Battery pack

Abstract

The technical concept of the present invention provides a battery pack. The battery pack includes a first battery cell assembly including 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 includes a first sidewall and a second sidewall spaced apart in a first direction with the first cell block interposed therebetween. The first sidewall includes a first flange fastened to the pack housing by a first fastening member, and the first flange includes a first hole through which the first fastening member passes. The length of the first hole in the first direction is longer than the length of the first hole in a second direction perpendicular to the first direction.

Description

[Technical Field]

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

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0106725, filed on August 16, 2023, and all contents disclosed in the documents of said Korean patent application are incorporated herein by reference. [Background technology]

[0003] Unlike primary batteries, secondary batteries can be charged and discharged multiple times. Secondary batteries are widely used as energy sources for various wireless devices such as handsets, laptops, and wireless vacuum cleaners. In recent years, improvements in energy density and economies of scale have dramatically reduced the manufacturing cost per unit capacity of secondary batteries. As the driving range of battery electric vehicles (BEVs) has increased to the same level as fuel-powered vehicles, the primary use of secondary batteries has shifted from mobile devices to mobility. To meet the rapid growth in demand for secondary batteries for mobility, cell manufacturers are forced to make huge capital expenditures. Companies are making various attempts to improve the productivity of the secondary battery manufacturing process. Summary of the Invention [Problem to be solved by the invention]

[0004] The technical problem that the present invention aims to achieve is to provide a battery pack. [Means for solving the problem]

[0005] In order to solve the above-mentioned problems, the technical idea of ​​the present invention provides a battery pack including a first battery cell assembly including a first cell block including a plurality of first battery cells and a first case accommodating the first cell block, wherein the first case includes the first battery cell assembly 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 that relative movement with respect to the pack housing in the first direction is limited, and the second side wall includes a second flange fastened to the pack housing by a second fastening member so that relative movement with respect to the pack housing in the first direction is limited, 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 longer than a length of the first hole in a second direction perpendicular to the first direction.

[0006] In an exemplary embodiment, 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.

[0007] In an exemplary embodiment, the length of the first hole in the first direction is longer than the length of the second hole in the first direction.

[0008] In an exemplary embodiment, the pack housing includes a first support rail configured to support the first flange, the first support rail including a first fastening hole to which the first fastening member is fastened, and a second support rail configured to support the second flange, the second support rail including a second fastening hole to which the second fastening member is fastened.

[0009] In an exemplary embodiment, the center of the first fastening hole is spaced apart from the center of the first hole in the first direction.

[0010] In an exemplary embodiment, the battery pack includes a second cell block including a plurality of second battery cells, and a second case that houses the second cell block, wherein the second case further includes a second battery cell assembly including a third side wall and a fourth side wall spaced apart in the first direction with the second cell block therebetween, wherein the third side wall includes a third flange fastened to the pack housing by a third fastening member so as to restrict relative movement with respect to the pack housing in the first direction, and the fourth side wall includes a fourth flange fastened to the pack housing by a fourth fastening member so as to restrict relative movement with respect to the pack housing in the first direction, the third side wall faces the second side wall, the third flange includes a third hole through which the third fastening member passes, and the fourth flange includes a fourth hole through which the fourth fastening member passes, and a length of the fourth hole in the first direction is longer than a length of the fourth hole in the second direction.

[0011] In an exemplary embodiment, the length of the third hole in the first direction is the same as the length of the third hole in the second direction.

[0012] In an exemplary embodiment, the pack housing includes a first support rail that supports the first flange, a second support rail that supports the second flange and the third flange, and a third support rail that supports the fourth flange, and the first support rail, the second support rail, and the third support rail are spaced apart from one another in the first direction.

[0013] In an exemplary embodiment, the second flange and the third flange are spaced apart in the second direction.

[0014] In an exemplary embodiment, 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 spaced apart in the second direction.

[0015] In an exemplary embodiment, the plurality of first battery cells are stacked in the first direction. [Effects of the Invention]

[0016] According to an exemplary embodiment of the present invention, a first flange for fastening one side of a battery cell assembly to a pack housing may have a slotted hole, and a second flange for fastening the other end of the battery cell assembly to the pack housing may have a datum hole. The slotted hole has a major axis extending in the swelling direction of the cell block, which facilitates the release of the fastening between the first flange and the pack housing during rework of the battery cell assembly. Furthermore, when the fastening between the first flange having the slotted hole and the pack housing is released, the thickness of the cell block is allowed to vary and the first flange is allowed to move, reducing the force acting on the fastening portion between the second flange and the pack housing, which may facilitate the release of the fastening between the second flange and the pack housing. Since the battery cell assembly can be more easily separated from the pack housing, the productivity of rework of the battery pack may be improved.

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

[0018] The effects that can be obtained from the exemplary embodiments of the present disclosure are not limited to the effects mentioned above, and other effects not mentioned can be clearly derived and understood from the following description by a person having ordinary skill in the art to which the exemplary embodiments of the present disclosure belong. In other words, unintended effects accompanying the implementation of the exemplary embodiments of the present disclosure can also be derived from the exemplary embodiments of the present disclosure by a person having ordinary skill in the art. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a plan view illustrating a battery pack according to an exemplary embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of the battery pack taken along line II-II′ in FIG. 1. [Figure 3] FIG. 2 is a plan view showing a portion of a first side wall provided on a first battery cell assembly of the battery pack. [Figure 4] FIG. 4 is a plan view showing a portion of a second side wall provided on a first battery cell assembly of the battery pack. [Figure 5a] 1 is a cross-sectional view illustrating a rework operation of a battery pack according to an exemplary embodiment of the present invention. FIG. [Figure 5b] 1 is a cross-sectional view illustrating a rework operation of a battery pack according to an exemplary embodiment of the present invention. FIG. [Figure 6] FIG. 1 is a plan view illustrating a battery pack according to an exemplary embodiment of the present invention. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII′ in FIG. [Figure 8] FIG. 7 is a cross-sectional view taken along line VIII-VIII′ in FIG. 6. [Figure 9] 1 is a schematic diagram illustrating an electric vehicle equipped with a battery pack according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Before that, the terms and words used in the specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted as meanings and concepts that are consistent with the technical idea of ​​the present invention, based on the principle that an inventor can appropriately define the concepts of terms to best describe his own invention.

[0021] Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent the entire technical idea of ​​the present invention, and there may be various equivalents and modifications that can replace them at the time of this application.

[0022] Furthermore, in the description of the present invention, if it is determined that a specific description of related publicly known configurations or functions may obscure the gist of the present invention, the detailed description will be omitted.

[0023] The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art, and therefore the shapes and sizes of components in the drawings may be exaggerated, omitted, or shown in a schematic manner for clearer explanation. Therefore, the sizes and proportions of each component do not completely reflect the actual sizes and proportions.

[0024] (First embodiment) 1 to 4 are views showing a battery pack 500 according to an exemplary embodiment of the present invention. FIG. 1 is a plan view showing the battery pack 500. FIG. 2 is a cross-sectional view of the battery pack 500 taken along line II-II' in FIG. 1. FIG. 3 is a plan view showing 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 showing a portion of a second side wall 140 provided on a first battery cell assembly 10 of the battery pack 500.

[0025] 1 to 4, the battery pack 500 may include a pack housing 501 and a first battery cell assembly 10 mounted in the pack housing 501. In FIG. 2, the battery pack 500 is shown as including one battery cell assembly (i.e., the first battery cell assembly 10), but is not limited thereto, and the battery pack 500 may include a plurality of battery cell assemblies spaced apart from each other in a first direction (X direction) within the pack housing 501.

[0026] The pack housing 501 may include a lower housing 510 having an accommodation space for accommodating the first battery cell assembly 10, and a pack lid 520 coupled to the lower housing 510 to cover the lower housing 510 accommodating the first battery cell assembly 10. The accommodation space of the lower housing 510 may be defined by a bottom wall facing the lower surface of the first cell block 110 of the first battery cell assembly 10 and side walls positioned at edges of the bottom wall. The pack housing 501 may also 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 may each extend in a second direction (Y direction).

[0027] The first battery cell assembly 10 may include a first cell block 110 and a first case CS1 that houses the first cell block 110.

[0028] 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 housed in the case may include a positive electrode, a negative electrode, and a separator interposed between the positive and negative electrodes. 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 wound 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.

[0029] The plurality of battery cells 111 may be connected in series and / or parallel. For example, the plurality of battery cells 111 may be connected in series to each other. For example, the plurality of battery cells 111 may be connected in parallel to each other. For example, when a set of two or more battery cells 111 connected in parallel to each other is defined as a bank, one bank consisting of two or more battery cells 111 connected in parallel to each other may be connected in series to another bank consisting of two or more battery cells 111 connected in parallel to each other.

[0030] Each battery cell 111 may correspond to a pouch-type battery cell, a cylindrical battery cell, or a prismatic battery cell. The electrode assembly of a pouch-type battery cell is housed in a pouch case including an aluminum laminate sheet. The electrode assembly of a cylindrical battery cell is housed in a cylindrical metal can. The electrode assembly of a prismatic battery cell is housed in a prismatic metal can.

[0031] In the exemplary embodiment, each battery cell 111 corresponds to a pouch-type battery cell, and the plurality of battery cells 111 may be stacked on top of each other in a first direction (X direction) within one first battery cell assembly 10. In the exemplary embodiment, each of the plurality of battery cells 111 in each first battery cell assembly 10 corresponds to a pouch-type battery cell whose length along the first direction (X direction) is shorter than its length along a second direction (Y direction), and the plurality of battery cells 111 may be stacked on top of each other in the first direction (X direction).

[0032] When viewed from above, the first cell block 110 may have a rectangular shape whose length along a first direction (X direction) is shorter than its length along a second direction (Y direction). The first cell block 110 may have two side surfaces facing each other in the first direction (X direction), a front surface and a rear surface facing each other in the second direction (Y direction), and a top surface and a bottom surface facing each other in a third direction (Z direction).

[0033] A busbar frame on which a busbar is mounted may be disposed on each of the front and rear surfaces of the first cell block 110. A plurality of busbars may be mounted on the busbar frame on the front surface of the first cell block 110, and a plurality of busbars may be mounted on the busbar frame on the rear surface 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 surface or the rear surface of the first cell block 110.

[0034] The bus bars may be coupled to the electrode leads of the battery cells 111. For example, the bus bars may be coupled to the electrode leads of the battery cells 111 by welding. For example, each bus bar may be an inter-bus bar that is coupled to electrode leads coupled to different battery cells 111 belonging to the first cell block 110 and electrically connects the different battery cells 111. For example, each bus bar may be a terminal bus bar that electrically connects the first battery cell assembly 10 to another external electric device.

[0035] In an exemplary embodiment, the first battery cell assembly 10 may include a single first cell block 110. In an exemplary embodiment, 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 each other.

[0036] The first case CS1 may include an upper cover plate 120 facing the top 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 bottom surface of the first cell block 110.

[0037] The first side wall 130 and the second side wall 140 may 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 may be mounted in the pack housing 501 using 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 may include a first support rail 531 and a second support rail 532 spaced apart 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 can fasten the first side wall 130 to the first support rail 531 of the pack housing 501 so as to limit 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. The second fastening member BT2 can fasten the second side wall 140 to the second support rail 532 of the pack housing 501 so as to limit 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.

[0038] More specifically, the first side wall 130 may include one or more first flanges 131 protruding in a first direction (X direction) or a direction away from one side of the first cell block 110. When the first side wall 130 includes multiple first flanges 131, the multiple first flanges 131 may be spaced apart from each other in a second direction (Y direction). The first flanges 131 may be seated on a first support rail 531 and fastened to and supported by a 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 the third direction (Z direction) with a first fastening hole 5311 of the first support rail 531 configured to be inserted and fastened by the first fastening member BT1. The first flange 131 may include two plates spaced apart in the third direction (Z direction) to form a hollow portion, and in this 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 formed 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).

[0039] The first fastening member BT1 may pass through the first hole 132 of the first flange 131 and be inserted into and fastened to the first fastening hole 5311 of the first support rail 531. When the first fastening member BT1 is inserted into and fastened to the first fastening hole 5311 of the first support rail 531, the first flange 131 may be fastened and fixed to the first support rail 531. When the first flange 131 is fastened and fixed to the first support rail 531 by the first fastening member BT1, relative movement between the first flange 131 and the first support rail 531 in the first direction (X direction) may be limited.

[0040] The second side wall 140 may include one or more second flanges 141 protruding in a first direction (X direction) or a direction away from the other side of the first cell block 110. If the second side wall 140 includes multiple second flanges 141, the multiple second flanges 141 may be spaced apart from each other in the second direction (Y direction). The second flanges 141 may be seated on the second support rail 532 and fastened to and supported by 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 the third direction (Z direction) with the second fastening hole 5321 of the second support rail 532 configured to be inserted and fastened by the second fastening member BT2. The second flange 141 may include two plates spaced apart in the third direction (Z direction) to form a hollow portion, and in this 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 formed of a single plate, and the second hole 142 may penetrate the single plate of the second flange 141 in the third direction (Z direction).

[0041] The second fastening member BT2 may pass through the second hole 142 of the second flange 141 and be inserted into and fastened to the second fastening hole 5321 of the second support rail 532. When the second fastening member BT2 is inserted into and fastened to the second fastening hole 5321 of the second support rail 532, the second flange 141 may be fastened and fixed to the second support rail 532. When the second flange 141 is fastened and fixed to the second support rail 532 by the second fastening member BT2, relative movement between the second flange 141 and the second support rail 532 in the first direction (X direction) may be limited.

[0042] In an exemplary embodiment, 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 from a plane, the length LX1 of the first hole 132 in the first direction (X direction) may be longer than the length LY1 of the first hole 132 in the second direction (Y direction). When viewed from a plane, the first hole 132 may have an elliptical or rectangular shape.

[0043] When viewed from above, the first fastening hole 5311 of the first support rail 531 may have a circular shape, and the length of the first fastening hole 5311 of the first support rail 531 in the first direction (X direction) may be shorter than the length LX1 of the first hole 132 of the first flange 131 in the first direction (X direction). In an exemplary embodiment, 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).

[0044] In an exemplary embodiment, the second hole 142 of the second flange 141 may be a datum hole. When viewed from a plane, a length LX2 of the second hole 142 in a first direction (X direction) may be substantially the same as or similar to a length LY2 of the second hole 142 in a second direction (Y direction). When viewed from a plane, the second hole 142 may have a circular or rectangular shape. In an exemplary embodiment, the length LX2 of the second hole 142 of the second flange 141 in the first direction (X direction) may be shorter than the length LX1 of the first hole 132 of the first flange 131 in the first direction (X direction).

[0045] The upper cover plate 120 may cover the upper surface of the first cell block 110. The upper cover plate 120 may be coupled to the upper ends 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 upper cover plate 120 may be coupled to the upper end of the first side wall 130 by welding, and the other side of the upper cover plate 120 may be coupled to the upper end of the second side wall 140 by welding.

[0046] The upper cover plate 120 may be attached to an upper surface of the first cell block 110 and may be thermally coupled to the first cell block 110. The upper cover plate 120 may 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 may include a thermal interface material (TIM).

[0047] The upper cover plate 120 may have cooling channels 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 the outside of the first battery cell assembly 10 may enter the cooling channels 121 through an inlet of the cooling channels 121, flow along the cooling channels 121, and then exit to the outside through an outlet of the cooling channels 121. For example, the cooling channels 121 may provide a single path connected from the inlet to the outlet. While the cooling fluid flows along the cooling channels 121, cooling of the first battery cell assembly 101 may be performed. For example, the upper cover plate 120 may be manufactured by bonding two plates, and the cooling channels 121 may include a space defined between the two plates.

[0048] 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 ends 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 end of the first side wall 130 by welding, and the other side of the lower cover plate 150 may be coupled to the lower end of the second side wall 140 by welding. The lower cover plate 150 may include a venting passage for exhausting high-temperature gas generated in the first cell block 110 to the space below the first cell block 110.

[0049] In an exemplary embodiment, when the battery pack 500 is mounted on a vehicle, a cabin room where passengers sit may be located above the pack lid 520, and the ground on which the vehicle travels 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 assembly mounted in the pack housing 501. For example, a free volume FV may be provided between the bottom wall of the lower housing 510 and the first battery cell assembly 10. Gases and flames generated in a thermal runaway situation can be transported through the free volume FV. That is, the free volume FV serves as a venting passage for transporting high-temperature gases and flames.

[0050] In addition, even when a strong impact occurs due to foreign objects flying onto the underside of the vehicle while driving on hard ground such as an unpaved road, the impact can be absorbed via the free volume FV. Therefore, the battery cell assemblies can be prevented from being damaged by the impact. The free volume FV may include an empty space provided between each battery cell assembly and the lower housing 510. When the lower housing 510 deforms toward the battery cell assemblies due to an impact applied to the underside of the vehicle, the free volume FV can be used as a space that allows the lower housing 510 to deform to a certain extent.

[0051] The height of the free volume FV and the distance between the bottom wall of the lower housing 510 and the battery cell assembly may be set sufficiently to absorb external impacts. The height of the free volume FV may be determined taking into consideration 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 rate of gas discharge during thermal runaway, and the like. For example, when the thickness or rigidity of the vehicle frame or the bottom wall of the lower housing 510 is relatively large, at least one of the size and height of the free volume FV may be relatively small. Furthermore, when the thickness or rigidity of the vehicle frame or the bottom wall of the lower housing 510 is relatively small, there is a high possibility of deformation of the bottom wall of the lower housing 510. Therefore, to protect the battery cell assembly, at least one of the size and height of the free volume FV may be relatively increased. Furthermore, when the size of the battery pack 500 is relatively large according to the battery pack 500 specifications, a relatively large free volume FV may be ensured. When the size of the battery pack 500 is relatively small, the height of the free volume FV that can be secured may be relatively small, and it may be necessary to relatively increase the thickness and rigidity of the bottom wall of the lower housing 510. Furthermore, if the height of the free volume FV is too low, the gas discharge path becomes small, and the internal pressure of the battery pack 500 may rise rapidly during thermal runaway. Therefore, the size and height of the free volume FV can be determined taking into account the amount of gas generated and the discharge speed.

[0052] The maximum height of the free volume FV may be determined depending on the degree of damage to the battery cells 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 so that the battery cell does not deform more than 1 mm when the lower housing 510 deforms 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 and rigidity of the lower housing 510. Therefore, the size and height of the free volume FV may be determined taking into consideration both the damage tolerance of the battery cell 111 and the thickness and rigidity of the lower housing 510.

[0053] In an exemplary embodiment, the upper surface of the battery cell assembly may be in tight contact with the lower surface of the pack lid 520. If there is a gap between the battery cell assembly and the pack lid 520, high-temperature gas may pass through the gap between the battery cell assembly and the pack lid 520 and propagate to multiple battery cell assemblies during thermal runaway. Heat and flames may also be transferred to the pack lid 520, potentially affecting the cabin room above the pack lid 520. Therefore, by tightly contacting the upper surface of the battery cell assembly and the lower surface of the pack lid 520, gas and flames generated inside the battery pack 500 can be guided to the free volume FV.

[0054] 5a and 5b are cross-sectional views showing a rework operation of a battery pack 500 according to an exemplary embodiment of the present invention. Hereinafter, with reference to Figs. 5a and 5b, a rework operation of the battery pack 500 described with reference to Figs. 1 to 4 will be described.

[0055] 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, and 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. Because the second flange 141 fastened to the second support rail 532 by the second fastening member BT2 remains fixed, fluctuations in the thickness of the first cell block 110 due to swelling of the first cell block 110 occur primarily in one direction.

[0056] 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. With the first fastening member BT1 and the second fastening member BT2 separated from the first case CS1, the first battery cell assembly 10 can be made separable from the pack housing 501. Thereafter, a new battery cell assembly can be loaded into the pack housing 501, or a first battery cell assembly 10 that has been repaired and has had its defects removed can be loaded into the pack housing 501.

[0057] In the case of a typical battery pack, when the battery cell assembly is separated from the pack housing, swelling of the cell blocks within the battery cell assembly causes a relatively large force to act on the fastening portion between the case of the battery cell assembly and the pack housing, and such force makes it difficult to release the fastening between the case of the battery cell assembly and the pack housing.

[0058] However, according to an exemplary embodiment 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 slotted 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. In the case of a slotted hole, since it has a major axis extending in the swelling direction of the first cell block 110, a release operation for separating the first fastening member BT1 from the first flange 131 and the first support rail 531 can be easily performed during a rework operation on the first battery cell assembly 10. Furthermore, during a rework operation on 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 slotted 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 holes and the pack housing 501 is released, thickness variations in the first direction (X direction) of the first cell block 110 due to swelling of the first cell block 110 and movement of the first flange 131 are permitted, and the force acting on the fastening portion between the second flange 141 having the datum holes and the pack housing 501 is reduced, making it easier to perform the fastening release operation of separating the second fastening member BT2 from the second flange 141 and the second support rail 532. This makes it easier to separate the first battery cell assembly 10 from the pack housing 501, thereby improving the productivity of rework operations for the battery pack 500.

[0059] (Second embodiment) Fig. 6 is a plan view showing a battery pack 500A according to an exemplary embodiment of the present invention. Fig. 7 is a cross-sectional view taken along line VII-VII' in Fig. 6. Fig. 8 is a cross-sectional view taken along line VIII-VIII' in Fig. 6.

[0060] 6 to 8, a battery pack 500A may include a first battery cell assembly 10 and a second battery cell assembly 20 arranged in sequence in a first direction (X direction).

[0061] The second battery cell assembly 20 may include a second cell block 210 including a plurality of battery cells and a second case CS2 that accommodates the second cell block 210. The second cell block 210 may be substantially identical to or similar to the first cell block 110. The second battery cell assembly 20 may be mounted to the pack housing 501 using a side mounting method. 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 that are spaced apart with the second cell block 210 interposed therebetween. In this case, 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 identical to or similar to the first battery cell assembly 10, except for the positions of slot holes in a flange provided for fastening between the second case CS2 and the pack housing 501 and the position of a datum hole in a flange provided for fastening between the second case CS2 and the pack housing 501.

[0062] 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 in the first direction (X direction) with the second cell block 210 therebetween. The third sidewall may face the second sidewall (see 140 in FIG. 2 ) of the first battery cell assembly 10. The second case CS2 differs from the first case CS1 in that the third sidewall of the second case CS2 facing the second sidewall 140 of the first battery cell assembly 10 may have a datum hole, and the fourth sidewall of the second case CS2 may have a slot hole.

[0063] 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 the first direction (X direction) and may extend in the second direction (Y direction).

[0064] The third side wall of the second case CS2 may include one or more third flanges 231 protruding in a first direction (X direction) or a direction away from one side of the second cell block 210. The third flanges 231 may be seated on second support rails 532 and fastened to and supported by third fastening members BT3. The third flanges 231 may include third holes 232 through which the third fastening members BT3 pass, and the third holes 232 of the third flanges 231 may overlap in the third direction (Z direction) with third fastening holes 5322 of the third support rails 533 configured to be inserted and fastened by the third fastening members BT3. The third fastening members BT3 may pass through the third holes 232 of the third flanges 231 and be inserted and fastened to the third fastening holes 5322 of the second support rails 532. The third fastening member BT3 is inserted into and fastened to the third fastening hole 5322 of the second support rail 532, thereby fastening and fixing the third flange 231 to the second support rail 532. By fastening and fixing the third flange 231 to the second support rail 532 by the third fastening member BT3, relative movement between the third flange 231 and the second support rail 532 in the first direction (X direction) can be limited.

[0065] The third hole 232 of the third flange 231 may be a slotted hole to allow movement of the third 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 from a plane, the length of the third hole 232 in the first direction (X direction) may be longer than the length of the third hole 232 in the second direction (Y direction). When viewed from a plane, the third hole 232 may have an oval or rectangular shape. In an exemplary embodiment, 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 can be spaced apart in the first direction (X direction).

[0066] The second support rail 532 may 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 may 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 may be spaced apart in the extension direction of the second support rail 532 or in the second direction (Y direction).

[0067] 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 of the second cell block 210. The fourth flanges 241 may be seated on the third support rails 533 and fastened to and supported by the third support rails 533 by fourth fastening members BT4. The fourth flanges 241 may include fourth holes 242 through which the fourth fastening members BT4 pass, and the fourth holes 242 of the fourth flanges 241 may overlap in the third direction (Z direction) with fourth fastening holes 5331 of the third support rails 533 configured to be inserted and fastened by the fourth fastening members BT4. The fourth fastening members BT4 may pass through the fourth holes 242 of the fourth flanges 241 and be inserted and fastened to the fourth fastening holes 5331 of the third support rails 533. The fourth fastening member BT4 is inserted into and fastened to the fourth fastening hole 5331 of the third support rail 533, thereby fastening and fixing the fourth flange 241 to the third support rail 533. By fastening and fixing the fourth flange 241 to the third support rail 533 by the fourth fastening member BT4, relative movement between the fourth flange 241 and the third support rail 533 in the first direction (X direction) can be limited.

[0068] The fourth hole 242 of the fourth flange 241 may be a datum hole. When viewed from a plane, 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 from a plane, the fourth hole 242 may have a circular or rectangular shape.

[0069] In an embodiment, the second support rail 532 is configured to support both the first battery cell assembly 10 and the second battery cell assembly 20, and 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 may be the same type of flange. For example, as shown, 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.

[0070] 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 second battery cell assembly 20 is released from the third flange 231 for a rework operation, the second battery cell assembly 20, which has been deformed due to swelling, may physically interfere with the first battery cell assembly 10. However, according to the embodiment, the second support rail 532 is configured to support only flanges of the same type, and therefore, physical interference between adjacent battery cell assemblies can be prevented or suppressed when one battery cell assembly is released from the fastening for a rework operation.

[0071] Furthermore, the battery pack 500A may include a third battery cell assembly 30 and a fourth battery cell assembly 40 arranged in a first direction (X direction).

[0072] The third battery cell assembly 30 may be substantially the same as the first battery cell assembly 10. Briefly, the third battery cell assembly 30 may include a third cell block 310 located between a third support rail 533 and a fourth support rail 534, and a third case CS3 fastened to the pack housing 501 and accommodating the third cell block 310. The third case CS3 may include a fifth sidewall facing the second battery cell assembly 20, a sixth sidewall opposite the fifth sidewall, an upper cover plate (see 320 in FIG. 10 ) with a cooling channel, and a lower cover plate. The fifth sidewall of the third case CS3 may include a fifth flange 331 fastened to the third support rail 533 by a fifth fastener BT5 such as a bolt, and the sixth sidewall of the third case CS3 may include a sixth flange 341 fastened to the fourth support rail 534 by a sixth fastener (not shown) such as a bolt. The fifth fastening member BT5 passes through the fifth hole 332 of the fifth flange 331 and is inserted into and fastened to the fifth fastening hole 5332 of the third support rail 533, thereby restricting relative movement in the first direction (X direction) between the fifth flange 331 and the third support rail 533. The sixth fastening member passes through the sixth hole 342 of the sixth flange 341 and is inserted into and fastened to the sixth fastening hole of the fourth support rail 534, thereby restricting relative movement in the first direction (X direction) between the sixth flange 341 and the fourth support rail 534. In this case, the fifth hole 332 of the fifth flange 331 may be a slot hole for accommodating 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.

[0073] The fourth battery cell assembly 40 may be substantially the same as the second battery cell assembly 20. Briefly, the fourth battery cell assembly 40 may include a fourth cell block 410 located between a fourth support rail 534 and a fifth support rail 535, and a fourth case CS4 that is fastened to the pack housing 501 and houses the fourth cell block 410. The fourth case CS4 may include a seventh side wall that faces the third battery cell assembly 30, an eighth side wall opposite the seventh side wall, an upper cover plate (see 420 in FIG. 10 ) provided with a cooling channel, and a lower cover plate. The seventh side wall of the fourth case CS4 may include a seventh flange 431 fastened to the fourth support rail 534 by 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 fastened to the fifth support rail 535 by an eighth fastening member (not shown), such as a bolt. The seventh fastening member passes through a seventh hole 432 of the seventh flange 431 and is inserted into and fastened to a seventh fastening hole of the fourth support rail 534, thereby limiting relative movement between the seventh flange 431 and the fourth support rail 534 in the first direction (X direction). A member passes through the eighth hole 442 of the eighth flange 441 and is inserted into and fastened to the eighth fastening hole of the fifth support rail 535, thereby restricting relative movement in the first direction (X direction) between the eighth flange 441 and the fifth support rail 535. In this case, 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.

[0074] In an embodiment, 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 of the plurality of support rails that are adjacent in the first direction (X direction). In this case, flanges provided on the cases of the battery cell assemblies fastened to odd-numbered support rails (e.g., the first support rail 531, the third support rail 533, and the fifth support rail 535) may include slot holes to accommodate flange movement caused by swelling of the cell blocks of the battery cell assemblies during rework. In addition, flanges provided on the cases of the battery cell assemblies fastened to even-numbered support rails (e.g., the second support rail 532 and the fourth support rail 534) may include datum holes.

[0075] In an embodiment, 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 flange. For example, the single support rail may be configured to support only flanges with slotted holes or only flanges with datum holes. For example, only flanges with slotted holes may be disposed on odd-numbered support rails (e.g., first support rail 531, third support rail 533, and fifth support rail 535) among the multiple support rails, and only flanges with datum holes may be disposed on even-numbered support rails (e.g., second support rail 532 and fourth support rail 534) among the multiple support rails.

[0076] If a flange having a slotted hole of one battery cell assembly and a flange having a datum hole of another battery cell assembly are supported by the same single support rail, physical interference may occur between the one battery cell assembly and another adjacent battery cell assembly when the flange having the slotted hole of the one battery cell assembly is released for a rework operation. However, according to an embodiment, the single support rail configured to support all of the adjacent battery cell assemblies is configured to support only flanges of the same type, so that physical interference between the battery cell assemblies can be prevented or suppressed when the one battery cell assembly is released for a rework operation.

[0077] (Third embodiment) FIG. 9 is a schematic diagram illustrating an electric vehicle 1000 equipped with a battery pack 1100 according to an exemplary embodiment of the present invention.

[0078] 9, for simplicity of illustration, only the vehicle body frame 1200 forming the lower skeleton of the vehicle, the battery pack 1100 coupled to the vehicle body frame 1200, and tires are shown. For example, the battery pack 1100 may include the battery pack 500A described with reference to FIGS. 6 to 8.

[0079] In a typical battery pack, a battery cell assembly is installed at the bottom of a pack housing of the battery pack. In this embodiment, a free volume (see FV in FIG. 2 ) may be provided below the battery cell assemblies (i.e., first to fourth battery cell assemblies 10, 20, 30, and 40) of the battery pack 1100. Since there is no space between the battery cell assemblies and the pack lid 520, gas generated in the battery cell assemblies can be prevented from being transmitted to the cabin room above the vehicle. Furthermore, gas generated in the battery cell assemblies is guided to the free volume FV provided between the battery cell assemblies and the pack housing of the battery pack 1100. The gas flows through the free volume FV and can be exhausted to the underside of the vehicle through a gas exhaust port provided in the battery pack 1100. Furthermore, according to this embodiment, since the free volume FV is provided between the battery cell assemblies and the pack housing within the battery pack 1100, damage to the battery cell assemblies can be prevented even if the pack housing is deformed.

[0080] According to the embodiment of the present invention, the battery pack 1100 and the electric vehicle 1000 including the battery pack 1100 can enhance passenger safety, protect the battery cell assembly, which is a core component, and improve the durability of the battery pack 1100 and the electric vehicle 1000.

[0081] The present invention has been described in more detail above through the drawings and embodiments, etc. However, the configurations shown in the drawings or embodiments in this specification are merely one embodiment of the present invention and do not represent all of the technical ideas of the present invention, and therefore, there may be various equivalents and modifications that can replace them at the time of filing this application. [Explanation of symbols]

[0082] 10 First battery cell assembly 20 Second Battery Cell Assembly 30 Third battery cell assembly 40 4th battery cell assembly 101 First battery cell assembly 110 Cell Block 1 111 Battery Cells 120 Upper cover plate 121 Cooling Channel 130 First Side Wall 131 First flange 132 Hole 1 140 Second Side Wall 141 Second flange 142 2nd Hall 150 Lower Cover Plate 210 Cell Block 2 231 Third flange 232 3rd Hall 241 4th flange 242 4th Hall 310 Cell Block 3 331 5th flange 332 5th hole 341 6th flange 342 Hole 6 410 Cell Block 4 431 7th flange 432 Hole 7 441 8th flange 442 Hole 8

Claims

1. a first battery cell assembly 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; a pack housing in which the first battery cell assembly is mounted; In a battery pack including the first side wall includes a first flange that is fastened to the pack housing by a first fastening member such that relative movement with respect to the pack housing in the first direction is limited; the second side wall includes a second flange that is fastened to the pack housing by a second fastening member such that relative movement with respect to the pack housing in the first direction is limited; 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 longer than a length of the first hole in a second direction perpendicular to the first direction.

2. 2. The battery pack of claim 1, wherein 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.

3. The battery pack of claim 2 , wherein the length of the first hole in the first direction is longer than the length of the second hole in the first direction.

4. The pack housing includes: a first support rail configured to support the first flange, the first support rail including a first fastening hole to which the first fastening member is fastened; a second support rail configured to support the second flange, the second support rail including a second fastening hole to which the second fastening member is fastened; 10. The battery pack of claim 1, comprising:

5. The battery pack of claim 4 , wherein a center of the first fastening hole is spaced apart from a center of the second hole in the first direction.

6. The battery pack A second battery cell assembly including a second cell block including a plurality of second battery cells and a second case accommodating the second cell block, wherein the second case includes a third side wall and a fourth side wall spaced apart in the first direction with the second cell block interposed therebetween. further comprising the third side wall includes a third flange that is fastened to the pack housing by a third fastening member such that relative movement with respect to the pack housing in the first direction is limited; the fourth side wall includes a fourth flange that is fastened to the pack housing by a fourth fastening member such that relative movement with respect to the pack housing in the first direction is limited; 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; The battery pack of claim 1 , wherein the length of the fourth hole in the first direction is longer than the length of the fourth hole in the second direction.

7. The battery pack of claim 6 , wherein a length of the third hole in the first direction is the same as a length of the third hole in the second direction.

8. The pack housing includes: a first support rail that supports the first flange; a second support rail that supports the second flange and the third flange; a third support rail that supports the fourth flange; Including, The battery pack of claim 6 , wherein the first support rail, the second support rail, and the third support rail are spaced apart from each other in the first direction.

9. The battery pack according to claim 8 , wherein the second flange and the third flange are spaced apart in the second direction.

10. 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; The battery pack of claim 8 , wherein the second fastening hole and the third fastening hole are spaced apart in the second direction.

11. The battery pack according to claim 1 , wherein the first battery cells are stacked in the first direction.

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