Battery module having improved gas venting structure and battery pack including same

Abstract

The present invention relates to a battery module with an improved gas venting structure and a battery pack including the same. By forming brackets on the inside of plates on which mesh structures are formed so that the mesh structures do not face each other, the battery module has excellent heat dissipation efficiency and can block the escape of sparks and fire sources even in the event of thermal runaway of the battery cells.

Description

[Technical field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2020-0099333, filed on August 7, 2020, and all contents disclosed in the documents of said Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a battery module having an improved gas venting structure and a battery pack including the same. [Background technology]

[0003] Generally, secondary batteries are batteries that can be used repeatedly by charging and discharging. They consist of a single battery module and are used in small portable electronic devices such as mobile phones, laptops, cameras, and camcorders, or consist of battery packs containing multiple battery modules and are used as power sources for driving motors in high-output hybrid electric vehicles (HEVs) and electric vehicles (EVs).

[0004] In particular, electric vehicles and the like use high-output electric energy, and therefore require a considerable number of batteries per vehicle. Therefore, there is a demand for a battery module combining a number of battery cells, or a battery pack including the battery module. A battery module has a structure in which a number of battery cells are housed, and there is a problem that heat is generated from each battery cell during charging and discharging, and the generated heat reheats the surrounding battery cells. In particular, when thermal runaway of a battery cell occurs due to abnormal operating conditions, sparks and fire are released along with the heat. In the process of discharging heat, existing battery modules also discharge sparks and fire, which may induce a fire outside the battery module. Therefore, when thermal runaway of a battery cell occurs, there is a need for a safety member that quickly dissipates the generated heat and prevents the sparks and fire from leaking out. In addition, such a safety member should not occupy an excessive volume or reduce process efficiency.

[0005] FIG. 1 is a perspective view and a cross-sectional view of a conventional battery module. Referring to FIG. 1, the conventional battery module 10 has a structure in which a number of battery cells 20 are accommodated in a module case 11. An end plate 14 on which a PCM substrate is mounted is located on one side of the module case 11, and a gas vent hole 10(a) for discharging gas is formed on one side of the end plate 14. Heat or gas discharged during charging and discharging of the battery cells is discharged through the gas vent hole 10(a). However, since the gas vent hole 10(a) is formed biasedly on one side of the battery module 10, there is a limitation that heat or gas is transferred to the surrounding battery cells 20 during the process of discharging, making it difficult to discharge gas. In some cases, an additional gas vent hole 10(b) is formed on the opposite side of the module case 10 where the end plate 14 is located. In this case, heat or gas can be more easily discharged. However, there is still a limitation that, during the process of discharging heat or gas, the heat is transferred to the surrounding battery cells 20, and the heat generated from a particular battery cell 20 is transferred to the surrounding battery cells 20 at a high speed.

[0006] Therefore, there is a need for a technology that can effectively exhaust heat or gas inside the battery module 10 while blocking heat transfer between the battery cells 20 housed therein. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] U.S. Patent Publication No. 2019-0097192 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been devised to solve the above problems, and an object of the present invention is to provide a battery module having an improved gas venting structure and a battery pack including the same. [Means for solving the problem]

[0009] The present invention provides a battery module. In one embodiment, the battery module according to the present invention includes a module case having a receiving portion for receiving a battery cell, and one or more battery cells received in the module case, and a gas venting structure is formed on one or more side surfaces of the module case. Specifically, the gas venting structure includes a first partition wall including a first gas venting hole and a first mesh structure configured to cover the first gas venting hole, and a second partition wall formed at a certain distance outside the first partition wall and including a second gas venting hole and a second mesh structure configured to cover the second gas venting hole. In addition, the first gas venting hole formed in the first partition wall and the second gas venting hole formed in the second partition wall are located in regions that do not face each other.

[0010] In another example, the gas venting structure is a structure formed on both opposing side surfaces of the module case.

[0011] In a specific example, the outflow path of the venting gas through the gas venting structure has a structure having two rotation paths based on the cross section, for example, each of the rotation paths is a path that is rotated in a vertical direction.

[0012] In another specific example, the outflow path of the venting gas through the above gas venting structure includes, based on the cross section, a primary rotation path in which the venting gas discharged through the first mesh structure formed in the first partition bends as it enters the space between the first partition and the second partition, and a secondary rotation path in which the venting gas passes through the space between the first partition and the second partition and then bends as it is discharged through the second mesh structure formed in the second partition.

[0013] In one example, the first gas venting hole and the second gas venting hole are each independently a structure in which a through structure on the first partition or the second partition continues in one direction, or a structure in which a plurality of holes are formed on the same axis at a certain distance apart.

[0014] In another example, the average diameter D1 of the pores formed in the first mesh structure is larger than the average diameter D2 of the pores formed in the second mesh structure, and satisfies the following condition 1. [Condition 1] 0.9xD2≧D1≧0.3xD2

[0015] In one embodiment, in the battery module according to the present invention, the second partition constitutes an outer surface of a module case, and the first partition has a bracket structure fastened to the inside of the second partition.

[0016] In one example, the module case includes a bottom plate having a plate-like structure, and a U-shaped top plate having both side ends bent in one direction to cover the bottom plate, and a gas venting structure is formed on one or both of the bent side ends of the top plate.

[0017] In another example, the battery cells are housed in the module case and oriented in a direction perpendicular to the side surface of the module case on which the gas venting structure is formed.

[0018] The present invention also provides a battery pack including the above-mentioned battery module. In one example, the battery pack according to the present invention includes one or more battery modules and a pack case that packages the battery modules. Effect of the Invention

[0019] The battery module and the battery pack including the same according to the present invention have a gas venting structure including a first partition wall and a second partition wall each having a mesh structure formed on one or more sides of the module case, thereby achieving excellent heat dissipation efficiency of the battery cells and preventing the escape of sparks or fire even during thermal runaway of the battery cells. [Brief description of the drawings]

[0020] [Figure 1] 1 is a perspective view of a conventional battery module and a cross-sectional view showing a gas venting path. [Diagram 2] 2 is a perspective view of a battery module according to an embodiment of the present invention and a cross-sectional view showing a gas venting path; [Diagram 3] 4 is an enlarged view showing a gas venting path of a battery module according to an embodiment of the present invention; [Figure 4] 5 is a partial cross-sectional view showing a gas venting path of a battery module according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] The present invention will be described in detail below. Before that, the terms or words used in the specification and claims should not be interpreted limited to their ordinary or dictionary meanings, but should be interpreted as meanings and concepts that are consistent with the technical idea of ​​the present invention, based on the principle that the inventor can appropriately define the concept of the term in order to best describe his own invention.

[0022] The present invention provides a battery module. In one embodiment, the battery module according to the present invention includes a module case having a receiving portion for receiving a battery cell, and one or more battery cells received in the module case, and a gas venting structure is formed on one or more side surfaces of the module case. The gas venting structure includes a first partition wall including a first gas venting hole and a first mesh structure configured to cover the first gas venting hole, and a second partition wall formed at a certain distance outside the first partition wall and including a second gas venting hole and a second mesh structure configured to cover the second gas venting hole, and the first gas venting hole formed in the first partition wall and the second gas venting hole formed in the second partition wall are located in regions that do not face each other.

[0023] The battery module according to the present invention includes a gas venting structure consisting of a double partition wall on one or more sides of the module case. For example, compared to a conventional battery module having a single gas venting hole on an end plate, the efficiency of discharging heat or gas can be improved. In particular, the conventional battery module has a limitation in that heat or gas is discharged in the direction of the gas venting hole, and heat is also transferred to the surrounding battery cells. However, the present invention has an advantage in that heat transfer to the surrounding battery cells is not induced when heat or gas is discharged by forming one side of the module case with a gas venting structure.

[0024] The gas venting structure may be formed on one side of the module case or on two or more side surfaces. In one embodiment, the gas venting structure is formed on both opposing sides of the module case. By forming the gas venting structure on both opposing sides of the module case, it is possible to facilitate the discharge of heat or gas and prevent the concentration of heat or gas in a battery cell at a specific position in the battery module.

[0025] In one embodiment, the gas venting structure is a structure formed in 50 to 100% of the area of ​​the side surface of the module case. Specifically, the gas venting structure is a structure formed in 50 to 95% or 60 to 85% of the area of ​​the side surface of the module case. The formation area of ​​the gas venting structure is a numerical value obtained by summing the areas of the first mesh structure formed in the first partition wall and the second mesh structure formed in the second partition wall. The first mesh structure and the second mesh structure may be formed in 15 to 60% or 30 to 50% of the area of ​​the first partition wall and the second partition wall, respectively. For example, the first mesh structure is formed in 40 to 60% of the area of ​​the first partition wall, and the second mesh structure is formed in 30 to 50% of the area of ​​the second partition wall, and the regions in which the first mesh structure and the second mesh structure are formed do not overlap each other.

[0026] In the present invention, the gas venting structure is not a structure that forms one specific hole, but a structure that is formed over an area above a certain level, thereby preventing the phenomenon that heat or gas is concentrated at a specific point during the process of exhausting.

[0027] In one embodiment, the outflow path of the venting gas through the gas venting structure has a structure having two rotation paths based on the cross section. If the internal gas is directly discharged without a rotation path, not only the heat and gas but also other conductive components may be discharged together. This may cause a thermal runaway phenomenon between battery cells or battery modules. The present invention prevents the thermal runaway phenomenon by configuring the outflow path of the venting gas to have two rotation paths. In a specific embodiment, the rotation paths are paths that rotate vertically.

[0028] For example, the outflow path of the venting gas through the gas venting structure includes a first rotation path in which the venting gas discharged through the first mesh structure formed in the first partition wall bends as it enters the space between the first partition wall and the second partition wall, and a second rotation path in which the venting gas passes through the space between the first partition wall and the second partition wall and is discharged through the second mesh structure formed in the second partition wall and bends. In the present invention, the heat or gas inside the battery module is prevented from being directly discharged through the mesh structure formed in the partition wall. Furthermore, each partition wall is formed with a gas venting hole having a certain area or more, thereby inducing smooth discharge of the heat or gas. In addition, the mesh structure formed in each partition wall serves to primarily block discharge of conductive particles, etc. Furthermore, the gas venting structure is configured to rotate twice, thereby preventing thermal runaway.

[0029] In one embodiment, the first gas venting hole and the second gas venting hole are each independently a structure in which a through structure on the first or second partition wall continues in one direction, or a structure in which a plurality of holes are formed on the same axis at a certain distance apart. For example, the first and / or second partition wall is formed with a through structure in a line shape, and each mesh structure is positioned within or covering the through structure. This induces smooth discharge of heat or gas inside the battery module. As another example, the first and / or second partition wall is formed with a structure in which a plurality of holes are formed at a certain distance apart, and each mesh structure is positioned within or covering the through structure. As a result, the present invention can prevent a decrease in mechanical strength of the module case due to the formation of the gas venting holes.

[0030] In another embodiment, the average diameter D1 of the pores formed in the first mesh structure is larger than the average diameter D2 of the pores formed in the second mesh structure, and the following condition 1 is satisfied. [Condition 1] 1.1xD2≧D1≧3.5xD2

[0031] In the present invention, the first mesh structure located on the inside has a structure in which relatively large pores are formed, and the second mesh structure located on the outside has a structure in which relatively small pores are formed. In a specific example, the average diameter D1 of the pores formed in the first mesh structure is in the range of 1.1 to 3.5 times, 1.1 to 2.5 times, 1.5 to 3 times, 2 to 3.5 times, or 1.5 to 2.5 times the average diameter D2 of the pores formed in the second mesh structure. In the present invention, the average diameter D1 of the pores formed in the first mesh structure is not excluded from the case where it is at the same level as the average diameter D2 of the pores formed in the second mesh structure. This allows the heat or gas to be smoothly discharged through the first mesh structure, and the particulate components that are not filtered by the first mesh structure are filtered by the second mesh structure. Through this arrangement, the efficiency of discharging heat or gas in the module case can be increased, and the safety of the battery module can be improved.

[0032] In the present invention, the first and second partitions forming the gas venting structure constitute one side of the module case. In one embodiment, the second partition constitutes the outer surface of the module case, and the first partition is a bracket structure fastened to the inside of the second partition. Specifically, the gas venting structure according to the present invention may be a structure in which a side surface having a gas venting hole formed therein is formed in the module case, and a bracket having a gas venting hole formed therein is fastened to the inside or outside of the side surface having the gas venting hole formed therein. Also, a mesh structure is formed to cover each of the gas venting holes.

[0033] In another embodiment, the module case includes a bottom plate having a plate-like structure, and a U-shaped top plate having both ends bent in one direction to cover the bottom plate, and a gas venting structure is formed on one or both ends of the bent ends of the top plate. Specifically, battery cells are stacked on the bottom plate having a plate-like structure, and a U-shaped top plate is positioned to cover the stacked battery cells. In this case, a gas venting structure is formed on one or both ends of the U-shaped top plate. This makes it easy to accommodate the battery cells, and at the same time, an effective gas venting structure can be formed. As another example of the present invention, the module case may include a bottom plate having a U-shaped structure having both ends bent in one direction, and a top plate having a plate-like structure covering the open upper surface of the bottom plate.

[0034] The battery module of the present invention has a structure in which a number of battery cells are housed. In one embodiment, the battery cells are housed in the module case while being oriented in a direction perpendicular to the side surface of the module case on which the gas venting structure is formed. In the present invention, the battery cells are positioned so that the direction in which the battery cells are housed is perpendicular to the surface on which the gas venting structure is formed. This effectively exhausts heat or gas generated from the battery cells, while minimizing the influence on the surrounding battery cells during the process of exhausting heat or gas. In the present invention, the term "perpendicular direction" in which the orientation direction of the battery cells and the side surface on which the gas venting structure is formed are not only physically perpendicular to each other at 90 degrees, but also includes directions in which they intersect each other. For example, it should be interpreted as including cases in which they form an angle of 80 degrees to 110 degrees.

[0035] The present invention also provides a battery pack including the above-mentioned battery module. In one embodiment, the battery pack according to the present invention includes one or more battery modules and a pack case for packaging the battery modules. The battery module is as described above, and detailed description is omitted. The battery pack can be used in various forms. For example, it can be applied as a power source for automobiles. For example, the battery pack can be applied as a power source for hybrid automobiles, electric automobiles, etc.

[0036] The present invention will be described in more detail with reference to the drawings, etc. However, since the configurations shown in the drawings in this specification are merely one embodiment of the present invention and do not fully represent the technical ideas of the present invention, it should be understood that there may be various equivalents and modifications that can replace them at the time of filing this application.

[0037] (First embodiment) 2 is a perspective view of a battery module according to an embodiment of the present invention and a cross-sectional view showing a gas venting path. Referring to Fig. 2, a battery module 100 according to an embodiment of the present invention includes a module case 101 having a receiving portion for receiving a battery cell 102, and a plurality of battery cells 102 received in the module case 101. Gas venting structures are formed on both sides of the module case 101.

[0038] The gas venting structure formed on one side includes a first partition 110(a) including a first gas venting hole and a first mesh structure having a structure covering the first gas venting hole, and a second partition 120(a) formed at a certain distance outside the first partition 110(a) and including a second gas venting hole and a second mesh structure having a structure covering the second gas venting hole, and is located in an area where the first gas venting hole formed in the first partition 110(a) and the second gas venting hole formed in the second partition do not face each other. Heat or gas generated from the accommodated battery cells 102 is discharged along a gas venting path 131 on the side where the gas venting structure is formed.

[0039] The gas venting structure formed on the other side includes a first partition wall 110(b) including a first gas venting hole and a first mesh structure having a structure covering the first gas venting hole, and a second partition wall 120(b) formed at a certain distance outside the first partition wall 110(b) and including a second gas venting hole and a second mesh structure having a structure covering the second gas venting hole, and the first gas venting hole formed in the first partition wall 110(b) and the second gas venting hole formed in the second partition wall are located in areas that do not face each other. Heat or gas generated from the accommodated battery cells 102 is discharged along a gas venting path 132 on the side where the gas venting structure is formed.

[0040] In the present invention, a gas venting structure is formed on both opposing sides of the module case to facilitate the discharge of heat or gas and prevent the concentration of heat or gas in a battery cell at a specific position within the battery module.

[0041] Second embodiment 3 is an enlarged view showing a gas venting path of a battery module according to an embodiment of the present invention, in which the outflow path of the venting gas through the gas venting structure of the present invention has a structure having two rotation paths based on the cross section.

[0042] The module case according to the present invention includes a bottom plate having a plate-like structure, a U-shaped top plate having both ends bent in one direction to cover the bottom plate, and a gas venting structure is formed at both ends of the bent top plate. The gas venting structure is exhausted to the outside through a first partition wall 210 and a second partition wall 220 in sequence. The bent ends of the U-shaped top plate form the second partition wall 220. In addition, a bracket fastened to the inside of the second partition wall 220 at a certain distance forms the first partition wall 210.

[0043] Specifically, the outflow path of the venting gas through the gas venting structure includes, based on the cross section, a primary rotation path in which the venting gas discharged through the first mesh structure 211 formed in the first partition 210 bends as it enters the space between the first partition 210 and the second partition 220, and a secondary rotation path in which the venting gas passes through the space between the first partition 210 and the second partition 220 and then bends as it is discharged through the second mesh structure 221 formed in the second partition 220.

[0044] In the present invention, the heat or gas in the battery module is prevented from being directly discharged in a straight line through the mesh structure formed in the partition. In addition, the first partition 210 has gas venting holes formed in about 50% of its area, which induces smooth discharge of heat or gas and serves as a primary barrier against discharge of conductive particles, etc. In addition, the second partition 220 has gas venting holes formed in about 40% of its area, which induces smooth discharge of heat or gas and serves as a primary barrier against discharge of conductive particles, etc. Furthermore, the gas venting path is configured to rotate twice, which can prevent thermal runaway.

[0045] Third embodiment 4 is a partial cross-sectional view showing a gas venting path of a battery module according to another embodiment of the present invention. Referring to FIG. 4, the inside of a module case 301 forms a receiving portion 330 in which a battery cell is received, and a gas venting structure is formed at one end. The gas venting structure includes a first barrier 310 located on the inside and a second barrier 320 located on the outside.

[0046] The outflow path of the venting gas through the gas venting structure is such that, based on the cross section, the venting gas discharged through the first mesh structure 311 formed in the first partition 310 turns while entering the space between the first partition 310 and the second partition 320, and then turns while being discharged through the second mesh structure 321 formed in the second partition 320 after passing through the space between the first partition 310 and the second partition 320, thereby making a second vertical rotation.

[0047] In this case, the first mesh structure 311 has relatively large pores, and the second mesh structure 321 located on the outside has relatively small pores. Specifically, the average diameter D1 of the pores formed in the first mesh structure 311 is approximately twice as large as the average diameter D2 of the pores formed in the second mesh structure 321. The distance between the first partition 310 and the second partition 320 is approximately 1 to 5 mm.

[0048] The above description is merely illustrative of the technical idea of ​​the present invention, and it can be said that various modifications and variations are possible within the scope of the essential characteristics of the present invention if one has ordinary knowledge in the technical field to which the present invention belongs. Therefore, the drawings disclosed in the present invention are for the purpose of explaining the technical idea of ​​the present invention, rather than limiting it, and the scope of the technical idea of ​​the present invention is not limited by such drawings. The scope of protection of the present invention should be interpreted by the claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present invention. [Explanation of symbols]

[0049] 100 Battery Module 101 Module Case 102 Battery Cell 110 1st bulkhead 120 2nd bulkhead 131 Gas Venting Path 132 Gas Venting Path 210 1st bulkhead 211 First mesh structure 220 2nd bulkhead 221 Second mesh structure 301 Module Case 310 1st bulkhead 311 First mesh structure 320 2nd bulkhead 321 Second mesh structure 330 Storage unit

Claims

1. A module case having a housing portion for housing the battery cell; and one or more battery cells housed within the module case; and a gas venting structure is formed on one or more sides of the module case; The gas venting structure includes: a first partition including a first gas vent hole and a first mesh structure configured to cover the first gas vent hole; a second partition wall formed at a predetermined distance from the first partition wall and including a second gas vent hole and a second mesh structure configured to cover the second gas vent hole; the first gas venting hole formed in the first partition and the second gas venting hole formed in the second partition are located in regions that do not face each other, A battery module, wherein an average diameter D1 of pores formed in the first mesh structure is larger than an average diameter D2 of pores formed in the second mesh structure, and the following condition 1 is satisfied. [Condition 1] 1.1xD2≦D1≦3.5xD2

2. The battery module according to claim 1 , wherein the gas venting structures are formed on both opposing side surfaces of the module case.

3. The battery module according to claim 1 , wherein an outflow path of the venting gas through the gas venting structure has a structure having a two-turn path based on a cross section.

4. The battery module according to claim 3 , wherein the rotation paths are each a vertically rotated path.

5. The outflow path of the venting gas through the gas venting structure is as follows based on the cross section: a primary rotation path along which the venting gas discharged through the first mesh structure formed in the first partition enters a space between the first partition and the second partition and turns; and 5. The battery module of claim 1 , further comprising: a secondary rotation path along which the venting gas passes through the separation space between the first partition and the second partition and then is discharged through the second mesh structure formed in the second partition.

6. the first gas venting hole and the second gas venting hole are each independently a through structure on the first partition wall or the second partition wall that continues in one direction; 6. The battery module according to claim 1, wherein a plurality of holes are formed on the same axis at a certain distance from each other.

7. the second partition constitutes an outer surface of the module case, The battery module of claim 1 , wherein the first partition has a bracket structure fastened to an inner side of the second partition.

8. A module case having a housing portion for housing the battery cell; and one or more battery cells housed within the module case; and a gas venting structure is formed on one or more sides of the module case; The gas venting structure includes: a first partition including a first gas vent hole and a first mesh structure configured to cover the first gas vent hole; a second partition wall formed at a predetermined distance from the first partition wall and including a second gas vent hole and a second mesh structure configured to cover the second gas vent hole; the first gas venting hole formed in the first partition and the second gas venting hole formed in the second partition are located in regions that do not face each other, The module case includes: A bottom plate having a plate-like structure, and A U-shaped top plate is provided with both side ends bent in one direction to cover the bottom plate, The gas venting structure is formed on one or both of the bent ends of the top plate.

9. 9. The battery module according to claim 1, wherein the battery cells are oriented in a direction perpendicular to the side surface of the module case on which the gas venting structure is formed, and are housed in the module case.

10. A battery pack comprising one or more battery modules according to any one of claims 1 to 9, and a pack case for packaging the battery modules.

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