Battery pack and method of manufacturing it

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 on January 3, 2024, and Korean Application No. 10-2024-0032767, filed on March 7, 2024, which are hereby incorporated by reference in their entirety.

Background Art

[0002] Unlike primary batteries, secondary batteries can be charged and discharged multiple times. Secondary batteries are widely used as an energy source for various cordless devices such as mobile phones, laptop computers, and cordless vacuum cleaners. In recent years, due to improvements in energy density and economies of scale, the manufacturing cost per unit capacity of secondary batteries has been significantly reduced, and as the driving range of battery electric vehicles (BEVs) has increased to a level comparable to that of fuel vehicles, the main application of secondary batteries has shifted from mobile devices to mobility.

[0003] The trend in the technological development of secondary batteries for mobility is the improvement of energy density and safety. The safety of secondary batteries for mobility is of great importance as it directly relates to the lives of passengers. The safety of secondary batteries can be achieved by mechanical robustness, reliability of electrical insulation, and heat transfer delay when a thermal runaway event occurs.

Summary of the Invention

Problems 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 Problems

[0005] According to an exemplary embodiment of the present invention for solving the above-mentioned problems, the steps include 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, wherein the center beam is perpendicular to the first cross beam and the second cross beam respectively, and providing a fire-resistant coating to the plurality of battery cell assemblies in a painting manner.

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

[0007] The process further includes the step of joining the mask covering the first crossbeam and the electrical components to the pack housing before providing the fire-resistant coating to the plurality of battery cell assemblies described above.

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

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

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

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

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

[0013] The system further includes a fifth fire-resistant coating applied to the second crossbeam described above.

[0014] Each of the above fire-resistant coatings 1 through 5 contains the same substance.

[0015] This further includes a sixth fire-resistant coating applied to the center beam mentioned above.

[0016] The center beam includes a second portion to which the sixth fire-resistant coating is applied and a first portion separated from the second fire-resistant coating, the first portion being separated from the second portion in the first direction. [Effects of the Invention]

[0017] According to exemplary embodiments of the present invention, a fire-resistant coating can be applied to multiple battery cell assemblies, crossbeams, and center beams of a battery pack. This can prevent thermal runaway events from propagating to the surroundings, thereby improving the safety of the battery pack.

[0018] The effects obtained from exemplary embodiments of the present invention are not limited to those mentioned above, and other effects not mentioned can be clearly derived and understood by a person of ordinary skill in the art to which the exemplary embodiments of this disclosure belong, from the following description. That is, unintended effects associated with carrying out exemplary embodiments of this disclosure can also be derived by a person of ordinary skill in the art from exemplary embodiments of this disclosure. [Brief explanation of the drawing]

[0019] [Figure 1] This is a flowchart illustrating a method for manufacturing a battery pack according to an exemplary embodiment. [Figure 2] This is a plan view illustrating a method for manufacturing a battery pack according to an exemplary embodiment. [Figure 3] This is a cross-sectional view along the cutting line 2I-2I' in Figure 2. [Figure 4] This is a cross-sectional view showing a battery cell according to an exemplary embodiment. [Figure 5] This is an exploded perspective view of a battery cell according to an exemplary embodiment. [Figure 6] This is a plan view illustrating a method for manufacturing a battery pack according to an exemplary embodiment. [Figure 7]It is a plan view for explaining a method of manufacturing a battery pack according to an exemplary embodiment. [Figure 8] It is a cross-sectional view taken along the cutting line 7I-7I' of FIG. 7.

Embodiments for Carrying Out the Invention

[0020] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. On the premise that terms and words used in this specification and the claims should not be construed as being limited to ordinary or dictionary meanings, they can be construed as meanings and concepts consistent with the technical idea of the present invention based on the principle that the inventor can appropriately define the concept of the terms in order to explain his own invention in the best way.

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

[0022] Also, in the description of the present invention, when it is determined that a specific description of a related known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

[0023] Embodiments of the present invention are provided to more fully explain the present invention to an ordinary technician. Therefore, the shapes and sizes of the components in the drawings may be exaggerated, omitted, or schematically shown for a clearer explanation. Therefore, the sizes and ratios of each component do not fully reflect the actual sizes and ratios.

[0024] (First Embodiment and Second Embodiment) FIG. 1 is a flowchart for explaining a method of manufacturing a battery pack according to an exemplary embodiment.

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

[0026] Figure 3 is a cross-sectional view along the cutting line 2I-2I' in Figure 2.

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

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

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

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

[0031] Figure 8 is a cross-sectional view along the cutting line 7I-7I' in Figure 7.

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

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

[0034] Here, we define the two directions substantially parallel to the mounting surface 111M of the base plate 111 as the X and Y directions, and the direction substantially perpendicular to the mounting surface 111M of the base plate 111 as the Z direction. The X, Y, and Z directions may be substantially perpendicular to each other. The mounting surface 111M may face the battery cell assembly 120.

[0035] The base plate 111 and the side walls 112, 113 can each be provided by an extrusion process. The extrusion direction of the base plate 111 and the side walls 112, 113 can each be the X direction. The side walls 114, 115 can also be provided by an extrusion process. The side walls 112, 113, 114, 115 can be substantially perpendicular to the base plate 111.

[0036] According to exemplary embodiments, the base plate 111 and the side walls 112, 113 can 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 can be extended in the X direction. The center beam 116 can be interposed between the side walls 112 and 113. The center beam 116 can be included in a center plate which is one of a plurality of unit plates that are friction stir welded to each other. Thus, the center beam 116 can be formed together with the center plate and the center beam 116 can be a continuous element as an integral part with the center plate.

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

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

[0040] The center beam 116 and cross beams 131 and 133 can isolate multiple battery cell assemblies 120 from each other. Multiple battery cell assemblies 120 can be separated in the Y direction with the center beam 116 in between. The center beam 116 can be interposed between multiple battery cell assemblies 120. Multiple battery cell assemblies 120 can be separated in the X direction with the cross beam 131 in between. The cross beam 131 can be interposed between multiple battery cell assemblies 120.

[0041] In Figure 2, the arrangement of the multiple battery cell assemblies 120 can be described as a 3x2 configuration. The arrangement of the multiple battery cell assemblies 120 disclosed in Figure 2 is a non-limiting example and does not limit the technical idea of ​​the present invention in any sense. A person of ordinary skill in the art can easily arrive at an arrangement of multiple battery cell assemblies 120 arranged in an MxN configuration (where M and N are integers greater than or equal to 2) based on what is described herein.

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

[0043] Referring to Figures 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 exemplary embodiments, 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 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 containing an aluminum laminate sheet. The technical idea of ​​the present invention will be described below based on an example in which the battery cell 121 is a pouch-type battery cell, but a person of the ordinary skill of the art will readily arrive at examples 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 separation membrane 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 winding structure of the positive electrode, the negative electrode, and the separation membrane interposed between them. The stack type electrode assembly 121EA may include a plurality of sequentially stacked positive electrodes, a plurality of negative electrodes, and a plurality of separation membranes interposed between them.

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

[0047] Each of the multiple negative electrodes of electrode assembly 121EA may include a negative electrode tab 121NT. Each negative electrode tab 121NT of the multiple negative electrodes of electrode assembly 121EA may be short-circuited to a negative electrode terminal 121N. Each negative electrode tab 121NT of the multiple negative electrodes of electrode assembly 121EA may be welded to a negative electrode terminal 121N.

[0048] The cell case 121C may include an internal resin layer, a metal layer, and an external resin layer. Adhesives and corrosion-preventive layers may be further provided between the internal resin layer and the metal layer, and between the external resin layer and the metal layer.

[0049] The internal resin layer may be heat-adhesive and may be called a sealant layer. The internal resin layer enables sealing of the cell case 121C. The internal resin layer may include polyolefin resins such as polypropylene (PP) and polyethylene (PE). The metal layer may include one of the following: 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 can block the entry and exit of gases from the cell case 121C. The external resin layer may be a surface protection layer. The external resin layer may include a material that is abrasion-resistant and heat-resistant, such as nylon resin.

[0050] The cell case 121C can be provided by joining a first cell case 121C1 and a second cell case 121C2. The first cell case 121C1 may be substantially flat. The first cell case 121C1 may not include a housing portion. The second cell case 121C2 may include a housing portion 121R. The housing portion 121R can be formed by a pouch forming process. The housing portion 121R is a portion of the second cell case 121C2 that is molded into a bowl shape to house the electrode assembly 121EA.

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

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

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

[0054] Insulating tape 121I can be applied to the positive terminal 121P and the negative terminal 121N. The positive terminal 121P and the negative terminal 121N can protrude outside the cell case 121C. The positive terminal 121P and the negative terminal 121N can protrude from the cell case 121C in the Y direction. This allows the resulting voltage and current of the battery cell 121 to 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] Referring again to Figures 1 to 3, multiple battery cells 121 can be arranged in the X direction. Multiple battery cells 121 can be joined together, for example, by adhesive.

[0056] Multiple battery cells 121 can constitute multiple banks. For example, some (e.g., three) battery cells 121 can be connected in parallel to each other to constitute a bank. Multiple banks can be connected in series. The resulting configuration of multiple battery cells 121 can be called 3 parallel-16 series (3P-16S), but this is for illustrative purposes only and does not limit the technical idea of ​​the present invention in any sense. The number of series-connected banks and the number of battery cells 121 included in the multiple banks can be determined depending on the magnitude of the voltage and current to be output from the battery cell assembly 120.

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

[0058] Since 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 differ from that 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 that 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 that of the battery cells 121 in the even-numbered banks. As a result, the positive terminal 121P (see Figure 5) of the battery cells 121 in the odd-numbered banks can be adjacent to the negative terminal 121N (see Figure 5) of the battery cells 121 in the even-numbered banks, and the positive terminal 121P (see Figure 5) of the battery cells 121 in the even-numbered banks can be adjacent to the negative terminal 121N (see Figure 5) of the battery cells 121 in the odd-numbered banks.

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

[0060] The first integrated circuit assembly 123 may include an insulating frame, an integrated circuit, busbars, a sensing plate, a sensing bar, a temperature sensor, wiring, and an insulating cover. The second integrated circuit assembly 124 may 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 connections between multiple battery cells 121, outputting the resulting voltages of the multiple battery cells 121, and measuring the voltage (or current) of nodes within a circuit composed of the multiple battery cells 121.

[0062] The insulating frame may include insulating materials such as plastic. The insulating frame can cover the front of multiple battery cells 121. The insulating frame can support integrated circuits, busbars, sensing plates, sensing bars, temperature sensors, and wiring.

[0063] The busbar can be short-circuited to the positive lead 121P of one or more battery cells 121 in the first bank and the negative lead 121N of one or more battery cells 121 in the last bank. The busbar can be welded to the positive lead 121P of one or more battery cells 121 in the first bank and the negative lead 121N of one or more battery cells 121 in the last bank. The resulting voltages of multiple battery cells 121 in the battery cell assembly 120 can be output through the busbar. The busbar can be fixed to an insulating frame.

[0064] The integrated circuit can be mounted on an insulating frame. Positive leads 121P and negative leads 121N, welded to each other, can constitute nodes inside the battery cell assembly 120. The integrated circuit can be configured to measure the voltage at the nodes via sensing plates and sensing bars.

[0065] The sensing bar may contain a conductive material. The sensing bar may have a rod shape. The sensing bar may be short-circuited to a busbar. The sensing bar may be coupled to a busbar. The voltage of the busbar may be measured via the sensing bar.

[0066] Each of the sensing plates may have a patch shape or a pad shape. The sensing plates may contain conductive material. The sensing plates may be short-circuited to the corresponding positive lead 121P and negative lead 121N of the battery cells 121.

[0067] Each of the multiple sensing plates can be connected to an integrated circuit. Through the multiple sensing plates, the voltages of multiple nodes inside the battery cell assembly 120 can be measured.

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

[0069] The insulating cover may contain insulating materials such as plastic. The insulating cover can be mated and coupled to an insulating frame. The insulating cover can cover integrated circuits, busbars, sensing plates, sensing bars, and temperature sensors, thereby protecting the electrical elements of the first and second integrated circuit assemblies.

[0070] Each of the multiple battery cell assemblies may further include a Flexible Flat Cable (FFC) assembly configured to provide an electrical connection between the integrated circuits of the first integrated circuit assembly 123 and the second integrated circuit assembly 124. This allows measured values ​​such as temperature and voltage collected from the integrated circuits of the second integrated circuit assembly 124 to be transmitted to the integrated circuits of the first integrated circuit assembly 123 via the FFC assembly. Measured values ​​such as temperature and voltage collected from the integrated circuits of the second integrated circuit assembly 124 may also be transmitted to the integrated circuits of the first integrated circuit assembly 123 via wireless communication.

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

[0072] The electrical components 150 can be placed on the electrical component mounting area EMR. The electrical component mounting area EMR may be the space between the crossbeam 131 and the side wall 115. The electrical component mounting area EMR may be defined by the base plate 111, the side walls 112, 113, 116, and the crossbeam 131.

[0073] The electrical component 150 may include, for example, a Battery Management System (BMS). The BMS can be configured to monitor, balance, and control the battery pack 100. Monitoring the battery pack 100 may include measuring the voltage and current at specific nodes within a plurality of battery cell assemblies 120 and measuring the temperature at a set location within the battery pack 100. The battery pack 100 may include measuring instruments for measuring the aforementioned voltage, current, and temperature.

[0074] Balancing the battery pack 100 is an operation that reduces deviations between multiple battery cell assemblies 120. Control of the battery pack 100 includes preventing overcharging, over-discharging, and overcurrent. Through monitoring, balancing, and control, the battery pack 100 can operate under optimal conditions, thereby preventing shortening of the 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), and a safety plug. The cooling device may include a cooling fan. The cooling fan can prevent each of the multiple battery cell assemblies 120 from overheating by circulating air inside the battery pack 100. The PRA can be configured to supply or cut off power from the high-voltage battery to an external load (e.g., the vehicle's motor). The PRA can protect the multiple battery cell assemblies 120 and the external load (e.g., the vehicle's motor) by cutting off the power supply to the external load (e.g., the vehicle's motor) in situations where abnormal voltages occur, such as voltage surges.

[0076] Next, referring to Figures 1, 2, and 6, the electrical component mounting area (EMR) can be masked in P120. Masking the electrical component mounting area (EMR) may include bonding a mask (MSK) to the pack housing 110. The mask (MSK) may be in contact with the crossbeam 131 and the side walls 112, 113, 116. The mask (MSK) may be bonded to the crossbeam 131 and the side walls 112, 113, 116 by mechanical means such as bolting, or it may simply be placed on the crossbeam 131 and the side walls 112, 113, 116. The mask (MSK) can cover the electrical components 150 on the electrical component mounting area (EMR).

[0077] Next, referring to Figures 1 and 6-8, at P130, a fire-resistant coating 160 can be formed on multiple battery cell assemblies 120, a center beam 116, and a cross beam 133. This allows the battery pack 100 to be provided.

[0078] The fire-resistant coating 160 can be formed by a coating machine SD. The coating machine SD can be configured to provide the coating material. For example, the coating machine SD may include a plurality of nozzles configured to spray the coating material. The coating machine SD can provide the fire-resistant coating 160 in an X-direction scanning manner. The operation of the coating machine SD can be repeated multiple times, and the thickness of the fire-resistant coating 160 can be increased 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 can provide a fire-resistant coating 160 with a thickness of approximately 40 μm.

[0079] The refractory coating 160 may contain refractory materials. The refractory coating 160 may be provided by a spray-type coating agent. The refractory coating 160 may also be provided by a paint-type coating agent. The refractory coating 160 may be provided using a ceramic water-soluble coating agent. The refractory coating 160 may be provided by any one of the following methods: spraying, painting, printing, vapor deposition, dipping, spin coating, roller coating, floating coating, curtain coating, sputtering, co-extrusion, etc.

[0080] According to exemplary embodiments, the melting temperature and / or ignition point of the refractory coating 160 may be about 300°C or higher. According to exemplary embodiments, the melting temperature and / or ignition point of the refractory coating 160 may be about 600°C or higher. According to exemplary embodiments, the melting temperature and / or ignition point of the refractory coating 160 may be about 1000°C or higher. According to exemplary embodiments, the melting temperature and / or ignition point of the refractory coating 160 may be 1500°C or higher.

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

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

[0083] When the thickness of the fire-resistant coating 160 is increased, the fire resistance performance of the fire-resistant coating 160 improves, but the thickness of the fire-resistant structure 121F also increases, which reduces the energy density of the battery device including the battery cells 121, for example, as in the battery cell assembly 120 (see Figure 7). In other words, the thickness of the fire-resistant coating 160 can be determined based on energy density and fire resistance 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 resistance performance to the fire-resistant structure 121F.

[0084] The battery pack 100 may further include multiple interbus bars configured to electrically connect multiple battery cell assemblies 120. Multiple battery cell assemblies 120 may be connected in series by multiple interbus 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 in Figure 7 to show the clear positional relationships between the components of the battery pack 100. The lid 170 can cover elements mounted inside the battery pack 100, such as multiple battery cell assemblies 120 and electrical components. The lid 170 can be secured to the pack housing 110 by mechanical coupling means, such as bolting.

[0086] The battery pack may further include exhaust devices 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 hot gases from inside the battery pack 100 to the outside in the event of a thermal runway event in one of the battery cell assemblies 120.

[0087] Here, thermal runaway of the multiple battery cell assemblies 120 is a state in which the temperature change of the multiple battery cell assemblies 120 is further accelerated, resulting in an uncontrollable positive feedback loop. In a thermal runaway state, the multiple battery cell assemblies 120 exhibit a rapid temperature increase and emit large amounts of high-pressure gas and combustion residue.

[0088] The crossbeam 131 and electrical components 150 covered by the mask MSK may not be subject to 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 on the electrical component mounting area (EMR). That is, the first portion of the center beam 116 may be 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 a plurality of battery cell assemblies 120.

[0090] A fire-resistant coating 160 can be applied to each of the crossbeams 133. The fire-resistant coating 160 can be applied to the top of each of the crossbeams 133. The fire-resistant coating 160 can be applied to the top surface 133U of each of the crossbeams 133. The top surface 133U of each of the crossbeams 133 may be substantially perpendicular to the Z direction. The fire-resistant coating 160 may also be applied to the top of each of the side walls 113S of the crossbeams 133. The top surface 133U of each of the crossbeams 133 may be substantially perpendicular to the X direction.

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

[0092] The fire-resistant coating 160 can be applied to each element of the multiple battery cell assembly 120. More specifically, the fire-resistant coating 160 can be applied to each part (e.g., the top) of the multiple battery cells 121 and each part (e.g., the top) of the pad 122. The tops of each of the multiple battery cells 121 and each of the tops of the pad 122 can face the lid 170.

[0093] The present invention has been described in more detail above with reference to the drawings and embodiments. However, the configurations described in the drawings or embodiments described herein are merely one embodiment of the present invention and do not represent the entire technical concept of the present invention. Therefore, there may be a variety of equivalents and modifications that can be substituted for them at the time of filing.

Claims

1. A step 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 defining an area for mounting electrical components, and a second cross beam not defining an area for mounting electrical components, wherein the center beam is perpendicular to the first cross beam and the second cross beam, A method for manufacturing a battery pack, comprising the step of providing a fire-resistant coating to exposed portions of the plurality of battery cell assemblies when they are arranged on the pack housing by a painting method.

2. A method for manufacturing a battery pack according to claim 1, wherein, in the step of providing a fire-resistant coating to the exposed portions of the plurality of battery cell assemblies when they are arranged on the pack housing, the fire-resistant coating is also provided to the second cross beam.

3. A method for manufacturing a battery pack according to claim 1, further comprising the step of joining a mask covering the first crossbeam and the electrical components to the pack housing before providing the fire-resistant coating to the exposed portions of the plurality of battery cell assemblies when they are arranged on the pack housing.

4. A method for manufacturing a battery pack according to claim 3, wherein, in the step of providing the fire-resistant coating to the exposed portions of the plurality of battery cell assemblies when they are arranged on the pack housing, the fire-resistant coating is not applied to the first crossbeam and the electrical components.

5. A method for manufacturing a battery pack according to claim 3, wherein the center beam includes a first portion covered by the mask and a second portion not covered by the mask.

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

7. A method for manufacturing a battery pack according to claim 5, wherein, in the step of providing the fire-resistant coating to the exposed portions of the plurality of battery cell assemblies when they are arranged on the pack housing, 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 side walls, The center beam on the base plate extends in a first direction parallel to the mounting surface of the base plate, A first crossbeam on the base plate that defines an area for mounting electrical components and a second crossbeam that does not define an area for mounting electrical components, wherein each of the first and second crossbeams is parallel to the mounting surface of the base plate and extends in a second direction perpendicular to the first direction. A plurality of battery cell assemblies arranged on the base plate and isolated by the center beam, the first cross beam and the second cross beam, each of the plurality of battery cell assemblies comprising a first integrated circuit assembly 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 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 electrically connected to the plurality of battery cells, The electrical components interposed between the side wall and the first cross beam, A first fire-resistant coating applied to the exposed portion of each of the plurality of battery cells in the plurality of battery cell assemblies when they are positioned on the pack housing, A second fire-resistant coating applied to the exposed portion of each of the plurality of pads of the plurality of battery cell assemblies when they are positioned on the pack housing, A third fire-resistant coating applied to the exposed portion of each of the plurality of battery cell assemblies when the first integrated circuit assembly is placed on the pack housing, A battery pack comprising: a fourth fire-resistant coating applied to the exposed portion of each of the plurality of battery cell assemblies when the second integrated circuit assembly is located on the pack housing.

9. The battery pack according to claim 8, further comprising a fifth fire-resistant coating applied to the second crossbeam.

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

11. The battery pack according to claim 10, further comprising a sixth fire-resistant coating applied to the center beam.

12. The battery pack according to claim 11, wherein the center beam includes a second portion to which the sixth fire-resistant coating is applied and a first portion separated from the second fire-resistant coating, the first portion being separated from the second portion in a first direction.

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