Battery pack

Abstract

According to exemplary embodiments, a battery pack is provided. The battery pack comprises: a pack housing; a battery cell assembly; an upper cover; and a fireproof sheet which is interposed between the upper cover and the battery cell assembly, and which includes a plurality of open guides overlapping the plurality of exhaust holes, wherein each of the plurality of open guides includes first to third dashed lines spaced apart from each other in a first direction, each of the first to third dashed lines extending in a second direction perpendicular to the first direction, and the first dashed line being different from second and third dashed lines.

Description

battery pack

[0001] The present invention relates to a battery pack. This application claims the benefit of Korean Application No. 10-2024-0001053, filed January 3, 2024, which is incorporated herein by reference in its entirety.

[0002] Unlike primary batteries, secondary batteries can be charged and discharged multiple times. They are widely used as a power source for various wireless devices, including handsets, laptops, and cordless vacuum cleaners. Recently, improved energy density and economies of scale have dramatically reduced the per-unit manufacturing cost of secondary batteries. Furthermore, as the range of battery electric vehicles (BEVs) has increased to match that of fuel-powered vehicles, the primary use of secondary batteries is shifting from mobile devices to mobility.

[0003] In the current trend emphasizing secondary batteries for mobility, the primary direction of secondary battery technology development is to reduce production costs and enhance safety. Secondary batteries account for the largest portion of BEV manufacturing costs. Therefore, the most crucial factor in increasing the market share of BEVs compared to internal combustion engine vehicles is secondary battery production costs. Reducing production costs can be achieved by reducing raw materials, reducing the number of steps in the production process, and shortening takt time. The safety of secondary batteries is crucial, as they directly impact the lives of vehicle occupants. A key challenge in enhancing secondary battery safety is delaying heat propagation in the event of a thermal runaway event.

[0004] The technical idea of ​​the present invention aims to solve a problem by providing a battery pack with improved safety.

[0005] According to exemplary embodiments of the present invention for solving the above-described problem, a battery pack is provided. The battery pack includes a pack housing including a base plate; a battery cell assembly disposed on the base plate and including a plurality of battery cells; an upper cover disposed on the battery cell assembly and including a plurality of exhaust holes; and a fireproof sheet including a plurality of open guides interposed between the upper cover and the battery cell assembly and overlapping the plurality of exhaust holes, wherein each of the plurality of open guides includes first to third dashed lines spaced apart from each other in a first direction, each of the first to third dashed lines extending in a second direction perpendicular to the first direction, and the first dashed line is different from the second and third dashed lines.

[0006] The above first broken line is interposed between the above second and third broken lines.

[0007] The first broken line includes a plurality of first line segments arranged along the second direction, the second broken line includes a plurality of second line segments arranged along the second direction, and the third broken line includes a plurality of third line segments arranged along the second direction.

[0008] The length of each of the above first line segments is different from the length of each of the above second line segments.

[0009] The length of each of the above first line segments is longer than the length of each of the above second line segments.

[0010] The length of each of the above first line segments is different from the length of each of the above third line segments.

[0011] The length of each of the above first line segments is longer than the length of each of the above third line segments.

[0012] The length of each of the second line segments is equal to the length of each of the third line segments.

[0013] Each of the plurality of open guides further includes fourth and fifth wave lines spaced apart from each other with the first to third wave lines therebetween, the fourth wave line including a plurality of fourth line segments arranged along the second direction, and the fifth wave line including a plurality of fifth line segments arranged along the second direction.

[0014] The length of each of the above fourth line segments is equal to the length of each of the above second line segments.

[0015] The length of each of the above first line segments is longer than the length of each of the above fourth line segments.

[0016] The length of each of the above fifth line segments is equal to the length of each of the above third line segments.

[0017] The length of each of the above first line segments is longer than the length of each of the above fifth line segments.

[0018] A battery pack according to exemplary embodiments of the present invention may include a refractory sheet with an improved opening guide. Accordingly, when a thermal runaway event occurs in a battery cell, the opening guide of the corresponding refractory sheet may rapidly rupture, and the heat propagation may be delayed due to the escape of gas and dust. Furthermore, when a thermal runaway event occurs, only the necessary portions of the opening guide of the refractory sheet may be opened in a limited manner, thereby preventing the thermal runaway event from spreading to battery cells where the thermal runaway event has not occurred.

[0019] The effects that can be obtained from the exemplary embodiments of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly derived and understood by those skilled in the art to which the exemplary embodiments of the present disclosure pertain from the following description. In other words, unintended effects resulting from practicing the exemplary embodiments of the present disclosure can also be derived by those skilled in the art from the exemplary embodiments of the present disclosure.

[0020] FIG. 1 is a plan view illustrating a battery pack according to exemplary embodiments.

[0021] FIG. 2 is a plan view illustrating a battery pack according to exemplary embodiments.

[0022] Figure 3 is an enlarged partial plan view of a portion of Figure 1.

[0023] Fig. 4 is a cross-sectional view taken along the cutting line 1I-1I' of Fig. 1.

[0024] FIG. 5 is a plan view illustrating a battery pack according to exemplary embodiments.

[0025] Figure 6 is an enlarged partial plan view of a portion of Figure 5.

[0026] Figure 7 is a cross-sectional view taken along the cutting line 5I-5I' of Figure 5.

[0027] FIG. 8 is a plan view illustrating a battery pack according to exemplary embodiments.

[0028] Figure 9 is an enlarged partial plan view of a portion of Figure 8.

[0029] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, it should be noted that the terms and words used in this specification and claims should not be construed as limited to their conventional or dictionary meanings. Based on the principle that the inventor can appropriately define the concepts of terms to best explain his or her invention, they should be interpreted in a way that aligns with the technical spirit of the present invention.

[0030] Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0031] In addition, when describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description is omitted.

[0032] Since the embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art, the shapes and sizes of components in the drawings may be exaggerated, omitted, or schematically illustrated for clearer explanation. Accordingly, the sizes and proportions of each component do not fully reflect the actual sizes or proportions.

[0033]

[0034] (Example 1)

[0035] FIG. 1 is a plan view illustrating a battery pack (100) according to exemplary embodiments. For a more complete understanding of the arrangement between elements of the battery pack (100), leads (150, see FIG. 4) are omitted in FIG. 1.

[0036] Fig. 2 is a plan view for explaining the battery pack (100) of Fig. 1. Compared to Fig. 1, the refractory sheet (130) and the upper cover (140) are omitted in Fig. 2.

[0037] Figure 3 is an enlarged partial plan view of a portion (PO1) of Figure 1.

[0038] Fig. 4 is a cross-sectional view taken along the cutting line 1I-1I' of Fig. 1.

[0039] Referring to FIGS. 1 to 4, a battery pack (100) may include a housing (110), a plurality of battery cell assemblies (120_1, 120_2, 120_3, 120_4, 120_5, 120_6, hereinafter referred to as 120_1 to 120_6), refractory sheets (130), upper covers (140), and a lid (150). The battery pack (100) is the final form of a battery system mounted on mobility, etc.

[0040] The housing (110) may provide a space for arranging a plurality of battery cell assemblies (120_1 to 120_6). The housing (110) may include a base plate (111), side walls (112, 113, 114, 115), and a center beam (116).

[0041] Two directions substantially parallel to the mounting surface (111M) of the base plate (111) are defined as the X direction and the Y direction, and a direction substantially perpendicular to the mounting surface (111M) of the base plate (111) is defined as the Z direction. Each of the X direction, the Y direction, and the Z direction can be substantially perpendicular to each other. Unless otherwise stated, the definitions of directions are the same for the drawings below.

[0042] The base plate (111) and the side walls (112, 113) may each be provided by an extrusion process. The extrusion direction of the base plate (111) and the side walls (112, 113) may be the X direction. The base plate (111) and the side walls (112, 113) may be arranged in the Y direction. The side walls (114, 115) may also be provided by an extrusion process.

[0043] According to exemplary embodiments, the base plate (111) and side walls (112, 113) may be joined by friction stir welding. The base plate (111) may include a plurality of unit plates joined by friction stir welding.

[0044] The pack housing (110) may include a center beam (116). The center beam (116) may extend in the X direction. The center beam (116) may be interposed between the side walls (112, 113). The center beam (116) may be included in a center plate that is positioned at the center of a plurality of unit plates that are friction stir welded to each other. Accordingly, the center beam (116) may be formed together with the center plate in an extrusion process, and the center beam (116) may be a continuous element integral with the center plate.

[0045] The base plate (111) may include a plurality of cooling channels. The plurality of cooling channels may provide passages for the movement of a coolant, such as water, for example. The plurality of cooling channels may be formed by an extrusion process. The plurality of cooling channels may extend in the X direction. The plurality of cooling channels may be spaced apart in the Y direction.

[0046] A plurality of battery cell assemblies (120_1 to 120_6) may be arranged on a base plate (111) of a housing (110). The base plate (111) may support the plurality of battery cell assemblies (120_1 to 120_6). Side walls (112, 113, 114, 115) may horizontally surround the plurality of battery cell assemblies (120_1 to 120_6).

[0047] Each of the plurality of battery cell assemblies (120_1 to 120_6) may include a plurality of battery cells (121), a plurality of pads (122), a first cross beam (125a), and a second cross beam (125b).

[0048] Each of the plurality of battery cells (121) may be a lithium ion battery. Each of the plurality of battery cells (121) includes an electrode assembly, an electrolyte, and a case. Each of the plurality of battery cells (121) may be any one of a cylindrical battery cell, a square battery cell, and a pouch-type battery cell. The electrode assembly of the cylindrical battery cell is housed in a cylindrical metal can. The electrode assembly of the square battery cell is housed in a square metal can. The electrode assembly of the pouch-type battery cell is housed in a pouch case including an aluminum laminate sheet.

[0049] The electrode assembly may include an anode, a cathode, and a separator interposed between the anode and the cathode. The electrode assembly may be either a jelly-roll type or a stack type. The jelly-roll type electrode assembly may include a winding structure of the anode, the cathode, and the separator interposed therebetween. The stack type electrode assembly may include a plurality of sequentially stacked anodes, a plurality of cathodes, and a plurality of separators interposed therebetween.

[0050] A plurality of battery cells (121) may constitute a plurality of banks. Each of the plurality of banks may include one or more battery cells (121). One or more battery cells (121) of each of the plurality of banks may be connected in parallel with each other. The plurality of banks may be connected in series with each other. The number of series-connected banks and the number of battery cells (121) included in the plurality of banks may be determined according to the magnitude of voltage and current to be output from each of the battery cell assemblies (120).

[0051] A plurality of pads (122) may be interposed between a plurality of battery cells (121). The plurality of pads (122) may horizontally pressurize the plurality of battery cells (121) and prevent or alleviate swelling of the plurality of battery cells (121). The plurality of pads (122) may isolate the plurality of battery cells (121) from each other. According to exemplary embodiments, each of the plurality of battery cells (121) may include polyurethane (PU). According to exemplary embodiments, each of the plurality of battery cells (121) may include a refractory material such as silicone.

[0052] According to exemplary embodiments, each of the plurality of pads (122) may be arranged alternately with two banks. According to exemplary embodiments, two of the plurality of banks may be interposed between adjacent pads (122). According to other exemplary embodiments, only one bank may be interposed between adjacent pads (122), or three or more banks may be interposed between adjacent pads (122).

[0053] The first cross beam (125a) and the second cross beam (125b) of each of the battery cell assemblies (120_1 to 120_6) may be spaced apart from each other with a plurality of battery cells (121) therebetween. The first cross beam (125a) and the second cross beam (125b) may cover the plurality of battery cells (121). The first cross beam (125a) and the second cross beam (125b) may horizontally support the plurality of battery cells (121). The first cross beam (125a) and the second cross beam (125b) may be fixed to the plurality of battery cells (121) by an adhesive material or the like.

[0054] According to exemplary embodiments, the first cross beam (125a) and the second cross beam (125b) may have different and complementary shapes. For example, the second cross beam (125b) of each of the battery cell assemblies (120_1 to 120_6) may be coupled with the first cross beam (125a) of the subsequent one of the battery cell assemblies (120_1 to 120_6). For example, the second cross beam (125b) of the battery cell assembly (120_1) may be coupled with the first cross beam (125a) of the battery cell assembly (120_2).

[0055] The first cross beam (125a) and the second cross beam (125b) coupled to each other can form a cross beam assembly (CBA). The first cross beam (125a) and the second cross beam (125b) of each of the cross beam assemblies (CBA) can be interlocked with each other. The first cross beam (125a) and the second cross beam (125b) of each of the cross beam assemblies (CBA) can be in contact with each other. Each of the cross beam assemblies (CBA) can extend in the Y direction.

[0056] The first cross beam (125a) of the battery cell assembly (120_1) adjacent to the side wall (114) can be coupled with the supporting beam (117a) disposed on the base plate (111). The second cross beam (125b) of the battery cell assembly (120_3) adjacent to the side wall (115) can be coupled with the supporting beam (117b) disposed on the second cross beam (125b). Similarly, the first cross beam (125a) of the battery cell assembly (120_6) adjacent to the side wall (115) can be coupled with the supporting beam (117a) disposed on the base plate (111). The second cross beam (125b) of the battery cell assembly (120_4) adjacent to the side wall (115) can be coupled with the supporting beam (117b) disposed on the second cross beam (125b).

[0057] The center beam (116) may extend in the X direction. The center beam (116) may overlap the center of the base plate. The center beam (116) may isolate the battery cell assemblies (120_1, 120_2, 120_3) from the battery cell assemblies (120_4, 120_5, 120_6). The center beam (116) may be interposed between the battery cell assemblies (120_1, 120_2, 120_3) and the battery cell assemblies (120_4, 120_5, 120_6).

[0058] In this example, the plurality of battery cell assemblies (120_1 to 120_6) are arranged in two rows and three columns. Accordingly, the plurality of battery cell assemblies (120_1 to 120_6) can be said to be arranged in a 3 * 2 configuration. A person skilled in the art will easily arrive at a battery pack including a plurality of battery cell assemblies (120_1 to 120_6) arranged in an M * N configuration based on the description herein. Here, M and N are each any integer greater than or equal to 2.

[0059] A plurality of refractory sheets (130) may be disposed on a plurality of battery cell assemblies (120_1 to 120_6). A plurality of upper covers (140) may be disposed on a plurality of refractory sheets (130). The plurality of upper covers (140) may cover the plurality of battery cell assemblies (120_1 to 120_6). The plurality of refractory sheets (130) may be interposed between the plurality of upper covers (140) and the plurality of battery cell assemblies (120_1 to 120_6).

[0060] Each of the plurality of upper covers (140) may include an insulating material. For example, each of the plurality of upper covers (140) may include a fire-resistant plastic. According to other exemplary embodiments, each of the plurality of upper covers (140) may include a metal such as aluminum and stainless steel. The plurality of upper covers (140) may overlap the plurality of battery cell assemblies (120_1 to 120_6) in the Z direction. The plurality of upper covers (140) may be substantially parallel to the mounting surface (111M) of the base plate (111). The plurality of upper covers (140) may be substantially perpendicular to the Z direction.

[0061] A plurality of upper covers (140) may be interposed between a plurality of battery cell assemblies (120_1 to 120_6) and a lid (150). The plurality of upper covers (140) may be spaced apart from the lid (150) in the Z direction. The space between the plurality of upper covers (140) and the lid (150) may be an exhaust path.

[0062] Each of the plurality of upper covers (140) may include a plurality of exhaust holes (140H) that expose portions of corresponding ones of the plurality of refractory sheets (130). The plurality of exhaust holes (140H) may overlap the plurality of battery cells (121) in the Z direction.

[0063] Each of the plurality of exhaust holes (140H) may be rectangular. The corners of each of the plurality of exhaust holes (140H) may have a round shape, but are not limited thereto. The length of each of the plurality of exhaust holes (140H) in the X direction may be different from the length of each of the plurality of exhaust holes (140H) in the Y direction. The length of each of the plurality of exhaust holes (140H) in the X direction may be smaller than the length of each of the plurality of exhaust holes (140H) in the Y direction.

[0064] The length of each of the plurality of exhaust holes (140H) in the Y direction may be different from the length of each of the plurality of battery cells (121) in the Y direction. The length of each of the plurality of exhaust holes (140H) in the Y direction may be shorter than the length of each of the plurality of battery cells (121) in the Y direction. Accordingly, each of the plurality of battery cells (121) may overlap with two or more (e.g., three) exhaust holes (140H) in the Z direction.

[0065] The length of each of the plurality of exhaust holes (140H) in the X direction may be different from the length of each of the plurality of battery cells (121) in the X direction. The length of each of the plurality of exhaust holes (140H) in the X direction may be longer than the length of each of the plurality of battery cells (121) in the X direction. Accordingly, the plurality of exhaust holes (140H) may overlap portions of two or more (e.g., six) battery cells (121) in the Z direction. In this example, there are six battery cells corresponding to two banks between the pads (122) or between the pads (122) and the cross beams (125a, 125b), and each of the plurality of exhaust holes (140H) may overlap portions of the six battery cells (121) in the Z direction.

[0066] Each of the plurality of refractory sheets (130) may include a refractory material, such as mica. Each of the plurality of refractory sheets (130) may have low thermal conductivity and a high flash point.

[0067] Each of the plurality of refractory sheets (130) may include a plurality of open guides (130G) overlapping a plurality of exhaust holes (140H). Each of the plurality of open guides (130G) may have a relatively weak physical strength. When a thermal runaway event occurs in one of the plurality of battery cell assemblies (120_1 to 120_6), the plurality of open guides (130G) overlapping the plurality of exhaust holes (140H) may be easily broken, thereby providing an exhaust path for high-temperature gas through the plurality of exhaust holes (140H).

[0068] Here, thermal runaway of multiple battery cell assemblies (120_1 to 120_6) is a state in which temperature changes of multiple battery cell assemblies (120_1 to 120_6) further accelerate the temperature change, which is an uncontrollable positive feedback. Multiple battery cell assemblies (120_1 to 120_6) in a state of thermal runaway exhibit a rapid temperature increase and emit a large amount of high-pressure gas and combustion debris.

[0069] Each of the plurality of open guides (130G) may include first to fifth wave lines (130D1, 130D2, 130D3, 130D4, 130D5, hereinafter, 130D1 to 130D5). According to exemplary embodiments, each of the first to fifth wave lines (130D1 to 130D5) may include a plurality of line segments arranged along the second direction.

[0070] According to exemplary embodiments, the first to fifth dashed lines (130D1 to 130D5) may be substantially identical to each other. Accordingly, each line segment of each of the first to fifth dashed lines (130D1 to 130D5) may be substantially identical to each other. The length and spacing of each line segment included in the first to fifth dashed lines (130D1 to 130D5) may be substantially identical to each other.

[0071] The first broken line (130D1) may be interposed between the second and third broken lines (130D2, 130D3). The fourth broken line (130D4) may be spaced apart from the first broken line (130D1) with the second broken line (130D2) interposed therebetween. The fifth broken line (130D5) may be spaced apart from the first broken line (130D1) with the third broken line (130D3) interposed therebetween.

[0072] The fourth broken line (130D4) may overlap in the Z direction the boundary between the first battery cell (121) and the second battery cell among the six battery cells (121) overlapping the exhaust hole (140H). The second broken line (130D2) may overlap in the Z direction the boundary between the second battery cell (121) and the third battery cell among the six battery cells (121) overlapping the exhaust hole (140H). The first broken line (130D1) may overlap in the Z direction the boundary between the third battery cell (121) and the fourth battery cell among the six battery cells (121) overlapping the exhaust hole (140H). The third broken line (130D3) may overlap in the Z direction the boundary between the fourth battery cell (121) and the fifth battery cell among the six battery cells (121) overlapping the exhaust hole (140H). The fifth broken line (130D5) may overlap the boundary of the fifth battery cell (121) and the sixth battery cell among the six battery cells (121) overlapping the exhaust hole (140H) in the Z direction.

[0073] Each of the plurality of exhaust holes (140H) overlaps with six battery cells (121), and the first to fifth broken lines (130D1 to 130D5) can divide the portion of the refractory sheet (130) overlapping with each of the plurality of exhaust holes (140H) into six regions. Accordingly, when a thermal runaway event occurs only in some of the plurality of battery cells (121), only the corresponding portion of the refractory sheet (130) can be opened, and high-temperature gas and dust discharged through the opened portion of the refractory sheet (130) can be blocked from the battery cells (121) in a normal state.

[0074] For example, if a thermal runaway event occurs in the first battery cell (121) overlapping the exhaust hole (140H), only the portion of the refractory sheet (130) between the fourth broken line (130D4) and the edge parallel to the Y direction of the exhaust hole (140H) may be broken.

[0075] For example, if a thermal runaway event occurs in the second battery cell (121) overlapping the exhaust hole (140H), only the portion of the refractory sheet (130) between the second broken line (130D2) and the fourth broken line (130D4) may be broken.

[0076] For example, if a thermal runaway event occurs in the third battery cell (121) overlapping the exhaust hole (140H), only the portion of the refractory sheet (130) between the first broken line (130D1) and the second broken line (130D2) may be broken.

[0077] For example, if a thermal runaway event occurs in the fourth battery cell (121) overlapping the exhaust hole (140H), only the portion of the refractory sheet (130) between the first broken line (130D1) and the third broken line (130D3) may be broken.

[0078] For example, if a thermal runaway event occurs in the fifth battery cell (121) overlapping the exhaust hole (140H), only the portion of the refractory sheet (130) between the third broken line (130D3) and the fifth broken line (130D5) may be broken.

[0079] For example, if a thermal runaway event occurs in the sixth battery cell (121) overlapping the exhaust hole (140H), only the portion of the refractory sheet (130) between the fifth broken line (130D5) and the edge parallel to the Y direction of the exhaust hole (140H) may be broken.

[0080] The lead (150) may be coupled to the side walls (112, 113, 114, 115). The lead (150) may be fixed to the side walls (112, 113, 114, 115) by mechanical means such as bolts. The lead (150) may cover elements disposed inside the battery pack (100), such as battery cell assemblies (120_1 to 120_6) and electrical components. A gasket may be interposed between the lead and the side walls (112, 113, 114, 115). The gasket may provide a liquid-tight seal to the battery pack (100).

[0081] The battery pack (100) may further include electrical components. The electrical components may include any electronic components necessary to operate the battery pack. The electrical components may be positioned on an electrical component mounting area (EMR).

[0082] The electrical components may include, for example, a Battery Management System (BMS). The BMS may be configured to monitor, balance, and control the battery pack. Monitoring of the battery pack (100) may include measuring voltage and current of specific nodes within a plurality of battery cell assemblies (120_1 to 120_6) and measuring 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.

[0083] Balancing of the battery pack (100) is an operation to reduce the deviation between the plurality of battery cell assemblies (120_1 to 120_6). Control of the battery pack (100) includes preventing the occurrence of overcharge, overdischarge, and overcurrent. Through monitoring, balancing, and control, the battery pack (100) can operate under optimal conditions, thereby preventing shortening of the lifespan of each of the plurality of battery cell assemblies (120_1 to 120_6).

[0084] 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 may prevent overheating of each of the plurality of battery cell assemblies (120_1 to 120_6) 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 may protect the plurality of battery cell assemblies (120_1 to 120_6) and the external load (e.g., a vehicle motor) by cutting off power supply to the external load (e.g., a vehicle motor) in a situation where an abnormal voltage such as a voltage surge occurs.

[0085] The battery pack (100) may further include a plurality of exhaust devices. The plurality of exhaust devices may be installed in any one of the lid (150) and the side walls (112, 113, 114, 115). The plurality of exhaust devices may provide a path for discharging high-temperature gases inside the battery pack (100) to the outside when a thermal runaway event occurs in some of the battery cell assemblies (120_1 to 120_6). Accordingly, thermal propagation may be delayed, and the stability of the battery pack (100) may be improved.

[0086]

[0087] (Example 2)

[0088] Fig. 5 is a plan view illustrating a battery pack (101) according to exemplary embodiments. In Fig. 5, the lead (150, see Fig. 7) is omitted.

[0089] Figure 6 is an enlarged partial plan view of a portion (POR5) of Figure 5.

[0090] Figure 7 is a cross-sectional view taken along the cutting line 5I-5I' of Figure 5.

[0091] Referring to FIGS. 5 to 7, a battery pack (101) may include a housing (110), a plurality of battery cell assemblies (120_1 to 120_6, see FIG. 2), refractory sheets (131), upper covers (141), and a lid (150). The battery pack (101) is the final form of a battery system mounted on mobility, etc.

[0092] The housing (110), the plurality of battery cell assemblies (120_1 to 120_6, see FIG. 2), and the lead (150) are substantially the same as those described with reference to FIGS. 1 to 6, and therefore, redundant descriptions thereof are omitted.

[0093] A plurality of refractory sheets (131) may be disposed on a plurality of battery cell assemblies (120_1 to 120_6, see FIG. 2). A plurality of upper covers (141) may be disposed on a plurality of refractory sheets (131). The plurality of upper covers (141) may cover a plurality of battery cell assemblies (120_1 to 120_6, see FIG. 2). The plurality of refractory sheets (131) may be interposed between the plurality of upper covers (141) and the plurality of battery cell assemblies (120_1 to 120_6, see FIG. 2).

[0094] Each of the plurality of upper covers (141) may include an insulating material. For example, each of the plurality of upper covers (141) may include a fire-resistant plastic. According to other exemplary embodiments, each of the plurality of upper covers (141) may include a metal such as aluminum and stainless steel. The plurality of upper covers (141) may overlap with the plurality of battery cell assemblies (120_1 to 120_6, see FIG. 2) in the Z direction.

[0095] A plurality of upper covers (141) may be interposed between a plurality of battery cell assemblies (120_1 to 120_6, see FIG. 2) and a lid (150). The plurality of upper covers (141) may be spaced apart from the lid (150) in the Z direction. The space between the plurality of upper covers (141) and the lid (150) may be an exhaust path.

[0096] Each of the plurality of upper covers (141) may include a plurality of exhaust holes (141H) that expose portions of corresponding ones of the plurality of refractory sheets (131). The plurality of exhaust holes (141H) may overlap the plurality of battery cells (121) in the Z direction.

[0097] Each of the plurality of exhaust holes (141H) may be rectangular. The length of each of the plurality of exhaust holes (141H) in the X direction may be different from the length of each of the plurality of exhaust holes (141H) in the Y direction. The length of each of the plurality of exhaust holes (141H) in the X direction may be smaller than the length of each of the plurality of exhaust holes (141H) in the Y direction.

[0098] The length of each of the plurality of exhaust holes (141H) in the Y direction may be different from the length of each of the plurality of battery cells (121) in the Y direction. The length of each of the plurality of exhaust holes (141H) in the Y direction may be shorter than the length of each of the plurality of battery cells (121) in the Y direction. Accordingly, each of the plurality of battery cells (121) may overlap with two or more (e.g., three) exhaust holes (141H) in the Z direction.

[0099] The length of each of the plurality of exhaust holes (141H) in the X direction may be different from the length of each of the plurality of battery cells (121) in the X direction. The length of each of the plurality of exhaust holes (141H) in the X direction may be longer than the length of each of the plurality of battery cells (121) in the X direction. Accordingly, the plurality of exhaust holes (141H) may overlap portions of two or more (e.g., three) battery cells (121).

[0100] In this example, there are six battery cells corresponding to two banks between the pads (122) or between the pads (122) and the cross beams (125a, 125b), and the plurality of exhaust holes (141H) may overlap portions of three battery cells (121) corresponding to one bank. That is, the exhaust hole (141H) and the opening guide (131G) of FIG. 7 may have a relatively smaller size in the X direction compared to the exhaust hole (140H) and the opening guide (130G) of FIG. 4, and accordingly, the size of the refractory sheet (131) that is maximally opened when a thermal runaway event occurs may be reduced.

[0101] Each of the plurality of refractory sheets (131) may include a refractory material, such as mica. Each of the plurality of refractory sheets (131) may have low thermal conductivity and a high ignition point.

[0102] Each of the plurality of refractory sheets (131) may include a plurality of open guides (131G) overlapping a plurality of exhaust holes (141H). Each of the plurality of open guides (131G) may have a relatively weak physical strength. When a thermal runaway event occurs in one of the plurality of battery cell assemblies (120_1 to 120_6, see FIG. 2), the plurality of open guides (131G) overlapping the plurality of exhaust holes (141H) may be easily broken, thereby providing an exhaust path for high-temperature gas through the plurality of exhaust holes (141H).

[0103] Each of the plurality of open guides (131G) may include first and second wave lines (131D1, 131D2). According to exemplary embodiments, each of the first and second wave lines (131D1, 131D2) may include a plurality of line segments arranged along the second direction.

[0104] According to exemplary embodiments, the first and second dashed lines (131D1, 131D2) may be substantially identical to each other. Accordingly, each of the line segments included in the first and second dashed lines (131D1, 131D2) may be substantially identical to each other. The length and spacing of each of the line segments included in the first and second dashed lines (131D1, 131D2) may be substantially identical to each other.

[0105] Each of the plurality of exhaust holes (141H) overlaps three battery cells (121), and the first and second broken lines (131D1, 131D2) can divide the portion of the refractory sheet (131) overlapping each of the plurality of exhaust holes (141H) into three regions. Accordingly, when a thermal runaway event occurs only in some of the plurality of battery cells (121), only the corresponding portion of the refractory sheet (131) can be opened, and high-temperature gas and dust discharged through the opened portion of the refractory sheet (131) can be blocked from the battery cells (121) in a normal state.

[0106] For example, if a thermal runaway event occurs in the first battery cell (121) overlapping the exhaust hole (141H), only the portion of the refractory sheet (131) between the first broken line (131D1) and the edge parallel to the Y direction of the exhaust hole (141H) may be broken.

[0107] For example, if a thermal runaway event occurs in the second battery cell (121) overlapping the exhaust hole (141H), only the portion of the refractory sheet (131) between the first broken line (131D1) and the second broken line (131D2) may be broken.

[0108] For example, if a thermal runaway event occurs in the third battery cell (121) overlapping the exhaust hole (141H), only the portion of the refractory sheet (131) between the second broken line (131D2) and the edge parallel to the Y direction of the exhaust hole (141H) may be broken.

[0109]

[0110] (Example 3)

[0111] Fig. 8 is a plan view illustrating a battery pack (102) according to exemplary embodiments. In Fig. 8, the lead (150, see Fig. 4) is omitted.

[0112] Figure 9 is an enlarged partial plan view of a portion (POR8) of Figure 8.

[0113] Referring to FIGS. 8 and 9, a battery pack (102) may include a housing (110), a plurality of battery cell assemblies (120_1 to 120_6, see FIG. 2), refractory sheets (132), upper covers (140), and a lid (150). The battery pack (102) is the final form of a battery system mounted on a mobility device, etc.

[0114] The housing (110), the plurality of battery cell assemblies (120_1 to 120_6, see FIG. 2), the upper cover (140) and the lid (150) are substantially the same as those described with reference to FIGS. 1 to 4, and therefore, a duplicate description thereof is omitted.

[0115] Each of the plurality of refractory sheets (132) may include a refractory material, such as mica. Each of the plurality of refractory sheets (132) may have low thermal conductivity and a high flash point.

[0116] Each of the plurality of refractory sheets (132) may include a plurality of open guides (132G) overlapping a plurality of exhaust holes (140H). Each of the plurality of open guides (132G) may have a relatively weak physical strength. When a thermal runaway event occurs in one of the plurality of battery cell assemblies (120_1 to 120_6, see FIG. 2), the plurality of open guides (132G) overlapping the plurality of exhaust holes (140H) may be easily broken, thereby providing an exhaust path for high-temperature gas through the plurality of exhaust holes (140H).

[0117] Each of the plurality of open guides (132G) may include first to fifth wave lines (132D1, 132D2, 132D3, 132D4, 132D5, hereinafter, 132D1 to 132D5). According to exemplary embodiments, each of the first to fifth wave lines (132D1 to 132D5) may include a plurality of line segments arranged along the second direction.

[0118] Each of the line segments of the first broken line (132D1) may be referred to as a first line segment. Each of the line segments of the second broken line (132D2) may be referred to as a second line segment. Each of the line segments of the third broken line (132D3) may be referred to as a third line segment. Each of the line segments of the fourth broken line (132D4) may be referred to as a fourth line segment. Each of the line segments of the fifth broken line (132D5) may be referred to as a fifth line segment.

[0119] According to exemplary embodiments, the first broken line (132D1) may be different from the second to fifth broken lines (132D2, 132D3, 132D4, 132D5, hereinafter, 132D2 to 132D5). According to exemplary embodiments, each of the first line segments may be different from each of the second to fifth line segments.

[0120] According to exemplary embodiments, the length of each of the first line segments may be different from the length of each of the second to fifth line segments. According to exemplary embodiments, the length of each of the first line segments may be longer than the length of each of the second to fifth line segments.

[0121] According to exemplary embodiments, the second to fifth dashed lines (132D2, 132D3, 132D4, 132D5) may be substantially equal to each other. Accordingly, the length and spacing of each of the second to fifth line segments may be substantially equal to each other.

[0122] The first broken line (132D1) may be interposed between the second and third broken lines (132D2, 132D3). The fourth broken line (132D4) may be spaced apart from the first broken line (132D1) with the second broken line (132D2) interposed therebetween. The fifth broken line (132D5) may be spaced apart from the first broken line (132D1) with the third broken line (132D3) interposed therebetween.

[0123] Each of the plurality of exhaust holes (140H) overlaps with six battery cells (121), and the first to fifth broken lines (132D1 to 132D5) can divide the portion of the refractory sheet (132) overlapping with each of the plurality of exhaust holes (140H) into six regions. Accordingly, when a thermal runaway event occurs only in some of the plurality of battery cells (121, see FIG. 4), only the corresponding portion of the refractory sheet (132) can be opened, and high-temperature gas and dust discharged through the opened portion of the refractory sheet (132) can be blocked from the battery cells (121) in a normal state.

[0124] Furthermore, the first broken line (132D1) can limit the opening portion of the refractory sheet (132) to approximately half of each of the plurality of exhaust holes (140H). According to exemplary embodiments, the physical strength of the first broken line (132D1) can be different from the physical strengths of the second to fifth broken lines (132D2 to 132D5), and thus, the maximum opening width of the refractory sheet (132) can be adjusted through the arrangement of the first broken line (132D1). A person skilled in the art will readily arrive at an embodiment in which the opening guide (132G) includes two or more first broken lines (132D1) based on the description herein.

[0125]

[0126] The present invention has been described in more detail through drawings and examples. However, the configurations described in the drawings or examples described in this specification are merely embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that various equivalents and modified examples may exist as of the time of this application.

Claims

1. Pack housing including base plate; A battery cell assembly disposed on the base plate and including a plurality of battery cells; An upper cover disposed on the battery cell assembly and including a plurality of exhaust holes; and A fireproof sheet is included, which is interposed between the upper cover and the battery cell assembly and includes a plurality of open guides overlapping the plurality of exhaust holes. Each of the above plurality of open guides includes first to third dashed lines spaced apart from each other in a first direction, Each of the first to third wave lines extends in a second direction perpendicular to the first direction, and A battery pack, wherein the first broken line is different from the second and third broken lines.

2. In paragraph 1, A battery pack, characterized in that the first broken line is interposed between the second and third broken lines.

3. In paragraph 1, The above first broken line includes a plurality of first line segments arranged along the second direction, and The second broken line includes a plurality of second line segments arranged along the second direction, and A battery pack, characterized in that the third broken line includes a plurality of third line segments arranged along the second direction.

4. In paragraph 3, A battery pack, characterized in that the length of each of the first line segments is different from the length of each of the second line segments.

5. In paragraph 3, A battery pack, characterized in that the length of each of the first line segments is longer than the length of each of the second line segments.

6. In paragraph 3, A battery pack, characterized in that the length of each of the first line segments is different from the length of each of the third line segments.

7. In paragraph 3, A battery pack, characterized in that the length of each of the first line segments is longer than the length of each of the third line segments.

8. In paragraph 3, A battery pack, characterized in that the length of each of the second line segments is the same as the length of each of the third line segments.

9. In paragraph 3, Each of the above plurality of open guides further includes fourth and fifth wave lines spaced apart from each other with the first to third wave lines interposed therebetween, The fourth broken line includes a plurality of fourth line segments arranged along the second direction, and A battery pack, characterized in that the fifth broken line includes a plurality of fifth line segments arranged along the second direction.

10. In paragraph 9, A battery pack, characterized in that the length of each of the fourth line segments is the same as the length of each of the second line segments.

11. In paragraph 9, A battery pack, characterized in that the length of each of the first line segments is longer than the length of each of the fourth line segments.

12. In paragraph 9, A battery pack, characterized in that the length of each of the fifth line segments is the same as the length of each of the third line segments.

13. In paragraph 9, A battery pack, characterized in that the length of each of the first line segments is longer than the length of each of the fifth line segments.

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