Battery pack

Abstract

According to an exemplary embodiment, a battery pack is provided. [Solution] The battery pack includes a pack housing including a base plate, and a plurality of battery cell assemblies on the base plate. Each of the plurality of battery cell assemblies includes a plurality of battery cells arranged in a first direction, a first side beam and a second side beam spaced apart in the first direction with the plurality of battery cells in between, and a first fire-resistant structure coupled to the first side beam. The first fire-resistant structure includes a first fire-resistant sheet and a first fire-resistant adhesive layer applied to the first fire-resistant sheet. The first fire-resistant sheet and the first fire-resistant adhesive layer contain different materials from each other.

Description

Technical Field

[0001] The present invention relates to a battery pack. This application claims the benefit of priority to Korean Application No. 10-2024-0032639, filed on March 7, 2024, which is hereby incorporated by reference in its 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 handsets, notebook 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 dramatically 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 because it can be directly related to the lives of passengers. Accordingly, various technologies for delaying heat propagation in thermal runaway events have been studied.

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.

Means for Solving the Problems

[0005] According to exemplary embodiments of the present invention for solving the above-mentioned problems, a battery pack is provided. The battery pack includes a pack housing including a base plate and a plurality of battery cell assemblies on the base plate, each of the plurality of battery cell assemblies including a plurality of battery cells arranged in a first direction, a first side beam and a second side beam spaced apart in the first direction with the plurality of battery cells in between, and a first fire-resistant structure coupled to the first side beam, the first fire-resistant structure including a first fire-resistant sheet and a first fire-resistant adhesive layer applied to the first fire-resistant sheet, the first fire-resistant sheet and the first fire-resistant adhesive layer comprising different materials from each other.

[0006] The first fire-resistant structure further includes a first fire-resistant coating on the first fire-resistant sheet, wherein the first fire-resistant coating contains a substance different from that of the first fire-resistant sheet.

[0007] The first side beam includes a first stepped structure, the second side beam includes a second stepped structure, and the first and second stepped structures have complementary shapes.

[0008] The first fire-resistant structure described above is bonded to the first stepped structure described above.

[0009] The first fire-resistant structure described above has a conformal shape to the first stepped structure described above.

[0010] Each of the above-mentioned plurality of battery cell assemblies includes a second fire-resistant structure coupled to the second side beam, the second fire-resistant structure including a second fire-resistant sheet and a second fire-resistant adhesive layer applied to the second fire-resistant sheet.

[0011] The above-described second fire-resistant structure further includes a second fire-resistant coating on the above-described second fire-resistant sheet.

[0012] According to an exemplary embodiment, a battery pack is provided. The battery pack includes a pack housing including a base plate, and a plurality of battery cell assemblies on the base plate, each of the plurality of battery cell assemblies including a plurality of battery cells arranged in a first direction, a first side beam and a second side beam spaced apart in the first direction with the plurality of battery cells in between, and a first fire-resistant coating on the first side beam.

[0013] Each of the above-mentioned battery cell assemblies further includes a second fire-resistant coating on the second side beam.

[0014] Each of the above-mentioned first and second fire-resistant coatings has a uniform thickness.

[0015] Each of the above-mentioned first and second fire-resistant coatings contains ceramic.

[0016] The first side beam includes a first stepped structure, and the second side beam includes a second stepped structure.

[0017] The first and second side beams described above have different and complementary shapes. [Effects of the Invention]

[0018] An exemplary embodiment of the present invention includes a fire-resistant coating applied to the side beams, which can prevent the propagation of thermal runaway events and thereby improve the safety of the battery pack.

[0019] 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 by those having ordinary knowledge in the technical field to which the exemplary embodiments of the present disclosure belong from the following description. That is, even the unintended effects associated with implementing the exemplary embodiments of the present disclosure can be derived from the exemplary embodiments of the present disclosure by those having ordinary knowledge in the technical field.

Brief Description of the Drawings

[0020] [Figure 1] It is a plan view for explaining a battery pack according to an exemplary embodiment. [Figure 2] It is a cross-sectional view taken along the cutting line 1I-1I' of FIG. 1. [Figure 3] It is a cross-sectional view showing the first side beam of FIG. 2. [Figure 4] It is a plan view showing the first side beam of FIG. 2. [Figure 5] It is a plan view showing a battery pack according to another exemplary embodiment. [Figure 6] It is a cross-sectional view taken along the cutting line 5I-5I' of FIG. 5. [Figure 7] It is a cross-sectional view of the fire-resistant structure of FIG. 6.

Modes for Carrying Out the Invention

[0021] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. On the premise that the terms and words used in this specification and the claims should not be construed as being limited to the ordinary or dictionary meanings, and based on the principle that the inventor can appropriately define the concept of the terms in order to explain the inventor's own invention in the best way, they can be construed as meanings and concepts consistent withthe technical idea of the present 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 all of the technical ideas of the present invention. Thus, at the time of this application, there may be various equivalents and modifications that can replace these.

[0023] 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.

[0024] 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 shown schematically for a clearer explanation. Thus, the sizes and ratios of each component do not fully reflect the actual sizes and ratios.

[0025] (First Embodiment) FIG. 1 is a perspective view for explaining a battery pack according to an exemplary embodiment.

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

[0027] FIG. 3 is a cross-sectional view showing the first side beam of FIG. 2.

[0028] FIG. 4 is a cross-sectional view showing the second side beam of FIG. 2.

[0029] Referring to FIGS. 1 to 4, the battery pack 100 may include a pack housing 110 and a plurality of battery cell assemblies 120_1, 120_2, 120_3, 120_4, 120_5, 120_6 (hereinafter, 120_1 to 120_6). The battery pack 100 may be a final product to be mounted in an application such as a vehicle.

[0030] The pack housing 110 may provide space for mounting multiple battery cell assemblies 120_1 to 120_6. The pack housing 110 may include a base plate 111 and side walls 112, 113, 114, and 115.

[0031] Here, we define 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 multiple battery cell assemblies 120_1 to 120_6.

[0032] 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.

[0033] According to exemplary embodiments, 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.

[0034] The pack housing 110 may include a center beam 116. The center beam 116 may extend in the X direction. The center beam 116 may be interposed between the side walls 112 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 to each other. Thus, the center beam 116 may be formed together with the center plate. The center beam 116 may then be a continuous element as an integral part with the center plate.

[0035] The base plate 111 may include a plurality of cooling channels. The plurality of cooling channels can provide passages for the movement of a coolant, such as water. The plurality of cooling channels may be formed by an extrusion process. The plurality of cooling channels may extend in the X direction. The plurality of cooling channels may be spaced apart in the Y direction.

[0036] Multiple battery cell assemblies 120_1 to 120_6 can be arranged on a base plate 111 of the pack housing 110. The base plate 111 can support the multiple battery cell assemblies 120_1 to 120_6. Side walls 112, 113, 114, and 115 can horizontally surround the multiple battery cell assemblies 120_1 to 120_6.

[0037] In the following description, the technical concept of the present invention will be explained primarily in an embodiment in which the battery pack 100 is of a moduleless type and each of the multiple battery cell assemblies 120_1 to 120_6 does not include a module frame. This is for illustrative purposes only and does not limit the technical concept of the present invention in any way. Those skilled in the art will readily conceive, based on what is described herein, an embodiment in which the battery pack is of a module type and each of the multiple battery cell assemblies includes a module frame.

[0038] Each of the multiple battery assemblies 120_1 to 120_6 may include multiple battery cells 121, multiple separators 122, a first side beam 125a, a second side beam 125b, a first fire-resistant coating 127a, and a second fire-resistant coating 127b. Each of the multiple battery assemblies 120_1 to 120_6 may further include an integrated circuit assembly for providing electrical connections to the multiple battery cells 121 and for monitoring the multiple battery cells 121.

[0039] Each of the multiple battery cells 121 is a basic unit of a lithium-ion battery, i.e., a secondary battery. Each of the multiple battery cells 121 may include an electrode assembly, an electrolyte, and a case. Each of the multiple battery cells 121 may be one of a cylindrical battery cell, a prismatic battery cell, or a pouch-type battery cell. The case for a cylindrical battery cell may be a cylindrical metal can. The case for a prismatic battery cell may be a prismatic can. The case for a pouch-type battery cell may include an aluminum laminate sheet.

[0040] An electrode assembly may include a positive electrode, a negative electrode, and a separator membrane interposed between the positive and negative electrodes. Depending on the form of assembly, electrode assemblies are classified into jelly roll type and stack type. A jelly roll type electrode assembly includes a winding structure of a positive electrode, a negative electrode, and a separator membrane interposed between them. A stack type electrode assembly includes multiple positive electrodes, multiple negative electrodes, and multiple separator membranes interposed between them, stacked sequentially.

[0041] According to an exemplary embodiment, a plurality of battery cells 121 can be connected in series and / or in parallel. A plurality of battery cells 121 connected in parallel can form a plurality of banks, each of which can be connected in series.

[0042] The separators 122 may contain stretchable material and can absorb the swelling of the battery cells 121. According to an exemplary embodiment, the separators 122 may act as a thermal barrier. According to an exemplary embodiment, each of the separators 122 may have a high melting temperature and low thermal conductivity. According to an exemplary embodiment, each of the separators 122 may contain a flame retardant material, such as ceramic and coated glass material. According to an exemplary embodiment, the separators 122 may be configured to release a fire retarding material and a fire extinguishing agent in the event of a thermal runaway event.

[0043] The first side beam 125a and the second side beam 125b can be spaced apart from each other in the X direction with a plurality of battery cells 121 in between. The first side beam 125a and the second side beam 125b can horizontally cover the plurality of battery cells 121. The first side beam 125a and the second side beam 125b can be fixed to the plurality of battery cells 121 by an adhesive or the like.

[0044] According to exemplary embodiments, the first side beam 125a and the second side beam 125b may have different and complementary shapes. The first side beam 125a and the second side beam 125b may fit together. The complementary shapes of the first side beam 125a and the second side beam 125b are a concept that includes clearance between them for assembly margins.

[0045] The first side beam 125a may include vertical ribs P1a, P2a and horizontal ribs R1a, R2a, R3a, R4a. The vertical ribs P1a, P2a may be substantially perpendicular to the X direction. The vertical ribs P1a, P2a may be spaced apart from each other in the X direction. The vertical rib P1a may be in contact with one of the multiple battery cells 121. The vertical rib P2a may be spaced apart from the multiple battery cells 121 with the vertical rib P1a in between. The length of the vertical rib P1a in the Z direction may be greater than the length of the vertical rib P2a in the Z direction. The vertical rib P2a may overlap the top of the vertical rib P1a in the X direction.

[0046] Horizontal ribs R1a, R2a, R3a, and R4a may be substantially perpendicular to the Z direction. Horizontal ribs R1a, R2a, R3a, and R4a may be separated from each other in the Z direction. Horizontal ribs R1a, R2a, R3a, and R4a may be interposed between vertical ribs P1a and P2a. Horizontal ribs R1a, R2a, R3a, and R4a may be connected to vertical ribs P1a and P2a. Horizontal ribs R3a and R4a may be interposed between horizontal ribs R1a and R2a.

[0047] There may be a gap 125aC between the vertical ribs P1a, P2a and the horizontal ribs R1a, R2a, R3a, R4a. This allows for a reduction in the weight of the first side beam 125a, and improves the energy density of the battery pack 100.

[0048] The first side beam 125a may include a stepped structure STa. More specifically, the lower part of the vertical rib P1a, the vertical rib P2a, and the horizontal rib R2a may constitute the stepped structure STa. The stepped structure STa may face outwards towards the multiple battery cell assemblies 120_1 to 120_6.

[0049] The second side beam 125b may include vertical ribs P1b, P2b and horizontal ribs R1b, R2b, R3b. The vertical ribs P1b, P2b may be substantially perpendicular to the X direction. The vertical ribs P1b, P2b may be spaced apart from each other in the X direction. The vertical rib P1b may be in contact with one of the multiple battery cells 121. The vertical rib P2b may be spaced apart from the multiple battery cells 121 with the vertical rib P1b in between. The length of the vertical rib P1b in the Z direction may be greater than the length of the vertical rib P2b in the Z direction. The vertical rib P2b may overlap the lower part of the vertical rib P1b in the X direction.

[0050] Horizontal ribs R1b, R2b, and R3b may be substantially perpendicular to the Z direction. Horizontal ribs R1b, R2b, and R3b may be spaced apart from each other in the Z direction. Horizontal ribs R1b, R2b, and R3b may be interposed between vertical ribs P1b and P2b. Horizontal ribs R1b, R2b, and R3b may be connected to vertical ribs P1b and P2b. Horizontal rib R3b may be interposed between horizontal ribs R1b and R2b.

[0051] A gap 125bC may exist between the vertical ribs P1b, P2b and the horizontal ribs R1b, R2b, R3b. This allows for a reduction in the weight of the second side beam 125b, and thus improves the energy density of the battery pack 100.

[0052] The second side beam 125b may include a stepped structure STb. More specifically, the upper part of the vertical rib P1b, the vertical rib P2b, and the horizontal rib R2b may constitute the stepped structure STb. The stepped structure STb may face outwards to a plurality of battery cell assemblies 120_1 to 120_6.

[0053] The distance between horizontal rib R3b and base plate 111 may be greater than the distance between horizontal rib R2b and base plate 111. The distance between horizontal rib R1b and base plate 111 may be greater than the distance between horizontal rib R3b and base plate 111. The distance between horizontal rib R2a and base plate 111 may be greater than the distance between horizontal rib R1b and base plate 111. The distance between horizontal rib R4a and base plate 111 may be greater than the distance between horizontal rib R2a and base plate 111. The distance between horizontal rib R3a and base plate 111 may be greater than the distance between horizontal rib R4a and base plate 111. The distance between horizontal rib R1a and base plate 111 may be greater than the distance between horizontal rib R3a and base plate 111.

[0054] According to an exemplary embodiment, each second side beam 125b of a plurality of battery assemblies 120_1 to 120_6 can be coupled to the first side beam 125a of the subsequent plurality of battery assemblies 120_1 to 120_6. According to an exemplary embodiment, each second side beam 125b of a plurality of battery assemblies 120_1 to 120_6 can be fixed to the base plate 111 by fasteners such as bolts to the first side beam 125a of the subsequent plurality of battery assemblies 120_1 to 120_6.

[0055] The lower part of the vertical rib P1a of multiple battery assemblies 120_1 to 120_6 may face the vertical rib P2b of the preceding battery assembly 120_1 to 120_6. The upper part of the vertical rib P1b of multiple battery assemblies 120_1 to 120_6 may face the vertical rib P2a of the preceding battery assembly 120_1 to 120_6. The horizontal rib R1b of multiple battery assemblies 120_1 to 120_6 may face the horizontal rib R2a of the preceding battery assembly 120_1 to 120_6.

[0056] Battery cell assemblies 120_1, 120_2, and 120_3 may be arranged in the X direction. The second side beam 125b of battery assembly 120_1 may be coupled to the first side beam 125a of battery assembly 120_2. The second side beam 125b of battery assembly 120_2 may be coupled to the first side beam 125a of battery assembly 120_3. The second side beam 125b of battery assembly 120_3 may be coupled to a supporting beam on the base plate 111.

[0057] The battery cell assemblies 120_4, 120_5, and 120_6 may be arranged in the X direction. The second side beam 125b of battery assembly 120_4 may be coupled to the first side beam 125a of battery assembly 120_5. The second side beam 125b of battery assembly 120_5 may be coupled to the first side beam 125a of battery assembly 120_6. The second side beam 125b of battery assembly 120_6 may be coupled to a supporting beam on the base plate 111.

[0058] The first fire-resistant coating 127a may be on the first side beam 125a. The second fire-resistant coating 127b may be on the second side beam 125b. Each of the first fire-resistant coating 127a and the second fire-resistant coating 127b may contain a fire-resistant material.

[0059] Each of the first refractory coating 127a and the second refractory coating 127b may have a high melting point and / or ignition point. According to an exemplary embodiment, the melting point and / or ignition point of each of the first refractory coating 127a and the second refractory coating 127b may be about 300°C or higher. According to an exemplary embodiment, the melting point and / or ignition point of each of the first refractory coating 127a and the second refractory coating 127b may be about 600°C or higher. According to an exemplary embodiment, the melting point and / or ignition point of each of the first refractory coating 127a and the second refractory coating 127b may be about 1000°C or higher. According to an exemplary embodiment, the melting point and / or ignition point of each of the first refractory coating 127a and the second refractory coating 127b may be 1500°C or higher.

[0060] Each of the first fire-resistant coating 127a and the second fire-resistant coating 127b may have a low thermal conductivity. According to an exemplary embodiment, the thermal conductivity of each of the first fire-resistant coating 127a and the second fire-resistant coating 127b may be about 20 W / mK or less. According to an exemplary embodiment, the thermal conductivity of each of the first fire-resistant coating 127a and the second fire-resistant coating 127b may be about 1 W / mK or less. According to an exemplary embodiment, the thermal conductivity of each of the first fire-resistant coating 127a and the second fire-resistant coating 127b may be about 0.3 W / mK or less. The thermal conductivity of each of the first fire-resistant coating 127a and the second fire-resistant coating 127b described above may be measured at room temperature (about 25°C).

[0061] Each of the first refractory coating 127a and the second refractory coating 127b may be provided by any one of the following methods: spraying, printing, vapor deposition, painting, dipping, spin coating, roller coating, floating coating, curtain coating, sputtering, co-extrusion, etc.

[0062] According to exemplary embodiments, each of the first fire-resistant coating 127a and the second fire-resistant coating 127b may have a uniform thickness. This allows each of the first fire-resistant coating 127a and the second fire-resistant coating 127b to have a conformal shape. That is, the shapes of the first stepped structure STa and the second stepped structure STb can be transferred to the first fire-resistant coating 127a and the second fire-resistant coating 127b. According to exemplary embodiments, the thickness of each of the first fire-resistant coating 127a and the second fire-resistant coating 127b may be in the range of about 10 μm to about 50 μm.

[0063] A TIM (Thermal Interface Material) layer 130 may be provided between the base plate 111 of the pack housing 110 and the multiple battery cell assemblies 120_1 to 120_6. The TIM layer 130 may contain a resin composition. The TIM layer 130 may be provided by a thermal resin coating process.

[0064] The resin composition may be a room-temperature curing composition; that is, the curing reaction of the resin composition may begin and proceed at room temperature. The curing reaction of the resin composition may be accelerated at temperatures higher than room temperature. The curing reaction rate of the resin composition at temperatures higher than room temperature may be faster than the curing reaction rate of the resin composition at room temperature. As a non-limiting example, the main component of the resin composition may be any one of silicone resin, polyol resin, epoxy resin, and acrylic resin.

[0065] The center beam 116 may extend in the X direction. The center beam 116 may isolate multiple battery cell assemblies 120_1 to 120_6 in the Y direction. The center beam 116 may be interposed between multiple battery cell assemblies 120_1 to 120_6.

[0066] In Figure 1, the arrangement of the multiple battery cell assemblies 120_1 to 120_6 can be described as a 3x2 arrangement. The arrangement of the multiple battery cell assemblies 120_1 to 120_6 disclosed in Figure 1 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 conceive of multiple battery cell assemblies 120_1 to 120_6 arranged in an MxN configuration (where M and N are integers greater than or equal to 2) based on what is described herein.

[0067] The battery pack 100 may further include a lid that is coupled to the side walls 112, 113, 114, and 115 of the pack housing 110. The lid may cover elements that are mounted inside the battery pack 100, such as a plurality of battery cell assemblies 120_1 to 120_6 and electrical components. The lid may be secured to the pack housing 110 by mechanical coupling means, such as bolting.

[0068] 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 devices may be configured to delay 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_1 to 120_6.

[0069] Here, thermal runaway in multiple battery cell assemblies 120_1 to 120_6 is a state in which the temperature change in multiple battery cell assemblies 120_1 to 120_6 further accelerates that temperature change, resulting in an uncontrollable positive feedback loop. In a thermal runaway state, multiple battery cell assemblies 120_1 to 120_6 exhibit a rapid temperature increase and emit large amounts of high-pressure gas and combustion residue.

[0070] Furthermore, each of the battery cell assemblies 120_1 to 120_6 according to the exemplary embodiment includes a first fire-resistant coating 127a and a second fire-resistant coating 127b, which can prevent thermal runaway events from propagating in the X direction, thereby improving the safety of the battery pack 100.

[0071] The battery pack 100 may further include a Battery Management System (BMS). The BMS may be configured to perform monitoring, balancing, and control of the battery pack 100. Monitoring of the battery pack 100 may include monitoring the voltage and current of specific nodes within a plurality of battery cell assemblies 120_1 to 120_6, and monitoring the temperature distribution at a set location within the battery pack 100.

[0072] Balancing the battery pack 100 is an operation that reduces deviations between multiple battery cell assemblies 120_1 to 120_6. 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. This can prevent shortening of the lifespan of each of the multiple battery cell assemblies 120_1 to 120_6.

[0073] The battery pack 100 may further include additional electrical components such as 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 overheating of each of the battery cell assemblies 120_1 to 120_6 by circulating air inside the battery pack 100. The PRA may be configured to supply or cut off power from the high-voltage battery to an external load (e.g., the vehicle's motor). The PRA can protect the battery cell assemblies 120_1 to 120_6 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. Additional electrical components may be interposed between the battery cell assemblies 120_1 to 120_6 and the side wall 115. The space between the battery cell assemblies 120_1 to 120_6 and the side wall 115 may be called the electrical component mounting area.

[0074] The battery pack 100 may further include a plurality of interbus bars configured to electrically connect a plurality of battery cell assemblies 120_1 to 120_6. The plurality of battery cell assemblies 120_1 to 120_6 may be connected in series by the plurality of interbus bars. This may configure the battery pack 100 to output a high voltage to an external load (e.g., a vehicle motor).

[0075] (Second Embodiment) Figure 5 is a plan view showing a battery pack 100' according to an exemplary embodiment.

[0076] Figure 6 is a cross-sectional view along the cutting line 5I-5I' in Figure 5.

[0077] Figure 7 is a cross-sectional view of the fire-resistant structures 127a' and 127b' shown in Figure 6.

[0078] Referring to Figures 5 to 7, the battery pack 100' may include a pack housing 110 and a plurality of battery cell assemblies 120_1', 120_2', 120_3', 120_4', 120_5', 120_6' (hereinafter referred to as 120_1' to 120_6'). The battery pack 100' may be a final product that is implemented in applications such as vehicles.

[0079] The pack housing 110 is substantially the same as that described with reference to Figure 1. Multiple battery cell assemblies 120_1' to 120_6' may be substantially the same as multiple battery cell assemblies 120_1 to 120_6, except that they include a first fire-resistant structure 127a' and a second fire-resistant structure 127b' instead of a first fire-resistant coating 127a and a second fire-resistant coating 127b.

[0080] The first fire-resistant structure 127a' may be on the first side beam 125a. The second fire-resistant structure 127b' may be on the second side beam 125b. Each of the first fire-resistant structure 127a' and the second fire-resistant structure 127b' may include a fire-resistant adhesive layer L1, a fire-resistant sheet L2, and a fire-resistant coating L3.

[0081] Each of the fire-resistant adhesive layer L1, fire-resistant sheet L2, and fire-resistant coating L3 may have a high melting point and / or ignition point. According to an exemplary embodiment, the melting point and / or ignition point of each of the fire-resistant adhesive layer L1, fire-resistant sheet L2, and fire-resistant coating L3 may be about 300°C or higher. According to an exemplary embodiment, the melting point and / or ignition point of each of the fire-resistant adhesive layer L1, fire-resistant sheet L2, and fire-resistant coating L3 may be about 600°C or higher. According to an exemplary embodiment, the melting point and / or ignition point of each of the fire-resistant adhesive layer L1, fire-resistant sheet L2, and fire-resistant coating L3 may be about 1000°C or higher. According to an exemplary embodiment, the melting point and / or ignition point of each of the fire-resistant adhesive layer L1, fire-resistant sheet L2, and fire-resistant coating L3 may be 1500°C or higher.

[0082] Each of the fire-resistant adhesive layer L1, fire-resistant sheet L2, and fire-resistant coating L3 may have a low thermal conductivity. According to an exemplary embodiment, the thermal conductivity of each of the fire-resistant adhesive layer L1, fire-resistant sheet L2, and fire-resistant coating L3 may be about 20 W / mK or less. According to an exemplary embodiment, the thermal conductivity of each of the fire-resistant adhesive layer L1, fire-resistant sheet L2, and fire-resistant coating L3 may be about 1 W / mK or less. According to an exemplary embodiment, the thermal conductivity of each of the fire-resistant adhesive layer L1, fire-resistant sheet L2, and fire-resistant coating L3 may be about 0.3 W / mK or less. The thermal conductivity of each of the fire-resistant adhesive layer L1, fire-resistant sheet L2, and fire-resistant coating L3 described above may be measured at room temperature (about 25°C).

[0083] The fire-resistant adhesive layer L1 may be a fire-resistant adhesive tape. The first fire-resistant structure 127a' and the second fire-resistant structure 127b' can be bonded to the first side beam 125a and the second side beam 125b by the fire-resistant adhesive layer L1 of the first fire-resistant structure 127a' and the second fire-resistant structure 127b'.

[0084] The fire-resistant sheet L2 may contain a different substance from the fire-resistant adhesive layer L1. The fire-resistant sheet L2 may contain a fire-resistant material. The fire-resistant sheet L2 may contain either NCG (Non Combustible Glass Fiber Sheet) or glass fiber-containing mPPO (Modified Polyphenylene Oxide).

[0085] The refractory coating L3 may contain a different substance from the refractory adhesive layer L1. The refractory coating L3 may contain a different substance from the refractory sheet L2. The refractory coating L3 may contain ceramics. The refractory coating L3 may be provided by a paint-type coating agent. The refractory coating L3 may be provided using a ceramic water-soluble coating agent. The refractory coating L3 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.

[0086] The fire-resistant adhesive layer L1 and the fire-resistant coating L3 may be provided centered on the fire-resistant sheet L2. That is, the fire-resistant adhesive layer L1 and the fire-resistant coating L3 may be provided by a tape adhesion step and a coating step on the fire-resistant sheet L2. The fire-resistant sheet L2 may be, for example, a substrate for forming a first fire-resistant structure 127a' and a second fire-resistant structure 127b'. According to an exemplary embodiment, the fire-resistant sheet L2 may be a fire-resistant sheet.

[0087] According to exemplary embodiments, each of the fire-resistant adhesive layer L1, fire-resistant sheet L2, and fire-resistant coating L3 may have a uniform thickness. According to exemplary embodiments, the thickness of each of the fire-resistant adhesive layer L1, fire-resistant sheet L2, and fire-resistant coating L3 may be in the range of about 10 μm to about 50 μm. According to exemplary embodiments, the combined thickness of the fire-resistant adhesive layer L1, fire-resistant sheet L2, and fire-resistant coating L3 may be in the range of about 50 μm to about 200 μm.

[0088] 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, at the time of filing, there may be a variety of equivalents and modifications that can substitute for them.

Claims

1. Pack housing including base plate, A battery pack comprising a plurality of battery cell assemblies on the base plate, Each of the aforementioned plurality of battery cell assemblies is Multiple battery cells arranged in the first direction, A first side beam positioned on one side of the battery assembly and a second side beam positioned on the other side of the battery assembly, which are spaced apart in the first direction with the plurality of battery cells in between. The first fire-resistant structure coupled to the first side beam, The second fire-resistant structure is coupled to the second side beam, Includes, The first side beam includes a first stepped structure, The second side beam includes a second stepped structure, The first stepped structure and the second stepped structure have complementary shapes. The second side beam of each of the aforementioned battery assemblies is coupled to the first side beam of the subsequent battery assembly to form a continuous fire-resistant structure. Battery pack.

2. The first fire-resistant structure includes a first fire-resistant sheet and a first fire-resistant adhesive layer applied to the first fire-resistant sheet. The first fire-resistant sheet and the first fire-resistant adhesive layer contain different materials from each other. The first fire-resistant structure further includes a first fire-resistant coating on the first fire-resistant sheet, The first fire-resistant coating contains a substance different from the first fire-resistant sheet. The battery pack according to claim 1.

3. The first fire-resistant structure is bonded to the first stepped structure. The battery pack according to claim 1.

4. The first fire-resistant structure has a shape conforming to the first stepped structure. The battery pack according to claim 3.

5. The second fire-resistant structure includes a second fire-resistant sheet and a second fire-resistant adhesive layer applied to the second fire-resistant sheet. The second fire-resistant structure further includes a second fire-resistant coating on the second fire-resistant sheet. The battery pack according to any one of claims 1 to 4.

6. Pack housing including base plate, A battery pack comprising a plurality of battery cell assemblies on the base plate, Each of the aforementioned plurality of battery cell assemblies is Multiple battery cells arranged in the first direction, A first side beam positioned on one side of the battery assembly and a second side beam positioned on the other side of the battery assembly, which are spaced apart in the first direction with the plurality of battery cells in between. The first fire-resistant coating on the first side beam, The second fire-resistant coating on the second side beam, Includes, The first side beam includes a first stepped structure, The second side beam includes a second stepped structure, The first side beam and the second side beam have different and complementary shapes. The second side beam of each of the aforementioned battery assemblies is coupled to the first side beam of a subsequent battery assembly to form a continuous fire-resistant coating. Battery pack.

7. Each of the first and second fire-resistant coatings has a uniform thickness. The battery pack according to claim 6.

8. Each of the first and second fire-resistant coatings contains ceramic, The battery pack according to claim 6.

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