Battery pack

Abstract

The technical idea of the present invention relates to a battery pack. The battery pack comprises: a first battery cell assembly comprising a first cell block including a plurality of first battery cells and a first case accommodating the first cell block; and a pack housing in which the first battery cell assembly is mounted. The first case comprises a first sidewall and a second sidewall spaced apart from each other in a first direction with the first cell block interposed therebetween. The first sidewall comprises a first flange coupled to the pack housing by means of a first coupling member, and the first flange has a first hole through which the first coupling member passes. The length of the first hole in the first direction is greater than the length of the first hole in a second direction perpendicular to the first 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. 10-2023-0106725, filed August 16, 2023, and all contents of the document in that Republic of Korea Patent Application are incorporated herein by reference.

[0003] Unlike primary batteries, secondary batteries can be charged and discharged multiple times. They are widely used as a power source for various wireless devices, such as 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. To meet the rapidly growing demand for mobility-use secondary batteries, cell manufacturers are undertaking massive capital expenditures. Each company is making various attempts to increase the productivity of its secondary battery manufacturing process.

[0004] The technical problem to be solved by the present invention is to provide a battery pack.

[0005] In order to solve the above-described problem, the technical idea of ​​the present invention provides a battery pack including a first cell block including a plurality of first battery cells and a first case accommodating the first cell block, the first case including a first side wall and a second side wall spaced apart in a first direction with the first cell block therebetween; and a pack housing in which the first battery cell assembly is mounted; wherein the first side wall includes a first flange fastened to the pack housing by a first fastening member so as to limit relative movement in the first direction with respect to the pack housing, and the second side wall includes a second flange fastened to the pack housing by a second fastening member so as to limit relative movement in the first direction with respect to the pack housing, and the first flange includes a first hole through which the first fastening member passes, and a length of the first hole in the first direction is greater than a length of the first hole in a second direction perpendicular to the first direction.

[0006] In exemplary embodiments, the second flange includes a second hole through which the second fastening member passes, and a length of the second hole in the first direction is the same as a length of the second hole in the second direction.

[0007] In exemplary embodiments, the length of the first hole in the first direction is characterized by being greater than the length of the second hole in the first direction.

[0008] In exemplary embodiments, the pack housing is characterized by including a first support rail that supports the first flange and includes a first fastening hole to which the first fastening member is fastened; and a second support rail that supports the second flange and includes a second fastening hole to which the second fastening member is fastened.

[0009] In exemplary embodiments, the center of the first fastening hole is characterized in that it is spaced apart from the center of the first hole in the first direction.

[0010] In exemplary embodiments, a second battery cell assembly further includes a second cell block including a plurality of second battery cells and a second case accommodating the second cell block, the second case including a third sidewall and a fourth sidewall spaced apart in the first direction with the second cell block therebetween, the third sidewall including a third flange fastened to the pack housing by a third fastening member so as to be limited in the first direction relative to the pack housing, the fourth sidewall including a fourth flange fastened to the pack housing by a fourth fastening member so as to be limited in the first direction relative to the pack housing, the third sidewall facing the second sidewall, the third flange including a third hole through which the third fastening member passes, the fourth flange including a fourth hole through which the fourth fastening member passes, and a length of the fourth hole in the first direction is greater than a length of the fourth hole in the second direction.

[0011] In exemplary embodiments, the length of the third hole in the first direction is characterized by being equal to the length of the third hole in the second direction.

[0012] In exemplary embodiments, the pack housing includes a first support rail supporting the first flange; a second support rail supporting the second flange and the third flange; and a third support rail supporting the fourth flange, wherein the first support rail, the second support rail, and the third support rail are spaced apart from each other in the first direction.

[0013] In exemplary embodiments, the second flange and the third flange are characterized in that they are spaced apart in the second direction.

[0014] In exemplary embodiments, the first support rail includes a first fastening hole to which the first fastening member is fastened, the second support rail includes a second fastening hole to which the second fastening member is fastened and a third fastening hole to which the third fastening member is fastened, the third support rail includes a fourth fastening hole to which the fourth fastening member is fastened, and the second fastening hole and the third fastening hole are characterized in that they are spaced apart in the second direction.

[0015] In exemplary embodiments, the plurality of first battery cells are characterized in that they are stacked in the first direction.

[0016] According to exemplary embodiments of the present invention, a first flange for fastening one side of a battery cell assembly to a pack housing may have a slot hole, and a second flange for fastening the other side of the battery cell assembly to the pack housing may have a datum hole. Since the slot hole has a long axis extending in the swelling direction of the cell block, the fastening between the first flange and the pack housing can be easily released during a rework operation on the battery cell assembly. In addition, when the fastening between the first flange having the slot hole and the pack housing is released, thickness variations of the cell block and movement of the first flange are permitted, and the force applied to the fastening portion of the second flange and the pack housing is reduced, thereby making the fastening between the second flange and the pack housing easier. Since the work of separating the battery cell assembly from the pack housing becomes easier, the productivity of the rework operation on the battery pack can be improved.

[0017] Additionally, according to exemplary embodiments of the present invention, a single support rail configured to support all adjacent battery cell assemblies is configured to support only the same type of flange, thereby preventing or suppressing physical interference between adjacent battery cell assemblies when releasing the fastening to one battery cell assembly for rework operations.

[0018] 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.

[0019] FIG. 1 is a plan view illustrating a battery pack according to exemplary embodiments of the present invention.

[0020] Fig. 2 is a cross-sectional view of a battery pack taken along line Ⅱ-Ⅱ' of Fig. 1.

[0021] FIG. 3 is a plan view showing a portion of a first side wall provided in a first battery cell assembly of a battery pack.

[0022] FIG. 4 is a plan view showing a portion of a second side wall provided on a first battery cell assembly of a battery pack.

[0023] FIGS. 5A and 5B are cross-sectional views illustrating a rework operation of a battery pack according to exemplary embodiments of the present invention.

[0024] FIG. 6 is a plan view illustrating a battery pack according to exemplary embodiments of the present invention.

[0025] Fig. 7 is a cross-sectional view taken along line Ⅶ-Ⅶ' of Fig. 6.

[0026] Fig. 8 is a cross-sectional view taken along line Ⅷ-Ⅷ' of Fig. 6.

[0027] FIG. 9 is a schematic diagram showing an electric vehicle equipped with a battery pack according to exemplary embodiments of the present invention.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032]

[0033] (Example 1)

[0034] FIGS. 1 to 4 are drawings illustrating a battery pack (500) according to exemplary embodiments of the present invention. FIG. 1 is a plan view illustrating a battery pack (500). FIG. 2 is a cross-sectional view of the battery pack (500) taken along line II-II' of FIG. 1. FIG. 3 is a plan view illustrating a portion of a first side wall (130) provided on a first battery cell assembly (10) of the battery pack (500). FIG. 4 is a plan view illustrating a portion of a second side wall (140) provided on a first battery cell assembly (10) of the battery pack (500).

[0035] Referring to FIGS. 1 to 4, a battery pack (500) may include a pack housing (501) and a first battery cell assembly (10) mounted on the pack housing (501). In FIG. 2, the battery pack (500) is illustrated as including one battery cell assembly (i.e., the first battery cell assembly (10)), but is not limited thereto, and the battery pack (50) may include a plurality of battery cell assemblies spaced apart from each other in a first direction (X direction) within the pack housing (501).

[0036] The pack housing (501) may include a lower housing (510) having a receiving space in which a first battery cell assembly (10) is received, and a pack lid (520) coupled to the lower housing (510) to cover the lower housing (510) in which the first battery cell assembly (10) is received. The receiving space of the lower housing (510) may be defined by a bottom wall facing a lower surface of a first cell block (110) of the first battery cell assembly (10), and a side wall positioned around the bottom wall. In addition, the pack housing (501) may include a plurality of support rails (e.g., a first support rail (531) and a second support rail (532)) provided on the bottom wall of the lower housing (510) and configured to support the first battery cell assembly (10). The plurality of support rails may be spaced apart from each other in a first direction (X direction), and the plurality of support rails may each extend in a second direction (Y direction).

[0037] The first battery cell assembly (10) may include a first cell block (110) and a first case (CS1) that accommodates the first cell block (110).

[0038] The first 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 an negative electrode active material.

[0039] 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.

[0040] 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.

[0041] In exemplary embodiments, each battery cell (111) corresponds to a pouch-type battery cell, and a plurality of battery cells (111) within one first battery cell assembly (10) may be stacked one upon another in a first direction (X direction). In exemplary embodiments, within each first battery cell assembly (10), the plurality of battery cells (111) correspond to pouch-type battery cells, each of which has a length along the first direction (X direction) that is smaller than a length along the second direction (Y direction), and the plurality of battery cells (111) may be stacked one upon another in the first direction (X direction).

[0042] When viewed from a plane, the first cell block (110) may have a rectangular shape in which a length along the first direction (X direction) is smaller than a length along the second direction (Y direction). The first cell block (110) may have two side surfaces that are opposite to each other in the first direction (X direction), a front surface and a back surface that are opposite to each other in the second direction (Y direction), and an upper surface and a lower surface that are opposite to each other in the third direction (Z direction).

[0043] A busbar frame on which a busbar is mounted may be arranged on each of the front and rear sides of the first cell block (110). A plurality of busbars may be mounted on the busbar frame on the front side of the first cell block (110), and a plurality of busbars may be mounted on the busbar frame on the rear side of the first cell block (110). The first battery cell assembly (10) may include an end plate for covering the busbar frame connected to the front or rear side of the first cell block (110).

[0044] The busbar may be connected to the electrode leads of the battery cells (111). For example, the busbar may be connected to the electrode leads of the battery cells (111) by welding. For example, the individual busbars may be connected to electrode leads connected to different battery cells (111) belonging to the first cell block (110), and may be inter-busbars for electrically connecting different battery cells (111). For example, the individual busbars may be terminal-busbars for electrically connecting the first battery cell assembly (10) with other external electrical devices.

[0045] In exemplary embodiments, the first battery cell assembly (10) may include a single first cell block (110). In exemplary embodiments, the first battery cell assembly (10) may also include a plurality of first cell blocks (110) spaced apart in the second direction (Y direction) and electrically connected to one another.

[0046] The first case (CS1) may include an upper cover plate (120) facing the upper surface of the first cell block (110), a first side wall (130) facing one side of the first cell block (110), a second side wall (140) facing the other side of the first cell block (110), and a lower cover plate (150) facing the lower surface of the first cell block (110).

[0047] The first side wall (130) and the second side wall (140) can be spaced apart from each other in the first direction (X direction) with the first cell block (110) therebetween. The first battery cell assembly (10) can be mounted on the pack housing (501) through a side mounting method in which the first side wall (130) and the second side wall (140) on both sides of the first cell block (110) are fastened to the pack housing (501). The pack housing (501) can include a first support rail (531) and a second support rail (532) spaced apart from each other in the first direction (X direction) with the first cell block (110) therebetween. The first side wall (130) may be fastened to the first support rail (531) by a first fastening member (BT1) such as a bolt, and the second side wall (140) may be fastened to the second support rail (532) by a second fastening member (BT2) such as a bolt. The first fastening member (BT1) may fasten the first side wall (130) to the first support rail (531) of the pack housing (501) so that relative movement in the first direction (X direction) between the first side wall (130) and the first support rail (531) of the pack housing (501) is limited. The second fastening member (BT2) may fasten the second side wall (140) to the second support rail (532) of the pack housing (501) so that relative movement in the first direction (X direction) between the second side wall (140) and the second support rail (532) of the pack housing (501) is limited.

[0048] More specifically, the first side wall (130) may include one or more first flanges (131) protruding in a first direction (X direction) or in a direction away from one side of the first cell block (110). When the first side wall (130) includes a plurality of first flanges (131), the plurality of first flanges (131) may be spaced apart from each other in the second direction (Y direction). The first flanges (131) may be mounted on the first support rail (531) and may be fastened and supported to the first support rail (531) by the first fastening member (BT1). The first flange (131) may include a first hole (132) through which the first fastening member (BT1) passes, and the first hole (132) of the first flange (131) may overlap in a third direction (Z direction) a first fastening hole (5311) of the first support rail (531) configured to allow the first fastening member (BT1) to be inserted and fastened. The first flange (131) may include two plates spaced apart in the third direction (Z direction) to form a hollow portion, in which case the first hole (132) may penetrate the two plates of the first flange (131) in the third direction (Z direction). Alternatively, the first flange (131) may be composed of a single plate, and the first hole (132) may penetrate the single plate of the first flange (131) in the third direction (Z direction).

[0049] The first fastening member (BT1) can pass through the first hole (132) of the first flange (131) and be inserted and fastened into the first fastening hole (5311) of the first support rail (531). By inserting and fastening the first fastening member (BT1) into the first fastening hole (5311) of the first support rail (531), the first flange (131) can be fastened and fixed to the first support rail (531). As the first flange (131) is fastened and fixed to the first support rail (531) by the first fastening member (BT1), relative movement in the first direction (X direction) between the first flange (131) and the first support rail (531) can be restricted.

[0050] The second side wall (140) may include one or more second flanges (141) protruding in the first direction (X direction) or in a direction away from the other side of the first cell block (110). When the second side wall (140) includes a plurality of second flanges (141), the plurality of second flanges (141) may be spaced apart from each other in the second direction (Y direction). The second flanges (141) may be mounted on the second support rail (532) and may be fastened and supported to the second support rail (532) by the second fastening member (BT2). The second flange (141) may include a second hole (142) through which the second fastening member (BT2) passes, and the second hole (142) of the second flange (141) may overlap in a third direction (Z direction) a second fastening hole (5321) of the second support rail (532) configured to allow the second fastening member (BT2) to be inserted and fastened. The second flange (141) may include two plates spaced apart in the third direction (Z direction) to form a hollow portion, in which case the second hole (142) may penetrate the two plates of the second flange (141) in the third direction (Z direction). Alternatively, the second flange (141) may be configured as a single plate, and the second hole (142) may penetrate the single plate of the second flange (141) in the third direction (Z direction).

[0051] The second fastening member (BT2) can pass through the second hole (142) of the second flange (141) and be inserted and fastened into the second fastening hole (5321) of the second support rail (532). By inserting and fastening the second fastening member (BT2) into the second fastening hole (5321) of the second support rail (532), the second flange (141) can be fastened and fixed to the second support rail (532). As the second flange (141) is fastened and fixed to the second support rail (532) by the second fastening member (BT2), relative movement in the first direction (X direction) between the second flange (141) and the second support rail (532) can be restricted.

[0052] In exemplary embodiments, the first hole (132) of the first flange (131) may be a slot hole having a major axis and a minor axis. The major axis of the first hole (132) of the first flange (131) may be parallel to a first direction (X-direction), and the minor axis of the first hole (132) of the first flange (131) may be parallel to a second direction (Y-direction) perpendicular to the first direction (X-direction). When viewed in a plan view, a length (LX1) of the first hole (132) in the first direction (X-direction) may be greater than a length (LY1) of the first hole (132) in the second direction (Y-direction). When viewed in a plan view, the first hole (132) may have an oval or rectangular shape.

[0053] When viewed from a plan view, the first fastening hole (5311) of the first support rail (531) may have a circular shape, and a length of the first fastening hole (5311) of the first support rail (531) in the first direction (X direction) may be smaller than a length of the first hole (132) of the first flange (131) in the first direction (X direction). In exemplary embodiments, when the first flange (131) is fastened to the first support rail (531) by the first fastening member (BT1), the center of the first hole (132) of the first flange (131) and the center of the first fastening hole (5311) of the first support rail (531) may be spaced apart in the first direction (X direction).

[0054] In exemplary embodiments, the second hole (142) of the second flange (141) may be a datum hole. When viewed in plan, the length (LX2) of the second hole (142) in the first direction (X direction) may be substantially the same as or similar to the length (LY2) of the second hole (142) in the second direction (Y direction). When viewed in plan, the second hole (142) may have a circular or rectangular shape. In exemplary embodiments, the length (LX2) of the second hole (142) of the second flange (141) in the first direction (X direction) may be smaller than the length (LX1) of the first hole (132) of the first flange (131) in the first direction (X direction).

[0055] The upper cover plate (120) can cover the upper surface of the first cell block (110). The upper cover plate (120) can be joined to the upper portions of each of the first side wall (130) and the second side wall (140) arranged on both sides of the first cell block (110). For example, one side of the upper cover plate (120) can be joined to the upper portion of the first side wall (130) through welding, and the other side of the upper cover plate (120) can be joined to the upper portion of the second side wall (140) through welding.

[0056] The upper cover plate (120) can be attached to the upper surface of the first cell block (110) and can be thermally coupled to the first cell block (110). The upper cover plate (120) can be attached to the upper surface of the first cell block (110) via a thermally conductive adhesive layer interposed between the upper cover plate (120) and the upper surface of the first cell block (110). For example, the thermally conductive adhesive layer can include a thermal interface material (TIM).

[0057] The upper cover plate (120) may have a cooling channel (121) configured to allow a cooling fluid to flow therethrough and may be configured to cool the first cell block (110). The upper cover plate (120) may be referred to as a cooling plate. The upper cover plate (120) may be thermally coupled to the first cell block (110) via a thermally conductive adhesive layer and configured to cool the first cell block (110). A cooling fluid provided from outside the first battery cell assembly (10) may enter the cooling channel (121) through an inlet of the cooling channel (121), flow along the cooling channel (121), and then flow out to the outside through an outlet of the cooling channel (121). For example, the cooling channel may provide a single path extending from its inlet to its outlet. Cooling of the first battery cell assembly (101) may be performed while the cooling fluid flows along the cooling channel (121). For example, the upper cover plate (120) may be manufactured by bonding two plates, and the cooling channel (121) may include a space defined between the two plates.

[0058] The lower cover plate (150) may extend along the lower surface of the first cell block (110) and cover the lower surface of the first cell block (110). The lower cover plate (150) may be coupled to the lower portions of each of the first side wall (130) and the second side wall (140) disposed on both sides of the first cell block (110). For example, one side of the lower cover plate (150) may be coupled to the lower portion of the first side wall (130) through welding, and the other side of the lower cover plate (150) may be coupled to the lower portion of the second side wall (140) through welding. The lower cover plate (150) may include a venting passage for exhausting high-temperature gas originating from the first cell block (110) to the space below the first cell block (110).

[0059] In exemplary embodiments, when the battery pack (500) is mounted on a vehicle, a cabin room for passengers may be located above the pack lid (520), and a ground on which the vehicle runs may be located below the lower housing (510). A free volume (FV) may be provided between the bottom wall of the lower housing (510) and the battery cell assemblies mounted on the pack housing (501). For example, the free volume (FV) may be provided between the bottom wall of the lower housing (510) and the first battery cell assembly (10). Gas and flame generated in a thermal runaway situation may move through the free volume (FV). That is, the free volume (FV) serves as a venting passage through which high-temperature gas and flame may move.

[0060] In addition, even when a foreign substance is thrown to the bottom of 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 (FV). Therefore, the battery cell assemblies can be prevented from being damaged by the impact. The free volume (FV) can include an empty space provided between each of the battery cell assemblies and the lower housing (510). When the lower housing (510) is deformed toward the battery cell assembly due to an impact applied to the bottom of the vehicle, the free volume (FV) can be utilized as a space to allow the deformation of the lower housing (510) to a certain extent.

[0061] The height of the free volume (FV) and the distance between the bottom wall of the lower housing (510) and the battery cell assembly can be set sufficiently to absorb external impact. The height of the free volume (FV) can be determined in consideration of the dimensions and rigidity of the vehicle frame, the dimensions and rigidity of the lower housing (510), the dimensions of the battery pack (500), the amount of gas generated and the discharge speed during thermal runaway, etc. For example, when the thickness or rigidity of the bottom wall of the vehicle frame or the lower housing (510) is relatively large, at least one of the size and height of the free volume (FV) can be relatively reduced. In addition, when the thickness or rigidity of the bottom wall of the vehicle frame or the lower housing (510) is relatively small, the possibility of deformation of the bottom wall of the lower housing (510) is high, and therefore, at least one of the size and height of the free volume (FV) can be relatively increased to protect the battery cell assembly. In addition, when the size of the battery pack (500) is relatively large in terms of the battery pack (500) specifications, a relatively large free volume (FV) can be secured. If the size of the battery pack (500) is relatively small, the height of the available free volume (FV) may be relatively small, and the thickness and rigidity of the bottom wall of the lower housing (510) may need to be relatively increased. In addition, if the height of the free volume (FV) is too small, the gas discharge passage may become small, which may cause the internal pressure of the battery pack (500) to rapidly increase in the event of thermal runaway. Therefore, the size and height of the free volume (FV) may be determined by taking into consideration the amount of gas generated and the discharge speed.

[0062] The maximum height of the free volume (FV) may be determined depending on the degree of damage to the battery cell included in the battery cell assembly. For example, if the damage tolerance of the battery cell is 1 mm, the free volume (FV) may be determined such that the battery cell is not deformed by more than 1 mm when the lower housing (510) is deformed and presses the lower surface of the battery cell. In this case, the amount of deformation of the lower housing (510) may vary depending on the thickness or rigidity of the lower housing (510). Therefore, the size or height of the free volume (FV) may be determined by considering both the damage tolerance of the battery cell (111) and the thickness and rigidity of the lower housing (510).

[0063] In exemplary embodiments, the upper surface of the battery cell assembly may be in close contact with the lower surface of the pack lid (520). If there is a space between the battery cell assembly and the pack lid (520), during thermal runaway, high-temperature gas may be transmitted to multiple battery cell assemblies through the space between the battery cell assembly and the pack lid (520). In addition, heat and flame may also be transmitted to the pack lid (520), which may affect the cabin room located above the pack lid (520). Therefore, by making the upper surfaces of the battery cell assemblies and the lower surface of the pack lid (520) in close contact, gas or flame generated inside the battery pack (500) may be guided to the free volume (FV).

[0064]

[0065] FIGS. 5A and 5B are cross-sectional views illustrating a rework operation of a battery pack (500) according to exemplary embodiments of the present invention. Hereinafter, with reference to FIGS. 5A and 5B, a rework operation for the battery pack (500) described with reference to FIGS. 1 to 4 will be described.

[0066] Referring to FIG. 5A together with FIG. 1, the first fastening member (BT1) is separated from the first flange (131) and the first support rail (531). When the first fastening member (BT1) is separated from the first flange (131) and the first support rail (531), the second flange (141) fastened to the second support rail (532) by the second fastening member (BT2) remains fixed, but the first side wall (130) and the first flange (131) move in the first direction (X direction) due to swelling of the first cell block (110). Since the second flange (141) fastened to the second support rail (532) by the second fastening member (BT2) remains fixed, the thickness variation of the first cell block (110) due to swelling of the first cell block (110) mainly occurs in one direction.

[0067] Referring to FIG. 5b together with FIG. 1, after the first fastening member (BT1) is separated from the first flange (131) and the first support rail (531), the second fastening member (BT2) is separated from the second flange (141) and the second support rail (532). As the first fastening member (BT1) and the second fastening member (BT2) are separated from the first case (CS1), the first battery cell assembly (10) can be separated from the pack housing (501). Thereafter, a new battery cell assembly can be mounted on the pack housing (501), or the first battery cell assembly (10) with defects removed through repair can be mounted on the pack housing (501).

[0068] In the case of a typical battery pack, when separating a battery cell assembly from a pack housing, a relatively large force is applied to the fastening portion between the case of the battery cell assembly and the pack housing due to swelling of the cell blocks within the battery cell assembly, and this force makes it difficult to release the fastening between the case of the battery cell assembly and the pack housing.

[0069] However, according to exemplary embodiments of the present invention, the first hole (132) for fastening one side of the first battery cell assembly (10) to the pack housing (501) may be configured as a slot hole, and the second hole (142) for fastening the other side of the first battery cell assembly (10) to the pack housing (501) may be configured as a datum hole. Since the slot hole has a long axis extending in the swelling direction of the first cell block (110), a fastening release operation for detaching the first fastening member (BT1) from the first flange (131) and the first support rail (531) during a rework operation for the first battery cell assembly (10) may be easily performed. In addition, when reworking the first battery cell assembly (10), the fastening between the first flange (131) provided on one side of the first battery cell assembly (10) and having a slot hole and the pack housing (501) can be first released, and then the fastening between the second flange (141) provided on the other side of the first battery cell assembly (10) and having a datum hole and the pack housing (501) can be released. When the fastening between the first flange (131) having the slot hole and the pack housing (501) is released, the thickness change in the first direction (X direction) of the first cell block (110) and the movement of the first flange (131) due to swelling of the first cell block (110) are allowed, and the force applied to the fastening portion between the second flange (141) having the datum hole and the pack housing (501) is reduced, so that the fastening release operation for separating the second fastening member (BT2) from the second flange (141) and the second support rail (532) can be easily performed. Accordingly, the operation of separating the first battery cell assembly (10) from the pack housing (501) becomes easier, so that the productivity of the rework operation for the battery pack (500) can be improved.

[0070]

[0071] (Example 2)

[0072] Fig. 6 is a plan view showing a battery pack (500A) according to exemplary embodiments of the present invention. Fig. 7 is a cross-sectional view taken along line VII-VII' of Fig. 6. Fig. 8 is a cross-sectional view taken along line VIII-VIII' of Fig. 6.

[0073] Referring to FIGS. 6 to 8, the battery pack (500A) may include a first battery cell assembly (10) and a second battery cell assembly (20) arranged sequentially in a first direction (X direction).

[0074] The second battery cell assembly (20) may include a second cell block (210) including a plurality of battery cells, and a second case (CS2) accommodating the second cell block (210). The second cell block (210) may be substantially the same as or similar to the first cell block (110). The second battery cell assembly (20) may be mounted on the pack housing (501) in a side-mounting manner. The second battery cell assembly (20) may be supported by a second support rail (532) and a third support rail (533) of the pack housing (501) spaced apart from each other with the second cell block (210) interposed therebetween. At this time, the second support rail (532) is configured to support both the first battery cell assembly (10) and the second battery cell assembly (20). The second battery cell assembly (20) may be substantially the same as or similar to the first battery cell assembly (10) except for the position of the slot hole of the flange provided for fastening between the second case (CS2) and the pack housing (501) and the position of the datum hole of the flange provided for fastening between the second case (CS2) and the pack housing (501).

[0075] The second case (CS2) may include an upper cover plate (see 220 in FIG. 10) facing the upper surface of the second cell block (210) and having a cooling channel, a third sidewall facing one side of the second cell block (210), a fourth sidewall facing the other side of the second cell block (210), and a lower cover plate facing the lower surface of the second cell block (210). The third sidewall and the fourth sidewall may be spaced apart from each other in the first direction (X direction) with the second cell block (210) interposed therebetween. The third sidewall may face the second sidewall (see 140 in FIG. 2) of the first battery cell assembly (10). The difference between the second case (CS2) and the first case (CS1) is that the third side wall of the second case (CS2) facing the second side wall (140) of the first battery cell assembly (10) may have a datum hole, and the fourth side wall of the second case (CS2) may have a slot hole.

[0076] More specifically, the third side wall of the second case (CS2) may be fastened to the second support rail (532) by a third fastening member (BT3) such as a bolt, and the fourth side wall of the second case (CS2) may be fastened to the third support rail (533) by a fourth fastening member (BT4) such as a bolt. The third support rail (533) may be spaced apart from the second support rail (532) in a first direction (X direction) and may extend in a second direction (Y direction).

[0077] A third side wall of the second case (CS2) may include one or more third flanges (231) protruding in the first direction (X direction) or in a direction away from one side of the second cell block (210). The third flange (231) is mounted on a second support rail (532) and may be fastened and supported to the second support rail (532) by a third fastening member (BT3). The third flange (231) may include a third hole (232) through which the third fastening member (BT3) passes, and the third hole (232) of the third flange (231) may overlap a third fastening hole (5322) of the third support rail (533) in a third direction (Z direction) into which the third fastening member (BT3) is inserted and fastened. The third fastening member (BT3) can pass through the third hole (232) of the third flange (231) and be inserted and fastened into the third fastening hole (5322) of the second support rail (532). By inserting and fastening the third fastening member (BT3) into the third fastening hole (5322) of the second support rail (532), the third flange (231) can be fastened and fixed to the second support rail (532). As the third flange (231) is fastened and fixed to the second support rail (532) by the third fastening member (BT3), relative movement in the first direction (X direction) between the third flange (231) and the second support rail (532) can be restricted.

[0078] The third hole (232) of the third flange (231) may be a slot hole for allowing movement of the second flange (231) caused by swelling of the second cell block (210) during a rework operation on the second battery cell assembly (20). The major axis of the third hole (232) of the third flange (231) may be parallel to the first direction (X direction), and the minor axis of the third hole (232) of the third flange (231) may be parallel to the second direction (Y direction). When viewed in a plan view, the length of the third hole (232) in the first direction (X direction) may be greater than the length of the third hole (232) in the second direction (Y direction). When viewed in a plan view, the third hole (232) may have an oval or rectangular shape. In exemplary embodiments, when the third flange (231) is fastened to the second support rail (532) by the third fastening member (BT3), the center of the third hole (232) of the third flange (231) and the center of the third fastening hole (5322) of the second support rail (532) may be spaced apart in the first direction (X direction).

[0079] The second support rail (532) can support both the second flange (141) of the first battery cell assembly (10) and the third flange (231) of the second battery cell assembly (20). On the second support rail (532), the second flange (141) and the third flange (231) can be spaced apart in the extension direction of the second support rail (532) or in the second direction (Y direction). In addition, on the second support rail (532), the second fastening hole (5321) and the third fastening hole (5322) can be spaced apart in the extension direction of the second support rail (532) or in the second direction (Y direction).

[0080] The fourth side wall of the second case (CS2) may include one or more fourth flanges (241) protruding in the first direction (X direction) or in a direction away from the other side surface of the second cell block (210). The fourth flange (241) is mounted on the third support rail (533) and may be fastened and supported to the third support rail (533) by a fourth fastening member (BT4). The fourth flange (241) may include a fourth hole (242) through which the fourth fastening member (BT4) passes, and the fourth hole (242) of the fourth flange (241) may overlap in the third direction (Z direction) with a fourth fastening hole (5331) of the third support rail (533) configured to allow the fourth fastening member (BT4) to be inserted and fastened. The fourth fastening member (BT4) can pass through the fourth hole (242) of the fourth flange (241) and be inserted and fastened into the fourth fastening hole (5331) of the third support rail (533). By inserting and fastening the fourth fastening member (BT4) into the fourth fastening hole (5331) of the third support rail (533), the fourth flange (241) can be fastened and fixed to the third support rail (533). As the fourth flange (241) is fastened and fixed to the third support rail (533) by the fourth fastening member (BT4), relative movement in the first direction (X direction) between the fourth flange (241) and the third support rail (533) can be restricted.

[0081] The fourth hole (242) of the fourth flange (241) may be a datum hole. When viewed in a plan view, the length of the fourth hole (242) in the first direction (X direction) may be substantially the same as or similar to the length of the fourth hole (242) in the second direction (Y direction). When viewed in a plan view, the fourth hole (242) may have a circular or rectangular shape.

[0082] In embodiments, the second support rail (532) is configured to support both the first battery cell assembly (10) and the second battery cell assembly (20), wherein the second flange (141) of the first battery cell assembly (10) and the third flange (231) of the second battery cell assembly (20) located on the second support rail (532) may be the same type of flange. For example, as illustrated, the second flange (141) of the first battery cell assembly (10) and the third flange (231) of the second battery cell assembly (20) may both be flanges having a hole for a datum.

[0083] If the second flange (141) of the first battery cell assembly (10) is a flange having a datum hole and the third flange (231) of the second battery cell assembly (20) is a flange having a slot hole, when the fastening to the third flange (231) of the second battery cell assembly (20) is released for rework, there is a concern that the second battery cell assembly (20), which is deformed by swelling, may physically interfere with the first battery cell assembly (10). However, according to embodiments, since the second support rail (532) is configured to support only flanges of the same type, it is possible to prevent or suppress physical interference between adjacent battery cell assemblies when the fastening to one battery cell assembly is released for rework.

[0084] Furthermore, the battery pack (500A) may include a third battery cell assembly (30) and a fourth battery cell assembly (40) arranged in the first direction (X direction).

[0085] The third battery cell assembly (30) may be substantially identical to the first battery cell assembly (10). Briefly, the third battery cell assembly (30) may include a third cell block (310) between a third support rail (533) and a fourth support rail (534), and a third case (CS3) fastened to the pack housing (501) and housing the third cell block (310). The third case (CS3) may include a fifth side wall facing the second battery cell assembly (20), a sixth side wall opposite to the fifth side wall, an upper cover plate having a cooling channel (see FIG. 10 320), and a lower cover plate. The fifth side wall of the third case (CS3) may include a fifth flange (331) that is fastened to the third support rail (533) via a fifth fastening member (BT5) such as a bolt, and the sixth side wall of the third case (CS3) may include a sixth flange (341) that is fastened to the fourth support rail (534) via a sixth fastening member (not shown) such as a bolt. By having the fifth fastening member (BT5) pass through the fifth hole (332) of the fifth flange (331) and be inserted and fastened into the fifth fastening hole (5332) of the third support rail (533), relative movement in the first direction (X direction) between the fifth flange (331) and the third support rail (533) may be limited. By inserting and fastening the sixth fastening member into the sixth fastening hole of the fourth support rail (534) by passing through the sixth hole (342) of the sixth flange (341), the relative movement in the first direction (X direction) between the sixth flange (341) and the fourth support rail (534) can be limited. At this time, the fifth hole (332) of the fifth flange (331) may be a slot hole for allowing movement of the fifth flange (331) caused by swelling of the third cell block (310) during a rework operation on the third battery cell assembly (30), and the sixth hole (342) of the sixth flange (341) may be a datum hole.

[0086] The fourth battery cell assembly (40) may be substantially identical to the second battery cell assembly (20). Briefly, the fourth battery cell assembly (40) may include a fourth cell block (410) between the fourth support rail (534) and the fifth support rail (535), and a fourth case (CS4) fastened to the pack housing (501) and housing the fourth cell block (410). The fourth case (CS4) may include a seventh side wall facing the third battery cell assembly (30), an eighth side wall opposite the seventh side wall, an upper cover plate having a cooling channel (see FIG. 10 420), and a lower cover plate. The seventh side wall of the fourth case (CS4) may include a seventh flange (431) that is fastened to the fourth support rail (534) via a seventh fastening member (not shown) such as a bolt, and the eighth side wall of the fourth case (CS4) may include an eighth flange (441) that is fastened to the fifth support rail (535) via an eighth fastening member (not shown) such as a bolt. By having the seventh fastening member pass through the seventh hole (432) of the seventh flange (431) and be inserted and fastened into the seventh fastening hole of the fourth support rail (534), relative movement in the first direction (X direction) between the seventh flange (431) and the fourth support rail (534) may be limited. By passing through the eighth hole (442) of the eighth flange (441) and being inserted and fastened into the eighth fastening hole of the fifth support rail (535), the relative movement in the first direction (X direction) between the eighth flange (441) and the fifth support rail (535) can be limited. At this time, the seventh hole (432) of the seventh flange (431) may be a datum hole, and the eighth hole (442) of the eighth flange (441) may be a slot hole for allowing movement of the eighth flange (441) caused by swelling of the fourth cell block (410) during a rework operation on the fourth battery cell assembly (40).

[0087] In embodiments, the battery pack (500A) may include a plurality of battery cell assemblies arranged in a first direction (X-direction), and the pack housing (501) may include a plurality of support rails arranged in the first direction (X-direction). Each battery cell assembly may be supported by two support rails that are adjacent in the first direction (X-direction) among the plurality of support rails. At this time, a flange provided on a case of a battery cell assembly fastened to an odd-numbered support rail among the plurality of support rails (e.g., the first support rail (531), the third support rail (533), and the fifth support rail (535)) may include a slot hole to allow movement of the flange caused by swelling of a cell block of the corresponding battery cell assembly during a rework operation. In addition, a flange provided on a case of a battery cell assembly fastened to an even-numbered support rail among the plurality of support rails (e.g., the second support rail (532) and the fourth support rail (534)) may be a datum hole.

[0088] In embodiments, two adjacent battery cell assemblies are supported by the same single support rail, and the flanges of the two adjacent battery cell assemblies on the single support rail may all be the same type of flanges. For example, the single support rail may be configured to support only flanges having slotted holes or only flanges having holes for datums. For example, only flanges having slotted holes may be disposed on odd-numbered support rails among the plurality of support rails (e.g., the first support rail (531), the third support rail (533), and the fifth support rail (535)), and only flanges having holes for datums may be disposed on even-numbered support rails among the plurality of support rails (e.g., the second support rail (532) and the fourth support rail (534)).

[0089] If a flange having a slot hole of one battery cell assembly and a flange having a datum hole of another battery cell assembly are supported on the same single support rail, there is a concern that physical interference may occur between the one battery cell assembly and the adjacent other battery cell assembly when the fastening to the flange having the slot hole of the one battery cell assembly is released for a rework operation. However, according to embodiments, a single support rail configured to support all adjacent battery cell assemblies is configured to support only flanges of the same type, and thus, when the fastening to the one battery cell assembly is released for a rework operation, physical interference between the cell assemblies can be prevented or suppressed.

[0090]

[0091] (Example 3)

[0092] FIG. 9 is a schematic diagram showing an electric vehicle (1000) equipped with a battery pack (1100) according to exemplary embodiments of the present invention.

[0093] In Fig. 9, for simplicity, only the body frame (1200) forming the lower skeleton of the vehicle and the battery pack (1100) and tires coupled to the body frame (1200) are shown. For example, the battery pack (1100) may include the battery pack (500A) described with reference to Figs. 6 to 8.

[0094] In a typical battery pack, battery cell assemblies are installed at the bottom of the pack housing of the battery pack. In embodiments, a free volume (see FV of FIG. 2) may be provided at the bottom of the battery cell assemblies (i.e., the first to fourth battery cell assemblies (10, 20, 30, 40)) of the battery pack (1100). Since there is no space between the battery cell assemblies and the pack lid (520), gases generated from the battery cell assemblies can be prevented from being transmitted to the cabin room at the top of the vehicle. In addition, gases generated from the battery cell assemblies are guided to the free volume (FV) provided in the battery cell assemblies and the pack housing of the battery pack (1100). The gases can flow through the free volume (FV) and be discharged to the lower part of the vehicle through a gas exhaust unit installed in the battery pack (1100). Additionally, according to the present embodiments, since a free volume (FV) is provided between the battery cell assembly pack housing within the battery pack (1100), damage to the battery cell assembly can be prevented even if the pack housing is deformed.

[0095] According to embodiments of the present invention, a battery pack (1100) and an electric vehicle (1000) equipped with the same can enhance passenger safety. Furthermore, the battery cell assembly, a key component, can be protected, and the durability of the battery pack (1100) and the electric vehicle (1000) can be improved.

[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. A first battery cell assembly comprising a first cell block including a plurality of first battery cells and a first case accommodating the first cell block, the first case including a first side wall and a second side wall spaced apart in a first direction with the first cell block interposed therebetween; and A pack housing in which the first battery cell assembly is mounted; Including, The first side wall includes a first flange fastened to the pack housing such that relative movement in the first direction with respect to the pack housing is limited by the first fastening member, The second side wall includes a second flange fastened to the pack housing such that relative movement in the first direction with respect to the pack housing is limited by the second fastening member, A battery pack, wherein the first flange includes a first hole through which the first fastening member passes, and a length of the first hole in the first direction is greater than a length of the first hole in a second direction perpendicular to the first direction.

2. In paragraph 1, A battery pack, wherein the second flange includes a second hole through which the second fastening member passes, and the length of the second hole in the first direction is the same as the length of the second hole in the second direction.

3. In paragraph 2, A battery pack, characterized in that the length of the first hole in the first direction is greater than the length of the second hole in the first direction.

4. In paragraph 1, The above pack housing, A first support rail that supports the first flange and includes a first fastening hole to which the first fastening member is fastened; and A second support rail that supports the second flange and includes a second fastening hole to which the second fastening member is fastened; A battery pack comprising:

5. In paragraph 4, A battery pack, characterized in that the center of the first fastening hole is spaced apart from the center of the first hole in the first direction.

6. In paragraph 1, A second battery cell assembly comprising a second cell block including a plurality of second battery cells and a second case accommodating the second cell block, the second case including a third side wall and a fourth side wall spaced apart in the first direction with the second cell block interposed therebetween; Including more, The third side wall includes a third flange fastened to the pack housing such that relative movement in the first direction with respect to the pack housing is limited by the third fastening member, The fourth side wall includes a fourth flange fastened to the pack housing such that relative movement in the first direction with respect to the pack housing is limited by the fourth fastening member, The third side wall faces the second side wall, The third flange includes a third hole through which the third fastening member passes, The fourth flange includes a fourth hole through which the fourth fastening member passes, A battery pack, characterized in that the length of the fourth hole in the first direction is greater than the length of the fourth hole in the second direction.

7. In paragraph 6, A battery pack, characterized in that the length of the third hole in the first direction is the same as the length of the third hole in the second direction.

8. In paragraph 6, The above pack housing, A first support rail supporting the first flange; A second support rail supporting the second flange and the third flange; and A third support rail supporting the fourth flange; Including, A battery pack, characterized in that the first support rail, the second support rail, and the third support rail are spaced apart from each other in the first direction.

9. In paragraph 8, A battery pack, characterized in that the second flange and the third flange are spaced apart in the second direction.

10. In paragraph 8, The first support rail includes a first fastening hole to which the first fastening member is fastened, The second support rail includes a second fastening hole to which the second fastening member is fastened and a third fastening hole to which the third fastening member is fastened, The third support rail includes a fourth fastening hole to which the fourth fastening member is fastened, A battery pack, characterized in that the second fastening hole and the third fastening hole are spaced apart in the second direction.

11. In paragraph 1, A battery pack, characterized in that the plurality of first battery cells are stacked in the first direction.

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