Battery pack

Abstract

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

Description

battery pack

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

[0002] This application claims the benefit of priority from Republic of Korea Patent Application No. 10-2024-0046509, filed April 5, 2024, the entire disclosure of which is 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.

[0006] In order to solve the above-described problem, the technical idea of ​​the present invention provides a battery pack including: a base frame; a cell block including a plurality of battery cells on the base frame; a cooling structure provided on the cell block and having a first cooling channel; and a heat transfer structure thermally connecting the cell block to the cooling structure and including a plurality of heat conductive pads attached to the cell block and a plurality of heat conductive rails attached to the cooling structure; wherein the plurality of heat conductive rails are arranged in a first direction on the cell block, and two adjacent heat conductive rails among the plurality of heat conductive rails overlap in a second direction.

[0007] In exemplary embodiments, the cooling structure further comprises a first thermally conductive adhesive layer that attaches each of the plurality of thermally conductive rails to the cooling structure.

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

[0009] In exemplary embodiments, each of the plurality of thermally conductive pads is attached to a corresponding one of the plurality of battery cells, and each of the plurality of thermally conductive rails is formed integrally with a corresponding one of the plurality of thermally conductive pads.

[0010] In exemplary embodiments, the plurality of thermally conductive rails each include a first plate and a second plate positioned at different levels, and the second plate of one of two adjacent thermally conductive rails among the plurality of thermally conductive rails is characterized in that it overlaps the first plate of the other of two adjacent thermally conductive rails among the plurality of thermally conductive rails in the second direction.

[0011] In exemplary embodiments, the first plate is characterized in that it overlaps a corresponding one of the plurality of battery cells in the second direction, and the second plate is characterized in that it overlaps two corresponding battery cells of the plurality of battery cells in the second direction.

[0012] In exemplary embodiments, the cooling structure comprises a first cooling plate and a second cooling plate spaced apart with an opening therebetween, and each of the plurality of battery cells is characterized by overlapping the opening in the second direction.

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

[0014] In exemplary embodiments, the cooling device further comprises: an inlet pipe configured to deliver the cooling fluid to the first channel of the first cooling plate, the inlet pipe comprising a first inlet channel communicating with the first channel of the first cooling plate; and an outlet pipe configured to discharge the cooling fluid to the outside, the outlet pipe comprising a first outlet channel communicating with the second channel of the second cooling plate.

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

[0016] In exemplary embodiments, each of the plurality of battery cells is characterized by including a central portion overlapping the opening of the cooling structure in the second direction; and an outer portion overlapping one of the first cooling plate and the second cooling plate in the second direction, and having an electrode lead connected thereto.

[0017] In exemplary embodiments, the plurality of battery cells are arranged in the first direction, and the plurality of battery cells are characterized in that they each extend in a third direction perpendicular to the first direction and the second direction.

[0018] In exemplary embodiments, the present invention further comprises: an inner frame disposed on the base frame and disposed on one side of the cell block; and a fixing bracket for fixing the cooling structure to the inner frame.

[0019] In exemplary embodiments, the device further comprises a pack cover covering the cell block and the cooling structure; and a compressible pad provided between the cooling structure and the pack cover.

[0020] In exemplary embodiments, the pack cover further comprises: a pack cover covering the cell block and the cooling structure; a bolt attached to the cooling structure and inserted into a hole of the pack cover; and a nut fastened to a protrusion of the bolt protruding from the pack cover.

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

[0022] According to exemplary embodiments of the present invention, since the outer portion of a battery cell, which generates relatively much heat, is thermally coupled to a cooling structure through a heat transfer structure, cooling of the outer portion of the battery cell can be enhanced and a temperature deviation within the battery cell can be reduced.

[0023] 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.

[0024] FIG. 1 is a cross-sectional view showing a battery pack according to exemplary embodiments of the present invention.

[0025] FIG. 2 is an exploded perspective view showing a portion of a cell assembly according to exemplary embodiments of the present invention.

[0026] FIG. 3 is a perspective view showing a portion of a heat transfer structure according to exemplary embodiments of the present invention.

[0027] FIG. 4 is an exploded perspective view showing a portion of a heat transfer structure according to exemplary embodiments of the present invention.

[0028] FIG. 5 is a perspective view showing a battery pack according to exemplary embodiments of the present invention.

[0029] FIG. 6 is a perspective view showing a portion of a battery pack according to exemplary embodiments of the present invention.

[0030] FIG. 7 is a perspective view showing a portion of a cooling structure of a battery pack according to exemplary embodiments of the present invention.

[0031] FIG. 8 is a cross-sectional view showing a portion of a battery pack according to exemplary embodiments of the present invention.

[0032] FIGS. 9A to 9D are cross-sectional views showing a method of manufacturing a battery pack according to exemplary embodiments of the present invention.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037]

[0038] (Example 1)

[0039] FIG. 1 is a cross-sectional view illustrating a battery pack (10) according to exemplary embodiments of the present invention. FIG. 2 is an exploded perspective view illustrating a portion of a cell assembly (200) according to exemplary embodiments of the present invention. FIG. 3 is a perspective view illustrating a portion of a heat transfer structure (250) according to exemplary embodiments of the present invention. FIG. 4 is an exploded perspective view illustrating a portion of a heat transfer structure (250) according to exemplary embodiments of the present invention.

[0040] Referring to FIGS. 1 to 4, a battery pack (10) may include a pack frame (100), a cell assembly (200), a cooling structure (400), a pipe (500), and a compressible pad (710).

[0041] The pack frame (100) can provide an internal space for accommodating a cell assembly (200). The pack frame (100) can include a base frame (110), a side frame (120), a pack cover (130), and a plurality of internal frames (140).

[0042] The base frame (110) can support the cell assemblies (200). The base frame (110) can have a flat plate shape extending approximately in a first horizontal direction (e.g., X direction) and a second horizontal direction (e.g., Y direction). A plurality of cell assemblies (200) arranged in the first horizontal direction (e.g., X direction) and the second horizontal direction (e.g., Y direction) can be provided on the base frame (110).

[0043] The base frame (110) may include a lower cooling channel (111) configured to allow a cooling fluid to flow. A cooling fluid provided from the outside of the battery pack (10) may be supplied to an inlet of the lower cooling channel (111), flow along the lower cooling channel (111), and discharged to the outside through an outlet of the lower cooling channel (111). While the cooling fluid flows along the lower cooling channel (111), cooling of the cell assembly (200) may be achieved. The cooling fluid may include a coolant and / or a refrigerant.

[0044] The side frame (120) can extend along the perimeter of the base frame (110) and surround the cell assembly (200).

[0045] The pack cover (130) can be fastened on the side frame (120) to cover the cell assembly (200). The pack cover (130) can have a flat shape extending in a first horizontal direction (e.g., X direction) and a second horizontal direction (e.g., Y direction).

[0046] A plurality of inner frames (140) can partition the inner space of the pack frame (100) into a plurality of accommodation spaces. One or more cell assemblies (200) can be arranged in each of the plurality of accommodation spaces of the pack frame (100) defined by the plurality of inner frames (140). In exemplary embodiments, the plurality of inner frames (140) can be spaced apart from each other in a first horizontal direction (e.g., X-direction), and each inner frame (140) can extend in a second horizontal direction (e.g., Y-direction). One cell assembly (200) can be arranged between a pair of inner frames (140).

[0047] A cell assembly (200) may include a cell block (210), a thermal barrier pad (230), and a heat transfer structure (250).

[0048] A cell block (210) may include a plurality of battery cells (220). Each battery cell (220) is a basic unit of a lithium ion battery, i.e., a secondary battery. Each battery cell (220) 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.

[0049] Each battery cell (220) may be 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.

[0050] A plurality of battery cells (220) provided in the cell assembly (200) may be connected in series and / or in parallel. For example, the plurality of battery cells (220) may be connected in series with each other. For example, the plurality of battery cells (220) may also be connected in parallel with each other. For example, when a set of two or more battery cells (220) connected in parallel with each other is defined as a bank, one bank composed of two or more battery cells (220) connected in parallel with each other and another bank composed of two or more battery cells (220) connected in parallel with each other may be connected in series.

[0051] In exemplary embodiments, a plurality of battery cells (220) provided in a cell assembly (200) may be arranged in a first horizontal direction (e.g., X-direction), and individual battery cells (220) may extend in a second horizontal direction (e.g., Y-direction). An electrode lead (229) may be provided at at least one of both ends of an individual battery cell (220) along the second horizontal direction (e.g., Y-direction). An individual battery cell (220) may have a central portion and a pair of peripheral portions, and an electrode lead (229) may be connected to each of the pair of peripheral portions of an individual battery cell (220). Electrode leads (229) of neighboring battery cells (220) among the plurality of battery cells (220) may be electrically and physically connected to each other.

[0052] A thermal barrier pad (230) may be disposed between battery cells (220). The thermal barrier pad (230) may have a flat plate shape extending approximately in a second horizontal direction (e.g., Y direction) and a vertical direction (e.g., Z direction). At least one of both side surfaces of the thermal barrier pad (230) may be in contact with the battery cell (220). The thermal barrier pad (230) may be attached to the corresponding battery cell (220) by an adhesive member (291), such as a double-sided tape or adhesive. The cell assembly (200) may include a plurality of thermal barrier pads (230). At least one battery cell (220) may be disposed between two adjacent thermal barrier pads (230). A thermal barrier pad (230) may be disposed between battery cells (220) to prevent or suppress thermal propagation between the battery cells (220). In addition, the thermal barrier pad (230) may be configured to be elastically deformed by an external force, and may be configured to support the corresponding battery cell (220). When the thickness of the battery cell (220) in the first horizontal direction (e.g., the X direction) increases due to swelling of the battery cell (220), the thermal barrier pad (230) may be elastically deformed to absorb or disperse the force applied by the swelling of the corresponding battery cell (220). In exemplary embodiments, the thermal barrier pad (230) may include polyurethane, silicone, or a combination thereof.

[0053] A heat transfer structure (250) can thermally connect the cell block (210) to the cooling structure (400). The heat transfer structure (250) can be attached to each of the plurality of battery cells (220) and can be attached to the cooling structure (400). The heat transfer structure (250) can provide a heat transfer path for thermally connecting each of the plurality of battery cells (220) to the cooling structure (400). The heat transfer structure (250) can include a material having excellent thermal conductivity, for example, copper, silver, gold, aluminum, tungsten, or a combination thereof. The thermal conductivity of the material of the heat transfer structure (250) can be greater than the thermal conductivity of the material of the thermal barrier pad (230).

[0054] The heat transfer structure (250) may include a plurality of thermally conductive pads (251) attached to the cell block (210) and a plurality of thermally conductive rails (253) provided on the cell block (210).

[0055] A plurality of thermally conductive pads (251) may be attached to a corresponding one or more battery cells (220) among a plurality of battery cells (220). Each thermally conductive pad (251) may have a flat plate shape extending approximately in a second horizontal direction (e.g., Y direction) and a vertical direction (e.g., Z direction). At least one of both side surfaces of each thermally conductive pad (251) may be in contact with a battery cell (220). Each thermally conductive pad (251) may be attached to an adjacent battery cell (220) by an adhesive member (291).

[0056] In the cell assembly (200), a plurality of battery cells (220) may be arranged in a first horizontal direction (e.g., X-direction), and thermally conductive pads (251) and thermal barrier pads (230) may be arranged alternately and repeatedly in the first horizontal direction (e.g., X-direction). In exemplary embodiments, one side of each battery cell (220) may be attached to the thermally conductive pad (251) by an adhesive member (291), and the other side of each battery cell (220) may be attached to the thermal barrier pad (230) by the adhesive member (291).

[0057] The cell assembly (200) can be thermally and physically coupled to the base frame (110) by a lower thermally conductive adhesive layer (310). The lower thermally conductive adhesive layer (310) can be in direct contact with each of the plurality of battery cells (220) and each of the plurality of thermally conductive pads (251). The lower thermally conductive adhesive layer (310) can include a thermal resin and / or a thermal interface material.

[0058] A plurality of thermally conductive rails (253) are provided on the cell block (210) and can be arranged in a first horizontal direction (e.g., X-direction). Two adjacent thermally conductive rails (253) among the plurality of thermally conductive rails (253) can be in contact with each other. Each of the plurality of thermally conductive rails (253) can be integrally formed with a corresponding thermally conductive pad (251) among the plurality of thermally conductive pads (251). The thermally conductive rails (253) and the thermally conductive pads (251) that are integrally formed with each other can form a heat transfer fin (259). The heat transfer structure (250) can be formed with a plurality of heat transfer fins (259) aligned in a first horizontal direction (e.g., X-direction).

[0059] The plurality of thermally conductive rails (253) may cover a portion of the upper surface of the cell block (210), but may not cover another portion of the upper surface of the cell block (210). In exemplary embodiments, the plurality of thermally conductive rails (253) may cover a pair of outer portions of an individual battery cell (220) to which the electrode leads (229) are connected, but may not cover a center portion of the individual battery cell (220). In exemplary embodiments, the plurality of thermally conductive rails (253) may include a first group of thermally conductive rails (253) and a second group of thermally conductive rails (253) spaced apart in a second horizontal direction (e.g., a Y direction). The first group of thermally conductive rails (253) may be arranged in the first horizontal direction (e.g., an X direction), and the second group of thermally conductive rails (253) may be arranged in the first horizontal direction (e.g., an X direction). The first group of thermally conductive rails (253) may cover one outer portion of each of the plurality of battery cells (220), and the second group of thermally conductive rails (253) may cover another outer portion of each of the plurality of battery cells (220). Between the first group of thermally conductive rails (253) and the second group of thermally conductive rails (253), an opening may be provided that overlaps vertically (e.g., in the Z direction) at the center of each of the plurality of battery cells (220).

[0060] Each thermally conductive rail (253) may have a stepped structure or a stepped structure. Each thermally conductive rail (253) may include a first plate (2531) at a first vertical level and a second plate (2533) at a second vertical level different from the first vertical level. Here, the vertical level may refer to a position along a vertical direction (e.g., a Z-direction). A distance along a vertical direction (e.g., a Z-direction) between the first plate (2531) and the cooling structure (400) may be greater than a distance along a vertical direction (e.g., a Z-direction) between the second plate (2533) and the cooling structure (400).

[0061] In exemplary embodiments, a length of the second plate (2533) of an individual thermally conductive rail (253) along the first horizontal direction (e.g., X-direction) may be greater than a length of the first plate (2531) of an individual thermally conductive rail (253) along the first horizontal direction (e.g., X-direction). The first plate (2531) of an individual thermally conductive rail (253) may be vertically overlapped (e.g., Z-direction) with a corresponding one of the plurality of battery cells (220). The second plate (2533) of an individual thermally conductive rail (253) may be vertically overlapped (e.g., Z-direction) with two corresponding battery cells (220) among the plurality of battery cells (220).

[0062] Among the plurality of thermally conductive rails (253), two thermally conductive rails (253) adjacent in a first horizontal direction (e.g., X-direction) may overlap in a vertical direction (e.g., Z-direction). A portion of one of the two thermally conductive rails (253) may overlap a portion of the other of the two thermally conductive rails (253) in a vertical direction (e.g., Z-direction). A second plate (2533) of one of the two thermally conductive rails (253) may overlap a first plate (2531) of the other of the two thermally conductive rails (253) in a vertical direction (e.g., Z-direction). A bottom surface of the second plate (2533) of one of the two thermally conductive rails (253) may contact an upper surface of the first plate (2531) of the other of the two thermally conductive rails (253). In this case, individual battery cells (220) may be vertically (e.g., in the Z direction) superimposed on the second plate (2533) of one of the two thermally conductive rails (253) and the first plate (2531) of the other of the two thermally conductive rails (253).

[0063] According to exemplary embodiments of the present invention, since a plurality of heat transfer fins (259) in the heat transfer structure (250) are arranged to have an overlapping structure that overlaps each other, the rigidity of the cell assembly (200) including the heat transfer structure (250) can be improved.

[0064] A cooling structure (400) may be disposed on the cell assembly (200). The cooling structure (400) may cover a plurality of battery cells (220) and a heat transfer structure (250). The cooling structure (400) may include a cooling channel (401) configured to allow a cooling fluid to flow. A cooling fluid provided from the outside of the battery pack (10) may be supplied to an inlet of the cooling channel (401), flow along the cooling channel (401), and discharged to the outside through an outlet of the cooling channel (401). While the cooling fluid flows along the cooling channel (401), cooling of the cell assembly (200) may be achieved.

[0065] The cell assembly (200) can be thermally and physically coupled to the cooling structure (400) by an upper thermally conductive adhesive layer (330). The upper thermally conductive adhesive layer (330) can be interposed between the plurality of thermally conductive rails (253) and the cooling structure (400). The upper thermally conductive adhesive layer (330) can thermally and physically couple the plurality of thermally conductive rails (253) to the cooling structure (400). The upper thermally conductive adhesive layer (330) can include a thermal resin and / or a thermal interface material.

[0066] The pipe (500) may be mounted to the pack frame (100) and configured to convey a cooling fluid. For example, the pipe (500) may be mounted to the side frame (120). The pipe (500) may include a first channel (501) communicating with a cooling channel (401) of the cooling structure (400) and a second channel (503) communicating with a lower cooling channel (111) of the base frame (110). In exemplary embodiments, the first channel (501) of the pipe (500) may be an inlet channel configured to convey a cooling fluid supplied from an external cooling fluid supply unit to an inlet of the cooling channel (401) of the cooling structure (400), and the second channel (503) of the pipe (500) may be an inlet channel configured to convey a cooling fluid supplied from an external cooling fluid supply unit to an inlet of the lower cooling channel (111) of the base frame (110). In exemplary embodiments, the first channel (501) of the pipe (500) may be an outlet channel configured to deliver cooling fluid discharged from an outlet of the cooling channel (401) to a cooling fluid supply, and the second channel (503) of the pipe (500) may be an outlet channel configured to deliver cooling fluid discharged from an outlet of the lower cooling channel (111) to a cooling fluid supply.

[0067] A compressible pad (710) may be provided between the cooling structure (400) and the pack cover (130). The compressible pad (710) may be attached to the cooling structure (400) and / or the pack cover (130). The compressible pad (710) may be configured to be elastically deformed by an external force. For example, the compressible pad (710) may include polyurethane, silicone, or a combination thereof. The compressible pad (710) may improve the durability of the battery pack (10) by reducing vibration of the pack cover (130).

[0068]

[0069] Fig. 5 is a perspective view illustrating a battery pack (10A) according to exemplary embodiments of the present invention. Fig. 6 is a perspective view illustrating a portion of a battery pack (10A) according to exemplary embodiments of the present invention. Fig. 7 is a perspective view illustrating a portion of a cooling structure (400A) of a battery pack (10A) according to exemplary embodiments of the present invention.

[0070] Referring to FIGS. 5 to 7, a cooling structure (400A) of a battery pack (10A) may include a first cooling plate (410), a second cooling plate (420), and a connecting plate (430). The first cooling plate (410) and the second cooling plate (420) may each extend in a first horizontal direction (e.g., an X-direction). In exemplary embodiments, the first cooling plate (410) and the second cooling plate (420) may extend in the first horizontal direction (e.g., an X-direction) to cover two or more cell assemblies (200) arranged in the first horizontal direction (e.g., an X-direction). The first cooling plate (410) and the second cooling plate (420) may be spaced apart in a second horizontal direction (e.g., a Y-direction) with an opening (450) therebetween. The connecting plate (430) can extend between the end of the first cooling plate (410) and the end of the second cooling plate (420).

[0071] The first cooling plate (410) may include a first channel configured to guide the cooling fluid (CF) in a first flow direction. The second cooling plate (420) may include a second channel configured to guide the cooling fluid (CF) in a second flow direction opposite to the first flow direction. The connecting plate (430) may include a third channel extending between the first channel of the first cooling plate (410) and the second channel of the second cooling plate (420). The first channel of the first cooling plate (410) may communicate with the second channel of the second cooling plate (420) through the third channel of the connecting plate (430).

[0072] The battery pack (10A) may include a fixing bracket for fixing the cooling structure (400A) to the pack frame (100). The battery pack (10A) may include a first fixing bracket (610) for fixing the first cooling plate (410) to the pack frame (100) and a second fixing bracket (620) for fixing the second cooling plate (420) to the pack frame (100). The first fixing bracket (610) may be joined to the first cooling plate (410) by welding and may be fastened to a corresponding internal frame (140) by a fastening member such as a bolt. The second fixing bracket (620) may be joined to the second cooling plate (420) by welding and may be fastened to a corresponding internal frame (140) by a fastening member such as a bolt.

[0073] The battery pack (10A) may include an inlet pipe (510) into which externally supplied cooling fluid (CF) is introduced and an outlet pipe (530) that discharges the cooling fluid (CF) to the outside.

[0074] The inlet pipe (510) may include a first portion (511) having a first inlet channel communicating with an inlet of a first channel of a first cooling plate (410) and a second portion (515) having a second inlet channel communicating with an inlet of a lower cooling channel (111) of a base frame (110). An externally provided cooling fluid (CF) may be delivered to the first channel of the first cooling plate (410) through the first inlet channel of the inlet pipe (510) and may be delivered to the lower cooling channel (111) of the base frame (110) through the second inlet channel of the inlet pipe (510). The first inlet channel and the second inlet channel may communicate with each other within the inlet pipe (510), and the cooling fluid provided to the inlet of the inlet pipe (510) may be separated into the first inlet channel and the second inlet channel.

[0075] The outlet pipe (530) may include a first portion (531) having a first outlet channel communicating with an outlet of a second channel of a second cooling plate (420) and a second portion (535) having a second outlet channel communicating with an outlet of a lower cooling channel (111) of a base frame (110). The first outlet channel of the outlet pipe (530) may transmit cooling fluid (CF) discharged from the second channel of the second cooling plate (420) to the outside. The second outlet channel of the outlet pipe (530) may transmit cooling fluid (CF) discharged from the lower cooling channel (111) of the base frame (110) to the outside. The first outlet channel and the second outlet channel can be communicated with each other within the outlet pipe (530), and the cooling fluid discharged from the second channel of the second cooling plate (420) and the lower cooling channel (111) of the base frame (110) can be combined within the outlet pipe (530).

[0076] The first inlet channel of the inlet pipe (510), the first channel of the first cooling plate (410), the third channel of the connecting plate (430), the second channel of the second cooling plate (420), and the first outlet channel of the outlet pipe (530) can be sequentially connected and form a first flow path of the cooling fluid (CF). The second inlet channel of the inlet pipe (510), the lower cooling channel (111) of the base frame (110), and the second outlet channel of the outlet pipe (530) can be sequentially connected and form a second flow path of the cooling fluid (CF).

[0077] According to exemplary embodiments of the present invention, the battery pack (10A) has a dual cooling structure configured to cool the battery cells (220) by flowing a cooling fluid (CF) through a lower cooling channel (111) of a base frame (110) located below the cell assembly (200) and a cooling channel (401) of a cooling structure (400A) located above the cell assembly (200), thereby improving the cooling performance for the battery cells (220).

[0078] In exemplary embodiments, the first cooling plate (410) may cover one outer portion of each of the plurality of battery cells (220), and the second cooling plate (420) may cover another outer portion of each of the plurality of battery cells (220). An opening (450) provided between the first cooling plate (410) and the second cooling plate (420) may overlap a central portion of each of the plurality of battery cells (220) in a vertical direction (e.g., in the Z direction). In this case, a pair of outer portions of each of the battery cells (220) to which the electrode leads (229) are connected may overlap each of the first cooling plate (410) and the second cooling plate (420) in a vertical direction (e.g., in the Z direction), and a central portion of each of the battery cells (220) may overlap each of the openings (450) of the cooling structure (400A) in a vertical direction (e.g., in the Z direction).

[0079] In exemplary embodiments, the opening (450) of the cooling structure (400A) may provide a venting passage through which high-temperature gases generated from a plurality of battery cells (220) flow and a passage through which wireless signals for components such as a battery management system (BMS) are transmitted. Since the cooling structure (400A) has the opening (450), when a thermal event such as thermal runaway occurs, high-temperature gases generated from the battery cells (220) may be vented upward through the opening (450) of the cooling plate.

[0080] In general, heat generation of individual battery cells (220) occurs more at the outer portion of the battery cell (220) where the electrode lead (229) is connected than at the center of the battery cell (220). According to exemplary embodiments, since the outer portion of the battery cell (220) where heat generation is relatively high is thermally coupled to the cooling structure (400A) through the heat transfer structure (250), cooling of the outer portion of the battery cell (220) can be enhanced and the temperature deviation within the battery cell (220) can be reduced.

[0081]

[0082] (Example 2)

[0083] FIG. 8 is a cross-sectional view showing a portion of a battery pack according to exemplary embodiments of the present invention.

[0084] Referring to FIG. 8, the battery pack may include a bolt (731) attached to a cooling structure (400) and a nut (735) fastened to the bolt (731).

[0085] The bolt (731) can be coupled to the cooling structure (400). For example, the bolt (731) can be coupled to the cooling structure (400) by a joint (733) formed by welding. For example, the bolt (731) is a projection stud and can be coupled to the cooling structure (400) by projection welding. The bolt (731) can be inserted into a hole of the pack cover (130), and the bolt (731) can include a protrusion protruding outward from the pack cover (130). The nut (735) can be fitted to the protrusion of the bolt (731) on the outside of the pack cover (130). A thread may be provided on the inner surface of the nut (735) to engage with a thread provided on the outer surface of the protrusion of the bolt (731). The cooling structure (400) can be fixed to the pack cover (130) by the nut (735) being fitted into the protrusion of the bolt (731). In exemplary embodiments, the cooling structure (400) can be fixed to the pack cover (130) by the bolt (731) and the nut (735), and a compressible pad (710 in FIG. 1) can be provided between the cooling structure (400) and the pack cover (130). Since the pack cover (130) is fixed to the cooling structure (400) by the bolt (731) and the nut (735), vibration of the pack cover (130) can be reduced, and durability of the battery pack can be improved.

[0086]

[0087] (Example 3)

[0088] FIGS. 9A to 9D are cross-sectional views showing a method of manufacturing a battery pack according to exemplary embodiments of the present invention.

[0089] Referring to FIG. 9A, a cell assembly (200) is mounted on a mounting area of ​​a base frame (110). The cell assembly (200) may include a plurality of battery cells (220), a plurality of thermal barrier pads (230), and a heat transfer structure (250). The cell assembly (200) may be attached to the base frame (110) by a lower thermally conductive adhesive layer (310) applied on the base frame (110).

[0090] Referring to FIG. 9b, an upper thermally conductive adhesive layer (330) is formed on a plurality of thermally conductive rails (253) of a heat transfer structure (250).

[0091] Referring to FIG. 9c, after forming an upper thermally conductive adhesive layer (330) on a plurality of thermally conductive rails (253) of a heat transfer structure (250), a cooling structure (400) is placed on a cell assembly (200). The cooling structure (400) can be attached to a plurality of thermally conductive rails (253) of the heat transfer structure (250) by the upper thermally conductive adhesive layer (330).

[0092] Referring to FIG. 9d, after the cooling structure (400) is placed on the cell assembly (200), a compressible pad (710) is placed on the cooling structure (400). The compressible pad (710) can be attached to the cooling structure (400) by an adhesive member.

[0093] Referring to FIG. 1, after the compressible pad (710) is placed on the cooling structure (400), the pack cover (130) is fastened to the side frame (120).

[0094] According to exemplary embodiments of the present invention, the battery pack has a dual cooling structure configured to cool the battery cells (220) by flowing a cooling fluid through a lower cooling channel (111) of a base frame (110) located below the cell assembly (200) and a cooling channel (401) of a cooling structure (400) located above the cell assembly (200), thereby improving the cooling performance for the battery cells (220).

[0095] According to exemplary embodiments of the present invention, since the outer portion of the battery cell (220) that generates relatively a lot of heat is thermally coupled to the cooling structure (400) through the heat transfer structure (250), cooling of the outer portion of the battery cell (220) can be enhanced and the temperature deviation within the battery cell (220) can be reduced.

[0096] 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. Base frame; A cell block including a plurality of battery cells on the base frame; A cooling structure provided on the above cell block and having a first cooling channel; and A heat transfer structure thermally connecting the cell block to the cooling structure, the heat transfer structure including a plurality of thermally conductive pads attached to the cell block and a plurality of thermally conductive rails attached to the cooling structure; Including, The above plurality of thermally conductive rails are arranged in a first direction on the cell block, A battery pack, wherein two adjacent thermally conductive rails among the plurality of thermally conductive rails overlap in the second direction.

2. In paragraph 1, A battery pack further comprising a first thermally conductive adhesive layer attaching each of the plurality of thermally conductive rails to the cooling structure.

3. In paragraph 1, The above base frame includes a second cooling channel, A battery pack further comprising a second thermally conductive adhesive layer that attaches each of the plurality of battery cells to the base frame.

4. In paragraph 1, Each of the plurality of thermally conductive pads is attached to a corresponding one of the plurality of battery cells, A battery pack characterized in that each of the plurality of thermally conductive rails is integrally formed with a corresponding one of the plurality of thermally conductive pads.

5. In paragraph 1, The above plurality of thermally conductive rails each include a first plate and a second plate positioned at different levels, A battery pack characterized in that a second plate of one of two adjacent thermally conductive rails among the plurality of thermally conductive rails overlaps a first plate of the other of two adjacent thermally conductive rails among the plurality of thermally conductive rails in the second direction.

6. In paragraph 5, The first plate is overlapped in the second direction on a corresponding one of the plurality of battery cells, A battery pack characterized in that the second plate overlaps two corresponding battery cells among the plurality of battery cells in the second direction.

7. In paragraph 1, The cooling structure includes a first cooling plate and a second cooling plate spaced apart with an opening therebetween, A battery pack, wherein each of the plurality of battery cells is overlapped in the second direction in the opening.

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

9. In paragraph 8, An inlet pipe including a first inlet channel communicating with the first channel of the first cooling plate and configured to deliver the cooling fluid to the first channel of the first cooling plate; and An outlet pipe including a first outlet channel communicating with the second channel of the second cooling plate and configured to discharge the cooling fluid to the outside; A battery pack characterized by further including:

10. In paragraph 9, The above base frame includes a second cooling channel, The above inlet pipe further includes a second inlet channel communicating with the inlet of the second cooling channel of the base frame, A battery pack, characterized in that the outlet pipe further includes a second outlet channel communicating with the outlet of the second cooling channel of the base frame.

11. In paragraph 7, Each of the above plurality of battery cells, a central portion overlapping the opening of the cooling structure in the second direction; and An outer portion overlapping one of the first cooling plate and the second cooling plate in the second direction and having an electrode lead connected thereto; A battery pack comprising:

12. In paragraph 11, The above plurality of battery cells are arranged in the first direction, A battery pack, wherein each of the plurality of battery cells extends in a third direction perpendicular to the first direction and the second direction.

13. In paragraph 1, an internal frame disposed on the base frame and disposed on one side of the cell block; and A fixing bracket for fixing the cooling structure to the inner frame; A battery pack characterized by further including:

14. In paragraph 1, a pack cover covering the cell block and the cooling structure; and A compressible pad provided between the cooling structure and the pack cover; A battery pack characterized by further including:

15. In paragraph 1, A pack cover covering the cell block and the cooling structure; A bolt attached to the cooling structure and inserted into a hole of the pack cover; and A nut fastened to a protrusion of the bolt protruding from the pack cover; A battery pack characterized by further including:

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