Battery assembly and battery pack comprising same

Abstract

The technical concept of the present invention is to provide a battery pack comprising: a pack housing including a first support structure; and a battery assembly accommodated in the pack housing, wherein the battery assembly includes: a cell block including a plurality of battery cells stacked in a first direction; a frame including a first side cover and a second side cover spaced apart from each other in the first direction with the cell block therebetween; and a top cover that includes a central part, which is coupled to the frame so as to cover the cell block, and a first outer part, which protrudes from the first side cover to the outside, the first outer part being fastened to the first support structure. A first buffer space extending in the first direction is provided between the first side cover and the first outer part of the top cover.

Description

Battery assembly and battery pack including same

[0001] The present invention relates to a battery assembly and a battery pack including the same.

[0002] This application claims the benefit of priority from Republic of Korea Patent Application No. 10-2024-0001300, filed January 4, 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 assembly and a battery pack including 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 including a first support structure; and a battery assembly accommodated in the pack housing, wherein the battery assembly includes: a cell block including a plurality of battery cells stacked in a first direction; a frame including a first side cover and a second side cover spaced apart in the first direction with the cell blocks interposed therebetween; and a top cover including a central portion coupled to the frame to cover the cell blocks and a first outer portion protruding outwardly from the first side cover, the first outer portion being fastened to the first support structure; and a first buffer space extending in the first direction is provided between the first outer portion of the top cover and the first side cover.

[0007] In exemplary embodiments, the first outer portion of the top cover is characterized by including: a first side plate spaced apart from the first side cover in the first direction with the first buffer space therebetween; a first extension extending in the first direction between the first side plate and the center of the top cover to cover the first buffer space; and at least one first flange connected to the first side plate and fastened to the first support structure.

[0008] In exemplary embodiments, the first side plate is characterized in that it extends in a second direction perpendicular to the first direction, and the first buffer space is characterized in that it extends continuously in the second direction between both ends of the first side plate along the second direction.

[0009] In exemplary embodiments, the length of the first buffer space in the second direction is characterized in that it is greater than the length of the first buffer space in the first direction.

[0010] In exemplary embodiments, the at least one first flange is characterized by comprising a plurality of first flanges spaced apart from each other in the second direction along a lower edge of the first side plate.

[0011] In exemplary embodiments, the first buffer space is characterized in that it communicates with a space provided between the lower portion of the first side cover and the first support structure.

[0012] In exemplary embodiments, the pack housing further includes a second support structure, the top cover further includes a second outer portion protruding outwardly from the second side cover and fastened to the second support structure, and a second buffer space extending in the first direction is provided between the second outer portion of the top cover and the second side cover.

[0013] In exemplary embodiments, the second outer portion of the top cover is characterized by including: a second side plate spaced apart from the second side cover in the first direction with the second buffer space therebetween; a second extension extending in the first direction between the second side plate and the center of the top cover to cover the second buffer space; and at least one second flange connected to the second side plate and fastened to the second support structure.

[0014] In exemplary embodiments, the second side plate extends in a second direction perpendicular to the first direction, the second buffer space extends continuously in the second direction between both ends of the second side plate along the second direction, a length of the second buffer space along the second direction is greater than a length of the second buffer space along the first direction, and the at least one second flange comprises a plurality of second flanges spaced apart from each other in the second direction along a lower edge of the second side plate.

[0015] In exemplary embodiments, the frame further comprises a bottom cover facing the bottom surface of the cell block, the bottom cover comprising a cooling channel configured to allow a cooling fluid to flow.

[0016] In exemplary embodiments, the bottom cover of the frame is characterized in that it is spaced apart from the bottom plate of the pack housing such that a space is formed between the bottom plate of the pack housing and the bottom cover of the frame.

[0017] In order to solve the above-described problem, the technical idea of ​​the present invention provides a battery assembly including: a cell block including a plurality of battery cells stacked in a first direction; a frame including a first side cover and a second side cover spaced apart in the first direction with the cell blocks interposed therebetween; and a top cover including a central portion coupled to the frame to cover the cell blocks and a first outer portion protruding outwardly from the first side cover, the first outer portion including a first flange configured to be fastened to an external first support structure; wherein a first buffer space extending in the first direction is provided between the first outer portion of the top cover and the first side cover.

[0018] In exemplary embodiments, the top cover further includes a second outer portion including a second flange configured to protrude outwardly from the second side cover and be fastened to an external second support structure, wherein a second buffer space extending in the first direction is provided between the second outer portion of the top cover and the second side cover.

[0019] In exemplary embodiments, the first outer portion of the top cover further includes a first side plate spaced apart from the first side cover in the first direction with the first buffer space therebetween and connected to the first flange; and a first extension portion extending in the first direction between the first side plate and the center portion of the top cover to cover the first buffer space; and the second outer portion of the top cover further includes a second side plate spaced apart from the second side cover in the first direction with the second buffer space therebetween and connected to the second flange; and a second extension portion extending in the first direction between the second side plate and the center portion of the top cover to cover the second buffer space.

[0020] In exemplary embodiments, the top cover is characterized by being a single integrated structure.

[0021] According to exemplary embodiments of the present invention, the swelling force generated by the swelling of battery cells can be attenuated and dispersed by a buffer space provided between the frame and the top cover. As the swelling force is attenuated and dispersed by the buffer space, the pressure applied to the fastening portion between the top cover and an external support structure can be reduced, thereby preventing damage to the fastening bolts, the top cover, and the support structure, and improving the uniformity of the surface pressure applied to the battery cells. Accordingly, the safety and reliability of the battery assembly and the battery pack including the same can be improved.

[0022] 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.

[0023] FIG. 1 is a cross-sectional view showing a battery pack according to exemplary embodiments of the present invention.

[0024] FIG. 2 is a perspective view illustrating a battery pack according to exemplary embodiments of the present invention.

[0025] FIG. 3 is a plan view illustrating a battery pack according to exemplary embodiments of the present invention.

[0026] FIG. 4 is a perspective view showing a frame and top cover of a battery assembly according to exemplary embodiments of the present invention.

[0027] FIG. 5 is a perspective view showing a portion of a battery assembly according to exemplary embodiments of the present invention.

[0028] Figure 6a is a cross-sectional view showing a battery pack having an initial battery assembly mounted thereon.

[0029] FIG. 6b is a cross-sectional view showing a battery pack having a battery assembly having battery cells deformed by swelling.

[0030] FIG. 7 is a schematic diagram showing an electric vehicle equipped with a battery pack according to exemplary embodiments of the present invention.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035]

[0036] (Example 1)

[0037] FIG. 1 is a cross-sectional view illustrating a battery pack (500) according to exemplary embodiments of the present invention. FIG. 2 is a perspective view illustrating a battery pack (500) according to exemplary embodiments of the present invention. FIG. 3 is a plan view illustrating a battery pack (500) according to exemplary embodiments of the present invention. FIG. 4 is a perspective view illustrating a frame (140) and a top cover (150) of a battery assembly (100) according to exemplary embodiments of the present invention. FIG. 5 is a perspective view illustrating a portion of a battery assembly (100) according to exemplary embodiments of the present invention.

[0038] Referring to FIGS. 1 to 5, a battery pack (500) may include a pack housing (501) and a battery assembly (100) mounted on the pack housing (501). The battery pack (500) may include one or more battery assemblies (100) mounted on the pack housing (501). In exemplary embodiments, the battery pack (500) may include two or more battery assemblies (100) arranged in a first horizontal direction (e.g., X-direction).

[0039] The pack housing (501) may include a housing body (510) having a receiving space in which a battery assembly (100) is received, and a pack lid (520) coupled to the housing body (510) to cover the battery assembly (100) received in the housing body (510). The receiving space of the housing body (510) may be defined by a bottom plate (511) facing the bottom surface of each battery assembly (100), and a side wall (513) extending along an edge of the bottom plate (511) to surround the battery assembly (100).

[0040] The housing body (510) may include a plurality of support structures (310) that support the battery assembly (100). The plurality of support structures (310) may be arranged on a bottom plate (511) of the housing body (510). The plurality of support structures (310) may be spaced apart from each other in a first horizontal direction (e.g., X-direction), and the plurality of support structures (310) may each extend in a second horizontal direction (e.g., Y-direction). Each battery structure may be fastened to and supported by two support structures (310) adjacent to each other in the first horizontal direction (e.g., X-direction).

[0041] The battery assembly (100) may include a cell block (110), a frame (140), and a top cover (150).

[0042] 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 case. The electrode assembly built into the 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 a negative electrode active material.

[0043] 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.

[0044] 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.

[0045] In exemplary embodiments, the plurality of battery cells (111) may correspond to a cell stack stacked in a first horizontal direction (e.g., X-direction). In exemplary embodiments, the plurality of battery cells (111) may correspond to pouch-type battery cells, each of which has a length along the first horizontal direction (e.g., X-direction) smaller than a length along a second horizontal direction (e.g., Y-direction) and a length along a vertical direction (e.g., Z-direction), and the plurality of battery cells (111) may be stacked in the first horizontal direction (e.g., X-direction).

[0046] When viewed from a plan view, the cell block (110) may have a rectangular shape in which a length along a first horizontal direction (e.g., X direction) is smaller than a length along a second horizontal direction (e.g., Y direction). In this case, the cell block (110) may have first and second side surfaces that are opposite to each other in the first horizontal direction (e.g., X direction), front and back surfaces that are opposite to each other in the second horizontal direction (e.g., Y direction), and top and bottom surfaces that are opposite to each other in the third direction (Z direction). The top surface of the cell block (110) may include top surfaces of a plurality of battery cells (111), and the bottom surface of the cell block (110) may include bottom surfaces of a plurality of battery cells (111).

[0047] In exemplary embodiments, the battery assembly (100) may include a single cell block (110). In exemplary embodiments, the battery assembly (100) may include a plurality of cell blocks (110) arranged in a second horizontal direction (e.g., Y direction). For example, the battery assembly (100) may include two cell blocks (110) (e.g., a first cell block and a second cell block) arranged in a second horizontal direction (e.g., Y direction) and electrically connected to each other.

[0048] The battery assembly (100) may include a busbar electrically connected to a battery cell (111), a busbar frame on which the busbar is mounted, and an end plate (170) for covering the busbar frame. The busbar may be coupled to an electrode lead provided at an end of the battery cell (111) along a second horizontal direction (e.g., Y direction). For example, the busbar may be coupled to the electrode lead of the battery cell (111) by welding. For example, the individual busbars may be inter-busbars that are connected to electrode leads connected to different battery cells (111) belonging to a cell block (110) to electrically connect different battery cells (111) to each other. For example, the individual busbars may be terminal busbars for electrically connecting the battery assembly (100) and other external electrical devices.

[0049] The frame (140) can accommodate a cell block (110). The frame (140) can include a bottom cover (141) that supports the cell block (110), and a first side cover (143) and a second side cover (145) that are spaced apart in a first horizontal direction (e.g., X direction) with the cell block (110) interposed therebetween. The frame (140) can have a U-shaped cross-section. The accommodation space of the frame (140) can extend in a second horizontal direction (e.g., Y direction).

[0050] The bottom cover (141) can support the cell block (110). The bottom cover (141) faces the bottom surface of the cell block (110) and can extend along the bottom surface of the cell block (110) to cover the bottom surface of the cell block (110). The bottom cover (141) can generally have a flat plate shape extending in a first horizontal direction (e.g., X direction) and a second horizontal direction (e.g., Y direction). The cell block (110) can be attached to the bottom cover (141) via a thermally conductive adhesive layer (191). The thermally conductive adhesive layer (191) can be interposed between the bottom surface of the cell block (110) and the bottom cover (141), and can thermally and physically couple the cell block (110) to the bottom cover (141). For example, the thermally conductive adhesive layer (191) may include a thermal interface material (TIM) and / or a thermal resin.

[0051] The bottom cover (141) may have a cooling channel (1411) configured to allow a cooling fluid to flow, and may be configured to cool the cell block (110). The bottom cover (141) may be referred to as a cooling plate. An inlet pipe (148) through which a cooling fluid flows and an outlet pipe (149) through which the cooling fluid flows may be connected to one side of the bottom cover (141). The bottom cover (141) may be thermally coupled to the cell block (110) through a thermally conductive adhesive layer (191), and may be configured to cool the cell block (110). Cooling fluid supplied from the outside of the battery assembly (100) may flow into the cooling channel (1411) through the inlet pipe (148), flow along the cooling channel (1411), and then be discharged to the outside through the outlet pipe (149). Cooling of the cell block (110) and the battery assembly (100) can be performed while the cooling fluid flows along the cooling channel (1411). For example, the bottom cover (141) can be manufactured by bonding two plates, and the cooling channel (1411) can include a space defined between the two plates.

[0052] The first side cover (143) may face the first side of the cell block (110) and may extend along the first side of the cell block (110) to cover the first side of the cell block (110). The first side cover (143) may contact and support the first side of the cell block (110). The first side cover (143) may generally have a flat plate shape extending in a second horizontal direction (e.g., Y direction) and a vertical direction (e.g., Z direction).

[0053] The second side cover (145) may face the second side of the cell block (110) and may extend along the second side of the cell block (110) to cover the second side of the cell block (110). The second side cover (145) may contact and support the second side of the cell block (110). The second side cover (145) may generally have a flat plate shape extending in a second horizontal direction (e.g., Y direction) and a vertical direction (e.g., Z direction). The first side cover (143) and the second side cover (145) may extend parallel to each other.

[0054] The top cover (150) may be coupled to the frame (140) to cover the upper surface of the cell block (110). In exemplary embodiments, the top cover (150) may be coupled to each of an upper edge of the first side cover (143) and an upper edge of the second side cover (145) through welding. In exemplary embodiments, a metal bonding layer may be interposed between the first side cover (143) and the top cover (150) and between the second side cover (145) and the top cover (150).

[0055] The top cover (150) can be fastened to the pack housing (501). The top cover (150) can be fastened to a first support structure (311) and a second support structure (313) spaced apart in a first horizontal direction (e.g., X direction) with the cell block (110) therebetween. By fastening the top cover (150) to the first support structure (311) and the second support structure (313), the battery assembly (100) can be mounted on the pack housing (501) in a side-mounting manner.

[0056] The top cover (150) may include a central portion (151) covering the cell block (110), a first outer portion (153) protruding in a first horizontal direction (e.g., in the X direction) from the first side cover (143), and a second outer portion (155) protruding in a first horizontal direction (e.g., in the X direction) from the second side cover (145). The top cover (150) may be a single piece or a single integrated structure.

[0057] The center portion (151) of the top cover (150) may generally have a flat shape extending in a first horizontal direction (e.g., X direction) and a second horizontal direction (e.g., Y direction). The center portion (151) of the top cover (150) may be coupled to an upper edge of a first side cover (143) and an upper edge of a second side cover (145).

[0058] A first outer portion (153) of the top cover (150) may protrude outwardly from the first side cover (143) away from the first side cover (143) and may be fastened to a first support structure (311). The top cover (150) may include a first side plate (213) spaced apart from the first side cover (143) in a first horizontal direction (e.g., X-direction), a first extension portion (211) extending between the first side plate (213) and a central portion (151) of the top cover (150), and at least one first flange (215) fastened to the first support structure (311).

[0059] The first side plate (213) may have a flat shape extending generally in the second horizontal direction (e.g., Y direction) and vertical direction (e.g., Z direction), and may be generally parallel to the first side cover (143).

[0060] The first extension portion (211) may extend in a first horizontal direction (e.g., X direction) between the upper edge of the first side plate (213) and the upper edge of the first side cover (143). The first extension portion (211) may generally have a flat plate shape extending in the first horizontal direction (e.g., X direction) and the second horizontal direction (e.g., Y direction).

[0061] The first flange (215) may extend outwardly from the lower edge of the first side plate (213). The first flange (215) may have a fastening hole into which a fastening bolt (BT) is inserted. The first outer portion (153) of the top cover (150) may be fastened to the first support structure (311) by inserting and fastening the fastening bolt (BT) into the fastening hole of the first flange (215) and the fastening hole of the first support structure (311) aligned in the vertical direction (e.g., the Z direction). The first outer portion (153) of the top cover (150) may include a plurality of first flanges (215), and the plurality of first flanges (215) may be spaced apart from each other in a second horizontal direction (e.g., the Y direction) along the lower edge of the first side plate (213).

[0062] The first outer portion (153) of the top cover (150) and the first side cover (143) can together define a first buffer space (217). The first buffer space (217) can alleviate a swelling force acting in a first horizontal direction (e.g., X direction) according to a thickness variation due to swelling of the battery cells (111). The first buffer space (217) can be provided between the first side plate (213) of the first outer portion (153) and the first side cover (143), and the first extension portion (211) can cover the first buffer space (217). The first buffer space (217) can extend continuously in a second horizontal direction (e.g., Y direction) between both ends of the first side plate (213) along the second horizontal direction (e.g., Y direction). Both ends of the first buffer space (217) along the second horizontal direction (e.g., Y direction) may be exposed to the outside of the battery assembly (100). The length of the first buffer space (217) along the vertical direction (e.g., Z direction) may be the same as the length of the first side plate (213) along the vertical direction (e.g., Z direction). The upper part of the first buffer space (217) may be covered by the first extension part (211), but the lower part of the first buffer space (217) may not be covered by another structure. A space extending in the first horizontal direction (e.g., X direction) and the second horizontal direction (e.g., Y direction) is provided between the lower part of the first side cover (143) and the first support structure (311), and the first buffer space (217) may be in vertical communication with the space provided between the lower part of the first side cover (143) and the first support structure (311) in the Z direction.

[0063] The length of the first buffer space (217) along the second horizontal direction (e.g., Y direction) may be greater than the length of the first buffer space (217) along the first horizontal direction (e.g., X direction). The length of the first buffer space (217) along the first horizontal direction (e.g., X direction) may range from several to several tens of mm. In exemplary embodiments, the length of the first buffer space (217) along the first horizontal direction (e.g., X direction) may be between 1 mm and 10 mm, between 2 mm and 9 mm, between 3 mm and 8 mm, or between 4 mm and 7 mm. The length of the first buffer space (217) along the second horizontal direction (e.g., Y direction) may be similar to the length of the cell block (110) along the second horizontal direction (e.g., Y direction). The length of the first buffer space (217) along the second horizontal direction (e.g., Y direction) may be between about 80% and about 120% of the length of the cell block (110) along the second horizontal direction (e.g., Y direction).

[0064] A second outer portion (155) of the top cover (150) may protrude outwardly from the second side cover (145) away from the second side cover (145) and may be fastened to a second support structure (313). The top cover (150) may include a second side plate (233) spaced apart from the second side cover (145) in a first horizontal direction (e.g., X-direction), a second extension portion (231) extending between the second side plate (233) and the center portion (151) of the top cover (150), and at least one second flange (235) fastened to the second support structure (313).

[0065] The second side plate (233) may have a flat shape extending generally in the second horizontal direction (e.g., Y direction) and vertical direction (e.g., Z direction), and may be generally parallel to the second side cover (145).

[0066] The second extension portion (231) may extend in a first horizontal direction (e.g., X direction) between the upper edge of the second side plate (233) and the upper edge of the second side cover (145). The second extension portion (231) may generally have a flat plate shape extending in the first horizontal direction (e.g., X direction) and the second horizontal direction (e.g., Y direction).

[0067] The second flange (235) may extend outwardly from the lower edge of the second side plate (233). The second flange (235) may have a fastening hole into which a fastening bolt (BT) is inserted. The second outer portion (155) of the top cover (150) may be fastened to the second support structure (313) by inserting and fastening the fastening bolt (BT) into the fastening hole of the second flange (235) and the fastening hole of the second support structure (313) aligned in the vertical direction (e.g., the Z direction). The second outer portion (155) of the top cover (150) may include a plurality of second flanges (235), and the plurality of second flanges (235) may be spaced apart from each other in a second horizontal direction (e.g., the Y direction) along the lower edge of the second side plate (233).

[0068] The second outer portion (155) and the second side cover (145) of the top cover (150) may together define a second buffer space (237). The second buffer space (237) may alleviate a swelling force acting in a first horizontal direction (e.g., X direction) according to a thickness change due to swelling of the battery cells (111). The second buffer space (237) may be provided between the second side plate (233) of the second outer portion (155) and the second side cover (145), and the second extension portion (231) may cover the second buffer space (237). The second buffer space (237) may extend continuously in a second horizontal direction (e.g., Y direction) between both ends of the second side plate (233) along the second horizontal direction (e.g., Y direction). The length of the second buffer space (237) in the vertical direction (e.g., the Z direction) may be the same as the length of the second side plate (233) in the vertical direction (e.g., the Z direction). The upper part of the second buffer space (237) may be covered by the second extension (231), but the lower part of the second buffer space (237) may not be covered by another structure. A space extending in a first horizontal direction (e.g., the X direction) and a second horizontal direction (e.g., the Y direction) is provided between the lower part of the second side cover (145) and the second support structure (313), and the second buffer space (237) may be in vertical communication with the space provided between the lower part of the second side cover (145) and the second support structure (313) in the Z direction.

[0069] The length of the second buffer space (237) along the second horizontal direction (e.g., Y direction) may be greater than the length of the second buffer space (237) along the first horizontal direction (e.g., X direction). The length of the second buffer space (237) along the first horizontal direction (e.g., X direction) may range from several to several tens of mm, and may be substantially the same as or similar to the length of the first buffer space (217) along the first horizontal direction (e.g., X direction). The length of the second buffer space (237) along the second horizontal direction (e.g., Y direction) may be similar to the length of the cell block (110) along the second horizontal direction (e.g., Y direction). The length of the second buffer space (237) along the second horizontal direction (e.g., Y direction) may be between about 80% and about 120% of the length of the cell block (110) along the second horizontal direction (e.g., Y direction).

[0070] In exemplary embodiments, the frame (140) can accommodate two cell blocks (110), and two top covers (150) can be coupled to the frame (140) to cover different cell blocks (110). The two cell blocks (110) can each be attached to the bottom cover (141) by a thermally conductive adhesive layer (191) and can be spaced apart from each other in a second horizontal direction (e.g., Y direction). The two top covers (150) can be spaced apart from each other in a second horizontal direction (e.g., Y direction). For example, when a first cell block and a second cell block spaced apart in a second horizontal direction (e.g., Y direction) are arranged in the receiving space of the frame (140), the battery assembly (100) may include a first top cover coupled to the frame (140) to cover the first cell block and a second top cover coupled to the frame (140) to cover the second cell block.

[0071] When the battery pack (500) is mounted on a vehicle, a cabin room for passengers may be located on the upper side of the pack lid (520), and the ground on which the vehicle runs may be located on the lower side of the housing body (510).

[0072] The battery assembly (100) is supported by a plurality of support structures (310) provided on the bottom plate (511) of the housing body (510) in a side-mounted manner, and a free volume (550) may be provided between the bottom plate (511) of the housing body (510) and the bottom cover (141) of the battery assembly (100). The free volume (550) is a space formed when the bottom cover (141) of the battery assembly (100) is spaced apart from the bottom plate (511) of the housing body (510), and may be simply referred to as a space. Gas and flame generated in a thermal runaway situation can move through the free volume (550). That is, the free volume (550) becomes a venting passage through which high-temperature gas and flame can move. In addition, even when a foreign substance is splashed under the vehicle and a strong impact occurs in a hard ground driving situation such as an unpaved road, the impact can be absorbed through the free volume (550). Accordingly, it is possible to prevent the plurality of battery assemblies (100) from being damaged by the impact. In the case where the housing body (510) is deformed toward the battery assembly (100) due to an impact applied to the lower part of the vehicle, the free volume (550) can be utilized as a space to allow for a certain degree of deformation of the housing body (510).

[0073] In the battery pack according to the comparative example, when the thickness of the battery cells changes due to swelling of the battery cells, the total thickness of the cell block along the first horizontal direction (e.g., X direction) increases, and strong pressure may be applied to the fastening portion of the mounting structure of the battery assembly and the support structure of the pack housing. The pressure may cause damage to the fastening bolts, the mounting structure of the battery assembly, and / or the support structure of the pack housing.

[0074] Fig. 6a is a cross-sectional view showing a battery pack (500) equipped with an initial battery assembly (100). Fig. 6b is a cross-sectional view showing a battery pack (500) equipped with a battery assembly (100) having battery cells (111) deformed by swelling.

[0075] Referring to FIGS. 6A and 6B together with FIGS. 1 to 5, the swelling force generated by the swelling of the battery cells (111) mainly acts in the first horizontal direction (e.g., X direction), which is the stacking direction of the battery cells (111). According to exemplary embodiments, the swelling force generated by the swelling of the battery cells (111) can be attenuated and distributed by the buffer space (i.e., the first buffer space (217) and the second buffer space (237)) provided between the frame (140) and the top cover (150). As the swelling force is attenuated and distributed by the buffer space, the pressure applied to the fastening portion between the top cover (150) and the support structure (310) can be reduced, thereby preventing damage to the fastening bolt (BT), the top cover (150), and the support structure (310), and improving the uniformity of the surface pressure acting on the battery cells (111). Accordingly, the safety and reliability of the battery assembly (100) and the battery pack (500) including the same can be improved.

[0076]

[0077] (Example 2)

[0078] FIG. 7 is a schematic diagram showing an electric vehicle (1000) equipped with a battery pack (1100) according to exemplary embodiments of the present invention.

[0079] In FIG. 7, for simplicity, only the vehicle frame (1200) forming the lower frame of the vehicle, and the battery pack (1100) and tires mounted on the vehicle frame (1200) are illustrated. The battery pack (1100) may include the battery pack (500) described with reference to FIGS. 1 to 5. According to exemplary embodiments, a free volume (550) is provided between the battery assembly (100) and the pack housing (501) within the battery pack (1100), so that the pack housing (501) can prevent damage to the battery assembly (100) due to deformation. In addition, according to embodiments of the present invention, the external force caused by swelling of the battery cells (111) can be reduced and distributed, so that the safety of the battery pack (500) and the electric vehicle (1000) including the same can be improved.

[0080]

[0081] 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. A pack housing including a first support structure; and A battery assembly housed within the pack housing; Including, The above battery assembly, A cell block comprising a plurality of battery cells stacked in a first direction; A frame including a first side cover and a second side cover spaced apart in the first direction with the cell block interposed therebetween; and A top cover comprising a central portion coupled to the frame to cover the cell block and a first outer portion protruding outwardly from the first side cover, the first outer portion being fastened to the first support structure; Including, A battery pack characterized in that a first buffer space extending in the first direction is provided between the first outer portion of the top cover and the first side cover.

2. In paragraph 1, The first outer portion of the above top cover, A first side plate spaced apart in the first direction from the first side cover with the first buffer space therebetween; A first extension portion extending in the first direction between the first side plate and the center of the top cover to cover the first buffer space; and At least one first flange connected to the first side plate and fastened to the first support structure; A battery pack comprising:

3. In paragraph 2, The above first side plate extends in a second direction perpendicular to the above first direction, A battery pack, characterized in that the first buffer space extends continuously in the second direction between both ends of the first side plate along the second direction.

4. In paragraph 3, A battery pack, characterized in that the length of the first buffer space in the second direction is greater than the length of the first buffer space in the first direction.

5. In paragraph 3, A battery pack, characterized in that said at least one first flange comprises a plurality of first flanges spaced apart from each other in the second direction along a lower edge of said first side plate.

6. In paragraph 1, A battery pack, characterized in that the first buffer space communicates with a space provided between the lower portion of the first side cover and the first support structure.

7. In paragraph 1, The above pack housing further comprises a second support structure, The top cover further includes a second outer portion protruding outwardly from the second side cover and fastened to the second support structure, A battery pack characterized in that a second buffer space extending in the first direction is provided between the second outer portion of the top cover and the second side cover.

8. In paragraph 7, The second outer portion of the above top cover, A second side plate spaced apart in the first direction from the second side cover with the second buffer space therebetween; A second extension portion extending in the first direction between the second side plate and the center of the top cover to cover the second buffer space; and At least one second flange connected to the second side plate and fastened to the second support structure; A battery pack comprising:

9. In paragraph 8, The second side plate extends in a second direction perpendicular to the first direction, The second buffer space extends continuously in the second direction between the two ends of the second side plate along the second direction, The length of the second buffer space in the second direction is greater than the length of the second buffer space in the first direction, A battery pack, characterized in that said at least one second flange comprises a plurality of second flanges spaced apart from each other in the second direction along a lower edge of said second side plate.

10. In paragraph 1, The above frame further includes a bottom cover facing the bottom surface of the cell block, A battery pack, characterized in that the bottom cover includes cooling channels configured to allow cooling fluid to flow.

11. In Article 10, A battery pack, characterized in that the bottom cover of the frame is spaced apart from the bottom plate of the pack housing such that a space is formed between the bottom plate of the pack housing and the bottom cover of the frame.

12. A cell block comprising a plurality of battery cells stacked in a first direction; A frame including a first side cover and a second side cover spaced apart in the first direction with the cell block interposed therebetween; and A top cover comprising a central portion coupled to the frame to cover the cell block and a first outer portion protruding outwardly from the first side cover, the first outer portion including a first flange configured to be fastened to an external first support structure; Including, A battery assembly characterized in that a first buffer space extending in the first direction is provided between the first outer portion of the top cover and the first side cover.

13. In paragraph 12, The top cover further includes a second outer portion including a second flange configured to protrude outwardly from the second side cover and be fastened to a second external support structure; A battery assembly characterized in that a second buffer space extending in the first direction is provided between the second outer portion of the top cover and the second side cover.

14. In paragraph 13, The first outer portion of the above top cover, A first side plate spaced apart in the first direction from the first side cover with the first buffer space therebetween and connected to the first flange; and A first extension portion extending in the first direction between the first side plate and the center of the top cover to cover the first buffer space; Including more, The second outer portion of the above top cover, A second side plate spaced apart from the second side cover in the first direction with the second buffer space therebetween and connected to the second flange; and A second extension portion extending in the first direction between the second side plate and the center of the top cover to cover the second buffer space; A battery assembly characterized by further including:

15. In paragraph 14, A battery assembly characterized in that the top cover has a single integrated structure.

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