Flame cover and battery pack comprising same

Abstract

According to exemplary embodiments, a battery pack is provided. The battery pack may comprise: a pack housing including a bottom portion; first and second battery cell assemblies on the bottom portion; and a flame cover on the first and second battery assemblies. Each of the first and second battery cell assemblies may include a plurality of battery cells arranged in a first direction parallel to the bottom portion. The flame cover may include a plate and a fire-resistant film on the plate. The plate may comprise: a first plate portion overlapping the first battery cell assembly in the vertical direction and including a plurality of first venting holes; a second plate portion overlapping the second battery cell assembly in the vertical direction and including a plurality of second venting holes; and bridges connecting the first plate portion and the second plate portion. The fire-resistant film may overlap each of the plurality of first venting holes and the plurality of second venting holes in the vertical direction.

Description

Flame cover and battery pack including the same

[0001] The present invention relates to a flame cover and a battery pack including the same. The present application claims the benefit of Korean application No. 10-2024-0158779, filed on November 11, 2024, which is incorporated herein by reference in its entirety.

[0002]

[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 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.

[0004] 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.

[0005] One of the powerful solutions for increasing the energy density of secondary batteries is the modular type battery pack (or cell-to-pack structure). Since the modules covering the battery cells are omitted in the modular type battery pack, the mass of the battery pack can be drastically reduced. The safety of secondary batteries is critical as it is directly linked to the lives of mobility users. A major challenge for improving secondary batteries is to provide solutions to prevent thermal propagation and thermal runaway in the battery pack.

[0006]

[0007] The problem that the technical concept of the present invention aims to solve is to provide a battery pack with improved safety.

[0008]

[0009] According to exemplary embodiments of the present invention for solving the above-described problem, a battery pack is provided. The battery pack may include a pack housing including a bottom portion; first and second battery cell assemblies on the bottom portion; and a flame cover on the first and second battery assemblies. Each of the first and second battery cell assemblies may include a plurality of battery cells arranged in a first direction parallel to the bottom portion. The flame cover may include a plate and a fire-resistant film on the plate. The plate may include a first plate portion that overlaps in a vertical direction with the first battery cell assembly and includes a plurality of first venting holes; a second plate portion that overlaps in a vertical direction with the second battery cell assembly and includes a plurality of second venting holes; and bridges connecting the first plate portion and the second plate portion. The fire-resistant film may overlap in a vertical direction with each of the plurality of first venting holes and the plurality of second venting holes.

[0010] The above plate may further include a first slit defined by the first plate portion, the second plate portion, and the bridges.

[0011] The length of each of the plurality of first venting holes in the first direction may be different from the length of the first slit in the first direction. The length of each of the plurality of second venting holes in the first direction may be different from the length of the first slit in the first direction.

[0012] The length of each of the plurality of first venting holes in the first direction may be greater than the length of the first slit in the first direction. The length of each of the plurality of second venting holes in the first direction may be greater than the length of the first slit in the first direction.

[0013] The length in a second direction parallel to the bottom portion and perpendicular to the first direction of each of the plurality of first venting holes may differ from the length of the first slit in the second direction. The length in the second direction of each of the plurality of second venting holes may differ from the length of the first slit in the second direction.

[0014] The length of each of the plurality of first venting holes in the second direction may be smaller than the length of the first slit in the second direction. The length of each of the plurality of second venting holes in the second direction may be smaller than the length of the first slit in the second direction.

[0015] The above fire-resistant film may include a second slit that overlaps in a vertical direction with the first slit of the plate.

[0016] The above pack housing may further include a cross beam between the first battery cell assembly and the second battery cell assembly. The first slit of the plate may overlap with the cross beam in a direction perpendicular to it.

[0017] It may further include bolts that pass through the first slit and fasten the flame cover to the cross beam.

[0018] Each of the plurality of first venting holes may overlap in a vertical direction with a corresponding one of the plurality of battery cells of the first battery cell assembly. Each of the plurality of second venting holes may overlap in a vertical direction with a corresponding one of the plurality of battery cells of the second battery cell assembly.

[0019] The plurality of first venting holes can be arranged in a matrix. The plurality of second venting holes can be arranged in a matrix.

[0020] According to exemplary embodiments of the present invention for solving the above-described problem, a battery pack is provided. The battery pack may include: a pack housing on which first and second battery cell assemblies are mounted; and a flame cover on the first and second battery assemblies. The flame cover may include: a first plate portion that overlaps in a vertical direction with the first battery cell assembly and includes a plurality of first venting holes; a second plate portion that overlaps in a vertical direction with the second battery cell assembly and includes a plurality of second venting holes; a plate including a first slit between the first plate portion and the second plate portion; and a fire-resistant film on the plate.

[0021] The above fire-resistant film may include a second slit that overlaps in a vertical direction with the first slit.

[0022] The above fire-resistant film can be overlapped in a vertical direction with the plurality of first venting holes and the plurality of second venting holes.

[0023] The above plate may further include bridges connecting the first plate and the second plate.

[0024]

[0025] According to exemplary embodiments of the present invention, a flame cover overlapping with a plurality of battery cell assemblies may be provided. Accordingly, heat propagation and thermal runaway of the battery pack can be prevented, and the manufacturing process of the battery pack can be simplified.

[0026] 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.

[0027]

[0028] FIG. 1 is a top view showing a battery pack according to exemplary embodiments.

[0029] FIG. 2 is an exploded perspective view showing battery cell assemblies and a flame cover according to exemplary embodiments.

[0030] FIG. 3 is a cross-sectional view of a battery pack according to exemplary embodiments.

[0031] FIG. 4 is a top view showing a plate of a flame cover according to exemplary embodiments.

[0032] FIG. 5 is a top view showing a flame cover according to exemplary embodiments.

[0033] FIG. 6 is a top view showing a plate of a flame cover according to exemplary embodiments.

[0034] FIG. 7 is a cross-sectional view showing a battery pack according to exemplary embodiments.

[0035]

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040]

[0041] (1st and 2nd embodiments)

[0042] FIG. 1 is a top view showing a battery pack (100) according to exemplary embodiments.

[0043] FIG. 2 is an exploded perspective view showing battery cell assemblies (120A1, 120A2, 120A3) and a flame cover (151) according to exemplary embodiments. FIG. 3 is a cross-sectional view of a battery pack (100) according to exemplary embodiments. FIG. 3 shows a cross-section along P-P' of FIG. 1.

[0044] FIGS. 4 and FIGS. 5 are top views showing a flame cover (151) according to exemplary embodiments. FIG. 4 shows a plate (131) of the flame cover (151). FIG. 5 shows a plate (131) and a fire-resistant film (141) of the flame cover (151).

[0045] FIGS. 6 and 7 illustrate a battery pack (100) in the event of an ignition event. FIG. 6 is a top view showing the plate (131) of the flame cover (151). FIG. 7 is a cross-sectional view of the battery pack (100). In FIGS. 6 and 7, arrows without drawing numbers indicate heat transfer paths.

[0046]

[0047] Referring to FIGS. 1 to 5, the battery pack (100) may include a pack housing (110), battery cell assemblies (120A1, 120A2, 120A3), and a flame cover (151).

[0048] The pack housing (110) may provide a space for arranging a plurality of battery cell assemblies (120A1, 120A2, 120A3). The pack housing (110) may include a bottom portion (111), a center beam (112), cross beams (113), and side walls (114).

[0049] Two directions substantially parallel to the mounting surface of the bottom portion (111) are defined as the X direction and the Y direction, and a direction substantially perpendicular to the mounting surface of the bottom 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 one another. Unless otherwise noted, the definitions of directions are the same for the following drawings.

[0050] Battery cell assemblies (120A1, 120A2, 120A3) can be placed on a bottom portion (111). The bottom portion (111) can support the battery cell assemblies (120A1, 120A2, 120A3) from below in the Z direction. The battery cell assemblies (120A1, 120A2, 120A3) can be separated from each other by a center beam (112) and cross beams (113). The battery cell assemblies (120A1, 120A2, 120A3) can be separated from each other in the Y direction by the center beam (112). The battery cell assemblies (120A1, 120A2, 120A3) can be separated from each other in the X direction by the cross beams (113).

[0051] The center beam (112) may extend in the X direction. The center beam (112) may be located at the center of the bottom portion (111). The cross beams (113) may extend in the Y direction. Each of the cross beams (113) may intersect the center beam (112) in the Y direction.

[0052] Battery cell assemblies (120A1, 120A2, 120A3) may each include a plurality of battery cells arranged in the X direction. A battery cell assembly (120A1) may include a plurality of battery cells (120CL1) arranged in the X direction. A battery cell assembly (120A2) may include a plurality of battery cells (120CL2) arranged in the X direction. A battery cell assembly (120A3) may include a plurality of battery cells (120CL3) arranged in the X direction.

[0053] In this example, the battery cell assemblies (120A1, 120A2, 120A3) are arranged in 3 rows and 2 columns. Accordingly, the battery cell assemblies (120A1, 120A2, 120A3) can be said to be arranged in a 3 * 2 configuration. A person skilled in the art would be able to easily arrive at a battery pack comprising battery cell assemblies (120A1, 120A2, 120A3) arranged in an M * N configuration based on what is described herein. Here, M and N are each any integer greater than or equal to 2.

[0054] The side walls (114) can horizontally surround the battery cell assemblies (120A1, 120A2, 120A3), the center beam (112), and the cross beams (113). Each of the side walls (114) can be perpendicular to the bottom portion (111). Each of the side walls (114) can be located on the edge of the bottom portion (111).

[0055]

[0056] The flame cover (151) may be located on the upper side of the battery cell assemblies (120A1, 120A2, 120A3) in the Z direction. The flame cover (151) may overlap with the battery cell assemblies (120A1, 120A2, 120A3) in the Z direction.

[0057] The flame cover (151) may include a plate (131) and a fire-resistant film (141). The fire-resistant film (141) may be located on the upper side of the plate (131) in the Z direction. The flame cover (151) may be positioned so that the plate (131) faces a plurality of battery cell assemblies (120A1, 120A2, 120A3).

[0058] The plate (131) may include a first plate portion (131A), a second plate portion (131B), and a third plate portion (131C). The first plate portion (131A) may overlap with the battery cell assembly (120A1) in the Z direction. The second plate portion (131B) may overlap with the battery cell assembly (120A2) in the Z direction. The third plate portion (131C) may overlap with the battery cell assembly (120A3) in the Z direction.

[0059] The first plate portion (131A) may include a plurality of venting holes (131AH1, 131AH2, 131AH3). The plurality of venting holes (131AH1, 131AH2, 131AH3) may overlap with the battery cell assembly (120A1) in the Z direction. The plurality of venting holes (131AH1) may be arranged in the X direction. The plurality of venting holes (131AH2) may be arranged in the X direction. The plurality of venting holes (131AH3) may be arranged in the X direction. Each of the plurality of venting holes (131AH1) may be spaced apart from each of the plurality of venting holes (131AH2) in the Y direction. Each of the plurality of venting holes (131AH2) may be spaced apart from each of the plurality of venting holes (131AH3) in the Y direction. Each of the plurality of venting holes (131AH1) can be aligned in the Y direction with a corresponding one of the plurality of venting holes (131AH2) and a corresponding one of the plurality of venting holes (131AH3). Each of the plurality of venting holes (131AH1, 131AH2, 131AH3) can be overlapped in the Z direction with a corresponding one of the battery cells (120CL1) of the battery cell assembly (120A1). Each of the battery cells (120CL1) of the battery cell assembly (120A1) can be overlapped in the Z direction with a corresponding one of the plurality of venting holes (131AH1), a corresponding one of the plurality of venting holes (131AH2), and a corresponding one of the plurality of venting holes (131AH3).

[0060] The second plate portion (131B) may include a plurality of venting holes (131BH1, 131BH2, 131BH3). The plurality of venting holes (131BH1, 131BH2, 131BH3) may overlap with the battery cell assembly (120A2) in the Z direction. The plurality of venting holes (131BH1) may be arranged in the X direction. The plurality of venting holes (131BH2) may be arranged in the X direction. The plurality of venting holes (131BH3) may be arranged in the X direction. Each of the plurality of venting holes (131BH1) may be spaced apart from each of the plurality of venting holes (131BH2) in the Y direction. Each of the plurality of venting holes (131BH2) may be spaced apart from each of the plurality of venting holes (131BH3) in the Y direction. Each of the plurality of venting holes (131BH1) can be aligned in the Y direction with a corresponding one of the plurality of venting holes (131BH2) and a corresponding one of the plurality of venting holes (131BH3). Each of the plurality of venting holes (131BH1, 131BH2, 131BH3) can be overlapped in the Z direction with a corresponding one of the battery cells (120CL2) of the battery cell assembly (120A2). Each of the battery cells (120CL2) of the battery cell assembly (120A2) can be overlapped in the Z direction with a corresponding one of the plurality of venting holes (131BH1), a corresponding one of the plurality of venting holes (131BH2), and a corresponding one of the plurality of venting holes (131BH3).

[0061] The third plate portion (131C) may include a plurality of venting holes (131CH1, 131CH2, 131CH3). The plurality of venting holes (131CH1, 131CH2, 131CH3) may overlap with the battery cell assembly (120A3) in the Z direction. The plurality of venting holes (131CH1) may be arranged in the X direction. The plurality of venting holes (131CH2) may be arranged in the X direction. The plurality of venting holes (131CH3) may be arranged in the X direction. Each of the plurality of venting holes (131CH1) may be spaced apart from each of the plurality of venting holes (131CH2) in the Y direction. Each of the plurality of venting holes (131CH2) may be spaced apart from each of the plurality of venting holes (131CH3) in the Y direction. Each of the plurality of venting holes (131CH1) can be aligned in the Y direction with a corresponding one of the plurality of venting holes (131CH2) and a corresponding one of the plurality of venting holes (131CH3). Each of the plurality of venting holes (131CH1, 131CH2, 131CH3) can be overlapped in the Z direction with a corresponding one of the battery cells (120CL3) of the battery cell assembly (120A3). Each of the battery cells (120CL3) of the battery cell assembly (120A3) can be overlapped in the Z direction with a corresponding one of the plurality of venting holes (131CH1), a corresponding one of the plurality of venting holes (131CH2), and a corresponding one of the plurality of venting holes (131CH3).

[0062]

[0063] In this example, the plurality of venting holes (131AH1, 131AH2, 131AH3) of the first plate section (131A), the plurality of venting holes (131BH1, 131BH2, 131BH3) of the second plate section (131B), and the plurality of venting holes (131CH1, 131CH2, 131CH3) of the third plate section (131C) are each arranged in 3 rows and 8 columns. However, the number, arrangement, and shape of the plurality of venting holes (131AH1, 131AH2, 131AH3) of the first plate portion (131A), the plurality of venting holes (131BH1, 131BH2, 131BH3) of the second plate portion (131B), and the plurality of venting holes (131CH1, 131CH2, 131CH3) of the third plate portion (131C) are not limited to those described above.

[0064] According to exemplary embodiments, each battery cell (120CL1) of the battery cell assembly (120A1) may overlap in the Z direction with at least two of the plurality of venting holes (131AH1) of the first plate portion (131A), at least two of the plurality of venting holes (131AH2) of the first plate portion (131A), and at least two of the plurality of venting holes (131AH3) of the first plate portion (131A). According to exemplary embodiments, each battery cell (120CL2) of the battery cell assembly (120A2) may overlap in the Z direction with at least two of the plurality of venting holes (131BH1) of the first plate portion (131B), at least two of the plurality of venting holes (131BH2) of the first plate portion (131B), and at least two of the plurality of venting holes (131BH3) of the first plate portion (131B). According to exemplary embodiments, each battery cell of the battery cell assembly (120A3) may overlap in the Z direction with two or more of the plurality of venting holes (131CH1) of the first plate portion (131C), two or more of the plurality of venting holes (131CH2) of the first plate portion (131C), and two or more of the plurality of venting holes (131CH3) of the first plate portion (131C).

[0065] According to exemplary embodiments, each of the plurality of venting holes (131AH1, 131AH2, 131AH3) of the first plate portion (131A) may overlap in the Z direction with two or more battery cells (120CL1) of the battery cell assembly (120A1). According to exemplary embodiments, each of the plurality of venting holes (131BH1, 131BH2, 131BH3) of the second plate portion (131B) may overlap in the Z direction with two or more battery cells (120CL2) of the battery cell assembly (120A2). According to exemplary embodiments, each of the plurality of venting holes (131CH1, 131CH2, 131CH3) of the third plate portion (131C) may overlap with two or more battery cells (120CL3) of the battery cell assembly (120A3) in the Z direction.

[0066] According to exemplary embodiments, each of the plurality of venting holes (131AH1), plurality of venting holes (131AH2), and plurality of venting holes (131AH3) of the first plate portion (131A) may be arranged in a zigzag pattern in the X direction. According to exemplary embodiments, each of the plurality of venting holes (131BH1), plurality of venting holes (131BH2), and plurality of venting holes (131BH3) of the second plate portion (131B) may be arranged in a zigzag pattern in the X direction. According to exemplary embodiments, each of the plurality of venting holes (131CH1), plurality of venting holes (131CH2), and plurality of venting holes (131CH3) of the third plate portion (131C) may be arranged in a zigzag pattern in the X direction. According to exemplary embodiments, each of the plurality of venting holes (131AH1), each of the plurality of venting holes (131AH2), and each of the plurality of venting holes (131AH3) may not be aligned with each other in the Y direction. According to exemplary embodiments, each of the plurality of venting holes (131BH1), each of the plurality of venting holes (131BH2), and each of the plurality of venting holes (131BH3) may not be aligned with each other in the Y direction. According to exemplary embodiments, each of the plurality of venting holes (131CH1), each of the plurality of venting holes (131CH2), and each of the plurality of venting holes (131CH3) may not be aligned with each other in the Y direction.

[0067]

[0068] The plate (131) may have an integrated structure including a first plate portion (131A), a second plate portion (131B), and a third plate portion (131C). The first plate portion (131A) may be connected to the second plate portion (131B). The second plate portion (131B) may be connected to the third plate portion (131C).

[0069] The first plate portion (131A) and the second plate portion (131B) may be connected by bridges (131CN1, 131CN2). The bridges (131CN1, 131CN2) may be spaced apart from each other in the Y direction. The first plate portion (131A), the second plate portion (131B), and the bridges (131CN1, 131CN2) may define a slit (131SL1). The slit (131SL1) may extend in the Y direction between a plurality of venting holes (131AH1, 131AH2, 131AH3) of the first plate (131A) and a plurality of venting holes (131BH1, 131BH2, 131BH3) of the second plate (131B).

[0070] The second plate portion (131B) and the third plate portion (131C) may be connected by bridges (131CN3, 131CN4). The bridges (131CN2, 131CN3) may be spaced apart from each other in the Y direction. The second plate portion (131B), the third plate portion (131C), and the bridges (131CN2, 131CN3) may define a slit (131SL2). The slit (131SL2) may extend in the Y direction between a plurality of venting holes (131BH1, 131BH2, 131BH3) of the second plate (131B) and a plurality of venting holes (131CH1, 131CH2, 131CH3) of the third plate (131C).

[0071]

[0072] The plate (131) may include a plurality of horizontal ribs and vertical ribs. The first plate portion (131A) may include a plurality of horizontal ribs (131HFA1, 131HFA2). Each of the plurality of horizontal ribs (131HFA1, 131HFA2) may extend in the X direction. The first plate portion (131A) may include a plurality of vertical ribs (131VFA). Each of the plurality of vertical ribs (131VFA) may extend in the Y direction. The plurality of horizontal ribs (131HFA1, 131HFA2) may intersect with the plurality of vertical ribs (131VFA). Each of the multiple venting holes (131AH1, 131AH2, 131AH3) can be defined by adjacent horizontal ribs (131HFA1, 131HFA2) and adjacent vertical ribs (131VFA).

[0073] The second plate portion (131B) may include a plurality of horizontal ribs (131HFB1, 131HFB2). Each of the plurality of horizontal ribs (131HFB1, 131HFB2) may extend in the X direction. The second plate portion (131B) may include a plurality of vertical ribs (131VFB). Each of the plurality of vertical ribs (131VFB) may extend in the Y direction. The plurality of horizontal ribs (131HFB1, 131HFB2) may intersect with the plurality of vertical ribs (131VFB). Each of the plurality of venting holes (131BH1, 131BH2, 131BH3) may be defined by adjacent horizontal ribs (131HFB1, 131HFB2) and adjacent vertical ribs (131VFB).

[0074] The third plate portion (131C) may include a plurality of horizontal ribs (131HFC1, 131HFC2). Each of the plurality of horizontal ribs (131HFC1, 131HFC2) may extend in the X direction. The third plate portion (131C) may include a plurality of vertical ribs (131VFC). Each of the plurality of vertical ribs (131VFC) may extend in the Y direction. The plurality of horizontal ribs (131HFC1, 131HFC2) may intersect with the plurality of vertical ribs (131VFC). Each of the plurality of venting holes (131CH1, 131CH2, 131CH3) may be defined by adjacent horizontal ribs (131HFC1, 131HFC2) and adjacent vertical ribs (131VFC).

[0075] Each of the horizontal ribs (131HFA1) of the first plate (131A) can be connected to each of the horizontal ribs (131HFB1) of the second plate (131B) by bridges (131CN1, 131CN2). Each of the horizontal ribs (131HFB1) of the second plate (131B) can be connected to each of the horizontal ribs (131HFC1) of the third plate (131C) by bridges (131CN3, 131CN4).

[0076] Each of the horizontal ribs (131HFA2) of the first plate (131A) can be spaced apart from each of the horizontal ribs (131HFB2) of the second plate (131B) in the X direction by the first slit (131SL1). Each of the horizontal ribs (131HFB2) of the second plate (131B) can be spaced apart from each of the horizontal ribs (131HFC2) of the third plate (131C) in the X direction by the first slit (131SL2).

[0077]

[0078] The fire-resistant film (141) may be positioned on the plate (131) in the Z direction. The fire-resistant film (141) may overlap with the first plate section (131A), the second plate section (131B), and the third plate section (131C) in the Z direction. The fire-resistant film (141) may overlap with the venting holes (131AH1, 131AH2, 131AH3) of the first plate section (131A) in the Z direction. The fire-resistant film (141) may overlap with the venting holes (131BH1, 131BH2, 131BH3) of the second plate section (131B) in the Z direction. The fire-resistant film (141) may overlap with the venting holes (131CH1, 131CH2, 131CH3) of the third plate section (131C) in the Z direction.

[0079] The fire-resistant film (141) may include slits (141SL1, 141SL2). The slit (141SL1) of the fire-resistant film (141) may overlap with the slit (131SL1) of the plate (131) in the Z direction. The slit (141SL2) of the fire-resistant film (141) may overlap with the slit (131SL2) of the plate (131) in the Z direction. The slit (131SL1) of the plate (131) and the slit (141SL1) of the fire-resistant film (141) may form the slit (151SL1) of the flame cover (151). The slit (131SL2) of the plate (131) and the slit (141SL2) of the fire-resistant film (141) may form the slit (151SL2) of the flame cover (151).

[0080] When an ignition event occurs in one of the battery cell assemblies (120A1, 120A2, 120A3) overlapping with the fire-resistant film (141), the fire-resistant film (141) may be configured to rupture. When the pressure in the receiving space of each of the battery cell assemblies (120A1, 120A2, 120A3) overlapping with the fire-resistant film (141) becomes greater than a reference pressure, the fire-resistant film (141) may be configured to rupture.

[0081] For example, referring together with FIG. 7, if a fire event occurs in one of the battery cells (120CL1) of the battery cell assembly (120A1), the pressure in the receiving space of the battery cell assembly (120A1) within the pack housing (110) may increase. The increased pressure in the receiving space of the battery cell assembly (120A1) may apply pressure to the fire-resistant film (141) through a plurality of venting holes (131AH1, 131AH2, 131AH3) of the plate (131). When the pressure in the receiving space of the battery cell assembly (120A1) exceeds a reference pressure, the fire-resistant film (141) may be configured to rupture. Heat, gas, and discharge generated from the ignited battery cell can move to the upper part of the flame cover (151) through a plurality of venting holes (131AH1, 131AH2, 131AH3) and a ruptured portion of the fire-resistant film (141). The heat, gas, and discharge moved to the upper part of the flame cover (151) can be discharged to the outside of the battery pack (100) through venting holes provided in the side walls (114) of the pack housing (110). This prevents heat propagation from the battery cell assembly (120A1) to the adjacent battery cell assembly (120A2).

[0082] However, the shape of the fire-resistant film (141) is not limited to that described above. According to exemplary embodiments, the battery pack (100) may include a plurality of fire-resistant films spaced apart in the X direction. For example, the battery pack (100) may include a first fire-resistant film overlapping with the first plate portion (131A) in the Z direction, a second fire-resistant film overlapping with the second plate portion (131B), and a third fire-resistant film overlapping with the third plate portion (131C). The first fire-resistant film, the second fire-resistant film, and the third fire-resistant film may be spaced apart from each other in the X direction. According to exemplary embodiments, the battery pack (100) may include a number of fire-resistant films equal to the number of battery cell assemblies (120A1, 120A2, 120A3).

[0083]

[0084] The flame cover (151) may be attached to the pack housing (110). According to exemplary embodiments, each flame cover (151) may be bolted to the cross beams (113). As illustrated in FIGS. 1 and 3, the flame cover (151) may be fastened to each cross beam (113) by bolts (170). The bolts (170) may overlap the slit (151SL1) of the flame cover (151) in the Z direction. The bolts (170) may overlap the slit (151SL2) of the flame cover (151) in the Z direction. However, the method of attaching the flame cover (151) is not limited thereto. According to exemplary embodiments, the flame cover (151) may be attached to the center beam (112).

[0085]

[0086] A flame cover (151) according to exemplary embodiments of the present invention can prevent heat propagation to adjacent battery cell assemblies when a fire event occurs in one of the plurality of battery cell assemblies (120A1, 120A2, 120A3).

[0087] Referring to FIGS. 6 and FIGS. 7 together, if a fire event occurs in the battery cell assembly (120A1), heat generated from the battery cell assembly (120A1) can be conducted to the first plate portion (131A). Heat generated from the battery cell assembly (120A1) can be conducted through the horizontal ribs (131HFA1, 131HFA2). A plurality of venting holes (131AH1, 131AH2, 131AH3) can delay heat conduction within the first plate portion (131A). Heat conducted through the horizontal ribs (131HFA1, 131HFA2) can be blocked by the slit (131SL1). The direction of heat conduction can be diverted to the vertical rib (131VHA) adjacent to the slit (131SL1). By doing so, heat conduction from the first plate portion (131A) to the second plate portion (131B) can be prevented or delayed.

[0088] In addition, the flame cover (151) according to exemplary embodiments of the present invention covers a plurality of battery cell assemblies (120A1, 120A2, 120A3) simultaneously, thereby reducing the number of parts required in the assembly process of the battery pack (100) and simplifying the work process. In contrast, in the case of a battery pack including a plurality of flame covers that cover each battery cell assembly one by one, each flame cover must be assembled onto each battery cell assembly, so the number of parts and the number of operations used in the assembly process increase. A flame cover (151) according to exemplary embodiments of the present invention can simultaneously cover a plurality of battery cell assemblies (120A1, 120A2, 120A3) and, by providing slits (151SL1, 151SL2) between adjacent plurality of battery cell assemblies (120A1, 120A2, 120A3), prevent heat propagation and thermal runaway between battery cell assemblies through the flame cover (151), while simplifying the assembly process of a battery pack (100).

[0089]

[0090] 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.

Claims

1. Pack housing including a bottom portion; First and second battery cell assemblies on the bottom portion above; and The above first and second battery assemblies include a flame cover; and Each of the first and second battery cell assemblies comprises a plurality of battery cells arranged in a first direction parallel to the bottom portion, and The flame cover above comprises a plate and a fire-resistant film on the plate, and The above plate comprises: a first plate portion that overlaps the first battery cell assembly in a vertical direction and includes a plurality of first venting holes; a second plate portion that overlaps the second battery cell assembly in a vertical direction and includes a plurality of second venting holes; and bridges connecting the first plate portion and the second plate portion. A battery pack characterized in that the fire-resistant film is superimposed in a vertical direction with each of the plurality of first venting holes and the plurality of second venting holes.

2. In Paragraph 1, A battery pack characterized in that the above plate further comprises a first plate portion, a second plate portion, and a first slit defined by the bridges.

3. In Paragraph 2, The length of each of the plurality of first venting holes in the first direction is different from the length of the first slit in the first direction, and A battery pack characterized in that the length of each of the plurality of second venting holes in the first direction is different from the length of the first slit in the first direction.

4. In Paragraph 3, The length of each of the plurality of first venting holes in the first direction is greater than the length of the first slit in the first direction, and A battery pack characterized in that the length of each of the plurality of second venting holes in the first direction is greater than the length of the first slit in the first direction.

5. In Paragraph 2, The length in the second direction parallel to the bottom portion of each of the plurality of first venting holes and perpendicular to the first direction is different from the length of the first slit in the second direction, and A battery pack characterized in that the length of each of the plurality of second venting holes in the second direction is different from the length of the first slit in the second direction.

6. In Paragraph 5, The length of each of the plurality of first venting holes in the second direction is smaller than the length of the first slit in the second direction, and A battery pack characterized in that the length of each of the plurality of second venting holes in the second direction is smaller than the length of the first slit in the second direction.

7. In Paragraph 2, A battery pack characterized in that the above-mentioned fire-resistant film includes a second slit that overlaps in a vertical direction with the first slit of the plate.

8. In Paragraph 2, The above pack housing further includes a cross beam between the first battery cell assembly and the second battery cell assembly, and A battery pack characterized in that the first slit of the above plate overlaps with the cross beam in a vertical direction.

9. In Paragraph 8, A battery pack characterized by further including bolts that pass through the first slit to fasten the flame cover to the cross beam.

10. In Paragraph 1, Each of the plurality of first venting holes overlaps in a vertical direction with a corresponding one of the plurality of battery cells of the first battery cell assembly, and A battery pack characterized in that each of the plurality of second venting holes overlaps in a vertical direction with a corresponding one of the plurality of battery cells of the second battery cell assembly.

11. In Paragraph 1, The above plurality of first venting holes are arranged in a matrix, and A battery pack characterized in that the plurality of second venting holes are arranged in a matrix.

12. A pack housing on which the first and second battery cell assemblies are mounted; and Flame covers on the first and second battery assemblies; including, The flame cover above is, A first plate portion that overlaps in a vertical direction with the first battery cell assembly and includes a plurality of first venting holes; a second plate portion that overlaps in a vertical direction with the second battery cell assembly and includes a plurality of second venting holes; and a plate including a first slit between the first plate portion and the second plate portion; and A battery pack comprising a fire-resistant film on the above plate.

13. In Paragraph 12, A battery pack characterized in that the above-mentioned fire-resistant film includes a second slit that overlaps in a vertical direction with the first slit.

14. In Paragraph 12, A battery pack characterized in that the fire-resistant film is superimposed in a vertical direction with the plurality of first venting holes and the plurality of second venting holes.

15. In Paragraph 12, A battery pack characterized in that the above plate further includes bridges connecting the first plate portion and the second plate portion.

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