspond to a pouch-type battery cell, a cylindrical battery cell, or a square battery cell. The electrode assembly of the pouch-type battery cell is housed in a pouch case including an aluminum laminate sheet. The electrode assembly of the cylindrical battery cell is housed in a cylindrical metal can. The electrode assembly of the square battery cell is housed in a square metal can.

[0049] In exemplary embodiments, a cell block (110) may include a plurality of battery cells (111) that are mutually stacked in a first horizontal direction (e.g., X-direction). In the cell block (110), adjacent battery cells (111) among the plurality of battery cells (111) may be fixed to each other through an adhesive material such as an adhesive tape. For example, the plurality of battery cells (111) may each correspond to a pouch-type battery cell in which a length along the first horizontal direction (e.g., X-direction) is smaller than a length along the second horizontal direction (e.g., Y-direction). Each battery cell (111) may extend in the second horizontal direction (e.g., Y-direction), and an electrode lead (see 1111 of FIG. 10) may be provided at at least one of both ends of each battery cell (111) along the second horizontal direction (e.g., Y-direction).

[0050] A cell block (110) may include pads (113) attached to the side surfaces of some of the battery cells (111) among a plurality of battery cells (111). The pads (113) may be attached to their corresponding battery cells (111) via an adhesive material such as an adhesive tape. The pads (113) may be arranged between battery cells (111) that are adjacent in a first horizontal direction (e.g., an X-direction) among the plurality of battery cells (111). The adjacent battery cells (111) may be spaced apart in the first horizontal direction (e.g., an X-direction) with the pads (113) interposed therebetween. The pads (113) may be arranged between the battery cells (111) and configured to support the battery cells (111). In exemplary embodiments, the pads (113) may be configured to thermally isolate the adjacent battery cells (111).

[0051] When viewed from a plan view, the cell block (110) may have a rectangular shape. The cell block (110) may include upper and lower surfaces that are opposed in a vertical direction (e.g., in the Z direction), two side surfaces (i.e., a first side surface and a second side surface) that are opposed to each other in a first horizontal direction (e.g., in the X direction), and a front surface and a back surface that are opposed to each other in a second horizontal direction (e.g., in the Y direction). The upper surface of the cell block (110) may include upper surfaces of a plurality of battery cells (111), and the lower surface of the cell block (110) may include lower surfaces of a plurality of battery cells (111).

[0052] On the front and rear sides of the cell block (110), busbar frames (143 in FIG. 10) that support busbars (145) and electrode leads (1111) of a plurality of battery cells (111) may be arranged, respectively. The busbar frames (143) on the front and rear sides of the cell block (110) may each include slits into which the electrode leads (1111) are inserted. In addition, the busbar frames (143) on the front and rear sides of the cell block (110) may each support at least one busbar (145) connected to at least one of the electrode leads (1111). At each end of the battery assembly (100) along the second horizontal direction (e.g., Y direction), an insulating cover (141) that covers the busbar frame (143) may be arranged.

[0053] The bus bars (145) may be connected to an end portion of a corresponding battery cell (111) among the plurality of battery cells (111) along the second horizontal direction (e.g., Y direction). The bus bars (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 joined 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 cell block (110) of a battery assembly (100) to a cell block (110) of another battery assembly (100) or to an external electrical device. In exemplary embodiments, the busbars (145) may include inter-busbars that are connected to electrode leads (1111) of different battery cells (111) to electrically connect the different battery cells (111).

[0054] A thermal diffusion film (121) may be attached to the lower surface of the cell block (110). The thermal diffusion film (121) may be configured to thermally couple the cell block (110) and the pack housing (501 in FIG. 5e) in which the battery assembly (100) is mounted.

[0055] The thermal diffusion film (121) covers the lower surface of the cell block (110) and may have a generally uniform thickness. For example, the thickness of the thermal diffusion film (121) may range from several to several hundred micrometers (㎛). In exemplary embodiments, the thickness of the thermal diffusion film (121) may be between about 5 ㎛ and about 30 ㎛, between about 10 ㎛ and about 25 ㎛, or between about 15 ㎛ and about 20 ㎛.

[0056] The thermal diffusion film (121) may have high thermal conductivity but may be electrically insulator. In exemplary embodiments, the thermal conductivity of the thermal 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 exemplary embodiments, the thermal conductivity of the thermal diffusion film (121) may be between about 1500 W / (m·K) and about 2300 W / (m·K), between about 1600 W / (m·K) and about 2200 W / (m·K), between about 1700 W / (m·K) and about 2100 W / (m·K), or between about 1800 W / (m·K) and about 2000 W / (m·K). The thermal conductivity of the thermal diffusion film (121) may be greater than the thermal conductivity of the thermally conductive resin layer (125).

[0057] The thermally conductive resin layer (125) is interposed between the thermal diffusion film (121) and the lower surface of the cell block (110), and can attach the cell block (110) to the thermal diffusion film (121). The thermally conductive resin layer (125) can completely or partially fill the space between the thermal diffusion film (121) and the lower surface of the cell block (110). The thermally conductive resin layer (125) can thermally couple the thermal diffusion film (121) and the cell block (110). For example, the thermally conductive resin layer (125) can include a resin layer and a thermally conductive filler contained in the resin layer.

[0058] The thermally conductive resin layer (125) can be in contact with the lower surface of the cell block (110). The thermally conductive resin layer (125) can be in direct contact with the lower surfaces of the plurality of battery cells (111) and can extend along the lower surfaces of the plurality of battery cells (111).

[0059] In exemplary embodiments, the thermally conductive resin layer (125) may include a thermosetting resin. In this case, the thermally conductive resin layer (125) may be formed by applying a thermosetting resin on the upper surface of the thermal diffusion film (121), placing the cell block (110) on the thermal diffusion film (121), and applying heat to the thermosetting resin so that the thermosetting resin hardens.

[0060] The fastening frame (130) can be attached to each of the battery cells (111) that are outermost in the first horizontal direction (e.g., X direction) among the plurality of battery cells (111). The fastening frame (130) can be fastened to the pack housing (501) through a fastening member (551) such as a bolt. For example, the battery assembly (100) can be mounted to the pack housing (501) in a side-mounting manner through the fastening frame (130).

[0061] The fastening frame (130) may include a first fastening frame (131) and a second fastening frame (135) spaced apart from each other with the cell block (110) therebetween. The first fastening frame (131) may be connected to one end of the cell block (110) along a first horizontal direction (e.g., X direction), and the second fastening frame (135) may be connected to the other end of the cell block (110) along the first horizontal direction (e.g., X direction). The first fastening frame (131) may include a first fixing plate (1311) attached to one end of the cell block (110) along the first horizontal direction (e.g., X direction) through an adhesive member such as an adhesive tape, and a first flange (1313) fastened to the pack housing (501) through a fastening member (551). The first fixing plate (1311) has a flat plate shape that covers one side of the cell block (110), and the first flange (1313) can be connected to the lower part of the first fixing plate (1311). The second fastening frame (135) can include a second fixing plate (1351) attached to the other end of the cell block (110) along the first horizontal direction (e.g., X direction) through an adhesive member such as an adhesive tape, and a second flange (1353) that is fastened to the pack housing (501) through a fastening member (551). The second fixing plate (1351) has a flat plate shape that covers one side of the cell block (110), and the second flange (1353) can be connected to the upper part of the second fixing plate (1351).

[0062] A venting plate (150) is provided on the cell block (110) and can cover an upper surface of the cell block (110). The venting plate (150) can include a plurality of venting portions (1531) configured to discharge gas. The venting plate (150) can include a support frame (151) including a plurality of openings (1511), and a cover sheet (153) attached to the support frame (151). The cover sheet (153) can cover an upper surface of the plurality of battery cells (111). The cover sheet (153) can include a heat-resistant sheet, a fire-resistant sheet, or a combination thereof. The cover sheet (153) can include a venting portion (1531) configured to discharge gas to each of the regions corresponding to the plurality of openings (1511) of the support frame (151). The above venting portion (1531) may correspond to a cut portion or cut line formed in the cover sheet (153). High-temperature gas generated from a plurality of battery cells (111) may be discharged to the external space on the upper side of the battery assembly (100) through the plurality of venting portions (1531) of the cover sheet (153).

[0063]

[0064] (Example 2)

[0065] Fig. 3 is a cross-sectional view showing a battery pack (500) according to exemplary embodiments of the present invention. Fig. 4 is an enlarged view showing an area indicated by "EX1" in Fig. 3.

[0066] Referring to FIGS. 3 and 4 together with FIGS. 1 and 2, a battery pack (500) may include a pack housing (501 of FIG. 5e) and battery assemblies (100) mounted in the pack housing (501). The battery pack (500) may include one or more battery assemblies (100) mounted in the pack housing (501). In exemplary embodiments, a plurality of battery assemblies (100) may be accommodated in a receiving space provided by the pack housing (501) and may be arranged in a first horizontal direction (e.g., X-direction) and / or a second horizontal direction (e.g., Y-direction) within the receiving space of the pack housing (501).

[0067] The pack housing (501) may include a bottom plate (510) and side walls (520 in FIG. 5E) connected to an edge of the bottom plate (510). The side walls (520) may extend along an edge of the bottom plate (510) to surround a receiving space of the pack housing (501). The pack housing (501) may further include a pack lid connected to the side walls (520) of the pack housing (501) to cover the receiving space. The receiving space of the pack housing (501) may be a closed space.

[0068] The above-mentioned bottom plate (510) may have a flat shape extending in a first horizontal direction (e.g., X direction) and a second horizontal direction (e.g., Y direction). The bottom plate (510) may support one or more battery assemblies (100).

[0069] The bottom plate (510) may include a cooling channel (511) configured to allow a cooling fluid to flow and may be configured to cool the battery assembly (100). A cooling fluid provided from the outside of the battery pack (500) may be supplied to an inlet of the cooling channel (511), flow along the cooling channel (511), and discharged to the outside through an outlet of the cooling channel (511). While the cooling fluid flows along the cooling channel (511), cooling of a plurality of battery cells (111) of the battery assembly (100) may be performed. The cooling fluid may include a coolant and / or a refrigerant. In exemplary embodiments, the bottom plate (510) may be formed through an extrusion process.

[0070] The battery assembly (100) can be attached to the bottom plate (510) by an adhesive layer (561) interposed between the lower surface of the heat diffusion film (121) and the upper surface of the bottom plate (510). For example, when assembling the battery assembly (100) to the pack housing (501), after applying the adhesive layer (561) on the upper surface of the bottom plate (510), the battery assembly (100) can be attached to the upper surface of the bottom plate (510) using the adhesive layer (561). The lower surface of the heat diffusion film (121) can be attached to the upper surface of the bottom plate (510) by the adhesive layer (561). When the battery assembly (100) is attached to the bottom plate (510), the thermally conductive resin layer (125) may be spaced from the bottom plate (510) with the thermal diffusion film (121) interposed therebetween and may not be in direct contact with the bottom plate (510). The adhesive layer (561) may include a resin layer and a heat-dissipating filler contained within the resin layer.

[0071] In exemplary embodiments, the adhesive layer (561) may be locally applied to the upper surface of the bottom plate (510). In exemplary embodiments, the adhesive layer (561) may be applied in the form of spots to multiple areas of the upper surface of the bottom plate (510). In exemplary embodiments, 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 exemplary embodiments, the thickness of the adhesive layer (561) may be smaller than the thickness of the thermally conductive resin layer (125).

[0072] In exemplary embodiments, the adhesive force between the thermal diffusion film (121) and the bottom plate (510) by the adhesive layer (561) may be less than the adhesive force between the thermal diffusion film (121) and the cell block (110) by the thermal conductive resin layer (125). The type of the adhesive layer (561), the application area of ​​the adhesive layer (561), etc. may be adjusted so that the adhesive force between the thermal diffusion film (121) and the bottom plate (510) by the adhesive layer (561) is less than the adhesive force between the thermal diffusion film (121) and the cell block (110) by the thermal conductive resin layer (125). By configuring the adhesive strength between the thermal diffusion film (121) and the bottom plate (510) by the adhesive layer (561) to be smaller than the adhesive strength between the thermal diffusion film (121) and the cell block (110) by the thermal conductive resin layer (125), the thermal diffusion film (121) can be easily removed from the pack housing (501) together with the cell block (110) when separating or disassembling the battery assembly (100) from the pack housing (501) for replacement of the battery assembly (100).

[0073] The battery assembly (100) can be fixed to the bottom plate (510) by a fastening member (551) such as a bolt. The battery assembly (100) can be fastened to the bottom plate (510) by the first fastening frame (131) and the second fastening frame (135) of the battery assembly (100) being fastened to the bottom plate (510) by the fastening members (551). The fastening members (551) can be fastened to the bottom plate (510) so as not to interfere with the cooling channel (511) of the bottom plate (510).

[0074] In exemplary embodiments, for battery assemblies (100) adjacent in a first horizontal direction (e.g., X-direction), a second fastening frame (135) of one of the adjacent battery assemblies (100) may be fastened to a first fastening frame (131) of the remaining of the adjacent battery assemblies (100). More specifically, a second flange (1353) of a second fastening frame (135) of one of the adjacent battery assemblies (100) may be seated on a first flange (1313) of a first fastening frame (131) of the remaining of the adjacent battery assemblies (100), and the second flange (1353) of the second fastening frame (135) may be fastened to the first flange (1313) of the first fastening frame (131) by a fastening member (551). Adjacent battery assemblies (100) can be fastened to each other by fastening a second fastening frame (135) of one of the adjacent battery assemblies (100) to a first fastening frame (131) of the remaining adjacent battery assemblies (100).

[0075]

[0076] (Example 3)

[0077] FIGS. 5A to 5F are drawings illustrating a method for manufacturing a battery pack (500) according to exemplary embodiments of the present invention. Hereinafter, a method for assembling a battery assembly (100) into a pack housing (501) will be described with reference to FIGS. 5A to 5F together with FIGS. 1 to 4 .

[0078] Referring to Fig. 5a, a thermal diffusion film (121) is prepared, and a thermally conductive resin (125a) is applied on the thermal diffusion film (121).

[0079] Referring to FIGS. 5b and 5c, a structure (101) including a cell block (110) is prepared, and the structure (101) is attached to a thermal diffusion film (121). The structure (101) may include a cell block (110), first and second fastening frames (131, 135), and a venting plate (150). The structure (101) may be temporarily bonded to the thermal diffusion film (121) by a thermally conductive resin (125a).

[0080] Referring to FIG. 5d, heat (310) may be applied to the thermally conductive resin (125a) to harden the thermally conductive resin (125a). As the thermally conductive resin (125a) hardens, the cell block (110) may be firmly attached to the thermal diffusion film (121). As the thermally conductive resin (125a) hardens, the thermally conductive resin layer (125) may be formed. The cell block (110), the first and second fastening frames (131, 135), the venting plate (150), the thermally conductive resin layer (125), and the thermal diffusion film (121) may constitute a battery assembly (100).

[0081] Referring to FIG. 5e, an adhesive layer (561) is applied to one mounting area on the upper surface of the bottom plate (510). The adhesive layer (561) may be locally applied to one mounting area on the upper surface of the bottom plate (510). In FIG. 5e, the adhesive layer (561) is illustrated as being applied to the bottom plate (510), but in some exemplary embodiments, the adhesive layer (561) may be applied to the lower surface of the thermal diffusion film (121).

[0082] Referring to FIG. 5f, a battery assembly (100) is attached to a mounting area on the upper surface of the bottom plate (510). The battery assembly (100) can be attached to the bottom plate (510) by an adhesive layer (561) applied to the upper surface of the bottom plate (510).

[0083] Thereafter, an adhesive layer (561) may be applied to the remaining mounting areas on the upper surface of the bottom plate (510), and a battery assembly (100) may be attached to each of the remaining mounting areas on the upper surface of the bottom plate (510).

[0084] Next, the battery assemblies (100) can be fastened to the bottom plate (510) by fastening members (551). The first and second fastening frames (131, 135) of each battery assembly (100) can be fastened to the bottom plate (510) by the fastening members (551), respectively. In the case of battery assemblies (100) adjacent in the first horizontal direction (e.g., X-direction), the second fastening frame (135) of one of the adjacent battery assemblies (100) and the first fastening frame (131) of the remaining of the adjacent battery assemblies (100) can be joined by the fastening members (551). Adjacent battery assemblies (100) can be joined by fastening a second fastening frame (135) of one of the adjacent battery assemblies (100) to a first fastening frame (131) of the remaining adjacent battery assemblies (100).

[0085] FIGS. 6A and 6B are cross-sectional views showing a method of manufacturing a battery pack (500) according to exemplary embodiments of the present invention.

[0086] Hereinafter, a method of replacing a battery assembly (100) in a battery pack (500) will be described with reference to FIGS. 6A and 6B together with FIGS. 1 to 4.

[0087] Referring to FIG. 6A, replacing a battery assembly (100) may include separating a defective battery assembly (100) from a pack housing (501). The step of separating the battery assembly (100) from the pack housing (501) may include releasing the fastening between the defective battery assembly (100) and the pack housing (501). To release the fastening between the defective battery assembly (100) and the bottom plate (510), fastening members (551) may be separated from the first and second fastening frames (131, 135) of the battery assembly (100).

[0088] Referring to FIG. 6B, the step of separating the battery assembly (100) from the pack housing (501) may include lifting the battery assembly (100) upward so that the heat diffusion film (121) is separated from the bottom plate (510). For example, after attaching a lifting mechanism to the defective battery assembly (100), the battery assembly (100) may be lifted with the lifting mechanism to separate the defective battery assembly (100) from the pack housing (501).

[0089] In exemplary embodiments, the adhesive force between the thermal diffusion film (121) and the bottom plate (510) by the adhesive layer (561) may be configured to be smaller than the adhesive force between the thermal diffusion film (121) and the cell block (110) by the thermally conductive resin layer (125). In this case, when the battery assembly (100) is lifted to separate the battery assembly (100) from the bottom plate (510), the thermal diffusion film (121) can be easily separated from the bottom plate (510) together with the cell block (110).

[0090] After the defective battery assembly (100) is separated from the pack housing (501), a new battery assembly (100) can be assembled to one mounting area of ​​the exposed bottom plate (510) after the defective battery assembly (100) is removed. The new battery assembly (100) can be assembled to the pack housing (501) using a method substantially the same as the method of assembling the battery assembly (100) described with reference to FIGS. 5A to 5F.

[0091] According to exemplary embodiments of the present invention, the battery assembly (100) may have a cell-to-pack structure that is directly assembled into the pack housing (501) of the battery pack (500). Since the battery cells (111) are thermally coupled to the bottom plate (510) of the pack housing (501) having a cooling function through a thermally conductive resin layer (125) and a thermal diffusion film (121) without an intermediate frame, heat generation of the battery cells (111) can be effectively controlled, thereby improving the safety and reliability of the battery pack (500).

[0092] In a typical battery pack, particularly a battery pack in which a cell-to-pack unit containing battery cells is fastened to a pack housing, the battery cells are directly attached to the pack housing by a resin layer. In this case, separating the battery cells from the pack housing would cause damage, such as tearing, to the battery cells. Therefore, unit-by-unit replacement, i.e., replacing one cell-to-pack unit with another, is not possible; only pack-by-pack replacement is possible.

[0093] According to exemplary embodiments of the present invention, since the cell block (110) is attached to the bottom plate (510) through the heat diffusion film (121), the battery assembly (100) corresponding to the cell-to-pack unit can be separated from the pack housing (501) without damaging the battery cells (111). Since the cell-to-pack unit unit can be replaced in the battery pack (500), costs can be reduced.

[0094]

[0095] (Example 4)

[0096] FIG. 7 is a cross-sectional view illustrating a battery assembly (100A) according to exemplary embodiments of the present invention. Below, the battery assembly (100A) illustrated in FIG. 7 will be described, focusing on differences from the battery assembly (100) described with reference to FIGS. 1 and 2.

[0097] Referring to FIG. 7, in the battery assembly (100A), the thermal 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 direction). The plurality of unit films (122) may overlap corresponding battery cells (111) among the plurality of battery cells (111) in a vertical direction (e.g., Z direction) and may be attached to the corresponding battery cells (111) by a thermally conductive resin layer (125). When separating or disassembling the battery assembly (100A) from the pack housing (501), only some of the battery cells (111) among the plurality of battery cells (111) may be removed. When replacing only the battery cell (111) that needs to be removed, the unit film (122) that overlaps the battery cell (111) that needs to be removed among the plurality of unit films (122) can be removed together.

[0098]

[0099] (Example 5)

[0100] FIG. 8 is a cross-sectional view illustrating a battery assembly (100B) according to exemplary embodiments of the present invention. Below, the battery assembly (100B) illustrated in FIG. 8 will be described, focusing on differences from the battery assembly (100) described with reference to FIGS. 1 and 2.

[0101] Referring to FIG. 8, in the battery assembly (100B), the thermal 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., X-direction). Two unit films (123) adjacent to each other in the first horizontal direction (e.g., X-direction) may be in contact with each other. The plurality of unit films (123) may each accommodate corresponding battery cells (111) among the plurality of battery cells (111). Each unit film (123) may have a folded shape to provide a space for accommodating corresponding battery cells (111) among the plurality of battery cells (111). When viewed in cross section, each unit film (123) may have a U-shape. For example, each unit film (123) may include a bottom portion facing the bottom of the corresponding battery cells (111) and a pair of side cover portions spaced apart from each other with the corresponding battery cells (111) therebetween. One of the pair of side cover portions may contact one side of the corresponding battery cells (111), and the other of the pair of side cover portions may contact the other side of the corresponding battery cells (111).

[0102]

[0103] (Example 6)

[0104] FIG. 9 is a cross-sectional view illustrating a battery pack (500A) according to exemplary embodiments of the present invention. Below, the battery pack (500A) illustrated in FIG. 9 will be described, focusing on differences from the battery pack (500) described with reference to FIGS. 3 and 4.

[0105] Referring to FIG. 9, in the battery pack (500A), the bottom plate (510) may include a groove (519) that accommodates an adhesive layer (561). The groove (519) of the plate may limit the application range of the adhesive layer (561). The groove (519) of the bottom plate (510) may be square or circular when viewed in a plan view. 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 may be applied to the surface of the bottom plate (510) around the groove (519) of the bottom plate (510). The bottom plate (510) may include a plurality of spaced apart grooves (519), and an adhesive layer (561) may be provided within each of the plurality of grooves (519) of the bottom plate (510).

[0106]

[0107] (Example 7)

[0108] FIG. 10 is a cross-sectional view illustrating a battery pack (500B) according to exemplary embodiments of the present invention. Hereinafter, the battery pack (500B) illustrated in FIG. 10 will be described, focusing on differences from the battery pack (500) described with reference to FIGS. 3 and 4.

[0109] Referring to FIG. 10, in the battery pack (500B), the thermally conductive resin layer (125A) may include a plurality of sub-thermal conductive resin layers having different material compositions, different thermal conductivities, and / or different adhesive strengths. The plurality of sub-thermal conductive resin layers of the thermally conductive resin layer (125A) may be attached to different regions of the cell block (110). The plurality of sub-thermal conductive resin layers may include a heat-dissipating filler, but the content of the heat-dissipating filler in the plurality of sub-thermal conductive resin layers may be different from each other. The heat-dissipating filler may include, for example, alumina, boron nitride, aluminum nitride, zinc oxide, magnesium oxide, or a combination thereof.

[0110] In exemplary embodiments, the thermally conductive resin layer (125A) may include a first sub-thermal conductive resin layer (1251) in contact with a first region of the cell block (110) and a second sub-thermal conductive resin layer (1253) in contact with a second region of the cell block (110). The first sub-thermal conductive resin layer (1251) may attach the first region of the cell block (110) to the thermal diffusion film (121), and the second sub-thermal conductive resin layer (1253) may attach the second region of the cell block (110) to the thermal diffusion film (121). The first sub-thermal conductive resin layer (1251) can attach portions of a plurality of battery cells (111) within a first region of the cell block (110) to a thermal diffusion film (121), and the second sub-thermal conductive resin layer (1253) can attach portions of a plurality of battery cells (111) within a second region of the cell block (110) to a thermal diffusion film (121).

[0111] The first sub-thermal conductive resin layer (1251) may have a first thermal conductivity and a first adhesive strength, and the second sub-thermal conductive resin layer (1253) may have a second thermal conductivity and a second adhesive strength. The first thermal conductivity of the first sub-thermal conductive resin layer (1251) may be greater than the second thermal conductivity of the second sub-thermal conductive resin layer (1253). The first adhesive strength of the first sub-thermal conductive resin layer (1251) may be less than the second adhesive strength of the second sub-thermal conductive resin layer (1253). The first sub-thermal conductive resin layer (1251) having a relatively high thermal conductivity may be attached to a portion of the cell block (110) where a relatively large amount of heat is generated, thereby enhancing cooling of the cell block (110). The second sub-thermal conductive resin layer (1253) having relatively low thermal conductivity can be attached to a portion of the cell block (110) where relatively little heat is generated. As the first sub-thermal conductive resin layer (1251) is attached to a portion of the cell block (110) where relatively much heat is generated and the second sub-thermal conductive resin layer (1253) is attached to a portion of the cell block (110) where relatively little heat is generated, a temperature deviation within the cell block (110) can be reduced. The second sub-thermal conductive resin layer (1253) having relatively high adhesive strength can be attached to a portion of the cell block (110) that is relatively vulnerable to vibration, thereby enhancing the structural stability of the cell block (110).

[0112] In exemplary embodiments, the first thermal conductivity of the first sub-thermal conductive resin layer (1251) may be between about 3 W / (m·K) and 10 W / (m·K), between about 4 W / (m·K) and 9 W / (m·K), between about 5 W / (m·K) and 8 W / (m·K), or between about 6 W / (m·K) and 7 W / (m·K). In exemplary embodiments, the second thermal conductivity of the second sub-thermal conductive resin layer (1253) may be between about 20% and about 80%, between about 30% and about 70%, or between about 40% and about 60% of the first thermal conductivity of the first sub-thermal conductive resin layer (1251).

[0113] In exemplary embodiments, the second adhesive strength of the second sub-thermal 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 exemplary embodiments, the first adhesive strength of the first sub-thermal 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 sub-thermal conductive resin layer (1253).

[0114] In exemplary embodiments, the plurality of battery cells (111) may each include a first portion that is relatively close to the electrode lead (1111) and a second portion that is relatively far from the electrode lead (1111). The first portions of the plurality of battery cells (111) may be within a first region of the cell block (110), and the second portions of the plurality of battery cells (111) may be within a second region of the cell block (110). The first sub-thermal conductive resin layer (1251) may be in contact with the first portions of the plurality of battery cells (111), and the second sub-thermal conductive resin layer (1253) may be in contact with the second portions of the plurality of battery cells (111). A first portion of the battery cell (111) that is relatively close to the electrode lead (1111) is a portion where relatively much heat is generated when the battery cell (111) operates, and a second portion of the battery cell (111) that is relatively far from the electrode lead (1111) is a portion where relatively little heat is generated when the battery cell (111) operates. A first sub-thermal conductive resin layer (1251) having relatively high 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). A second sub-thermal conductive resin layer (1253) having relatively low thermal conductivity may be attached to the second portion of each of the plurality of battery cells (111). As 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), a temperature deviation can be reduced in each of the plurality of battery cells (111). In each battery cell (111), the first portion of the battery cell (111) is supported by the busbar frame (143) and the insulating cover (141) and thus has relatively high structural stability, and the second portion of the battery cell (111) is relatively far from the busbar frame (143) and the insulating cover (141) and thus has relatively low structural stability.A second sub-thermal conductive resin layer (1253) having a relatively high adhesive strength can attach the second portion of each of the plurality of battery cells (111) to the thermal diffusion film (121), thereby enhancing the structural safety of the plurality of battery cells (111).

[0115] In exemplary embodiments, 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 a center portion between the first outer portion and the second outer portion. The battery cell (111) may extend in a second horizontal direction (e.g., in the Y-axis direction), and the center portion of the battery cell (111) may be between the first outer portion of the battery cell (111) and the second outer portion of the battery cell (111) in the second horizontal direction (e.g., in the Y-axis direction). The first outer portion and the second outer portion of an individual battery cell (111) may be within a first region of the cell block (110), and the center portion of an individual battery cell (111) may be within a second region of the cell block (110).

[0116] The first sub-thermal conductive resin layer (1251) can be in contact with the first outer portion and the second outer portion of each battery cell (111), and the second sub-thermal conductive resin layer (1253) can be in contact with the center portion of each battery cell (111). The first outer portion and the second outer portion of each battery cell (111) are relatively close to the electrode leads (1111), respectively, and are portions where relatively much heat is generated when the battery cell (111) operates, and the center portion of the battery cell (111) is relatively far from the electrode leads (1111), and are portions where relatively little heat is generated when the battery cell (111) operates. The first sub-thermal conductive resin layer (1251) having relatively high thermal conductivity can be attached to the first outer portion and the second outer portion of each of the plurality of battery cells (111), thereby enhancing cooling for the plurality of battery cells (111). A second sub-thermal conductive resin layer (1253) having relatively low thermal conductivity may be attached to the central portion of each of the plurality of battery cells (111). As the first sub-thermal conductive resin layer (1251) is attached to the first outer portion and the second outer portion of each of the plurality of battery cells (111) and the second sub-thermal conductive resin layer (1253) is attached to the central portion of each of the plurality of battery cells (111), a temperature deviation in each of the plurality of battery cells (111) may be reduced. By adjusting the dimensions of the central portion of the battery cell (111) in contact with the second sub-thermal conductive resin layer (1253), a temperature deviation between regions of the battery cell (111) may be more effectively controlled. For example, the length of the center of the battery cell (111) in contact with the second sub-thermal conductive resin layer (1253) along the second horizontal direction (e.g., Y-axis direction) may be between about 10% and about 70%, between about 20% and about 60%, or between about 30% and about 50% of the length of the battery cell (111) along the second horizontal direction (e.g., Y-axis direction).

[0117] The first outer portion and the second outer portion of the battery cell (111) are supported by the busbar frame (143) and the insulating cover (141), respectively, and thus have relatively high structural safety, while the center portion of the battery cell (111) is relatively far from the busbar frame (143) and the insulating cover (141), and thus has relatively low structural safety. The second sub-thermally conductive resin layer (1253) having relatively high adhesive strength can attach the center portion of each of the plurality of battery cells (111) to the thermal diffusion film (121), thereby enhancing the structural safety of the plurality of battery cells (111).

[0118] According to the battery pack (500B) according to exemplary embodiments, a portion of each battery cell (111) where relatively a lot of heat is generated can be attached to a heat diffusion film (121) with a heat conductive resin layer having relatively high thermal conductivity, and a portion of each battery cell (111) that is relatively vulnerable to vibration can be attached to a heat diffusion film (121) with a heat conductive resin layer having relatively high adhesive strength. Accordingly, compared to a case where the battery cells (111) are attached to the heat diffusion film (121) with a single adhesive layer, the temperature uniformity of the battery cells (111) can be improved, and the structural safety of the battery cells (111) can be strengthened.

[0119] The present invention has been described in more detail through drawings and examples. However, the configurations described in the drawings or examples described in this specification are merely embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that various equivalents and modified examples may exist as of the time of this application.

Claims

1. Pack housing; and A battery assembly mounted in the above pack housing; Including, The above battery assembly, A heat diffusion film attached to the bottom plate of the above pack housing; A cell block comprising a plurality of battery cells; and A thermally conductive resin layer that attaches the above cell block to the above thermal diffusion film; Battery pack containing.

2. In paragraph 1, A battery pack characterized in that the bottom plate includes cooling channels configured to allow cooling fluid to flow.

3. In paragraph 1, A battery pack, characterized in that the thermally conductive resin layer is in direct contact with the plurality of battery cells.

4. In paragraph 3, A battery pack characterized in that the thermally conductive resin layer does not contact the bottom plate.

5. In paragraph 1, A battery pack, characterized in that the thermally conductive resin layer comprises a thermosetting resin.

6. In paragraph 1, A battery pack further comprising an adhesive layer configured to attach the thermal diffusion film to the bottom plate, wherein the upper surface of the thermal diffusion film is in contact with the thermally conductive resin layer, and the lower surface of the thermal diffusion film is in contact with the adhesive layer.

7. In paragraph 6, A battery pack, characterized in that the adhesive force between the heat diffusion film and the bottom plate is smaller than the adhesive force between the heat diffusion film and the cell block.

8. In paragraph 6, A battery pack, characterized in that the bottom plate includes a groove for accommodating the adhesive layer.

9. In paragraph 1, The above plurality of battery cells are arranged in a first direction, A battery pack characterized in that the battery assembly further includes a fastening frame connected to one end of the cell block along the first direction and fastened to the pack housing.

10. In paragraph 1, A battery pack further comprising a venting plate covering the cell block and including a venting portion configured to discharge gas.

11. In paragraph 1, The above plurality of battery cells are arranged in a first direction, The plurality of battery cells each extend in a second direction perpendicular to the first direction, A battery pack, characterized in that the battery assembly further includes a busbar electrically connected to at least one of the plurality of battery cells.

12. In paragraph 1, The above thermal diffusion film comprises a plurality of unit films, A battery pack characterized in that each of the plurality of unit films of the thermal diffusion film provides a space for accommodating corresponding battery cells among the plurality of battery cells.

13. In paragraph 1, The above thermally conductive resin layer, a first sub-thermal conductive resin layer configured to attach a first region of the cell block to the thermal diffusion film; and A second sub-thermal conductive resin layer configured to attach a second region of the cell block to the thermal diffusion film; Including, The thermal conductivity of the first sub-thermal conductive resin layer is greater than the thermal conductivity of the second sub-thermal conductive resin layer, A battery pack, characterized in that the adhesive strength of the first sub-thermal conductive resin layer is smaller than the adhesive strength of the second sub-thermal conductive resin layer.

14. In paragraph 13, Each of the plurality of battery cells includes a first outer portion, a second outer portion, and a central portion between the first outer portion and the second outer portion, 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, A battery pack, characterized in that the second sub-thermal conductive resin layer is in contact with the central portion of each of the plurality of battery cells.

15. A step of applying a thermally conductive resin on the upper surface of the thermal diffusion film; A step of attaching a cell block including a plurality of battery cells to the upper surface of the thermal diffusion film to form a battery assembly including the cell block, the thermal diffusion film, and the thermally conductive resin; A step of applying an adhesive layer on the bottom plate of the pack housing; and A step of attaching the thermal diffusion film to the bottom plate using the adhesive layer; A method for manufacturing a battery pack comprising:

16. In paragraph 15, A method for manufacturing a battery pack, characterized in that the step of forming the battery assembly comprises attaching the cell block on the upper surface of the thermal diffusion film and applying heat to the thermally conductive resin to harden the thermally conductive resin.

17. In paragraph 16, The above thermal diffusion film covers the lower surface of the cell block facing the upper surface of the bottom plate, The above thermally conductive resin is in direct contact with the plurality of battery cells but does not contact the bottom plate, The above thermal diffusion film is attached to the floor plate by an adhesive layer locally applied to the upper surface of the floor plate, A method for manufacturing a battery pack, characterized in that the adhesive force between the heat diffusion film and the bottom plate is smaller than the adhesive force between the heat diffusion film and the cell block.

18. In paragraph 15, a step of separating the battery assembly from the bottom plate; and A step of attaching a new battery assembly to the bottom plate; A method for manufacturing a battery pack, characterized in that it further includes.

19. In paragraph 18, In the above cell block, the plurality of battery cells are arranged in the first direction, The battery assembly further includes a fastening frame provided at one end of the cell block along the first direction and fastened to the pack housing, After the step of attaching the battery assembly to the bottom plate, the step of attaching the fastening frame to the pack housing using a fastening member is further included. A method for manufacturing a battery pack, characterized in that the step of separating the battery assembly from the bottom plate includes the step of releasing the fastening between the fastening frame and the pack housing.

Images