Battery module frame

Abstract

The disclosed invention relates to a battery module frame that houses a plurality of battery cells therein, the battery module frame including a first layer made of aluminum or aluminum alloy material, a second layer laminated on the first layer and made of a metal material with a mesh structure, and a third layer laminated on the second layer and made of aluminum or aluminum alloy material.

Description

[Technical field]

[0001] The present invention relates to a battery module frame, and more particularly to a battery module frame that can prevent the spread of secondary damage such as an external fire or explosion by preventing the flame from being exposed to the outside of the frame even if a battery cell mounted inside the frame overheats and generates a flame.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0075257 dated June 21, 2022, and Korean Patent Application No. 10-2022-0182542 dated December 23, 2022, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference. [Background technology]

[0003] Unlike primary batteries, secondary batteries can be recharged, and they have been much researched and developed in recent years due to their potential for miniaturization and large capacity. The demand for secondary batteries as an energy source is rapidly increasing due to the increasing technological development and demand for mobile devices, as well as the emergence of electric vehicles and energy storage systems in response to the modern demand for environmental protection.

[0004] Secondary batteries are classified into coin type batteries, cylindrical type batteries, square type batteries, and pouch type batteries according to the shape of the battery case. In secondary batteries, the electrode assembly installed inside the battery case is a power generating element capable of charging and discharging, which is made of a laminated structure of electrodes and a separator.

[0005] Since secondary batteries are required to be used continuously for long periods of time, it is necessary to effectively control the heat generated during the charging and discharging process.If secondary batteries are not cooled smoothly, a positive feedback chain reaction occurs in which an increase in temperature causes an increase in current, and the increase in current causes another increase in temperature, ultimately leading to a catastrophic state of thermal runaway.

[0006] In addition, when secondary batteries are grouped together in the form of a module or pack, a thermal propagation phenomenon occurs in which a thermal runaway that occurs in any one secondary battery causes other surrounding secondary batteries to continuously overheat. Furthermore, if a flame generated by an overheated secondary battery is exposed to the outside, it may not only damage surrounding devices, but may also spread to secondary damage such as fire or explosion, so measures against such fire hazards must be taken. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Korean Patent Publication No. 2020-0078344 Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a battery module frame that can prevent the spread of secondary damage such as an external fire or explosion by preventing the flame from being exposed to the outside of the frame even if a battery cell mounted inside overheats and causes a flame.

[0009] However, the technical problem that the present invention aims to solve is not limited to the above-mentioned problem, and other problems not mentioned will be clearly understood by those of ordinary skill in the art from the description of the invention described below. [Means for solving the problem]

[0010] The present invention relates to a battery module frame that houses a plurality of battery cells therein. In one example, the battery module frame includes a first layer made of aluminum or aluminum alloy material, a second layer laminated on the first layer and made of a metal material with a mesh structure, and a third layer laminated on the second layer and made of aluminum or aluminum alloy material.

[0011] In one aspect of the present invention, the battery module frame may be formed by pressing the first layer, the second layer, and the third layer together in a stacked state.

[0012] A fastening portion is formed in the first layer or the third layer, and the fastening portion may be a welded portion or a bolted portion.

[0013] The second layer may be made of a metal material having a higher melting point than the melting points of the first and third layers, for example, the metal material of the second layer may be a steel or stainless steel material.

[0014] Meanwhile, according to one aspect of the present invention, at least one surface of the battery module frame may be formed with a ventilation portion that exposes the second layer in a portion of the first layer and the third layer.

[0015] For example, the ventilation portion may be formed on an upper surface of the battery module frame.

[0016] The ventilation portion may be formed in a plurality of diagonal directions on the upper surface of the battery module frame.

[0017] It can be said that the second layer mesh structure included in the upper surface of the battery module frame is preferably denser than the second layer mesh structure included in the other surface of the battery module frame.

[0018] It can be said that it is preferable that the inner ventilation portion formed in the first layer and the outer ventilation portion formed in the third layer do not overlap each other.

[0019] In addition, the outer ventilation portion formed in the third layer may be spaced apart diagonally from the inner ventilation portion formed in the first layer on the upper surface of the battery module frame.

[0020] The outer ventilation portion may include a plurality of ventilation holes whose ventilation area increases with increasing distance from the inner ventilation portion. Effect of the Invention

[0021] The battery module frame of the present invention having the above-mentioned configuration is made of a composite material in which a structural layer of aluminum material is sandwiched between a metal layer of a mesh structure, thereby forming a lightweight frame structure. At the same time, even if a flame occurs inside, the mesh structure acts to extinguish the flame, preventing the flame from being exhausted to the outside.

[0022] In addition, by incorporating the mesh structure and wrapping its exterior with a structural layer made of aluminum material, an assembly structure can be easily realized by welding, bolting, etc.

[0023] In addition, the arrangement and shape of the ventilation parts can be optimized to effectively extinguish any fire that occurs inside, further reducing the risk of fire.

[0024] However, the technical effects that can be obtained by the present invention are not limited to the effects described above, and other effects not mentioned will be clearly understood by those of ordinary skill in the art from the description of the invention described below. [Brief description of the drawings]

[0025] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention described below, serve to further understand the technical concept of the present invention. Therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings. [Figure 1] 1 is a view illustrating an example of a battery module including a battery module frame according to the present invention. [Diagram 2] 1 is a view illustrating a cross-sectional structure of a battery module frame before press forming. [Diagram 3]1 is a diagram illustrating an example of forming a main frame by press molding. [Figure 4] 1 is a view illustrating an embodiment in which an air hole is formed in an upper plate; [Diagram 5] 1 is a diagram illustrating a mesh structure of a main frame and an upper plate. [Figure 6] 13 is a diagram illustrating an example of connecting a main frame and an upper plate with bolts. [Figure 7] 1 is a diagram illustrating an arrangement structure of an inner ventilation part and an outer ventilation part. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Since the present invention can be modified in various ways and can have various embodiments, specific embodiments will be described in detail below.

[0027] However, this is not intended to limit the invention to any particular embodiment, but is to be understood as including all modifications, equivalents, or alternatives falling within the spirit and scope of the invention.

[0028] In the present invention, the terms "comprise" and "have" are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are to be understood as not precluding the presence or additional possibility of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0029] In addition, in the present invention, when a layer, film, region, plate, or other portion is described as being "on" another portion, this includes not only the case where it is "directly on" the other portion, but also the case where there is another portion in between. Conversely, when a layer, film, region, plate, or other portion is described as being "under" the other portion, this includes not only the case where it is "directly under" the other portion, but also the case where there is another portion in between. In addition, in the present application, being "on" can include not only the case where it is located at the top, but also the case where it is located at the bottom.

[0030] The present invention relates to a battery module frame that houses a plurality of battery cells therein. In one example, the battery module frame includes a first layer made of aluminum or aluminum alloy material, a second layer laminated on the first layer and made of a metal material with a mesh structure, and a third layer laminated on the second layer and made of aluminum or aluminum alloy material.

[0031] The battery module frame of the present invention having the above-mentioned configuration is made of a composite material in which a structural layer of aluminum material and a metal layer with a mesh structure are sandwiched between them, thereby forming a lightweight frame structure. At the same time, even if a flame occurs inside, the mesh structure acts to extinguish the flame, preventing the flame from being exhausted to the outside.

[0032] In addition, by incorporating the mesh structure and wrapping its exterior with a structural layer made of aluminum material, an assembly structure can be easily realized by welding, bolting, etc.

[0033] Hereinafter, a detailed description will be given of a specific embodiment of a battery module frame of the present invention with reference to the accompanying drawings. For reference, the directions of front, back, up, down, left and right specifying relative positions used in the following description are intended to facilitate understanding of the invention, and unless otherwise specified, are based on the directions shown in the drawings.

[0034] (First embodiment) 1 is a diagram illustrating an example of a battery module 10 including a battery module frame 100 of the present invention. The battery module 10 refers to a battery assembly in which a certain number of battery cells are bundled together and placed in a frame to protect the battery cells from external impact, heat, vibration, etc. The battery module 10 is made up of a number of battery cells connected to each other in series and / or parallel, and is embedded in the battery module frame 100, which is a mechanical structure.

[0035] Each battery cell acts as a source of energy, storing it and supplying it to the outside when needed, but because the capacity of a single battery cell is small, they are bundled together to create modules, and several modules are then combined to create a large-capacity battery pack.

[0036] The present invention relates to a battery module frame 100, which is a mechanical structure that protects a number of battery cells. The battery module 10 illustrated in Fig. 1 as an example includes a battery cell assembly 400 in which a number of battery cells are connected in series and / or parallel to form an assembly. Structures that are mechanically and electrically coupled to end plate assemblies 500 are provided on both ends of the battery cell assembly 400.

[0037] The battery module frame 100 includes a main frame 102 having a U-shaped cross section and forming a space therein for accommodating the battery cell assemblies 400, and an upper plate 104 covering the open upper surface of the main frame 102. End plate assemblies 500 are coupled to both open sides of the battery module frame 100 to seal the battery module 10, but in general, the end plate assemblies 500 may also be included in the battery module frame 100.

[0038] The battery module 10 has a polyhedral shape, hexahedral shape in Fig. 1, that accommodates a plurality of battery cells, and the cross-sectional structure of the battery module frame 100 is shown in Fig. 2. That is, Fig. 2 illustrates the cross-sectional structures of the main frame 102 and the upper plate 104, and further, the end plate assembly 500 may also have the cross-sectional structure of Fig. 2.

[0039] Referring to FIG. 2, the battery module frame 100 includes a first layer 110 made of aluminum or aluminum alloy material, a second layer 120 laminated on the first layer 110 and made of a metal material with a mesh structure, and a third layer 130 laminated on the second layer 120 and made of aluminum or aluminum alloy material.

[0040] That is, the battery module frame 100 of the present invention is made of a composite material in which structural layers of the first layer 110 and the third layer 130 made of an aluminum material are sandwiched between the structural layers and a metal layer with a mesh structure. Here, the structural layer means that the first layer 110 and the third layer 130 made of an aluminum material are layers that play a role in maintaining the mechanical structure of the battery module frame 100.

[0041] The second layer 120 sandwiched between the first layer 110 and the third layer 130 made of aluminum material is made of a metal layer with a mesh structure. The metal layer with a mesh structure can be understood as a porous metal layer in a broad sense. For example, the second layer 120 can be made of a metal net, wire mesh, or a metal thin film with a large number of through holes. Alternatively, a flat wire mass made of thin metal threads wound in a spiral shape can be inserted into the metal layer with the mesh structure.

[0042] The battery module frame 100 of the present invention uses aluminum material as a structural layer and includes a mesh metal layer in the middle, so that in addition to the weight reduction achieved by the aluminum material, a lightweight frame structure can be realized due to the weight reduction achieved by the mesh structure.

[0043] In addition, the battery module frame 100 of the present invention has a mesh-structured second layer 120 interposed between the first layer 110 and the third layer 130 made of aluminum material, which not only allows flames generated during thermal runaway of the battery cells to pass through and breaks them into small pieces, but also causes an endothermic reaction that absorbs the flame energy, thereby reducing temperature and extinguishing the flame.

[0044] More specifically, the mesh structure of second layer 120 has many small holes, so that vapors such as gases and steam can easily pass through second layer 120, but flames have a relatively low chance of passing through.

[0045] In addition, the mesh structure of the second layer 120 absorbs and dissipates heat generated from the combusted gas mixture when the mixture of combustible gas and air inside the battery cell is ignited, thereby lowering the combustion temperature so that the surrounding gas does not rise to its spontaneous ignition temperature. This is because the high-temperature gas absorbs heat into the porous structure of the metal material as it passes through the mesh-structured second layer 120. In other words, the second layer 120 is made of a metal material with numerous holes and functions as a flame arrester with a very wide cross-sectional area.

[0046] Therefore, the flame generated by the thermal runaway of the battery cell loses an amount of heat that is too large to sustain the flame while passing through the battery module frame 100 of the present invention, thereby effectively suppressing the heat propagation phenomenon and external fires.

[0047] In one embodiment of the present invention, the second layer 120, which is a mesh metal layer, may be made of a metal material having a higher melting point than the melting points of the first layer 110 and the third layer 130, such as aluminum. For example, the metal material constituting the second layer 120 may be a steel or stainless steel material.

[0048] When a fire occurs in the battery cell assembly 400, it attempts to melt the first layer 110 of the battery module frame 100 and erupt to the outside. In order for the second layer 120, which is a mesh metal layer, to maintain its flame-extinguishing function for a long period of time, the mesh structure needs to have heat-resistant properties, so it is preferable that the second layer 120 has a higher melting point than the first layer 110 and the third layer 130, which are made of an aluminum material.

[0049] In addition, it is preferable to select a material having mechanical properties to withstand explosion pressure as well as flame-extinguishing ability to prevent flames for the second layer 120. In this regard, the second layer 120 may be made of a steel or stainless steel material that is heat-resistant and has excellent mechanical strength.

[0050] For example, the second layer 120 can be made of a heat-resistant stainless steel, which can be a ferritic stainless steel alloy such as X10CrAlSi7, X10CrAl13, X10CrAl18, and X18CrN28, an austenitic stainless steel alloy such as X15CrNiSi20-12, X15CrNiSi25-20, X15CrNiSi25-21, and X12CrNiTi18-10, or a nickel-chromium stainless steel alloy such as NiCr15Fe, NiCr23Fe, NiCr22Mo9Nb, NiCr21Mo, and NiCr28FeSiCe.

[0051] In this way, since the second layer 120 of the mesh structure is a thin plate, an increase in size of the battery module frame 100 can be suppressed. In addition, since the second layer 120 has a large number of holes, an increase in weight can also be suppressed. Therefore, the battery module frame 100 of the present invention improves the safety of the battery module 10 by preventing the flame from erupting to the outside in the event of a fire erupting from a battery cell while suppressing an increase in size and weight of the battery module 10 and further the battery pack.

[0052] Meanwhile, Fig. 3 is a view illustrating an example of forming a main frame 102 by press molding. Referring to Fig. 3, the battery module frame 100 of the present invention may be formed collectively by press processing in a flat plate state in which the first layer 110 to the third layer 130 are all stacked.

[0053] Since the second layer 120 of the mesh structure is a thin plate, for example with a thickness of about 1 to 2 mm, the second layer 120 of the mesh structure is manufactured into a flat plate shape (see FIG. 2) by bonding the second layer 120 of the mesh structure between the first layer 110 and the third layer 130 of an aluminum material, and then, as shown in FIG. 3, the flat battery module frame 100 is placed between an upper mold UM and a lower mold BM and pressed to create a main frame 102 with a "U"-shaped cross section.

[0054] That is, the first layer 110 and the third layer 130 are made of aluminum, which is easy to sinter, and are therefore suitable for press processing, while the metal material constituting the second layer 120 is a steel or stainless steel material that has high mechanical strength, but is thin enough to be easily processed by press processing.

[0055] In this way, the battery module frame 100 of the present invention can be deformed into various shapes by pressing a flat preliminary frame in which the mesh-structured second layer 120 is bonded between the first layer 110 and third layer 130 made of aluminum material, and therefore can maintain the same level of productivity as existing frames that do not have a mesh metal layer.

[0056] Second embodiment Meanwhile, in the second embodiment of the present invention, an air vent may be formed in the upper plate 104 constituting the battery module frame 100. FIG. 4 illustrates an exemplary embodiment in which an air vent is formed in the upper plate 104.

[0057] For reference, in the second embodiment, a vent hole is formed in the upper plate 104 in the battery module frame 100 as an example. This is in consideration of the fact that flames mainly propagate upwards, and it goes without saying that a vent hole may also be formed in the main frame 102. Here, the position of the vent hole needs to be selected in consideration of the risk of an external fire or secondary damage to surrounding components due to high-temperature gas or partial flames ejected from the vent hole.

[0058] 4, an outer ventilation part 320 is formed in a part of the third layer 130 of the upper plate 104 forming the upper surface of the battery module frame 100, and the second layer 120 is exposed to the outside through the outer ventilation part 320. And, referring to FIGS. 5 to 7, an inner ventilation part 310 exposing the second layer 120 is also formed in the first layer 110 of the upper plate 104.

[0059] The ventilation part 300 including the inner ventilation part 310 and the outer ventilation part 320 is formed by cutting a part of the first layer 110 and the third layer 130 of the battery module frame 100, respectively, and the second layer 120 is exposed by the ventilation part 300. When a fire occurs in the battery module 10 and the temperature and pressure increase, a part of the battery module frame 100 melts and the flame erupts to the outside. The location from which the flame erupts may be determined by the point where the fire started or the local strength of the battery module frame 100, but it is difficult to predict such a location.

[0060] Therefore, in the second embodiment of the present invention, ventilation portion 300 is formed by intentionally cutting a part of each of first layer 110 and third layer 130, thereby restricting the position of the flame to erupt at a specified point, i.e., ventilation portion 300. Therefore, by appropriately designing the position of ventilation portion 300, the risk of secondary damage such as an external fire can be significantly reduced.

[0061] In an embodiment of the present invention, a plurality of ventilation parts 300 may be formed diagonally on one surface, for example, the upper surface of the battery module frame 100 in the drawing. Since the ventilation parts 300 are areas where flames pass through the second layer 120, which is a mesh metal layer, and erupt to the outside of the third layer 130, when a plurality of ventilation parts 300 are formed, they should be spaced far apart from each other so that the flames can pass through the second layer 120 for a sufficient distance and time to lose heat.

[0062] It is also preferable that the inner ventilation part 310 formed in the first layer 110 and the outer ventilation part 320 formed in the third layer 130 do not overlap each other. This is because if the inner ventilation part 310 and the outer ventilation part 320 are directly connected, it is difficult to ensure a sufficient flame path for the second layer 120 to exert a flame quenching effect.

[0063] 7, the outer ventilation portion 320 formed in the third layer 130 may be spaced apart in a diagonal direction from the inner ventilation portion 310 formed in the first layer 110. Due to such an arrangement of the inner ventilation portion 310 and the outer ventilation portion 320, the inner ventilation portion 310 and the outer ventilation portion 320 do not overlap each other, and the distance between the inner ventilation portion 310 and the outer ventilation portion 320 may be increased.

[0064] The outer ventilation part 320 may be configured in a form in which a plurality of ventilation holes form one group, and in this case, it is preferable that the outer ventilation part 320 has an arrangement of stepped sizes in which the ventilation area of ​​the ventilation hole increases as the distance d from the inner ventilation part 310 increases. This is because the flame path passing through the mesh structure of the second layer 120 is long, and it is advantageous from the standpoint of flame extinguishing to allow the flame that has sufficiently lost heat to be discharged more from the outer ventilation holes that are farther away from the inner ventilation part 310 than the outer ventilation holes.

[0065] Also, in consideration of the fact that flames mainly flow toward the upper surface of the battery module frame 100, the mesh structure of the second layer 120 included in the upper surface of the battery module frame 100, i.e., the mesh structure of the upper plate 104, may be made denser than the mesh structure of the second layer 120 included on the other surface. This is because the denser the mesh structure, the greater the heat transfer area and the improved flame suppression capability.

[0066] A fastening portion 200 may be formed in the first layer 110 or the third layer 130, which are made of an aluminum material, and the fastening portion 200 may be a welded portion 210 or a bolted portion 220. Fig. 5 illustrates an example in which the fastening portion 200 is formed as a welded portion 210, and Fig. 6 illustrates an example in which the fastening portion 200 is formed as a bolted portion 220.

[0067] The battery module frame 100 of the present invention includes a mesh metal layer for flame suppression, and the second layer 120 of the mesh structure is embedded between the first layer 110 and the third layer 130 which are made of an aluminum material, so that the first layer 110 and the third layer 130 form a strong structural layer of the battery module frame 100. Therefore, the battery module frame 100 of the present invention has a built-in mesh structure, and the exterior of the mesh structure is wrapped in a structural layer made of an aluminum material, so that a fastening structure such as welding or bolting can be easily realized.

[0068] For reference, Figures 5 and 6 each illustrate an example in which a welding part 210 and a bolting part 220 constitute the fastening part 200, but it goes without saying that one battery module frame 100 may include a combination of a welding part 210 and a bolting part 220 as the fastening part 200.

[0069] The present invention has been described in more detail above with reference to the drawings and embodiments, etc. However, the configurations described in the drawings or embodiments, etc. in this specification are merely one embodiment of the present invention and do not represent all of the technical ideas of the present invention, so it should be understood that there may be various equivalents and modifications that can replace them at the time of filing this application. [Explanation of symbols]

[0070] 10: Battery module 100: Battery module frame 102: Mainframe 104: Upper plate 110: 1st layer 120: 2nd layer 130:Third layer 200: Fastening part 210: Welded parts 220: Bolting Department 300: Ventilation section 310: Inner ventilation section 320: Outer ventilation section 400: Battery cell assembly 500: End plate assembly UM: Upper mold BM: Lower mold

Claims

1. A battery module frame that accommodates a plurality of battery cells therein, The battery module frame includes: a first layer made of an aluminum or aluminum alloy material; a second layer made of a metal material having a mesh structure and laminated on the first layer; a third layer laminated on the second layer and made of aluminum or an aluminum alloy material; Including, the battery module frame.

2. The battery module frame includes: The battery module frame according to claim 1 , wherein the first layer, the second layer, and the third layer are molded together by pressing in a stacked state.

3. The battery module frame according to claim 2 , wherein a fastening portion is formed on the first layer or the third layer.

4. The battery module frame according to claim 3 , wherein the fastening portion is a welding portion or a bolting portion.

5. The battery module frame according to claim 1 , wherein the second layer is made of a metal material having a melting point higher than melting points of the first layer and the third layer.

6. The battery module frame according to claim 5 , wherein the metal material constituting the second layer is a steel or stainless steel material.

7. 7. The battery module frame according to claim 1, wherein at least one surface of the battery module frame has a ventilation portion formed in a portion of the first layer and the third layer to expose the second layer.

8. The battery module frame according to claim 7 , wherein the ventilation portion is formed on an upper surface of the battery module frame.

9. The battery module frame according to claim 8 , wherein the ventilation portion is formed in a plurality of diagonal directions on the upper surface of the battery module frame.

10. The battery module frame according to claim 8 , wherein the second layer mesh structure included on the upper surface of the battery module frame is denser than the second layer mesh structure included on the other surface of the battery module frame.

11. The battery module frame of claim 8 , wherein the inner ventilation portion formed in the first layer and the outer ventilation portion formed in the third layer do not overlap each other.

12. 12. The battery module frame of claim 11, wherein the outer ventilation portion formed in the third layer is spaced apart from the inner ventilation portion formed in the first layer in a diagonal direction on the upper surface of the battery module frame.

13. The battery module frame of claim 12 , wherein the outer ventilation portion includes a plurality of ventilation holes, the ventilation area of ​​which increases with increasing distance from the inner ventilation portion.

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