Battery pack

Abstract

According to exemplary embodiments of the present invention, a battery pack is provided. The battery pack comprises a housing; and first and second battery assemblies disposed on the upper surface of a plate portion of the housing, wherein each of the first and second battery assemblies comprises a cell stack and first and second cross beams spaced apart from each other with the cell stack in between, wherein the first cross beam of the second battery assembly is different from and has a complementary shape to the second cross beam of the first battery assembly, and the first cross beam of the second battery assembly is spaced apart from the second cross beam of the first battery assembly.

Description

Technology Field

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

[0002] 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 cordless vacuum cleaners. Recently, as the manufacturing cost per unit capacity of secondary batteries has decreased dramatically due to improved energy density and economies of scale, and as the driving range of BEVs (battery electric vehicles) has increased to a level equivalent to that of fuel vehicles, the primary use of secondary batteries is shifting from mobile devices to mobility.

[0003] The technological development trend for rechargeable batteries in mobility is the improvement of energy density and safety. Here, the energy density of a rechargeable battery is defined as the maximum electrical energy that can be stored by the battery's mass. As high energy density is directly linked to driving efficiency and range in mobility applications, various studies are being conducted to improve this energy density. Prior art literature

[0004] Korean Patent Publication No. 10-2022-0014027 The problem to be solved

[0005] The problem that the technical concept of the present invention aims to solve is to provide a battery pack with enhanced energy density. means of solving the problem

[0006] According to exemplary embodiments of the present invention for solving the above-described problem, a battery pack is provided. The battery pack comprises a housing including a plate portion; and first and second battery assemblies disposed on the upper surface of the plate portion of the housing and including a plurality of battery cells, wherein each of the first and second battery assemblies includes a cell stack and first and second cross beams spaced apart from each other with the cell stack in between, wherein the first cross beam of the second battery assembly is different from and has a complementary shape to the second cross beam of the first battery assembly, the first cross beam of the second battery assembly faces the second cross beam of the first battery assembly, and the first cross beam of the second battery assembly is spaced apart from the second cross beam of the first battery assembly.

[0007] It further includes an insulating material interposed between the first cross beam of the second battery assembly and the second cross beam of the first battery assembly.

[0008] There is an air gap between the first cross beam of the second battery assembly and the second cross beam of the first battery assembly.

[0009] The first cross beam of each of the first and second battery assemblies comprises: a first plate covering a first side of the cell stack; a second plate spaced apart from the cell stack with the first plate in between; and first and second ribs connected to each of the first and second plates and interposed between the first and second plates.

[0010] The second cross beam of each of the first and second battery assemblies comprises: a third plate covering a second side of the cell stack, wherein the second side is opposite to the first side; a fourth plate spaced apart from the cell stack with the third plate in between; and third and fourth ribs connected to each of the third and fourth plates and interposed between the third and fourth plates.

[0011] The thickness of each of the first to fourth plates and the first to fourth ribs is 10 mm or less.

[0012] Each of the first to fourth ribs includes a plurality of elongated holes.

[0013] The plurality of elongated holes of each of the first to fourth ribs overlap each other.

[0014] The first battery assembly and the second battery assembly are spaced apart from each other in a first direction.

[0015] The length of the first direction of the above-mentioned slots is greater than the length of the second direction perpendicular to the first direction.

[0016] It further includes an insulating material interposed between the first cross beam of the second battery assembly and the second cross beam of the first battery assembly.

[0017] The above insulation material is in contact with the first to fourth plates and the second and third ribs.

[0018] It further includes a plurality of fixers that fix the first cross beam of the second battery assembly and the second cross beam of the first battery assembly.

[0019] The above plurality of fixing devices penetrate the insulation material.

[0020] It further includes an insulating material interposed between the first cross beam of the second battery assembly and the second cross beam of the first battery assembly.

[0021] The insulation material is in contact with the second and third plates, and the insulation material is spaced apart from either of the second and third ribs.

[0022] There is an air gap between the first cross beam of the second battery assembly and the second cross beam of the first battery assembly.

[0023] The second battery assembly further comprises an insulating material interposed between the first cross beam of the second battery assembly and the second cross beam of the first battery assembly, wherein the insulating material is spaced apart from either of the second and third plates, and the insulating material is in contact with the second and third ribs. Effects of the invention

[0024] A battery pack according to exemplary embodiments of the present invention comprises battery assemblies comprising crossbeams composed of plates and ribs of about 10 mm or less. Accordingly, the energy density of the battery pack is increased.

[0025] The effects obtainable from the exemplary embodiments of the present invention are not limited to those mentioned above, and other unmentioned effects can be clearly derived and understood by those skilled in the art to which the exemplary embodiments of the present disclosure belong from the following description. That is, unintended effects resulting from the implementation of 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. Brief explanation of the drawing

[0026] FIG. 1 is a perspective view illustrating a battery pack according to exemplary embodiments. Figure 2 is a cross-sectional view taken along the cutting line 1I-1I' of Figure 1. Figure 3 is a cross-sectional view illustrating the first cross beam of Figure 2. Figure 4 is a plan view illustrating the first cross beam of Figure 2. Figure 5 is a cross-sectional view illustrating the second cross beam of Figure 2. Figure 6 is a plan view illustrating the second cross beam of Figure 2. Figure 7 shows the part corresponding to Figure 2. Figure 8 shows the part corresponding to Figure 2. Figure 9 shows the part corresponding to Figure 2. Specific details for implementing the invention

[0027] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings. Instead, based on the principle that the inventor can appropriately define the concepts of terms to best describe his invention, they should be interpreted in a meaning and concept consistent with the technical spirit of the present invention.

[0028] Therefore, 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; thus, it should be understood that various equivalents and modifications that can replace them may exist at the time of filing this application.

[0029] In addition, in describing the present invention, if it is determined that a detailed description of related known components or functions may obscure the essence of the invention, such detailed description is omitted.

[0030] Since embodiments of the present invention are provided to more fully explain the invention to those skilled in the art, the shapes and sizes of the components in the drawings may be exaggerated, omitted, or schematically depicted for clearer explanation. Accordingly, the size or proportion of each component does not entirely reflect the actual size or proportion.

[0032] (1st embodiment)

[0033] FIG. 1 is a perspective view illustrating a battery pack according to exemplary embodiments.

[0034] Figure 2 is a cross-sectional view taken along the cutting line 1I-1I' of Figure 1.

[0035] Figure 3 is a cross-sectional view illustrating the first cross beam of Figure 2.

[0036] Figure 4 is a plan view illustrating the first cross beam of Figure 2.

[0037] Figure 5 is a cross-sectional view illustrating the second cross beam of Figure 2.

[0038] Figure 6 is a plan view illustrating the second cross beam of Figure 2.

[0039] Referring to FIGS. 1 through 6, the battery pack (100) may include a housing (110), a plurality of battery assemblies (120), a center beam (130), and a plurality of exhaust devices (140). The battery pack (100) is the final form of a battery system mounted on a mobility device, etc.

[0040] The housing (110) may provide a space for arranging a plurality of battery assemblies (120). The housing (110) may include a plate portion (111) and side walls (112).

[0041] The plate portion (111) may include an upper surface (111U) and a lower surface (111L) that are substantially parallel to each other. Two directions substantially parallel to the upper surface (111U) of the plate portion (111) are defined as the X direction and the Y direction, and a direction substantially perpendicular to the upper surface (111U) of the plate portion (111) is defined as the Z direction. Each of the X direction, the Y direction, and the Z direction may be substantially perpendicular to each other. Unless otherwise noted, the definitions of directions are the same for the following drawings.

[0042] According to exemplary embodiments, the plate portion (111) may include a plurality of plates welded together by friction stir welding. When the plate portion (111) is provided by friction stir welding, the plate portion (111) may include the interface between different plates. According to exemplary embodiments, the plate portion (111) may be composed of a single plate.

[0043] The plate portion (111) may include a plurality of cooling channels that serve as flow paths for the cooling fluid. The plate portion (111) may include a plurality of cavities for weight reduction of the plate portion (111). Each of the plurality of cooling channels and the plurality of cavities may extend in the X direction.

[0044] The side walls (112) can be joined to the plate portion (111). The side walls (112) can be extended in the Z direction. The side walls (112) may include an internal empty space, and accordingly, the side walls (112) can be made lighter.

[0045] A plurality of battery assemblies (120) may be disposed on the upper surface (111U) of the plate portion (111) of the housing (110). The plate portion (111) may support the plurality of battery assemblies (120). The first to fourth side walls (112, 113, 114, 115) may horizontally surround the plurality of battery assemblies (120).

[0046] Hereinafter, the technical concept of the present invention is described with reference to an embodiment in which the battery pack (100) is of the modular type and each of the plurality of battery assemblies (120) does not include a module frame. However, this is a non-limiting example and does not limit the technical concept of the present invention in any sense. A person skilled in the art will be able to easily arrive at a plurality of battery assemblies including a module frame and a modular type battery pack including the same based on what is described herein.

[0047] Each of the plurality of battery assemblies (120) may include a cell stack (121), a plurality of separators, a first cross beam (125a), and a second cross beam (125b). The cell stack (121) may include a plurality of battery cells. Each of the plurality of battery assemblies (120) may further include a bus bar plate.

[0048] A battery cell is the basic unit of a lithium-ion battery, or a secondary battery. A battery cell includes an electrode assembly, an electrolyte, and a case. Battery cells are classified into lithium-ion batteries, lithium-ion polymer batteries, and lithium-ion polymer batteries depending on the composition of the electrode assembly and the electrolyte. Lithium-ion polymer batteries are increasing their market share within the secondary battery sector due to their low risk of electrolyte leakage and ease of manufacturing.

[0049] The battery cell may be any one of a cylindrical battery cell, a prismatic battery cell, and a pouch-type battery cell. The electrode assembly of the cylindrical battery cell is embedded in a cylindrical metal can. The electrode assembly of the prismatic battery cell is embedded in a prismatic metal can. The electrode assembly of the pouch-type battery cell is embedded in a pouch case containing an aluminum laminate sheet.

[0050] The electrode assembly embedded in the battery case includes a positive electrode, a negative electrode, and a separator interposed between the positive and negative electrodes. The electrode assembly is classified into a jelly-roll type and a stack type depending on the assembly form. The jelly-roll type consists of a positive electrode, a negative electrode, and a separator interposed between them wound together. The stack type includes a plurality of positive electrodes, a plurality of negative electrodes, and a plurality of separators interposed between them that are sequentially stacked.

[0051] According to exemplary embodiments, a plurality of battery cells of a cell stack (121) may be connected in series and / or in parallel. For example, a plurality of battery cells may be connected in series with each other. For another example, a plurality of battery cells may be connected in parallel with each other. For another example, the cell stack (121) may include a plurality of banks connected in series in parallel with each other, and each of the plurality of banks may include a plurality of battery cells connected in parallel with each other.

[0052] According to exemplary embodiments, the cell stack (121) may further include a plurality of separators. The plurality of separators can prevent swelling of the plurality of battery cells by horizontally supporting the plurality of battery cells. According to exemplary embodiments, the plurality of separators may be thermal barriers. According to exemplary embodiments, each of the plurality of separators may have a high melting temperature and low thermal conductivity. According to exemplary embodiments, each of the plurality of separators may include a flame-retardant material such as ceramic and coated glass material. According to exemplary embodiments, the plurality of separators may be configured to release a fire retarding material and a fire extinguishing agent in the event of a thermal runaway event.

[0053] The first cross beam (125a) and the second cross beam (125b) of each of the plurality of battery assemblies (120) may be spaced apart from each other with the cell stack (121) in between. The first cross beam (125a) and the second cross beam (125b) may cover the cell stack (121). The first cross beam (125a) and the second cross beam (125b) may be fixed to the cell stack (121) by an adhesive material or the like.

[0054] Each of the plurality of battery assemblies (120) may have a first cross beam (125a) that includes plates (P1a, P2a) and ribs (R1a, R2a, R3a, R4a). The plates (P1a, P2a) may be substantially perpendicular to the X direction. The plates (P1a, P2a) may be spaced apart from each other in the X direction. Plate (P1a) may be in contact with the cell stack (121). Plate (P1a) may cover a first side (121S1) of the cell stack (121). Plate (P2a) may be spaced apart from the cell stack (121) with plate (P1a) in between. The length of plate (P1a) in the Z direction may be greater than the length of plate (P2a) in the Z direction.

[0055] The ribs (R1a, R2a, R3a, R4a) may be substantially perpendicular to the Z direction. The ribs (R1a, R2a, R3a, R4a) may be spaced apart from each other in the Z direction. The ribs (R1a, R2a, R3a, R4a) may be interposed between the plates (P1a, P2a). The ribs (R1a, R2a, R3a, R4a) may be connected to the plates (P1a, P2a). The ribs (R3a, R4a) may be interposed between the ribs (R1a, R2a).

[0056] Each of the ribs (R1a, R2a, R3a, R4a) may include a plurality of slotted holes (SLa). The length of each of the slotted holes (SLa) in the X direction may be greater than the length of each of the slotted holes (SLa) in the Y direction. The slotted holes (SLa) of each of the ribs (R1a, R2a, R3a, R4a) may overlap each other in the Z direction.

[0057] There may be empty spaces between the plates (P1a, P2a) and the ribs (R1a, R2a, R3a, R4a). Accordingly, the first cross beam (125a) can be made lighter, and the energy density of the battery pack (100) can be increased. Plate (P1a) may be referred to as the first plate, plate (P2a) may be referred to as the second plate, rib (R1a) may be referred to as the first rib, and rib (R2a) may be referred to as the second rib.

[0058] Each of the multiple battery assemblies (120) may have a second cross beam (125b) that includes plates (P1b, P2b) and ribs (R1b, R2b, R3b). The plates (P1b, P2b) may be substantially perpendicular to the X direction. The plates (P1b, P2b) may be spaced apart from each other in the X direction. Plate (P1b) may be in contact with the cell stack (121). Plate (P1b) may cover a second side (121S2) of the cell stack (121). The second side (121S2) may be opposite to the first side (121S1). Plate (P2b) may be spaced apart from the cell stack (121) with plate (P1b) in between. The length of plate (P1b) in the Z direction may be greater than the length of plate (P2b) in the Z direction.

[0059] The ribs (R1b, R2b, R3b) may be substantially perpendicular to the Z direction. The ribs (R1b, R2b, R3b) may be spaced apart from each other in the Z direction. The ribs (R1b, R2b, R3b) may be interposed between the plates (P1b, P2b). The ribs (R1b, R2b, R3b) may be connected to the plates (P1b, P2b). The rib (R3b) may be interposed between the ribs (R1b, R2b).

[0060] Each of the ribs (R1b, R2b, R3b) may include multiple elongated holes (SLb). The length of each of the multiple elongated holes (SLb) in the X direction may be greater than the length of each of the multiple elongated holes (SLb) in the Y direction. The multiple elongated holes (SLb) of each of the ribs (R1b, R2b, R3b) may overlap each other in the Z direction. The multiple elongated holes (SLb) of each of the ribs (R1b, R2b, R3b) may overlap with the multiple elongated holes (SLa) of each of the ribs (R1a, R2a, R3a, R4a) in the Z direction.

[0061] There may be empty spaces between the plates (P1b, P2b) and the ribs (R1b, R2b, R3b). Accordingly, the first partition (125b) may be made lighter, and the energy density of the battery pack (100) may be increased. Plate (P1b) may be referred to as the third plate, plate (P2b) may be referred to as the fourth plate, rib (R1b) may be referred to as the third rib, and rib (R2b) may be referred to as the fourth rib.

[0062] According to exemplary embodiments, the second cross beam (125b) of each of the plurality of battery assemblies (120) can be combined with the first cross beam (125a) of the subsequent plurality of battery assemblies (120). Accordingly, the lower part of the plate (P1a) can face the plate (P2b), the upper part of the plate (P1b) can face the plate (P2a), and the rib (R2a) can face the rib (R1b).

[0063] The distance between the rib (R3b) and the plate portion (111) may be greater than the distance between the rib (R2b) and the plate portion (111). The distance between the rib (R1b) and the plate portion (111) may be greater than the distance between the rib (R3b) and the plate portion (111). The distance between the rib (R2a) and the plate portion (111) may be greater than the distance between the rib (R1b) and the plate portion (111). The distance between the rib (R4a) and the plate portion (111) may be greater than the distance between the rib (R2a) and the plate portion (111). The distance between the rib (R3a) and the plate portion (111) may be greater than the distance between the rib (R4a) and the plate portion (111). The distance between the rib (R1a) and the plate portion (111) may be greater than the distance between the rib (R3a) and the plate portion (111).

[0064] According to exemplary embodiments, the thickness of each of the plates (P1a, P2a, P1b, P2b) and ribs (R1a, R2a, R3a, R4a, R1b, R2b, R3b) may be about 10 mm or less. According to exemplary embodiments, since the thickness of each of the plates (P1a, P2a, P1b, P2b) and ribs (R1a, R2a, R3a, R4a, R1b, R2b, R3b) is about 10 mm or less, the first and second cross beams (125a, 125b) may be lighter. According to exemplary embodiments, the thickness of each of the plates (P1a, P2a, P1b, P2b) and ribs (R1a, R2a, R3a, R4a, R1b, R2b, R3b) may be about 0.5 mm or more. According to exemplary embodiments, since the thickness of each of the plates (P1a, P2a, P1b, P2b) and ribs (R1a, R2a, R3a, R4a, R1b, R2b, R3b) is about 0.5 mm or more, the first and second cross beams (125a, 125b) can have sufficient rigidity.

[0065] The insulating material (150) may be interposed between the second cross beam (125b) of each of the plurality of battery assemblies (120) and the first cross beam (125a) of the subsequent plurality of battery assemblies (120). The second cross beam (125b) of each of the plurality of battery assemblies (120) and the first cross beam (125a) of the subsequent plurality of battery assemblies (120) may be spaced apart in the X direction with the insulating material (150) in between. Accordingly, the plurality of battery assemblies (120) may be spaced apart in the X direction with the insulating material (150) in between.

[0066] The insulation material (150) may be in contact with the first cross beam (125a) and the second cross beam (125b). The insulation material (150) may be in contact with the lower part of plate (P1a), plate (P2a), rib (R2a), the upper part of plate (P1b), plate (P2b), and rib (R2a).

[0067] The first cross beam (125a), the second cross beam (125b), and the insulation (150) can form a cross beam assembly (CBA). The cross beam assembly (CBA) can extend in a direction perpendicular to the center beam (130) (i.e., the Y direction). The cross beam assembly (CBA) can isolate cell stacks (121) in the X direction. The cross beam assembly (CBA) can be interposed between adjacent cell stacks (121).

[0068] The second cross beam (125b) of each of the plurality of battery assemblies (120) and the first cross beam (125a) of the subsequent plurality of battery assemblies (120) can be joined by mechanical fasteners (160), such as bolts. The fasteners (160) can be joined to the plate portion (111) by penetrating the plurality of elongated holes (SLa) of each of the ribs (R1a, R2a, R3a, R4a) and the plurality of elongated holes (SLb) of each of the ribs (R1b, R2b, R3b). Accordingly, the second cross beam (125b) of each of the plurality of battery assemblies (120) and the first cross beam (125a) of the subsequent plurality of battery assemblies (120) can be fixed to each other. The fasteners (160) can penetrate the insulation material (150). Accordingly, the insulation material (150) may include a plurality of holes. Multiple holes in the insulation material (150) can overlap with multiple elongated holes (SLa, SLb).

[0069] According to exemplary embodiments, the first cross beam (125a) and the second cross beam (125b) may have different and complementary shapes. The first cross beam (125a) and the second cross beam (125b) of each of the bulkhead assemblies (125) may interlock with each other.

[0070] The first cross beam (125a) of a plurality of battery assemblies (120) arranged at both ends in the X direction can be combined with a support (116) arranged on a plate portion (111) of a housing (110). The first cross beam (125a) and the support (116) can be secured by fixers (160).

[0071] Multiple battery assemblies (120) may be arranged in the X direction and the Y direction. In FIG. 1, the number of multiple battery assemblies (120) arranged in the X direction is three, and the number of multiple battery assemblies (120) arranged in the Y direction is two. Thus, this arrangement of multiple battery assemblies (120) can be described as a 3 * 2 arrangement. A person skilled in the art will be able to easily arrive at an arrangement of multiple battery assemblies (120) arranged in an M * N arrangement based on what is described herein. Here, M and N are each integers greater than or equal to 2.

[0072] The center beam (130) can isolate elements placed on the housing (110) from one another. Accordingly, the center beam (130) can protect a plurality of battery assemblies (120) while preventing unwanted short circuits between them.

[0073] The center beam (130) may extend between opposing side walls (112). The center beam (130) may extend in the X direction. The center beam (130) may be in contact with any one of the side walls (112). The center beam (130) may isolate a plurality of battery assemblies (120) from one another. The center beam (130) may be interposed between a plurality of battery assemblies (120).

[0074] A plurality of exhaust devices (140) may be coupled to some of the side walls (112). The side walls (112) may include exhaust paths connected to the plurality of exhaust devices (140). The plurality of exhaust devices (140) may be configured to delay thermal propagation by releasing high-temperature gas inside the battery pack (100) to the outside when at least one of the plurality of battery assemblies (120) is in a thermal runway state.

[0075] Here, thermal runaway of multiple battery assemblies (120) is a state in which a temperature change of multiple battery assemblies (120) further accelerates the temperature change, which is an uncontrollable positive feedback. Multiple battery assemblies (120) in a thermal runaway state exhibit a rapid temperature rise and emit large amounts of high-pressure gas and combustion residue.

[0076] The battery pack (100) may further include electrical components. The electrical components may be placed on the housing (110). The electrical components may be placed between the side wall (112) where the exhaust devices (140) are installed and the plurality of battery assemblies (120). The electrical components may include any electronic components necessary to drive the battery pack.

[0077] Electrical components may include, for example, a Battery Management System (BMS). The BMS may be configured to perform monitoring, balancing, and control of the battery pack. Monitoring of the battery pack (100) may include measuring the voltage and current of specific nodes within a plurality of battery assemblies (120) and measuring the temperature of set locations within the battery pack (100). The battery pack (100) may include measuring instruments for measuring the voltage, current, and temperature described above.

[0078] Balancing of the battery pack (100) is an operation that reduces deviations between multiple battery assemblies (120). Control of the battery pack (100) includes preventing overcharging, over-discharging, and overcurrent. Through monitoring, balancing, and control, the battery pack (100) can operate under optimal conditions, and accordingly, the shortening of the lifespan of each of the multiple battery assemblies (120) can be prevented.

[0079] The electrical components may further include a cooling device, a PRA (Power Relay Assembly), a safety plug, etc. The cooling device may include a cooling fan. The cooling fan can prevent overheating of each of the multiple battery assemblies (120) by circulating air inside the battery pack (100). The PRA may be configured to supply or cut off power from the high-voltage battery to an external load (e.g., a vehicle motor). The PRA can protect the multiple battery assemblies (120) and the external load (e.g., a vehicle motor) by cutting off power supply to the external load (e.g., a vehicle motor) in situations where abnormal voltage occurs, such as a voltage surge.

[0080] The battery pack (100) may further include a plurality of busbars configured to electrically connect a plurality of battery assemblies (120). The plurality of battery assemblies (120) may be connected in series by the plurality of busbars. Accordingly, the battery pack (100) may be configured to output a high voltage to an external load (e.g., a motor of a vehicle).

[0081] The battery pack (100) may further include lead plates coupled to the side walls (112). The lead plates may cover elements placed inside the battery pack (100), such as battery assemblies (120) and electrical components. The lead plates may be secured to the battery pack (100) by mechanical coupling means, such as bolts.

[0083] (2nd Example)

[0084] FIG. 7 shows a part corresponding to FIG. 2. Accordingly, the cross beam assembly (CBAa) shown in FIG. 7 can replace the cross beam assembly (CBA) of FIG. 2.

[0085] Referring to FIG. 7, the cross beam assembly (CBAa) may not include thermal insulation. Accordingly, there may be an air gap (AG) between the first cross beam (125a) and the second cross beam (125b), and the cross beam assembly (CBAa) may be lightweight. Additionally, the air gap (AG) between the first cross beam (125a) and the second cross beam (125b) may function as thermal insulation.

[0087] (3rd Example)

[0088] FIG. 8 shows a part corresponding to FIG. 2. Accordingly, the cross beam assembly (CBAb) shown in FIG. 8 can replace the cross beam assembly (CBA) of FIG. 2.

[0089] Referring to FIGS. 3, 5, and 8, the insulation material (151) of the cross beam assembly (CBAb) may have a smaller size than the insulation material (150) of FIG. 2. Accordingly, there may be an air gap (AG) between the first cross beam (125a) and the second cross beam (125b), and the cross beam assembly (CBAb) may be made lighter.

[0090] More specifically, the insulation material (151) may be in contact with the ribs (R2a, R1b). The insulation material (151) may be spaced apart from some of the plates (P1a, P2a, P1b, P2b). The insulation material (151) may be spaced apart from any one of the plates (P2a, P1b). Accordingly, there may be an air gap (AG) between the plates (P1a, P2a, P1b, P2b).

[0092] (Fourth Example)

[0093] FIG. 9 shows a part corresponding to FIG. 2. Accordingly, the cross beam assembly (CBAc) shown in FIG. 9 can replace the cross beam assembly (CBA) of FIG. 2.

[0094] Referring to FIGS. 3, 5, and 8, the insulating materials (152) of the cross beam assembly (CBAc) may have a smaller size than the insulating material (150) of FIG. 2. Accordingly, there may be an air gap (AG) between the first cross beam (125a) and the second cross beam (125b), and the cross beam assembly (CBAc) may be made lighter.

[0095] More specifically, the insulation materials (152) may be in contact with the plates (P1a, P2a, P1b, P2b) and spaced apart from any one of the ribs (R2a, R1b). Accordingly, there may be an air gap (AG) between the ribs (R2a, R1b).

[0097] The present invention has been described in more detail above through drawings and embodiments. However, the configurations described in the drawings or embodiments described in this specification are merely one embodiment of the present invention and do not represent all technical concepts of the present invention; therefore, it should be understood that various equivalents and modifications that can replace them may exist at the time of filing this application. Explanation of the symbols

[0098] 100: Battery pack, 110: Housing, 120: Battery assembly 130: Center beam, 140: Exhaust device, 150, 151, 152: Insulation, AG: Air gap

Claims

Claim 1 Housing including a plate portion; and comprises first and second battery assemblies disposed on the upper surface of the plate portion of the housing and including a plurality of battery cells, wherein each of the first and second battery assemblies includes a cell stack and first and second cross beams spaced apart from each other in a first direction with the cell stack in between, wherein the first cross beam of the second battery assembly is different from and has a complementary shape to the second cross beam of the first battery assembly, wherein the first cross beam of the second battery assembly faces the second cross beam of the first battery assembly, and the first cross beam of the second battery assembly is spaced apart from the second cross beam of the first battery assembly, and the first cross beam of each of the first and second battery assemblies includes a first plate covering a first side of the cell stack, a second plate spaced apart from the cell stack with the first plate in between, and first and second ribs connected to each of the first and second plates and interposed between the first and second plates, and the first and second batteries A battery pack characterized in that each of the assemblies has a second cross beam that includes a third plate covering a second side opposite to the first side of the cell stack, a fourth plate spaced apart from the cell stack with the third plate in between, and third and fourth ribs connected to each of the third and fourth plates and interposed between the third and fourth plates, wherein each of the first to fourth ribs includes a plurality of elongated holes, the length of each of the plurality of elongated holes in the first direction is greater than the length of each of the plurality of elongated holes in the second direction perpendicular to the first direction, and the plurality of elongated holes of each of the first to fourth ribs overlap in a third direction perpendicular to each of the first and second directions. Claim 2 A battery pack according to claim 1, further comprising an insulating material interposed between the first cross beam of the second battery assembly and the second cross beam of the first battery assembly. Claim 3 A battery pack according to claim 1, characterized in that there is an air gap between the first cross beam of the second battery assembly and the second cross beam of the first battery assembly. Claim 4 delete Claim 5 A battery pack according to claim 1, characterized in that the thickness of each of the first to fourth plates and the first to fourth ribs is 10 mm or less. Claim 6 delete Claim 7 delete Claim 8 A battery pack according to claim 1, wherein the first battery assembly and the second battery assembly are spaced apart from each other in the first direction. Claim 9 A battery pack according to claim 1, further comprising an insulating material interposed between the first cross beam of the second battery assembly and the second cross beam of the first battery assembly, wherein the insulating material is in contact with the first to fourth plates and the second and third ribs. Claim 10 A battery pack according to claim 9, further comprising a plurality of fixing members that fix the first cross beam of the second battery assembly and the second cross beam of the first battery assembly, wherein the plurality of fixing members penetrate the insulating material. Claim 11 A battery pack according to claim 1, further comprising an insulating material interposed between the first cross beam of the second battery assembly and the second cross beam of the first battery assembly, wherein the insulating material is in contact with the second and third plates and the insulating material is spaced apart from either of the second and third ribs. Claim 12 A battery pack according to claim 11, characterized in that there is an air gap between the first cross beam of the second battery assembly and the second cross beam of the first battery assembly. Claim 13 A battery pack according to claim 1, further comprising an insulating material interposed between the first cross beam of the second battery assembly and the second cross beam of the first battery assembly, wherein the insulating material is spaced apart from either of the second and third plates and the insulating material is in contact with the second and third ribs.

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