Battery pack

Abstract

According to an exemplary embodiment, a battery pack is provided, the battery pack including: a base plate; a plurality of battery cell assemblies disposed on the base plate; a center beam interposed between the plurality of battery cell assemblies; and a fire-resistant layer coated on the center beam, the fire-resistant layer including an intumescent fire-resistant material.

Description

[Technical Field]

[0001] The present invention relates to a battery pack. This application claims the benefit of Korean Application No. 10-2023-0088246, filed on July 7, 2023, which is incorporated herein by reference in its entirety. [Background technology]

[0002] Unlike primary batteries, secondary batteries can be charged and discharged multiple times. Secondary batteries are widely used as energy sources for a variety of wireless devices, such as handsets, laptops, and wireless vacuum cleaners. In recent years, improvements in energy density and economies of scale have dramatically reduced the manufacturing cost per unit capacity of secondary batteries. As the driving range of battery electric vehicles (BEVs) has increased to the same level as fuel-powered vehicles, the primary use of secondary batteries has shifted from mobile devices to mobility.

[0003] The technological development trends for secondary batteries for mobility applications are toward improvements in energy density and safety. The safety of secondary batteries for mobility applications is extremely important because it directly affects the lives of passengers. The safety of secondary batteries can be achieved through mechanical robustness, reliable electrical insulation, and delayed heat transfer in the event of a thermal runaway event. Summary of the Invention [Problem to be solved by the invention]

[0004] The problem to be solved by the technical idea of ​​the present invention is to provide a battery pack with improved safety and energy density. [Means for solving the problem]

[0005] According to an exemplary embodiment of the present invention to solve the above-mentioned problems, there is provided a battery pack including: a base plate; a plurality of battery cell assemblies disposed on the base plate; a center beam interposed between the plurality of battery cell assemblies; and a fire-resistant layer coated on the center beam, the fire-resistant layer including a foamable fire-resistant material.

[0006] Each of the plurality of battery cell assemblies includes a lead cover assembly, and the lead cover assembly of each of the plurality of battery cell assemblies overlaps the center beam.

[0007] Each of the plurality of battery cell assemblies includes a lead cover assembly, and the lead cover assembly includes a lead cover frame and an integrated circuit mounted on the lead cover frame.

[0008] The intumescent fireproof material is configured to form an insulative char layer in the event of a thermal runaway event in the battery pack.

[0009] The foamed layer is porous.

[0010] The foamed layer covers the lead cover assembly of each of the plurality of battery cell assemblies.

[0011] The fire-resistant layer covers the top surface of the center beam.

[0012] The fire-resistant layer covers the top and sides of the center beam.

[0013] According to an exemplary embodiment, a battery pack is provided, the battery pack including: a housing including a base plate and a side wall; a plurality of battery cell assemblies disposed on the base plate; a center beam interposed between the plurality of battery cell assemblies; lead plates coupled to the side wall; and a fire-resistant layer coated on the lead plates, the fire-resistant layer including a foamable fire-resistant material.

[0014] The fire-resistant layer overlaps the center beam.

[0015] The intumescent fireproof material is configured to form an insulative char layer in the event of a thermal runaway event in the battery pack.

[0016] Each of the plurality of battery cell assemblies includes a lead cover assembly, and the lead cover assembly includes a lead cover frame and an integrated circuit mounted on the lead cover frame.

[0017] The foamed layer covers the lead cover assembly of each of the plurality of battery cell assemblies. [Effects of the Invention]

[0018] A battery pack according to an exemplary embodiment of the present invention includes a fire-resistant layer including a foamable fire-resistant material coated on a center beam or a lead plate, which can prevent a thermal runaway event from propagating between adjacent battery cell assemblies, thereby improving the safety of the battery pack.

[0019] The effects that can be obtained from the exemplary embodiments of the present disclosure are not limited to the effects mentioned above, and other effects not mentioned can be clearly derived and understood from the following description by a person having ordinary skill in the art to which the exemplary embodiments of the present disclosure belong. In other words, unintended effects accompanying the implementation of the exemplary embodiments of the present disclosure can also be derived from the exemplary embodiments of the present disclosure by a person having ordinary skill in the art. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a top view of a battery pack according to an exemplary embodiment. [Figure 2] 1A is a cross-sectional view taken along section line 1I-1I' of FIG. 1 according to an exemplary embodiment. [Figure 3] 10A and 10B are cross-sectional views for explaining the effects of the battery pack according to the exemplary embodiment; [Figure 4] FIG. 10 is a cross-sectional view illustrating a battery pack according to another exemplary embodiment. [Figure 5] FIG. 10 is a cross-sectional view illustrating a battery pack according to another exemplary embodiment. [Figure 6] FIG. 10 is a cross-sectional view illustrating a battery pack according to another exemplary embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Before that, the terms and words used in the specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted as meanings and concepts that are consistent with the technical idea of ​​the present invention, based on the principle that an inventor can appropriately define the concepts of terms to best describe his or her own invention.

[0022] Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent the entire technical idea of ​​the present invention, and there may be various equivalents and modifications that can replace them at the time of this application.

[0023] Furthermore, in the description of the present invention, if it is determined that a detailed description of related publicly known structures or functions may obscure the gist of the present invention, the detailed description will be omitted.

[0024] Since the embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art, the shapes and sizes of components in the drawings may be exaggerated, omitted, or shown in a schematic manner for clearer explanation. Therefore, the sizes and proportions of each component do not completely reflect the actual sizes and proportions.

[0025] (First embodiment) 1 shows a battery pack 100 according to an exemplary embodiment. In FIG. 1, the lead plate 150 is omitted.

[0026] FIG. 2 is a cross-sectional view taken along the line 1I-1I' in FIG.

[0027] 3 is a diagram illustrating the effect of the battery pack 100 according to an exemplary embodiment. More specifically, FIG. 3 corresponds to FIG. 2 and illustrates the battery pack 100 when a thermal runaway event occurs.

[0028] 1 to 3, a battery pack 100 may include a housing 110, a plurality of battery cell assemblies 120, a center beam 131, cross beams 133, a fire-resistant layer 140, and lead plates 150.

[0029] The housing 110 may provide a space for mounting a plurality of battery cell assemblies 120. The housing 110 may include a base plate 111 and side walls 112, 113, 114, and 115.

[0030] Two directions substantially parallel to the upper surface 111U of the base plate 111 are defined as the X direction and the Y direction, and a direction substantially perpendicular to the upper surface 111U of the base plate 111 is defined as the Z direction. The X direction, the Y direction, and the Z direction may be substantially perpendicular to each other. Unless otherwise specified, the definitions of the directions are the same for the following drawings.

[0031] The base plate may include multiple plates friction stir welded together. The base plate may include multiple cooling channels, multiple cavities, and ribs. Each of the cooling channels, multiple cavities, and ribs may extend in the X direction. The cooling channels may provide paths for a cooling fluid to flow. The cooling channels may be spaced apart in the Y direction. The cooling channels may be arranged along the Y direction. The multiple cavities are empty spaces formed inside the base plate 111. The formation of the cavities may reduce the mass of the base plate 111, thereby improving the energy density of the battery pack 100. The ribs may define the multiple cooling channels and the multiple cavities. The ribs may surround the multiple cooling channels and the multiple cavities. The ribs may maintain the multiple cooling channels and the multiple cavities airtight.

[0032] The side walls 112, 113, 114, 115 can be coupled to the base plate 111. The side walls 112, 113, 114, 115 can be coupled to the base plate 111 by, for example, friction stir welding.

[0033] The sidewalls 112, 113 may be substantially perpendicular to the X direction. The sidewalls 112, 113 may be spaced apart from each other in the X direction. The sidewalls 114, 115 may be substantially perpendicular to the Y direction. The sidewalls 114, 115 may be spaced apart from each other in the Y direction.

[0034] The plurality of battery cell assemblies 120 may be disposed on a base plate 111 of the housing 110. The base plate 111 may support the plurality of battery cell assemblies 120. The side walls 112, 113, 114, and 115 may horizontally surround the plurality of battery cell assemblies 120. The side walls 112, 113, 114, and 115 may protect the plurality of battery cell assemblies 120.

[0035] In one example, the battery pack 100 may be of a moduleless type, and each of the plurality of battery cell assemblies 120 may not include a module frame. In another example, the battery pack 100 may be of a modular type, and each of the plurality of battery cell assemblies 120 may include a module frame.

[0036] Each of the plurality of battery cell assemblies 120 may include a cell stack 121 and a lead cover assembly 123. The lead cover assembly 123 may be coupled to the cell stack 121.

[0037] The cell stack 121 may include a plurality of banks connected in series to each other. Each of the plurality of banks may include one or more parallel-connected battery cells. The number of series-connected banks and the number of parallel-connected battery cells may be determined depending on the magnitude of the voltage and current to be output from the cell stack 121.

[0038] The battery cells are the basic units of a lithium-ion battery, i.e., a secondary battery. Each of the battery cells includes an electrode assembly, an electrolyte, a case, and an electrode lead. Each of the battery cells may be any one of a cylindrical battery cell, a prismatic battery cell, and a pouch-type battery cell. The electrode assembly of a cylindrical battery cell is housed in a cylindrical metal can. The electrode assembly of a prismatic battery cell is housed in a prismatic metal can. The electrode assembly of a pouch-type battery cell is housed in a pouch case including an aluminum laminate sheet.

[0039] The electrode assembly may include a positive electrode, a negative electrode, and a separator interposed between the positive and negative electrodes. The electrode assembly may be either a jelly roll type or a stack type. A jelly roll type electrode assembly may include a rolled structure of a positive electrode, a negative electrode, and a separator interposed therebetween. A stack type electrode assembly may include a plurality of sequentially stacked positive electrodes, a plurality of negative electrodes, and a plurality of separators interposed therebetween.

[0040] The electrode lead may be connected to any one of the positive electrode tabs of the plurality of positive electrodes and the negative electrode tabs of the plurality of negative electrodes. The electrode lead may be welded to any one of the positive electrode tabs and the negative electrode tabs. The electrode lead may be an external connection terminal for each of the plurality of battery cells.

[0041] The lead cover assembly 123 may include a lead cover frame 123F and an integrated circuit 123C. The lead cover frame 123F may include an insulating material such as plastic. The lead cover frame 123F may cover the electrode leads of the cell stack 121. In this way, the lead cover frame 123F may prevent undesired short-circuiting between the electrode leads of the cell stack 121 and external elements. An example of an undesired short-circuiting between the electrode leads of the cell stack 121 and external elements includes a short-circuiting between the electrode leads of adjacent battery cell assemblies 120.

[0042] The integrated circuit 123C may be mounted on the lead cover frame 123F. The integrated circuit 123C may be fixed to the lead cover frame 123F by a method such as heat fusion. The integrated circuit 123C may be configured to sense the voltage of the electrode leads of the cell stack 121. The integrated circuit 123C may include a sensing plate or conductive wire that contacts the electrode leads of the cell stack 121. The integrated circuit 123C may also include a temperature sensor.

[0043] The plurality of battery cell assemblies 120 may be arranged in the X direction and the Y direction. In FIG. 1 , the number of the plurality of battery cell assemblies 120 arranged in the X direction is three, and the number of the plurality of battery cell assemblies 120 arranged in the Y direction is two. Therefore, such an arrangement of the plurality of battery cell assemblies 120 can be said to be a 3*2 arrangement. Based on what is described herein, a person of ordinary skill in the art can easily arrive at an arrangement of M*N battery cell assemblies 120 (where M and N are each an integer of two or more).

[0044] The center beam 131 may be disposed on the base plate 111. The center beam 131 may extend in the X direction. The center beam 131 may be coupled to the base plate 111. The center beam 131 may be welded to the base plate 111. Alternatively, the center beam may be formed together with the base plate by an extrusion process, in which case the center beam may be included in the base plate.

[0045] The center beam 131 may be interposed between the plurality of battery cell assemblies 120. The center beam 131 may separate the plurality of battery cell assemblies 120 in the Y direction. The plurality of battery cell assemblies 120 may be spaced apart in the Y direction with the center beam 131 therebetween.

[0046] The cross beam 133 may be disposed on the base plate 111. The cross beam 133 may extend in the Y direction. The cross beam 133 may be coupled to the base plate 111. The cross beam 133 may be welded to the base plate 111. The cross beam 133 may be included in the battery cell assembly 120 in some cases. In this case, the battery cell assembly 120 may be said to have a beam-integrated structure.

[0047] The cross beams 133 may be interposed between the plurality of battery cell assemblies 120 or may separate the electrical component mounting region EMR and the plurality of battery cell assemblies 120. The cross beams 133 may separate the plurality of battery cell assemblies 120 in the X direction. The plurality of battery cell assemblies 120 may be spaced apart in the X direction with the cross beams 133 interposed therebetween.

[0048] 1 is a non-limiting example and does not limit the technical concept of the present invention in any way. Based on what is described herein, a person skilled in the art can easily arrive at a battery pack including a variety of arrangements and numbers of center beams, cross beams, and battery cell assemblies.

[0049] The fire-resistant layer 140 may be coated on the center beam 131. The fire-resistant layer 140 may cover a side surface 131S of the center beam 131. The fire-resistant layer 140 may cover an upper surface 131U of the center beam 131.

[0050] The fire-resistant layer 140 can include an intumescent fire-resistant material, which can be configured to foam when heated. The foaming can include melting a surface coating, bubbling, swelling, creating a thermal barrier, and creating a ceramic layer. The fire-resistant layer 140 can be applied by methods such as painting, coating, and spraying.

[0051] In the event of a thermal runaway event occurring inside the battery pack 100, the fire-resistant layer 140 may be configured to form a foamed layer 140F, as shown in FIG. 3 . The foamed layer 140F may have a larger volume than the fire-resistant layer 140. The foamed layer 140F may fill the space between the frame 220 and the battery pack 100. The foamed layer 140F may be an insulating char layer. The foamed layer 140F may be porous. The foamed layer 140F may have a high ignition point, a high melting point, and low thermal conductivity. As a result, the foamed layer 140F may prevent a fire in one of the battery cell assemblies 120 from spreading to an adjacent battery cell assembly 120.

[0052] Because the lead cover frame 123F includes an integrated circuit receiving portion in which the integrated circuit 123C is received, the thickness of the upper part of the lead cover frame 123F may be thicker than the thickness of the lower part of the lead cover frame 123F. As a result, the center beam 131 isolates only the lower parts of the battery cell assemblies 120, and the upper parts of the battery cell assemblies 120 can face each other without being isolated.

[0053] Here, the upper and lower parts of a certain element can be defined with reference to the upper surface 111U of the base plate 111. For example, the upper part of the element may be farther from the upper surface 111U of the base plate 111 than the lower part of the element.

[0054] When a thermal runaway event occurs among the multiple battery cell assemblies 120, the spaces between the battery cell assemblies 120 that are not covered by the center beam 131 can be filled with the foamed layer 140F, thereby providing physical, thermal, and electrical isolation between the battery cell assemblies 120 and improving the safety of the battery pack 100.

[0055] Here, thermal runaway of the battery cell assemblies 120 is a state in which a temperature change in the battery cell assemblies 120 further accelerates the temperature change, which is an uncontrollable positive feedback. The battery cell assemblies 120 in a thermal runaway state exhibit a rapid temperature rise and emit a large amount of high-pressure gas and combustion debris.

[0056] The lead plate 150 may be coupled to the side walls 112, 113, 114, and 115. The lead plate 150 may cover elements mounted inside the battery pack 100, such as the battery cell assembly 120 and electrical components. The lead plate 150 may be fixed to the side walls 112, 113, 114, and 115 by mechanical coupling means, such as fasteners.

[0057] The battery pack 100 may further include exhaust devices. The exhaust devices may be coupled to, for example, the sidewalls 112. The sidewalls 112 may include exhaust holes, and the exhaust devices may be coupled to the exhaust holes of the sidewalls 112. Each of the exhaust devices may include a spring type or a rupture disk. Each of the exhaust devices may be configured to exhaust gas inside the battery pack 100 when the pressure inside the battery pack 100 exceeds a threshold value.

[0058] The exhaust device may be configured to slow down thermal propagation by releasing high-temperature gases inside the battery pack 100 to the outside when at least one of the plurality of battery cell assemblies 120 is in a thermal runway state.

[0059] The battery pack 100 may further include electrical components. The electrical components may be mounted on an electrical component mounting region EMR of the housing 110. The electrical components may include any electronic elements necessary to operate the battery pack.

[0060] The electrical components may include, for example, a BMS (Battery Management System). The BMS may be configured to monitor, balance, and control the battery pack. Monitoring the battery pack 100 may include measuring the voltage and current of specific nodes within the multiple battery cell assemblies 120 and measuring the temperature at a set position within the battery pack 100. The battery pack 100 may include measuring instruments for measuring the voltage, current, and temperature described above.

[0061] Balancing the battery pack 100 is an operation to reduce the deviation between the multiple battery cell assemblies 120. Controlling 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, thereby preventing a shortening of the lifespan of each of the multiple battery cell assemblies 120.

[0062] The electrical components may further include a cooling device, a power relay assembly (PRA), a safety plug, etc. The cooling device may include a cooling fan. The cooling fan circulates air inside the battery pack 100 to prevent overheating of each of the plurality of battery cell assemblies 120. 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 plurality of battery cell assemblies 120 and the external load (e.g., a vehicle motor) by cutting off the power supply to the external load (e.g., a vehicle motor) in the event of an abnormal voltage such as a voltage surge.

[0063] The battery pack 100 may further include a plurality of bus bars configured to electrically connect the plurality of battery cell assemblies 120. The plurality of battery cell assemblies 120 may be connected in series by the plurality of bus bars. This allows the battery pack 100 to be configured to output a high voltage to an external load (e.g., a vehicle motor).

[0064] (Second embodiment) FIG. 4 is a diagram illustrating a battery pack 101 according to another exemplary embodiment.

[0065] Referring to FIG. 4, the battery pack 101 may include a housing 110, a plurality of battery cell assemblies 120, a center beam 131, a cross beam 133 (see FIG. 1), a fire-resistant layer 141, and a lead plate 150.

[0066] The housing 110, the plurality of battery cell assemblies 120, the center beam 131, the cross beam 133 (see FIG. 1), and the lead plate 150 are substantially the same as those described with reference to FIGS. 1 to 3, and therefore, redundant description thereof will be omitted.

[0067] The fire-resistant layer 141 may be coated on the center beam 131. The fire-resistant layer 141 may include a foamable fire-resistant material, such that the fire-resistant layer 141 may be configured to form a foamed layer 140F (see FIG. 3 ) in the event of a thermal runaway event inside the battery pack 101.

[0068] The fire-resistant layer 141 may cover the upper surface 131U of the center beam 131. The fire-resistant layer 141 may cover only the upper surface 131U of the center beam 131. The fire-resistant layer 141 may not cover the side surface 131S of the center beam 131. The fire-resistant layer 141 may be spaced apart from the side surface 131S of the center beam 131.

[0069] According to the exemplary embodiment, the fire-resistant layer 141 is applied only partially to the upper surface 131U of the center beam 131, so that the manufacturing cost of the battery pack 101 can be reduced and the energy density of the battery pack 101 can be improved.

[0070] (Third embodiment) FIG. 5 is a diagram illustrating a battery pack 102 according to another exemplary embodiment.

[0071] Referring to FIG. 5, the battery pack 102 may include a housing 110, a plurality of battery cell assemblies 120, a center beam 131, a cross beam 133 (see FIG. 1), a fire-resistant layer 142, and a lead plate 150.

[0072] The housing 110, the plurality of battery cell assemblies 120, the center beam 131, the cross beam 133 (see FIG. 1), and the lead plate 150 are substantially the same as those described with reference to FIGS. 1 to 3, and therefore, redundant description thereof will be omitted.

[0073] The fire-resistant layer 142 may be coated on the center beam 131. The fire-resistant layer 142 may include a foamable fire-resistant material, such that the fire-resistant layer 142 may be configured to form a foamed layer 140F (see FIG. 3 ) in the event of a thermal runaway event inside the battery pack 102.

[0074] The fire-resistant layer 142 can cover the upper surface 131U of the center beam 131. The fire-resistant layer 142 can partially cover the side surface 131S of the center beam 131. The portion of the fire-resistant layer 142 covering the side surface 131S of the center beam 131 can be formed by flow of the fire-resistant layer 142 after coating and before hardening.

[0075] According to an exemplary embodiment, the fire-resistant layer 142 partially covers the center beam 131, so that the manufacturing cost of the battery pack 102 can be reduced and the energy density of the battery pack 102 can be improved.

[0076] (Fourth embodiment) FIG. 6 is a diagram illustrating a battery pack 103 according to another exemplary embodiment.

[0077] Referring to FIG. 6, the battery pack 103 may include a housing 110, a plurality of battery cell assemblies 120, a center beam 131, a cross beam 133 (see FIG. 1), a fire-resistant layer 143, and a lead plate 150.

[0078] The housing 110, the plurality of battery cell assemblies 120, the center beam 131, the cross beam 133 (see FIG. 1), and the lead plate 150 are substantially the same as those described with reference to FIGS. 1 to 3, and therefore, redundant description thereof will be omitted.

[0079] The fire-resistant layer 143 may be coated on the lead plate 150. The fire-resistant layer 143 may partially cover the lead plate 150. The fire-resistant layer 143 may include a foamable fire-resistant material. Thus, the fire-resistant layer 143 may be configured to form a foamed layer 140F (see FIG. 3 ) when a thermal runaway event occurs inside the battery pack 103. The fire-resistant layer 143 may overlap the center beam 131 in the Z direction. The fire-resistant layer 143 may overlap the lead cover assemblies 123 of each of the plurality of battery cell assemblies 120 in the Z direction.

[0080] The present invention has been described in more detail above through the drawings and embodiments, etc. However, the configurations shown in the drawings or embodiments in this specification are merely one embodiment of the present invention and do not represent all of the technical ideas of the present invention, and therefore, there may be various equivalents and modifications that can replace them at the time of filing this application. [Explanation of symbols]

[0081] 1I-1I' cutting line 100 battery packs 101 Battery Pack 102 Battery Pack 103 Battery Pack 110 Housing 111 Base Plate 111U top 112 Side wall 113 Side wall 114 Side wall 115 Side wall 120 Battery Cell Assembly 121 Cell Stack 123 Lead cover assembly 123C Integrated Circuit 123F Lead Cover Frame 131 Center beam 131S side 131U top 133 Cross Beam 140 Fireproof layer 140F foamed layer 141 Fireproof layer 142 Fireproof layer 143 Fireproof layer 150 Reed Plate 220 frames EMR implementation area

Claims

1. A base plate and a plurality of battery cell assemblies disposed on the base plate; a center beam interposed between the plurality of battery cell assemblies; a fire-resistant layer coated on the center beam; The battery pack, wherein the fire-resistant layer includes an intumescent fire-resistant material.

2. each of the plurality of battery cell assemblies includes a lead cover assembly; The battery pack according to claim 1 , wherein the lead cover assembly of each of the plurality of battery cell assemblies overlaps the center beam.

3. each of the plurality of battery cell assemblies includes a lead cover assembly; The lead cover assembly includes: a lead cover frame; 10. The battery pack of claim 1, further comprising: an integrated circuit mounted on the lead cover frame.

4. 4. The battery pack of claim 3, wherein the intumescent fireproof material is configured to form an insulative charred layer in the event of a thermal runaway event in the battery pack.

5. The battery pack of claim 4 , wherein the foamed layer is porous.

6. The battery pack according to claim 4 or 5, wherein the foamed layer covers the lead cover assembly of each of the plurality of battery cell assemblies.

7. The battery pack according to claim 1 , wherein the fire-resistant layer covers an upper surface of the center beam.

8. The battery pack according to claim 1 , wherein the fire-resistant layer covers a top surface and a side surface of the center beam.

9. a housing including a base plate and a sidewall; a plurality of battery cell assemblies disposed on the base plate; a center beam interposed between the plurality of battery cell assemblies; a lead plate coupled to the side wall; a fire-resistant layer coated on the lead plate, The battery pack, wherein the fire-resistant layer includes an intumescent fire-resistant material.

10. The battery pack of claim 9 , wherein the fire-resistant layer overlaps the center beam.

11. 11. The battery pack of claim 9 or 10, wherein the intumescent fireproof material is configured to form an insulative charred layer in the event of a thermal runaway event in the battery pack.

12. each of the plurality of battery cell assemblies includes a lead cover assembly; The lead cover assembly includes: a lead cover frame; and an integrated circuit mounted on the lead cover frame.

13. The battery pack according to claim 12 , wherein the foamed layer covers the lead cover assembly of each of the plurality of battery cell assemblies.

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