Battery pack and method for manufacturing same

Abstract

According to an exemplary embodiment, the method includes the steps of: arranging a plurality of battery cell assemblies and electrical components on a pack housing including a base plate, a center beam on the base plate, a first cross beam, and a second cross beam, the center beam being perpendicular to each of the first cross beam and the second cross beam; and providing a fire-resistant coating on the plurality of battery cell assemblies by painting.

Description

[Technical Field]

[0001] The present invention relates to a battery pack and a method for manufacturing the same. This application claims the benefit of Korean Application No. 10-2024-0010445, filed January 3, 2024, and Korean Application No. 10-2024-0032767, filed March 7, 2024, which are incorporated herein by reference in their entireties. [Background technology]

[0002] Unlike primary batteries, secondary batteries can be charged and discharged multiple times. Secondary batteries are widely used as energy sources for various cordless devices such as mobile phones, laptops, and cordless 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 main 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 heat transfer delay 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 a method for manufacturing the same. [Means for solving the problem]

[0005] According to an exemplary embodiment of the present invention for solving the above-mentioned problems, the method includes the steps of arranging a plurality of battery cell assemblies and electrical components on a pack housing including a base plate, a center beam on the base plate, a first cross beam and a second cross beam, the center beam being perpendicular to each of the first cross beam and the second cross beam, and providing a fire-resistant coating on the plurality of battery cell assemblies by painting.

[0006] In the step of providing a fire-resistant coating on the plurality of battery cell assemblies, the second cross beam is also provided with the fire-resistant coating.

[0007] The method further includes the step of bonding a mask covering the first cross beam and the electrical components to the pack housing before applying the fire-resistant coating to the plurality of battery cell assemblies.

[0008] In the step of providing the fire-resistant coating to the plurality of battery cell assemblies, the fire-resistant coating is not applied to the first cross beam and the electrical components.

[0009] The mask covers a first portion of the center beam and exposes a second portion of the center beam.

[0010] In the step of providing the fire-resistant coating on the plurality of battery cell assemblies, the fire-resistant coating is not applied to the first portion of the center beam when providing the fire-resistant coating.

[0011] When providing the fire-resistant coating in the step of providing the plurality of battery cell assemblies, the fire-resistant coating is applied to the second portion of the center beam.

[0012] According to an exemplary embodiment, a battery pack is provided, the battery pack including: a pack housing including a base plate and a side wall; a center beam on the base plate, the center beam extending in a first direction parallel to a mounting surface of the base plate; first and second cross beams on the base plate, each of the first and second cross beams extending in a second direction parallel to the mounting surface of the base plate and perpendicular to the first direction; a plurality of battery cell assemblies disposed on the base plate and separated by the center beam, the first and second cross beams, each of the plurality of battery cell assemblies including a plurality of battery cells arranged in the first direction, a plurality of pads interposed between the plurality of battery cells, and a plurality of battery cell assemblies disposed on the base plate and separated by the center beam, the first and second cross beams; the battery cell assembly includes a first integrated circuit assembly including a first integrated circuit electrically connected to a battery cell, and a second integrated circuit assembly spaced apart from the first integrated circuit assembly in the second direction and including a second integrated circuit electrically connected to the plurality of battery cells, the battery cell assembly including an electrical component interposed between the side wall and the first cross beam; a first fire-resistant coating applied on the plurality of battery cells of each of the plurality of battery cell assemblies; a second fire-resistant coating applied on the plurality of pads of each of the plurality of battery cell assemblies; a third fire-resistant coating applied on the first integrated circuit assembly of each of the plurality of battery cell assemblies; and a fourth fire-resistant coating applied on the second integrated circuit assembly of each of the plurality of battery cell assemblies.

[0013] Further comprising a fifth refractory coating applied on the second cross beam.

[0014] Each of the first to fifth fire-resistant coatings includes the same material.

[0015] Further included is a sixth refractory coating applied on the center beam.

[0016] The center beam includes a second portion to which the sixth refractory coating is applied and a first portion spaced apart from the second refractory coating, and the first portion is spaced apart from the second portion in the first direction. [Effects of the Invention]

[0017] According to an exemplary embodiment of the present invention, a fire-resistant coating may be applied to the battery cell assemblies, cross beams, and center beam of a battery pack, thereby preventing a thermal runaway event from propagating to the surroundings and improving the safety of the battery pack.

[0018] The effects 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 from the following description by a person having ordinary skill in the art to which the exemplary embodiments of the present disclosure belong. In other words, unintended effects accompanying the implementation of the exemplary embodiments of the present disclosure can also be derived from the exemplary embodiments of the present disclosure by a person having ordinary skill in the art. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a flowchart illustrating a method for manufacturing a battery pack according to an exemplary embodiment. [Figure 2] 10A to 10C are plan views illustrating a method of manufacturing a battery pack according to an exemplary embodiment. [Figure 3] FIG. 2 is a cross-sectional view taken along the line 2I-2I′ in FIG. [Figure 4] FIG. 1 illustrates a cross-sectional view of a battery cell according to an exemplary embodiment. [Figure 5] FIG. 1 is an exploded perspective view of a battery cell according to an exemplary embodiment. [Figure 6] 10A to 10C are plan views illustrating a method of manufacturing a battery pack according to an exemplary embodiment. [Figure 7]10A to 10C are plan views illustrating a method of manufacturing a battery pack according to an exemplary embodiment. [Figure 8] FIG. 7 is a cross-sectional view taken along the line 7I-7I′ in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. As a premise, the terms and words used in this 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 concept of terms in order to best describe his / her own invention.

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

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

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

[0024] (First and second embodiments) FIG. 1 is a flowchart illustrating a method for manufacturing a battery pack according to an exemplary embodiment.

[0025] FIG. 2 is a plan view illustrating a method for manufacturing a battery pack according to an exemplary embodiment.

[0026] FIG. 3 is a cross-sectional view taken along section line 2I-2I' of FIG.

[0027] FIG. 4 is a cross-sectional view of a battery cell according to an exemplary embodiment.

[0028] FIG. 5 is an exploded perspective view of a battery cell according to an exemplary embodiment.

[0029] FIG. 6 is a plan view illustrating a method for manufacturing a battery pack according to an exemplary embodiment.

[0030] FIG. 7 is a plan view illustrating a method for manufacturing a battery pack according to an exemplary embodiment.

[0031] FIG. 8 is a cross-sectional view taken along section line 7I-7I' of FIG.

[0032] 1 to 3, in the P110, a plurality of battery cell assemblies 120 and electrical components 150 can be arranged on a pack housing 110.

[0033] The pack housing 110 can provide a space for mounting a plurality of battery cell assemblies 120 and electrical components 150. The pack housing 110 can include a base plate 111, side walls 112, 113, 114, 115, and a center beam 116. Cross beams 131, 133 can further be provided on the base plate 111.

[0034] Here, 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. The X direction, the Y direction, and the Z direction may be substantially perpendicular to one another. The mounting surface 111M may face the battery cell assembly 120.

[0035] 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 side walls 114, 115 may also be provided by an extrusion process. The side walls 112, 113, 114, 115 may be substantially perpendicular to the base plate 111.

[0036] According to an exemplary embodiment, the base plate 111 and the 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.

[0037] The center beam 116 may extend in the X direction. The center beam 116 may be interposed between the side walls 112 and 113. The center beam 116 may be included in a center plate, which is one of a plurality of unit plates friction stir welded together. Thus, the center beam 116 may be formed together with the center plate, and the center beam 116 may be a continuous element integral with the center plate.

[0038] The base plate 111 may include a plurality of cooling channels. The cooling channels may provide a passageway for the movement of a coolant, such as water. The cooling channels may be formed by an extrusion process. The cooling channels may extend in the X direction. The cooling channels may be spaced apart in the Y direction.

[0039] The plurality of battery cell assemblies 120 can be disposed on a base plate 111 of the pack housing 110. The base plate 111 can support the plurality of battery cell assemblies 120. The side walls 112, 113, 114, and 115 can horizontally surround the plurality of battery cell assemblies 120. The side walls 112, 113, 114, and 115 can protect the plurality of battery cell assemblies 120.

[0040] The center beam 116 and cross beams 131, 133 can separate the multiple battery cell assemblies 120 from one another. The multiple battery cell assemblies 120 can be spaced apart in the Y direction with the center beam 116 therebetween. The center beam 116 can be interposed between the multiple battery cell assemblies 120. The multiple battery cell assemblies 120 can be spaced apart in the X direction with the cross beam 131 therebetween. The cross beam 131 can be interposed between the multiple battery cell assemblies 120.

[0041] 2, the arrangement of the plurality of battery cell assemblies 120 can be said to be a 3x2 arrangement. The arrangement of the plurality of battery cell assemblies 120 disclosed in FIG. 2 is a non-limiting example and does not limit the technical idea of ​​the present invention in any way. A person skilled in the art can easily arrive at an MxN arrangement of the plurality of battery cell assemblies 120 (where M and N are each an integer of 2 or greater) based on what is described herein.

[0042] Each of the plurality of battery cell assemblies 120 can include a plurality of battery cells 121, pads 122, a first integrated circuit assembly 123, and a second integrated circuit assembly 124.

[0043] 4 and 5, the battery cell 121 may include a cell case 121C, an electrode assembly 121EA, a positive terminal 121P, and a negative terminal 121N. The battery cell 121 may further include an electrolyte.

[0044] According to an exemplary embodiment, the battery cell 121 may include one of a cylindrical battery cell, a prismatic battery cell, and a pouch-type battery cell. The electrode assembly of the cylindrical battery cell is housed in a cylindrical metal can. The electrode assembly of the prismatic battery cell is housed in a prismatic metal can. The electrode assembly of the pouch-type battery cell is housed in a pouch case including an aluminum laminate sheet. Hereinafter, the technical concept of the present invention will be described based on an example in which the battery cell 121 is a pouch-type battery cell, but a person of ordinary skill in the art can easily arrive at an example in which the battery cell 121 is one of a cylindrical battery cell and a prismatic battery cell based on what is described herein.

[0045] The electrode assembly 121EA may include a positive electrode, a negative electrode, and a separator interposed between the positive and negative electrodes. The electrode assembly 121EA may be either a jelly roll type or a stack type. The jelly roll type electrode assembly 121EA may include a rolled structure of a positive electrode, a negative electrode, and a separator interposed therebetween. The stack type electrode assembly 121EA may include a plurality of sequentially stacked positive electrodes, a plurality of negative electrodes, and a plurality of separators interposed therebetween.

[0046] Each of the positive electrodes of the electrode assembly 121EA may include a positive electrode tab (not shown). The positive electrode tab (not shown) of each of the positive electrodes of the electrode assembly 121EA may be short-circuited to the positive electrode terminal 121P. The positive electrode tab (not shown) of each of the positive electrodes of the electrode assembly 121EA may be welded to the positive electrode terminal 121P.

[0047] Each of the negative electrodes of the electrode assembly 121EA may include a negative electrode tab 121NT. The negative electrode tab 121NT of each of the negative electrodes of the electrode assembly 121EA may be shorted to the negative electrode terminal 121N. The negative electrode tab 121NT of each of the negative electrodes of the electrode assembly 121EA may be welded to the negative electrode terminal 121N.

[0048] The cell casing 121C may include an inner resin layer, a metal layer, and an outer resin layer, and adhesive and corrosion prevention layers may be provided between the inner resin layer and the metal layer and between the outer resin layer and the metal layer.

[0049] The internal resin layer may have thermal adhesive properties and may be referred to as a sealant layer. The internal resin layer enables sealing of the cell casing 121C. The internal resin layer may include, for example, a polyolefin resin such as polypropylene (PP) or polyethylene (PE). The metal layer may include one of an alloy of iron, carbon, chromium, and manganese, an alloy of iron, chromium, and nickel, and aluminum. The metal layer may be a gas barrier. The metal layer may block the entry and exit of gas from the cell casing 121C. The external resin layer may be a surface protection layer. The external resin layer may include a material having wear resistance and heat resistance, such as nylon resin.

[0050] The cell casing 121C may be provided by joining a first cell casing 121C1 and a second cell casing 121C2. The first cell casing 121C1 may be substantially flat. The first cell casing 121C1 may not include a receiving portion. The second cell casing 121C2 may include a receiving portion 121R. The receiving portion 121R may be formed by a pouch forming process. The receiving portion 121R is a portion of the second cell casing 121C2 that is shaped like a bowl to receive the electrode assembly 121EA.

[0051] The terrace 121T of the second cell casing 121C2 may surround the receiving portion 121R. The terrace 121T of the second cell casing 121C2 may be joined to the edge of the first cell casing 121C1, thereby providing the cell casing 121C. The sealing portion 121CS may be provided by joining the first case 121C1 and the second case 121C2. That is, the sealing portion 121CS may be the joining portion between the first case 121C1 and the second case 121C2.

[0052] 2, when the receiving portion is formed only in the second cell case 121C2 of the first case 121C1 and the second case 121C2, the sealing portion 121CS may be connected to the first main surface 121FS1. The sealing portion 121CS may include a portion that is coplanar with the first main surface 121FS1.

[0053] The cell casing 121C may have a substantially rectangular parallelepiped shape, and the first and second main surfaces 121FS1 and 121FS2 of the cell casing 121C may be the widest surfaces of the cell casing 121C. The first and second main surfaces 121FS1 and 121FS2 may be substantially parallel to the electrode assembly 121EA or at least one of the positive electrodes and negative electrodes included in the electrode assembly 121EA. The first and second main surfaces 121FS1 and 121FS2 may be opposite to each other. The first and second main surfaces 121FS1 and 121FS2 may be substantially perpendicular to the X direction, but are not limited to this.

[0054] An insulating tape 121I may be applied to the positive terminal 121P and the negative terminal 121N. The positive terminal 121P and the negative terminal 121N may protrude to the outside of the cell casing 121C. The positive terminal 121P and the negative terminal 121N may protrude in the Y direction from the cell casing 121C. Thus, the resulting voltage and current of the battery cell 121 may be output through the positive terminal 121P and the negative terminal 121N. The positive terminal 121P may be a positive lead. The negative terminal 121N may be a negative lead. The Y direction may be substantially perpendicular to the X direction.

[0055] 1 to 3 again, the plurality of battery cells 121 may be arranged in the X direction. The plurality of battery cells 121 may be bonded together by, for example, an adhesive.

[0056] The plurality of battery cells 121 may form a plurality of banks. For example, some (e.g., three) battery cells 121 may be connected in parallel to form a bank. The plurality of banks may be connected in series. The resulting connection configuration of the plurality of battery cells 121 may be referred to as 3 parallel-16 series (3P-16S), but this is for illustrative purposes only and does not limit the technical spirit of the present invention in any way. The number of series-connected banks and the number of battery cells 121 included in the plurality of banks may be determined depending on the magnitude of the voltage and current to be output from the battery cell assembly 120.

[0057] In this example, two banks can form unit stacks. The unit stacks can be alternated with pads 122. One of the pads 122 can be disposed between two of the unit stacks, and one of the unit stacks can be disposed between two of the pads 122.

[0058] Because the odd-numbered banks are connected in series with the even-numbered banks, the orientation of the battery cells 121 in the odd-numbered banks may be different from the orientation of the battery cells 121 in the even-numbered banks. The orientation of the battery cells 121 in the odd-numbered banks may be opposite to the orientation of the battery cells 121 in the even-numbered banks. That is, the orientation of the battery cells 121 in the odd-numbered banks rotated 180 degrees around the Z axis may be the same as the orientation of the battery cells 121 in the even-numbered banks. Thus, the positive terminal 121P (see FIG. 5) of the battery cell 121 in the odd-numbered banks may be adjacent to the negative terminal 121N (see FIG. 5) of the battery cell 121 in the even-numbered banks, and the positive terminal 121P (see FIG. 5) of the battery cell 121 in the even-numbered banks may be adjacent to the negative terminal 121N (see FIG. 5) of the battery cell 121 in the odd-numbered banks.

[0059] The pads 122 can absorb swelling of the multiple battery cells 121. Each of the pads 122 can include PU (Poly Urethane). Each of the pads 122 can include a fire-resistant material such as silicone. As a non-limiting example, two of the banks can be interposed between adjacent pads 122.

[0060] The first integrated circuit assembly 123 can include an insulating frame, an integrated circuit, a bus bar, a sensing plate, a sensing bar, a temperature sensor, wiring, and an insulating cover, and the second integrated circuit assembly 124 can include an insulating frame, an integrated circuit, a sensing plate, a temperature sensor, wiring, and an insulating cover.

[0061] The first integrated circuit assembly 123 and the second integrated circuit assembly 124 may include physical and functional configurations for providing electrical coupling between the multiple battery cells 121, outputting the resulting voltages of the multiple battery cells 121, and measuring the voltages (or currents) of nodes within a circuit made up of the multiple battery cells 121.

[0062] The insulating frame may include an insulating material such as plastic, and may cover the front of the plurality of battery cells 121. The insulating frame may support an integrated circuit, a bus bar, a sensing plate, a sensing bar, a temperature sensor, and wiring.

[0063] The bus bar may be shorted to the positive leads 121P of one or more battery cells 121 in the first bank and the negative leads 121N of one or more battery cells 121 in the last bank. The bus bar may be welded to the positive leads 121P of one or more battery cells 121 in the first bank and the negative leads 121N of one or more battery cells 121 in the last bank. A resultant voltage of the multiple battery cells 121 in the battery cell assembly 120 may be output through the bus bar. The bus bar may be fixed to an insulating frame.

[0064] The integrated circuit can be mounted on an insulating frame. The positive and negative leads 121P and 121N welded together can form a node inside the battery cell assembly 120. The integrated circuit can be configured to measure the voltage of the node via the sensing plate and the sensing bar.

[0065] The sensing bar may include a conductive material. The sensing bar may have a rod shape. The sensing bar may be shorted to the bus bar. The sensing bar may be coupled to the bus bar. The voltage of the bus bar may be measured via the sensing bar.

[0066] Each of the plurality of sensing plates may have a patch or pad shape. The plurality of sensing plates may include a conductive material. The plurality of sensing plates may be shorted to corresponding ones of the positive electrode leads 121P and the negative electrode leads 121N of the plurality of battery cells 121.

[0067] Each of the plurality of sensing plates may be coupled to an integrated circuit, and the voltages of the plurality of nodes within the battery cell assembly 120 may be measured through the plurality of sensing plates.

[0068] The temperature sensors can be configured to measure the temperature at multiple points in the battery cell assembly 120. The temperature sensors can be spatially distributed, allowing the temperature distribution within the battery cell assembly 120 to be measured.

[0069] The insulating cover may include an insulating material such as plastic. The insulating cover may be mated with the insulating frame. The insulating cover may cover the integrated circuits, bus bars, sensing plate, sensing bar, and temperature sensor, thereby protecting the electrical elements of the first integrated circuit assembly and the second integrated circuit assembly.

[0070] Each of the plurality of battery cell assemblies may further include a flexible flat cable (FFC) assembly configured to provide electrical coupling between the integrated circuit of the first integrated circuit assembly 123 and the integrated circuit of the second integrated circuit assembly 124. This allows measurements such as temperature and voltage collected from the integrated circuit of the second integrated circuit assembly 124 to be transmitted to the integrated circuit of the first integrated circuit assembly 123 via the FFC assembly. The measurements such as temperature and voltage collected from the integrated circuit of the second integrated circuit assembly 124 may also be transmitted to the integrated circuit of the first integrated circuit assembly 123 via wireless communication.

[0071] The TIM layer 140 may be provided on the base plate 111 of the pack housing 110. The TIM layer 140 may be interposed between each of the plurality of battery cells 121 and the base plate 111. The TIM layer 140 may include a resin composition. The TIM layer 140 may be provided by a thermal resin coating process. The TIM layer 140 may mediate heat transfer between each of the plurality of battery cells 121 and the base plate 111.

[0072] The electrical component 150 can be disposed on the electrical component mounting region EMR. The electrical component mounting region EMR can be a space between the cross beam 131 and the side wall 115. The electrical component mounting region EMR can be defined by the base plate 111, the side walls 112, 113, 116, and the cross beam 131.

[0073] The electrical components 150 may include, for example, a BMS (Battery Management System). The BMS may be configured to monitor, balance, and control the battery pack 100. 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.

[0074] 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 shortened lifespan of each of the multiple battery cell assemblies 120.

[0075] The electrical components 150 may include a cooling device, a power relay assembly (PRA), a safety plug, and the like. 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.

[0076] 1, 2, and 6, in P120, the electrical component mounting region EMR can be masked. Masking the electrical component mounting region EMR can include coupling a mask MSK to the pack housing 110. The mask MSK can be in contact with the cross beam 131 and the side walls 112, 113, and 116. The mask MSK can be coupled to the cross beam 131 and the side walls 112, 113, and 116 by a mechanical method such as bolting, or can simply be placed on the cross beam 131 and the side walls 112, 113, and 116. The mask MSK can cover the electrical components 150 on the electrical component mounting region EMR.

[0077] 1 and 6-8, at P130, a fire-resistant coating 160 may be formed on the plurality of battery cell assemblies 120, the center beam 116, and the cross beams 133. This may provide the battery pack 100.

[0078] The fire-resistant coating 160 may be formed by a coating machine SD. The coating machine SD may be configured to apply a coating material. For example, the coating machine SD may include multiple nozzles configured to spray the coating material. The coating machine SD may apply the fire-resistant coating 160 in an X-direction scanning manner. The operation of the coating machine SD may be repeated multiple times, and the thickness of the fire-resistant coating 160 may increase with each repetition. For example, if one operation of the coating machine SD provides a fire-resistant coating 160 with a thickness of approximately 10 μm, four operations may provide a fire-resistant coating 160 with a thickness of approximately 40 μm.

[0079] The fire-resistant coating 160 may include a fire-resistant material. The fire-resistant coating 160 may be applied using a spray-type coating agent. The fire-resistant coating 160 may also be applied using a paint-type coating agent. The fire-resistant coating 160 may be applied using a ceramic water-soluble coating agent. The fire-resistant coating 160 may be applied by any one of methods such as spraying, painting, printing, vapor deposition, dipping, spin coating, roller coating, floating coating, curtain coating, sputtering, and co-extrusion.

[0080] According to exemplary embodiments, the melting temperature and / or fire point of the fire-resistant coating 160 may be approximately 300°C or greater. According to exemplary embodiments, the melting temperature and / or fire point of the fire-resistant coating 160 may be approximately 600°C or greater. According to exemplary embodiments, the melting temperature and / or fire point of the fire-resistant coating 160 may be approximately 1000°C or greater. According to exemplary embodiments, the melting temperature and / or fire point of the fire-resistant coating 160 may be approximately 1500°C or greater.

[0081] According to an exemplary embodiment, the thermal conductivity of the fire-resistant coating 160 may be approximately 20 W / mK or less. According to an exemplary embodiment, the thermal conductivity of the fire-resistant coating 160 may be approximately 1 W / mK or less. According to an exemplary embodiment, the thermal conductivity of the fire-resistant coating 160 may be approximately 0.3 W / mK or less. The thermal conductivity of the fire-resistant coating 160 described above may be measured at room temperature (approximately 25°C).

[0082] According to exemplary embodiments, the thickness of the fire-resistant coating 160 may range from approximately 10 μm to approximately 50 μm. According to exemplary embodiments, the thickness of the fire-resistant coating 160 may be approximately 15 μm or greater. According to exemplary embodiments, the thickness of the fire-resistant coating 160 may be approximately 20 μm or greater. According to exemplary embodiments, the thickness of the fire-resistant coating 160 may be approximately 25 μm or greater. According to exemplary embodiments, the thickness of the fire-resistant coating 160 may be approximately 100 μm or less. According to exemplary embodiments, the thickness of the fire-resistant coating 160 may be approximately 90 μm or less. According to exemplary embodiments, the thickness of the fire-resistant coating 160 may be approximately 90 μm or less. According to exemplary embodiments, the thickness of the fire-resistant coating 160 may be approximately 80 μm or less. According to exemplary embodiments, the thickness of the fire-resistant coating 160 may be approximately 70 μm or less. According to exemplary embodiments, the thickness of the fire-resistant coating 160 may be approximately 60 μm or less. According to exemplary embodiments, the thickness of the fire-resistant coating 160 may be about 50 μm or less. According to exemplary embodiments, the thickness of the fire-resistant coating 160 may be about 40 μm or less. According to exemplary embodiments, the thickness of the fire-resistant coating 160 may be about 30 μm or less.

[0083] As the thickness of the fire-resistant coating 160 increases, the fire-resistant performance of the fire-resistant coating 160 improves, but as the thickness of the fire-resistant structure 121F increases, the energy density of a battery device including the battery cells 121, such as the battery cell assembly 120 (see FIG. 7), decreases. That is, the thickness of the fire-resistant coating 160 can be determined based on the energy density and the fire-resistant performance, which are in a trade-off relationship with each other. The above-described thickness range of the fire-resistant coating 160 allows the fire-resistant coating 160 to prevent the thickness of the fire-resistant structure 121F from becoming excessively large while providing sufficient fire-resistant performance to the fire-resistant structure 121F.

[0084] The battery pack 100 may further include a plurality of inter-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 inter-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).

[0085] The battery pack 100 may further include a lid 170 coupled to the side walls 112, 113, 114, and 115 of the pack housing 110. The lid 170 is omitted from FIG. 7 to clearly show the positional relationship between the components of the battery pack 100. The lid 170 may cover elements mounted inside the battery pack 100, such as the multiple battery cell assemblies 120 and electrical components. The lid 170 may be fixed to the pack housing 110 by a mechanical coupling means, such as bolting.

[0086] The battery pack may further include an exhaust device coupled to the side walls 114, 115. One of the side walls 114, 115 may include an exhaust hole connected to the exhaust device. The exhaust device may be configured to slow thermal propagation by releasing high-temperature gas inside the battery pack 100 to the outside when a thermal runway event occurs in the plurality of battery cell assemblies 120.

[0087] Here, thermal runaway of the battery cell assemblies 120 is a state in which the temperature change of the battery cell assemblies 120 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.

[0088] The cross beam 131 and the electrical components 150 covered by the mask MSK may not be coated with the fire-resistant coating 160. This prevents the electrical components 150, which require precise operation, from malfunctioning due to the application of the fire-resistant coating 160, thereby improving the reliability of the battery pack 100.

[0089] The center beam 116 may include a first portion to which the fire-resistant coating 160 is not applied and a second portion to which the fire-resistant coating 160 is applied. The first portion of the center beam 116 may be located on the electrical component mounting region EMR. That is, the first portion of the center beam 116 may be located between the side wall 115 and the first cross beam 131 in the X direction. The second portion of the center beam 116 may be interposed between the multiple battery cell assemblies 120.

[0090] A fire-resistant coating 160 may be applied to each of the cross beams 133. The fire-resistant coating 160 may be applied to an upper portion of each of the cross beams 133. The fire-resistant coating 160 may be applied to an upper surface 133U of each of the cross beams 133. The upper surface 133U of each of the cross beams 133 may be substantially perpendicular to the Z direction. The fire-resistant coating 160 may be applied to an upper portion of each side wall 113S of the cross beam 133. The upper surface 133U of each of the cross beams 133 may be substantially perpendicular to the X direction.

[0091] Each of the fire-resistant coatings 160 applied on the plurality of battery cells 121 may be referred to as a first fire-resistant coating. Each of the fire-resistant coatings 160 applied on the plurality of pads 122 may be referred to as a second fire-resistant coating. Each of the fire-resistant coatings 160 applied on the first integrated circuit assembly 123 may be referred to as a third fire-resistant coating. Each of the fire-resistant coatings 160 applied on the second integrated circuit assembly 124 may be referred to as a fourth fire-resistant coating. Each of the fire-resistant coatings 160 applied on the second cross beam 133 may be referred to as a fifth fire-resistant coating. The fire-resistant coating 160 applied on the center beam 116 may be referred to as a sixth fire-resistant coating. According to an exemplary embodiment, the fire-resistant coatings 160 applied to the plurality of battery cells 121, the plurality of pads 122, the first integrated circuit assembly 123, the second integrated circuit assembly 124, the center beam 116, and the second cross beam 133 may be formed simultaneously and may include the same material.

[0092] A fire-resistant coating 160 may be applied to each element of the plurality of battery cell assemblies 120. More specifically, the fire-resistant coating 160 may be applied to a portion (e.g., an upper portion) of each of the plurality of battery cells 121 and a portion (e.g., an upper portion) of each of the pads 122. The upper portions of each of the plurality of battery cells 121 and each of the pads 122 may face the lid 170.

[0093] The present invention has been described in more detail above with reference to 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.

Claims

1. arranging a plurality of battery cell assemblies and electrical components on a pack housing including a base plate, a center beam on the base plate, and first and second cross beams, the center beam being perpendicular to each of the first and second cross beams; A method for manufacturing a battery pack, comprising the step of providing a fire-resistant coating on the plurality of battery cell assemblies by painting.

2. The method for manufacturing a battery pack according to claim 1 , wherein in the step of providing a fire-resistant coating on the plurality of battery cell assemblies, the second cross beam is also provided with the fire-resistant coating.

3. 2. The method for manufacturing a battery pack according to claim 1, further comprising the step of bonding a mask covering the first cross beam and the electrical components to the pack housing before applying the fire-resistant coating to the plurality of battery cell assemblies.

4. 4. The method for manufacturing a battery pack according to claim 3, wherein in the step of providing the fire-resistant coating to the plurality of battery cell assemblies, the fire-resistant coating is not applied to the first cross beam and the electrical components.

5. 4. The method of manufacturing a battery pack of claim 3, wherein the mask covers a first portion of the center beam and exposes a second portion of the center beam.

6. 6. The method for manufacturing a battery pack according to claim 5, wherein, in the step of providing the fire-resistant coating on the plurality of battery cell assemblies, the fire-resistant coating is not applied to the first portion of the center beam when providing the fire-resistant coating.

7. 6. The method of manufacturing a battery pack according to claim 5, wherein in the step of providing the fire-resistant coating on the plurality of battery cell assemblies, the fire-resistant coating is applied to the second portion of the center beam when providing the fire-resistant coating.

8. a pack housing including a base plate and a sidewall; a center beam on the base plate, the center beam extending in a first direction parallel to a mounting surface of the base plate; a first cross beam and a second cross beam on the base plate, each of the first cross beam and the second cross beam being parallel to the mounting surface of the base plate and extending in a second direction perpendicular to the first direction; a plurality of battery cell assemblies disposed on the base plate and separated by the center beam, the first cross beam, and the second cross beam, each of the plurality of battery cell assemblies including: a plurality of battery cells arranged in the first direction; a plurality of pads interposed between the plurality of battery cells; a first integrated circuit assembly including a first integrated circuit electrically connected to the plurality of battery cells; and a second integrated circuit assembly spaced apart from the first integrated circuit assembly in the second direction and including a second integrated circuit electrically connected to the plurality of battery cells; an electrical component interposed between the side wall and the first cross beam; a first fire-resistant coating applied onto the plurality of battery cells of each of the plurality of battery cell assemblies; a second fire-resistant coating applied onto the pads of each of the battery cell assemblies; and a third fire-resistant coating applied over the first integrated circuit assembly of each of the plurality of battery cell assemblies; and a fourth fire-resistant coating applied over the second integrated circuit assembly of each of the plurality of battery cell assemblies.

9. 10. The battery pack of claim 8, further comprising a fifth fire resistant coating applied on the second cross beam.

10. The battery pack of claim 9 , wherein each of the first through fifth fire-resistant coatings comprises the same material.

11. 11. The battery pack of claim 10, further comprising a sixth fire resistant coating applied on the center beam.

12. 11. The battery pack of claim 10, wherein the center beam includes a second portion having the sixth fire-resistant coating applied thereto and a first portion spaced apart from the second fire-resistant coating, the first portion being spaced apart from the second portion in the first direction.

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