Safety-enhanced battery module

Abstract

A battery module according to one embodiment of the present invention includes a cell assembly having a plurality of battery cells, a module case that houses the cell assembly in an internal space and has vent holes formed therein, an inner fireproof sheet interposed between the module case and the cell assembly, and an outer fireproof sheet configured to cover at least the portion of the module case where the vent holes are formed from the outside.

Description

[Technical Field]

[0001] The present invention relates to a battery, and more particularly to a battery module with enhanced safety, a battery pack including the same, and a vehicle.

[0002] This application claims priority based on Korean Patent Application No. 10-2022-0172497 filed on December 12, 2022 and Korean Patent Application No. 10-2023-0038231 filed on March 23, 2023, and the contents disclosed in the specifications and drawings of said applications are incorporated herein in their entirety. [Background technology]

[0003] As demand for portable electronic products such as smartphones, notebook PCs, and wearable devices surges and robots and electric vehicles are becoming more commercially viable, research into high-performance secondary batteries that can be repeatedly charged and discharged is actively underway.

[0004] Currently, commercially available secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium secondary batteries. Of these, lithium secondary batteries are attracting attention due to their advantages over nickel-based secondary batteries, such as almost no memory effect, freedom in charging and discharging, a very low self-discharge rate, and high energy density.

[0005] A secondary battery includes an electrode assembly in which a positive electrode plate and a negative electrode plate, each coated with a positive electrode active material and a negative electrode active material, are arranged with a separator sandwiched therebetween, and an exterior material, i.e., a battery case, that seals and houses the electrode assembly together with an electrolyte.

[0006] Generally, secondary batteries are classified into can-type secondary batteries, in which an electrode assembly is housed in a metal can, and pouch-type secondary batteries, in which an electrode assembly is housed in a pouch made of an aluminum laminate sheet, depending on the shape of the exterior material.

[0007] Recently, secondary batteries have been widely used for driving and storing energy not only in small devices such as portable electronic devices but also in medium- to large-sized devices such as electric vehicles and energy storage systems (ESS).

[0008] A plurality of such secondary batteries may be electrically connected and housed together inside a module case to form a battery module, and a plurality of such battery modules may be connected to form a battery pack.

[0009] However, in the case of such a battery module or battery pack, a thermal event such as thermal runaway may occur in the battery cells contained therein, and in such a case, vent gas may be generated from the battery module. In this case, the vent gas needs to be properly discharged to the outside. If the vent gas is not discharged promptly, the battery module or battery pack may explode, causing more serious problems.

[0010] In addition, because vent gas is very hot and may contain flames or sparks, if the vent gas is not properly controlled, it may cause thermal runaway in other nearby battery cells or other battery modules. In this case, thermal runaway may spread between cells or modules or become more severe. Furthermore, because multiple battery cells or battery modules are densely packed in a small space, if the vent gas and the flames contained therein are not properly controlled, the problem of thermal runaway may become more serious. Summary of the Invention [Problem to be solved by the invention]

[0011] The present invention has been made in consideration of the above problems, and aims to provide a battery module that effectively suppresses thermal runaway propagation and improves safety, a battery pack including the same, and an automobile.

[0012] However, the technical problems that the present invention aims to solve are not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art from the following description of the invention. [Means for solving the problem]

[0013] To achieve the above object, a battery module according to one embodiment of the present invention includes a cell assembly having a plurality of battery cells, a module case that houses the cell assembly in an internal space and has a vent hole formed therein, an inner fireproof sheet interposed between the module case and the cell assembly, and an outer fireproof sheet configured to cover at least the portion of the module case where the vent hole is formed from the outside.

[0014] Preferably, the plurality of battery cells may be configured to discharge vent gas from a top seal portion.

[0015] In one aspect of the present invention, a plurality of the vent holes may be formed in the upper portion of the module case.

[0016] In another aspect of the present invention, the cell assembly may include a plurality of battery cells arranged horizontally.

[0017] Here, the inner fireproof sheet may be configured to cover the top of the cell assembly.

[0018] In yet another aspect of the present invention, the inner fire-resistant sheet may have a first vent portion at a position corresponding to the vent hole.

[0019] Preferably, the first vent portion may include a mesh.

[0020] In yet another aspect of the present invention, the outer fire-resistant sheet may include an upper sheet covering an upper portion of the module case, and a side sheet covering a side portion of the module case.

[0021] In yet another aspect of the present invention, the outer fire-resistant sheet may have a second vent portion at a position corresponding to the vent hole.

[0022] Preferably, the outer fireproof sheet may be configured to seal the second vent portion in a steady state, and to open the second vent portion when vent gas flows into the second vent portion from inside the module case.

[0023] In another aspect of the present invention, the second vent may be configured to be open only in a direction toward the outside of the battery module.

[0024] In yet another aspect of the present invention, the second vent portion may be configured to be larger than the vent hole.

[0025] In yet another aspect of the present invention, the outer fire-resistant sheet may be a flame-retardant sheet.

[0026] The present invention also provides a battery pack including at least one battery cell according to the above-described embodiments.

[0027] The present invention further provides a motor vehicle, the motor vehicle including at least one battery pack according to the above-described embodiments. [Effects of the Invention]

[0028] According to the present invention, the safety of a battery module, a battery pack, or the like can be improved.

[0029] In particular, according to one aspect of the present invention, a multi-layer fire-resistant and flame-blocking structure can be formed by the inner and outer fire-resistant sheets.

[0030] Furthermore, according to one embodiment of the present invention, in a module in a thermal event where thermal runaway occurs, high-temperature gas and flames inside the module can be smoothly discharged, and the structure of the module case can be prevented from collapsing.

[0031] In addition, the battery module adjacent to the module experiencing the thermal event can prevent high-temperature gases and flames generated from the module experiencing the thermal event from penetrating into the interior of the module.

[0032] Therefore, the chain reaction of thermal events between battery modules can be controlled to improve the safety of the battery modules or battery packs.

[0033] The present invention also provides various other effects, which will be explained in each embodiment, and explanations of effects that can be easily inferred by ordinary engineers will be omitted.

[0034] That is, the effects obtained from the present invention are not limited to the effects described above, and other technical effects not mentioned above will be clearly understood by those skilled in the art from the following description of the invention.

[0035] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention, serve to further understand the technical concept of the present invention, so the present invention should not be interpreted as being limited to the matters described in the drawings. [Brief explanation of the drawings]

[0036] [Figure 1] 1 is an assembled perspective view schematically illustrating a configuration of a battery module according to an embodiment of the present invention; [Figure 2] 1 is an exploded perspective view illustrating a schematic configuration of a battery module according to an embodiment of the present invention; [Figure 3] 1 is an exploded perspective view of a partial configuration of a battery module according to an embodiment of the present invention; [Figure 4] 1 is a diagram illustrating a battery cell included in a battery module according to an embodiment of the present invention; [Figure 5] 1 is a diagram illustrating a module case and an inner fireproof sheet according to an embodiment of the present invention. FIG. [Figure 6] 1 is a diagram illustrating a module case and an outer fireproof sheet according to an embodiment of the present invention. FIG. [Figure 7] FIG. 7 is an enlarged view showing an area A in FIG. 6. [Figure 8] 10 is a diagram illustrating a discharge path of vent gas when a thermal event occurs inside a battery module according to an embodiment of the present invention. FIG. [Figure 9] 10A and 10B are diagrams illustrating a process of blocking the inflow of vent gas when a thermal event occurs outside a battery module according to an embodiment of the present invention. [Figure 10] 1 is a diagram illustrating an assembled state of an outer fireproof sheet according to an embodiment of the present invention. FIG. [Figure 11] 10 is a diagram illustrating the effect of suppressing the spread of gas, flame, etc. in a configuration including two or more battery modules according to an embodiment of the present invention. FIG. [Figure 12] 2 is a diagram for explaining a battery pack including the battery module of FIG. 1. FIG. [Figure 13] FIG. 13 is a diagram illustrating a vehicle including the battery pack of FIG. 12. DETAILED DESCRIPTION OF THE INVENTION

[0037] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms and words used in the specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted as having meanings and concepts corresponding to the technical ideas of the present invention, in accordance with the principle that the inventors themselves can appropriately define the concepts of terms in order to best explain the invention.

[0038] Therefore, it should be understood that the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiment of the present invention and do not represent the entire technical idea of ​​the present invention, and that there may be various equivalents and modifications that can be substituted for them at the time of this application.

[0039] In order to facilitate understanding of the invention, the accompanying drawings may be drawn not to scale but with some components exaggerated. The same reference numerals may be used to refer to the same components in different embodiments.

[0040] Fig. 1 is an assembled perspective view schematically illustrating the configuration of a battery module 10 according to an embodiment of the present invention. Fig. 2 is an exploded perspective view schematically illustrating the configuration of a battery module 10 according to an embodiment of the present invention. Fig. 3 is an exploded perspective view of a portion of the configuration of a battery module 10 according to an embodiment of the present invention.

[0041] 1 to 3, a battery module 10 according to the present invention includes a cell assembly 100, a module case 200, an inner fireproof sheet 300, and an outer fireproof sheet 400.

[0042] The cell assembly 100 may include a plurality of battery cells 110. The plurality of battery cells 110 may be stacked in at least one direction. More specifically, the plurality of battery cells 110 may be arranged at least horizontally. The plurality of battery cells 110 may be configured to be arranged side by side in the left-right direction while standing upright.

[0043] Hereinafter, each of the plurality of battery cells 110 will be described in more detail.

[0044] FIG. 4 is a diagram illustrating a battery cell 110 included in a battery module 10 according to an embodiment of the present invention.

[0045] 4, the battery cells 110 may be secondary batteries, for example, pouch-type battery cells 110. However, this does not limit the type of the battery cells 110, and battery cells 110 of other shapes, such as cylindrical cells or prismatic cells, may also be used in the battery module 10 of the present invention.

[0046] Hereinafter, the battery cell 110 will be described as a pouch-type cell, as shown in Fig. 4. Referring to Fig. 4, the battery cell 110 may include an electrode assembly 111, a receiving portion 113 that receives the electrode assembly 111, a sealing portion 115 formed on the periphery of the receiving portion 113, and a pair of electrode leads 117 connected to the electrode assembly 111 and extending to the outside of the sealing portion 115.

[0047] The pair of electrode leads 117 may be coupled to electrode tabs (not shown) provided on the electrode assembly 111 and may be drawn out from the sealing portion 115 to the outside of the sealing portion 115. The pair of electrode leads 117 may have a shape extending along the longitudinal direction of the battery cell 110. The pair of electrode leads 117 may be drawn in the same direction or in opposite directions.

[0048] Referring to FIG. 4 , the battery cell 110 may be configured to exhaust vent gas from an upper sealing portion 115. The sealing portion 115 may include a vent region formed to prevent an increase in internal pressure due to gas generated inside the battery cell 110. The vent region is formed in a portion of the sealing portion 115 and is structurally weaker than the peripheral region, so that it is easily broken when internal pressure is applied. The vent region may be, for example, a region formed with a weaker sealing force than the peripheral region. In this case, the vent region may be formed on one of both edges of the sealing portion 115. In particular, the vent region may be formed on the upper edge of both edges of the sealing portion 115.

[0049] According to this structure, gas generated inside the battery cell 110 can be discharged to the outside of the battery cell 110 through the vent region formed at the upper end of the battery cell 110. As a result, the gas can be discharged to the outside of the battery module 10 through the module case 200, the inner fireproof sheet 300, and the outer fireproof sheet 400 located at the upper end of the battery cell 110. That is, according to this structure, high-temperature gas and flames inside the module can be smoothly discharged.

[0050] In one aspect of the present invention, the cell assembly 100 may include a plurality of battery cells 110, a bottom plate, a bus bar assembly 130, and a side plate.

[0051] For example, the plurality of battery cells 110 may be configured by gathering a certain number of battery cells 110. In this case, a lower plate may support the plurality of battery cells 110 at the lower ends of the plurality of battery cells 110.

[0052] Referring to FIG. 3, the cell assembly 100 of the present invention may include a bus bar assembly 130 for electrically connecting the plurality of battery cells 110. The bus bar assembly 130 may be provided on one side of the cell assembly 100 and electrically connected to the plurality of battery cells 110. The bus bar assembly 130 may include an upper plate covering an upper end of the cell assembly 100. Here, the upper plate may have a plurality of holes formed at positions corresponding to the vent holes H formed in the inner fireproof sheet 300. Referring to FIG. 3, the upper end sealing portion 115 of the battery cell 110 can be seen through the holes. That is, the plurality of holes formed in the bus bar assembly 130 may be formed at positions adjacent to the upper end sealing portion 115 of the battery cell 110.

[0053] According to this structure, when a thermal event occurs in the battery cell 110 and high-temperature gas is generated, the gas can be discharged through the holes provided in the upper plate of the bus bar assembly 130. That is, the gas discharged from the holes can be discharged to the outside through the first vent hole H of the inner fire-resistant sheet 300.

[0054] Meanwhile, side plates may be provided between the plurality of battery cells 110 and / or on the sides of the cell assembly 100. The side plates may be substantially flat so as to abut against the receiving portions 113 of the battery cells 110. The side plates serve to vertically support the battery cells 110 on the outside and inside of the cell assembly 100.

[0055] 2, the module case 200 has an internal space formed therein, and the internal space can accommodate the cell assembly 100. For example, the module case 200 can include a tubular mono-frame that surrounds the upper, lower, left, and right sides of the cell assembly 100, and end frames that seal the front and rear open ends of the mono-frame.

[0056] A vent hole H, as indicated by H, may be formed in the module case 200. The vent hole H may be formed to penetrate the module case 200 in the thickness direction so as to connect the internal space of the module case 200 to the external space.

[0057] In one aspect of the present invention, referring to FIG. 2, the vent hole H may be formed in the upper portion of the module case 200 .

[0058] According to this structure, gas discharged from the upper sealing portion 115 of the battery cell 110 can be discharged to the outside of the battery module 10 through the vent hole H formed in the upper part of the module case 200. That is, according to this structure, high-temperature gas and flames inside the module can be smoothly discharged.

[0059] 2, a plurality of vent holes H may be formed in the upper portion of the module case 200. For example, the module case 200 may include a plurality of slit-shaped vent holes H formed along the sealing portions 115 of the battery cells 110 in the upper portion of the module case 200.

[0060] According to this structure, even if a large amount of gas is generated inside the battery module 10, the gas is smoothly discharged to the outside of the battery module 10 through the plurality of vent holes H. Furthermore, according to a structure in which the vent holes H are slit-shaped formed along the sealing parts 115 of the battery cells 110, the gas discharged from the sealing parts 115 of the battery cells 110 can be quickly discharged to the outside through the vent holes H. In other words, the time that the vent gas remains inside the module case 200 can be minimized.

[0061] 3, the inner fire-resistant sheet 300 may be interposed between the module case 200 and the cell assembly 100. In particular, the inner fire-resistant sheet 300 may be positioned in the interior space of the module case 200 and configured to cover at least one side of the cell assembly 100 housed in the interior space of the module case 200. In particular, the inner fire-resistant sheet 300 may be configured to cover at least the upper portion of the cell assembly 100.

[0062] FIG. 5 is a diagram illustrating a module case 200 and an inner fireproof sheet 300 according to an embodiment of the present invention.

[0063] 5, in one aspect of the present invention, the inner fire-resistant sheet 300 may have a first vent portion V1 at a position corresponding to the vent hole H. The first vent portion V1 may be configured to allow gas to freely communicate. The first vent portion V1 may have a configuration on the inner fire-resistant sheet 300 that matches the vent hole H of the module case 200, for example, a position, size, shape, etc. that corresponds to the vent hole H of the module case 200.

[0064] According to this structure, gas discharged from the upper end sealing portion 115 of the battery cell 110 can be discharged to the outside of the battery module 10 through the first vent portion V1 formed on the upper portion of the inner fire-resistant sheet 300. That is, according to this structure, high-temperature gas and flames inside the module can be smoothly discharged.

[0065] 2, the inner fire-resistant sheet 300 may be provided inside a portion of the module case 200 where the vent hole H is formed. Therefore, the inner fire-resistant sheet 300 may be configured to surround the outside of a portion of the cell assembly 100 that faces the vent hole H.

[0066] In yet another aspect of the present invention, and referring to FIG. 2, the first vent portion V1 may include a mesh.

[0067] This structure allows high-temperature gas generated in the cell assembly 100 to be easily discharged to the outside, and the mesh can prevent sparks generated in the cell assembly 100 from scattering outside the cell assembly 100. In addition, it can prevent the spread of fire from the battery module 10 where a thermal event has occurred to other adjacent battery modules 10.

[0068] Meanwhile, the inner fireproof sheet 300 may be made of a fireproof material that can withstand high heat and flames, such as mica, or may partially include such a material.

[0069] The outer fire-resistant sheet 400 may be provided on the outside of the module case 200. The outer fire-resistant sheet 400 may be configured to surround at least the upper part of the module case 200. In particular, the outer fire-resistant sheet 400 may be configured to cover at least the part where the vent hole H is formed from the outside of the module case 200. That is, the outer fire-resistant sheet 400 may be configured to surround from the outside the side of the module case 200 where the vent hole H is formed.

[0070] The outer fire-resistant sheet 400 may also be made of a fire-resistant material that can withstand high heat and flames. For example, the outer fire-resistant sheet 400 may be made of a mica material or may partially contain such a mica material.

[0071] FIG. 6 is a diagram illustrating the module case 200 and the outer fireproof sheet 400 according to one embodiment of the present invention.

[0072] 6, the outer fire-resistant sheet 400 may include an upper sheet 410 that covers the upper portion of the module case 200 and a side sheet 420 that covers the side portion of the module case 200. For example, the upper sheet 410 and the side sheet 420 may be connected to each other and have a folded shape. The outer fire-resistant sheet 400 may be configured to surround at least a portion of the upper portion and at least a portion of the side portion of the module case 200. That is, the upper sheet 410 may cover the upper portion of the module case 200. The side sheet 420 may cover the side portion of the module case 200.

[0073] For example, the outer fireproof sheet 400 may be a single sheet member, and both ends may be folded to surround the upper plate, left plate, and right plate of the mono-frame.

[0074] According to this structure, the outer fireproof sheet 400 completely surrounds the side of the module case 200, so that heat transfer to the adjacent battery modules 10 can be effectively blocked.

[0075] 6, in one aspect of the present invention, the outer fire-resistant sheet 400 may have a second vent portion V2 at a position corresponding to the vent hole H. The second vent portion V2 may be provided on the upper sheet 410 of the outer fire-resistant sheet 400.

[0076] The second vent portion V2 may have a configuration in the outer fireproof sheet 400 that matches the vent hole H of the module case 200, for example, a position and shape corresponding to the vent hole H of the module case 200.

[0077] According to this structure, gas discharged from the upper end sealing portion 115 of the battery cell 110 can be discharged to the outside of the battery module 10 through the second vent portion V2 formed on the upper portion of the outer fire-resistant sheet 400. That is, according to this structure, high-temperature gas and flames inside the module can be smoothly discharged.

[0078] Figure 7 is an enlarged view of region A in Figure 6. Figure 8 is a diagram illustrating a discharge path of vent gas when a thermal event occurs inside battery module 10 according to an embodiment of the present invention, and Figure 9 is a diagram illustrating a process of blocking the inflow of vent gas when a thermal event occurs outside battery module 10 according to an embodiment of the present invention.

[0079] In another aspect of the present invention, the outer fire-resistant sheet 400 may be configured to seal the second vent portion V2 in a steady state and to open the second vent portion V2 when vent gas flows into the second vent portion V2 from inside the module case 200.

[0080] More specifically, the second vent portion V2 maintains a sealed state in a steady state as shown in Fig. 7. For example, as shown in Fig. 7, a preliminary cut line C may be formed around the second vent portion V2. The preliminary cut line C may be thinner or less dense than the surrounding area of ​​the upper sheet 410, so that it is more easily broken than the surrounding area. Therefore, in a steady state, the outer fire-resistant sheet 400 may have a structure surrounding the module case 200 with the preliminary cut line C unbroken, as shown in Fig. 8.

[0081] According to this structure, the outer fireproof sheet 400 covers the module case 200, so even if a thermal event occurs in an adjacent battery module 10, the high-temperature gas and flame generated in the adjacent battery module 10 can be prevented from penetrating into the battery module 10. This effectively blocks the chain reaction of thermal runaway, thereby ensuring the safety of the battery module 10 and the battery pack 1.

[0082] Meanwhile, the second vent portion V2 may be opened when vent gas flows into the second vent portion V2 from inside the module case 200. As a result, gas discharged from the upper end sealing portion 115 of the battery cell 110 may be discharged to the outside of the battery module 10 through the second vent portion V2 formed on the upper portion of the outer fire-resistant sheet 400. That is, this structure makes it possible to smoothly discharge high-temperature gas and flames inside the module.

[0083] 9, when vent gas is discharged from the battery cells 110 housed inside the module case 200, the vent gas may proceed to the second vent portion V2 via the first vent portion V1 and the vent hole H. At this time, the second vent portion V2 is blocked by the outer fire-resistant sheet 400, but the pressure of the vent gas may cause a corresponding portion of the outer fire-resistant sheet 400 to open or burst. This may open the second vent portion V2. That is, the outer fire-resistant sheet 400 may be configured to open the second vent portion V2 when the internal pressure of the module case 200 exceeds a certain level due to the generation of vent gas.

[0084] According to this structure, in a steady state, the outer fireproof sheet 400 covers the module case 200, so that even if a thermal event occurs in an adjacent battery module 10, the high-temperature gas and flame generated in the adjacent battery module 10 are prevented from penetrating into the interior of the battery module 10, and if a thermal event occurs within the battery module 10, the gas generated inside the battery module 10 can be easily discharged by opening the second vent portion V2.

[0085] As a result, the first vent portion V1 and the second vent portion V2 allow gas generated inside the battery module 10 to be smoothly discharged to the outside of the battery module 10. This prevents the structure of the module case 200 from collapsing due to high-temperature gas and flames generated inside the battery module 10.

[0086] In yet another aspect of the present invention, the second vent portion V2 may be configured to be open only in a direction toward the outside of the battery module 10.

[0087] 9, the second vent portion V2 is sealed in a steady state, and when a thermal event occurs inside the battery module 10 and gas is generated, the second vent portion V2 may be opened by the internal pressure of the battery module 10. In this case, the second vent portion V2 may be opened toward the outside of the battery module 10 as shown in FIG. 9. For example, when the internal pressure of the battery module 10 increases due to gas generated inside the battery module 10, the preliminary cutting line C of the second vent portion V2 shown in FIG. 7 may be broken, and the second vent portion V2 may be opened to the outside.

[0088] According to this structure, even if a thermal event occurs inside the battery module 10 and gas is generated, the gas can be efficiently discharged to the outside of the battery module 10.

[0089] The second vent portion V2 does not have to be open toward the inside of the battery module 10. Referring to FIG. 8 , when a thermal event occurs outside the battery module 10 and gas is generated, the outer fire-resistant sheet 400 may receive external pressure toward the inside of the battery module 10. In this case, the second vent portion V2 of the present invention does not open toward the inside of the battery module 10. That is, the second vent portion V2 may be configured to open only toward the outside of the battery module 10.

[0090] Therefore, with this structure, even if a thermal event occurs in a battery module 10 adjacent to the battery module 10, the high-temperature gas and flame generated in the adjacent battery module 10 can be prevented from penetrating into the battery module 10. In other words, with this structure, the battery module 10 can be protected from the high-temperature, high-pressure gas and flame generated in the battery module 10 where a thermal event occurs. As a result, a chain reaction of thermal runaway events between modules can be suppressed. Ultimately, the battery module 10 is protected by the outer fireproof sheet 400 outside the battery module 10, thereby controlling the chain reaction of a thermal event and ensuring the safety of the battery pack 1.

[0091] FIG. 10 is a diagram illustrating the assembled state of the outer fire-resistant sheet 400 according to one embodiment of the present invention.

[0092] Referring to FIG. 10, the second vent portion V2 may be configured to be larger than the vent hole H.

[0093] The second vent portion V2 may have a configuration in the outer fire-resistant sheet 400 that matches the vent hole H of the module case 200, for example, a position and shape that correspond to the vent hole H of the module case 200. For example, referring to FIG. 10, the second vent portion V2 and the vent hole H may both be oval shapes extending in one direction. The second vent portion V2 and the vent hole H may be formed at positions that correspond to each other. That is, the second vent portion V2 and the vent hole H may be positioned on the same line in the vertical direction. Here, the second vent portion V2 may have the same center as the vent hole H and may be larger in size than the vent hole H.

[0094] According to this structure, the gas discharged from the vent hole H is directly ejected to a partial area of ​​the second vent portion V2, so that the second vent portion V2 can be easily opened.

[0095] Furthermore, even if high-temperature gas or flames outside the battery module 10 cause high pressure outside the battery module 10, the size of the second vent portion V2 is larger than the size of the vent hole H, so that even if the second vent portion V2 is broken, the vent hole H can be completely covered by the second vent portion V2. That is, because the second vent portion V2 can completely block the vent hole H, it is possible to effectively prevent high-temperature gas or flames generated outside the battery module 10 from flowing into the interior of the battery module 10.

[0096] According to one aspect of the present invention, it is possible to improve the safety of a battery module 10 or a battery pack 1 including a plurality of such battery modules 10. This will be explained further with reference to FIG.

[0097] FIG. 11 is a diagram illustrating the effect of suppressing the spread of gas, flame, etc. in a configuration including two or more battery modules 10 according to an embodiment of the present invention.

[0098] Referring to FIG. 11, when vent gas and flame are emitted from one of two adjacent battery modules 10 (the battery module 10 where a thermal runaway event occurred), the penetration of the gas and flame into the other adjacent battery module 10 (the battery module 10 adjacent to the battery module 10 where the thermal runaway event occurred) can be suppressed.

[0099] More specifically, in a battery module 10 in which a thermal runaway event occurs, high-temperature, high-pressure gas and flames are generated as the event progresses, and these may naturally be discharged to the outside through the vent hole H formed in the module case 200 of the battery module 10. At this time, because the first vent portion V1 of the inner fire-resistant sheet 300 of the battery module 10 in which the event occurred is aligned with the vent hole H, the structure is not destroyed by the high-temperature gas and flames. That is, according to the present invention, the first vent portion V1 formed in the inner fire-resistant sheet 300, the vent hole H formed in the module case 200, and the second vent portion V2 formed in the outer fire-resistant sheet 400 easily discharge the high-temperature gas and / or flames generated inside the battery module 10 to the outside of the battery module 10, thereby effectively preventing explosion, rupture, or collapse of the module case 200 due to an increase in the internal pressure of the battery module 10. Therefore, the stable structure of the module case 200 is maintained, preventing explosion or structural collapse of the battery module 10 in which a thermal runaway event occurs.

[0100] In addition, the battery module 10 in which the thermal runaway event occurred and the adjacent battery modules 10 can be protected from high-temperature, high-pressure gas and flames generated from the battery module 10 in which the thermal runaway event occurred by the outer fireproof sheet 400 that protects the outside of the module case 200. This makes it possible to prevent a chain reaction of thermal runaway events from occurring between modules.

[0101] That is, the modules adjacent to the battery module 10 in which a thermal runaway event has occurred are protected by the outer fire-resistant sheet 400 outside the module to prevent high-temperature gases and flames generated from the battery module 10 in which a thermal runaway event has occurred from penetrating back into the module, thereby controlling the chain reaction and ensuring the safety of the battery pack 1. That is, in the battery module 10 in which a thermal runaway event has occurred, the outer fire-resistant sheet 400, like the inner fire-resistant sheet 300, serves as an ejection path for gases and flames inside the battery module 10 in which a thermal runaway event has occurred, but can also block the flames and gases transferred from the battery module 10 in which a thermal runaway event from penetrating back into the battery modules 10 adjacent to the battery module 10 in which a thermal runaway event has occurred.

[0102] In one aspect of the present invention, the outer fire-resistant sheet 400 may be a fire-retardant sheet. That is, according to one aspect of the present invention, the inner fire-resistant sheet 300 is provided inside the module case 200, and the outer fire-resistant sheet 400 is provided on the outside of the module as a fire-retardant sheet, thereby forming a multi-layer fire-resistant and fire-resistant structure.

[0103] The outer fireproof sheet 400 may be made of a flameproof and / or fire-resistant material that can withstand high heat and flames, such as a mica material, or may partially include such a material.

[0104] FIG. 12 is a diagram for explaining the battery pack 1 including the battery module 10 of FIG.

[0105] 12, a battery pack 1 according to the present invention may include at least one battery module 10 according to the present invention. The battery pack 1 according to the present invention may also include a pack case 50 that houses the at least one battery module 10. In addition to the battery module 10, the battery pack 1 may further include various other components, such as a BMS, a pack case, a relay, a current sensor, and other components of a battery pack 1 that are known at the time of filing of the present invention.

[0106] FIG. 13 is a diagram for explaining an automobile V including the battery pack 1 of FIG.

[0107] Referring to FIG. 13, a vehicle V according to the present invention may include at least one battery pack 1 according to the present invention.

[0108] The battery module 10 according to the present invention is applicable to a vehicle V such as an electric vehicle V or a hybrid vehicle V. That is, the vehicle V according to the present invention may include the battery module 10 according to the present invention or the battery pack according to the present invention. The vehicle V according to the present invention may further include various other components included in the vehicle V in addition to the battery module 10 or the battery pack 1. For example, the vehicle V according to the present invention may further include a vehicle body, a motor, a control device such as an ECU (electronic control unit), etc. in addition to the battery module 10 according to the present invention.

[0109] The various embodiments described above can improve the safety of the battery module 10 or the battery pack 1. That is, according to one aspect of the present invention, a multi-layer fireproof and flame-resistant structure is formed by the inner fireproof sheet 300 and the outer fireproof sheet 400. As a result, according to the present invention, high-temperature gas and flames inside a module experiencing a thermal event when thermal runaway occurs can be smoothly discharged, and the structure of the module case 200 can be prevented from collapsing. Furthermore, the battery module 10 adjacent to the module experiencing the thermal event can prevent high-temperature gas and flames generated from the module experiencing the thermal event from penetrating into the module. Therefore, the chain reaction of a thermal event in the battery module 10 can be controlled, thereby improving the safety of the battery module 10 or the battery pack 1. Therefore, the various embodiments described above can provide a battery module 10 with improved safety, a battery pack 1 including the same, and an automobile V.

[0110] Although terms indicating directions such as up and down are used in this specification, it will be obvious to those skilled in the art that these terms are used merely for convenience of explanation and may vary depending on the position of the object in question, the position of the observer, etc.

[0111] Although the preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific preferred embodiments described above, and it goes without saying that various modifications can be made by anyone having ordinary skill in the art to which the invention pertains without departing from the gist of the present invention as claimed in the claims. [Explanation of symbols]

[0112] 1 battery pack 10 Battery Module 50 pack case 100 Cell Assembly 110 battery cells 111 Electrode assembly 113 Storage Unit 115 Sealing part 117 Electrode Lead 130 Busbar assembly 200 Module Case 300 Inner fireproof sheet 400 Outer fireproof sheet 410 Upper seat 420 side seat H Vent Hole V Automobile V1 First vent V2 Second vent

Claims

1. a cell assembly including a plurality of battery cells; a module case that houses the cell assembly in an internal space and has a vent hole; an inner fireproof sheet interposed between the module case and the cell assembly; an outer fireproof sheet configured to cover at least a portion of the module case where the vent hole is formed from the outside of the module case.

2. The battery module according to claim 1 , wherein the plurality of battery cells are configured to discharge vent gas from an upper end sealing portion.

3. The battery module according to claim 1 , wherein the vent holes are formed in a plurality in an upper portion of the module case.

4. The cell assembly includes a plurality of battery cells arranged horizontally, The battery module according to claim 1 , wherein the inner fireproof sheet is configured to cover an upper portion of the cell assembly.

5. The battery module according to claim 1 , wherein the inner fireproof sheet has a first vent portion at a position corresponding to the vent hole.

6. The battery module according to claim 5 , wherein the first vent portion includes a mesh.

7. The outer fireproof sheet is an upper sheet covering an upper portion of the module case; The battery module according to claim 1 , further comprising: a side sheet covering a side of the module case.

8. The outer fireproof sheet is The battery module according to claim 1 , further comprising a second vent portion at a position corresponding to the vent hole.

9. The outer fireproof sheet is 9. The battery module according to claim 8, wherein the second vent is sealed in a steady state, and is configured to open the second vent when vent gas flows into the second vent from inside the module case.

10. The second vent portion is The battery module according to claim 8, wherein the battery module is configured to be opened only in a direction toward the outside of the battery module.

11. The battery module according to claim 8 , wherein the second vent portion is larger than the vent hole.

12. The battery module according to claim 1 , wherein the outer fire-resistant sheet is a flame-retardant sheet.

13. A battery pack comprising at least one battery module according to any one of claims 1 to 12.

14. A motor vehicle comprising at least one battery pack according to claim 13.

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