Safety-enhanced battery module

Abstract

The present invention discloses a battery module having an improved structure for stably discharging gases, flames, etc. generated inside the battery module. A battery module according to one aspect of the present invention includes a cell assembly having one or more battery cells, a module case that houses the cell assembly in an internal space and has a vent hole formed therein so that vent gas generated from the cell assembly can be discharged, and a vent unit that is provided on the outside of the module case and has an outer housing and an inner housing made of different materials, and that allows the vent gas discharged through the vent hole to flow along the surface of the inner housing and be discharged to the outside.

Description

[Technical Field]

[0001] This application claims priority based on Korean Patent Application No. 10-2021-0081116, filed on June 22, 2021, and the entire contents disclosed in the specification and drawings of that application are incorporated herein by reference.

[0002] The present invention relates to a battery, and more particularly to a battery module with enhanced safety, a battery pack including the same, a vehicle, and the like. [Background technology]

[0003] In recent years, as the demand for portable electronic products such as laptops, video cameras, and mobile phones has grown rapidly and the commercialization of robots, electric vehicles, and the like has progressed in earnest, active research has been conducted into high-performance secondary batteries that can be repeatedly charged and discharged.

[0004] Currently, commercially available secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium secondary batteries. Among these, lithium secondary batteries are attracting attention due to their advantages of being free to charge and discharge because they have almost no memory effect compared to nickel-based secondary batteries, a very low self-discharge rate, and a high energy density.

[0005] This type of lithium secondary battery mainly uses a lithium-based oxide and a carbon material as the positive and negative electrode active materials, respectively, and includes an electrode assembly in which a positive electrode plate and a negative electrode plate, each coated with the positive and negative electrode active materials, are arranged with a separator sandwiched therebetween, and an exterior material, i.e., a battery case, that encapsulates the electrode assembly together with an electrolyte.

[0006] Generally, lithium secondary batteries are classified according to the shape of their exterior packaging 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.

[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). A battery module can be formed by electrically connecting a plurality of such secondary batteries and housing them together inside a module case. A battery pack can be formed by connecting a plurality of such battery modules.

[0008] However, when multiple battery modules are included in a battery pack, the battery pack may be vulnerable to thermal chain reactions between the battery modules. For example, if an event such as thermal runaway occurs in one battery module, the propagation of such thermal runaway to other battery modules must be prevented. If the propagation of thermal runaway between battery modules is not prevented, an event occurring in a specific battery module may trigger a chain reaction among multiple battery modules, potentially causing or escalating an explosion or fire.

[0009] In particular, if an event such as thermal runaway occurs in one of the battery modules, there is a concern that gas, flame, etc. may be emitted to the outside. If the emission of gas, flame, etc. cannot be appropriately controlled, the gas, flame, etc. may be emitted toward other battery modules, causing a thermal chain reaction in the other battery modules. Summary of the Invention [Problem to be solved by the invention]

[0010] Therefore, the present invention has been devised to solve the above problems, and aims to provide a battery module having an improved structure for stably discharging gases, flames, etc. generated inside the battery module, and a battery pack and a vehicle including the same.

[0011] 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 detailed description of the invention described below. [Means for solving the problem]

[0012] To achieve the above object, one aspect of the present invention provides a battery module including a cell assembly having one or more battery cells; a module case that houses the cell assembly in an internal space and has a vent hole formed therein so that vent gas generated from the cell assembly can be discharged; and a vent unit that is provided on the outside of the module case and has an outer housing and an inner housing made of different materials, and that allows the vent gas discharged from the vent hole to flow in and flow along the surface of the inner housing and be discharged to the outside.

[0013] Here, the outer housing may be configured in a plate shape with at least one end bent, and the inner housing may be configured in a shape that covers the inner surface of the outer housing.

[0014] The outer housing may be joined in a form in which at least a portion of its outer periphery is welded to the outer surface of the module case.

[0015] Furthermore, the outer housing and the inner housing may be made of different metal materials and may be configured such that at least a portion of each is bonded together.

[0016] Furthermore, the inner housing may be made of a material having a higher melting point than the outer housing.

[0017] Furthermore, the inner housing may have portions whose thicknesses vary along the flow direction of the vent gas.

[0018] Furthermore, the vent hole may be formed in a side surface of the module case, the vent unit may be attached to the side surface of the module case, and the inner housing may have portions whose thicknesses vary in the vertical direction.

[0019] In addition to these, a part between the outer housing and the inner housing may be configured to be separated by a predetermined distance.

[0020] In order to achieve the above object, a battery pack according to another aspect of the present invention includes a battery module according to the present invention.

[0021] Furthermore, in order to achieve the above object, a vehicle according to yet another aspect of the present invention includes a battery module according to the present invention. [Effects of the Invention]

[0022] According to the present invention, even if an event such as thermal runaway occurs in a specific battery module, the thermal runaway situation can be prevented from spreading to other battery modules.

[0023] In particular, according to one aspect of the present invention, the vent structure provided in the battery module remains stable and does not collapse despite high-temperature gases or flames, thereby making it possible to continue to ensure the vent control function of the battery module.

[0024] Furthermore, according to one aspect of the present invention, it is possible to achieve the effect of controlling the vent of the battery module with a simple structure and preventing heat transfer between the battery modules.

[0025] In addition to these, the present invention can achieve various other effects, which will be described in each embodiment, and descriptions of effects that can be easily inferred by a person skilled in the art will be omitted. [Brief explanation of the drawings]

[0026] 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, and therefore the present invention should not be interpreted as being limited to only the matters depicted in such drawings.

[0027] [Figure 1] 1 is a perspective view illustrating a schematic configuration of a battery module in an assembled state according to an embodiment of the present invention; [Figure 2] FIG. 2 is an exploded perspective view of a portion of the configuration in FIG. [Figure 3] FIG. 1 is a perspective view schematically illustrating a configuration of a vent unit according to an embodiment of the present invention. [Figure 4] FIG. 4 is a diagram showing the vent unit of FIG. 3 as viewed from the front. [Figure 5] 1 is a diagram showing a configuration of a battery module according to an embodiment of the present invention as viewed from the side; [Figure 6] 1 is a cross-sectional view schematically showing the configuration of a vent unit according to one embodiment of the present invention. [Figure 7] FIG. 10 is a cross-sectional view schematically showing the configuration of a vent unit according to another embodiment of the present invention. [Figure 8] FIG. 10 is a diagram showing the configuration of a vent unit according to still another embodiment of the present invention, viewed from the front. [Figure 9] FIG. 10 is a cross-sectional view schematically showing the configuration of a vent unit according to still another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0028] 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 inventor himself can appropriately define the concepts of terms in order to best explain the invention.

[0029] Therefore, it should be understood that the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent the entire technical idea of ​​the present invention, and that there may be various equivalents and modifications that can be substituted therefor at the time of this application.

[0030] FIG. 1 is a perspective view showing a schematic configuration of a battery module according to an embodiment of the present invention in an assembled state, and FIG. 2 is an exploded perspective view of a portion of the configuration in FIG.

[0031] 1 and 2, a battery module according to the present invention includes a cell assembly 100, a module case 200, and a vent unit 300.

[0032] The cell assembly 100 may include one or more battery cells. Here, each battery cell may refer to a secondary battery. The secondary battery may include an electrode assembly, an electrolyte, and a battery case. In particular, the battery cell provided in the cell assembly 100 may be a pouch-type secondary battery. However, other types of secondary batteries, such as cylindrical batteries and prismatic batteries, may also be employed in the cell assembly 100 of the present invention.

[0033] A plurality of secondary batteries may be stacked on top of one another to form a cell assembly 100. For example, a plurality of secondary batteries may be stacked in a horizontal arrangement (X-axis direction in the figure) with each battery cell standing upright (Z-axis direction in the figure). Each battery cell may have an electrode lead, and such an electrode lead may be located at both ends of each battery cell or at one end. A secondary battery with electrode leads protruding in both directions may be called a bidirectional cell, and a secondary battery with electrode leads protruding in one direction may be called a unidirectional cell. The present invention is not limited in any way by the specific type or configuration (shape, type) of such a secondary battery, and various types of secondary batteries already known at the time of filing of the present invention may be used in the cell assembly 100 of the present invention.

[0034] The module case 200 may be configured to have an empty space formed therein and to accommodate the cell assembly 100 in the interior space. For example, the module case 200 may be configured to include a top plate, a bottom plate, a left plate, a right plate, a front plate, and a rear plate to define the interior space. Here, at least two of the top plate, the bottom plate, the left plate, the right plate, the front plate, and the rear plate may be configured as an integrated shape.

[0035] Furthermore, the module case 200 may have a vent hole formed on at least one side, as shown by H1 in FIG. 2 . For example, a vent hole H1 may be formed on each of the left and right side plates of the module case 200. The vent hole H1 may be configured to allow vent gas generated and ejected from the cell assemblies 100 housed in the internal space to be discharged to the external space of the module case 200. For example, the vent hole H1 may be formed in a completely open shape penetrating the module case 200 from the inside to the outside. However, the vent hole H1 may not be completely open, but may be closed under normal conditions and openable in response to changes in pressure, temperature, etc. Furthermore, the vent hole H1 may be formed in a shape that extends elongated in one direction. For example, as shown in FIG. 2 , the vent hole H1 may be formed in a shape that extends elongated in the vertical direction. The vent hole H1 may also be formed on the side surfaces of the module case 200, particularly the left and right sides. However, such vent hole H1 may be formed in other parts of module case 200, such as the top surface, bottom surface, front surface, and / or back surface. In addition to this shape, vent hole H1 formed in module case 200 may be configured in a variety of other shapes.

[0036] The vent unit 300 may be provided on the outside of the module case 200. In particular, the vent unit 300 may be attached to a portion of the module case 200 where the vent hole H1 is formed. For example, as shown in FIG. 2, if the vent hole H1 is formed on the left and right sides of the module case 200, the vent unit 300 may be attached to the outside of each of the left and right sides of the module case 200.

[0037] The configuration of such a vent unit 300 will be described in more detail with further reference to FIGS.

[0038] FIG. 3 is a perspective view that schematically shows the configuration of a vent unit 300 according to one embodiment of the present invention, and FIG. 4 is a view showing the vent unit 300 of FIG. 3 as viewed from the front.

[0039] 1 to 4, the vent unit 300 may be configured so that vent gas discharged from the vent hole H1 flows into and is discharged to the outside. That is, the vent unit 300 may be configured to define an internal space to function as a vent channel. More specifically, referring to FIGS. 3 and 4, the vent unit 300 may be configured so that the right side, upper, lower, and front sides are closed and the left side and rear sides are open. Here, the closed right side, upper, lower, and front sides define an internal space, and such an internal space may function as a vent channel. Furthermore, the open left side and rear sides may allow vent gas to flow in and out. Furthermore, in the embodiment of FIGS. 3 and 4, vent gas from the module case 200 may flow into the open left side and be discharged to the open rear side. In this case, vent gas discharged from the module case 200 may flow into the vent unit 300 and then be discharged to the outside.

[0040] In particular, as shown in FIGS. 3 and 4, the vent unit 300 may include an outer housing 320 and an inner housing 310. Here, the outer housing 320 and the inner housing 310 may be made of different materials. The vent unit 300 may be configured so that vent gas discharged from the vent hole H1 flows into the inner housing 310, flows along the surface of the inner housing 310, and is discharged to the outside. That is, the inner housing 310 of the vent unit 300 forms a vent channel and is the part that actually comes into contact with the vent gas. Furthermore, the outer housing 320 of the vent unit 300 may be configured to enclose at least a portion of the outside of the inner housing 310. Conversely, the inner housing 310 of the vent unit 300 may be configured to cover at least a portion of the inside of the outer housing 320.

[0041] In such an implementation, vent unit 300 may be configured so that vent gas flows into the interior space and primarily contacts inner housing 310 before being exhausted to the exterior. Additionally, vent unit 300 may be configured so that vent gas contacts only inner housing 310 and not outer housing 320. However, in some embodiments, vent gas may be configured to partially contact outer housing 320.

[0042] According to this configuration of the present invention, the inside and outside of the vent unit 300 are made of different materials, allowing materials to be selected that are appropriate for their positions and functions. In particular, the inner housing 310 located inside the vent unit 300 may be a portion that mainly comes into contact with the vent gas, while the outer housing 320 located outside the vent unit 300 may be a portion that is exposed to the outside of the battery module and comes into contact with the module case 200. Therefore, each component of the inner housing 310 and the outer housing 320 can be made of materials that are appropriate for their respective functions and positions. This can be advantageous in ensuring stable venting performance and structural rigidity of the vent unit 300.

[0043] The outer housing 320 may be configured in a plate shape with at least one end bent. For example, referring to FIGS. 3 and 4, the outer housing 320 may be configured in a generally upright plate shape, with the upper end, lower end, and front end bent toward the left side (negative X-axis direction) where the module case 200 is located. The inner housing 310 may also be configured in a shape that covers the inner surface of the outer housing 320. For example, in the configurations of FIGS. 3 and 4, when the module case 200 is located on the left side of the outer housing 320, the inner housing 310 may be positioned on the left surface of the outer housing 320 so that a portion or the entire left surface of the outer housing 320 is not exposed. Furthermore, the inner housing 310 may be formed in a shape that corresponds to the shape of the left surface of the outer housing 320 to cover the left surface, i.e., the inner surface, of the outer housing 320. Therefore, the inner housing 310 is only slightly smaller than the outer housing 320 in size, and like the outer housing 320, it is configured in the shape of a roughly upright plate, with the upper end, lower end, and front end bent toward the module case 200.

[0044] According to this configuration of the present invention, the vent unit 300 can be configured with a simple structure. In particular, in this case, a wide opening can be formed in the internal space of the vent unit 300. Therefore, when the vent unit 300 is attached to the module case 200, the position of the vent hole formed in the module case 200 can be unrestricted. For example, referring to the configurations of FIGS. 3 and 4 , the entire left side of the internal space of the vent unit 300 is open, and the entire left side of the vent unit 300 forms an inlet. Therefore, when attaching the vent unit 300 to the outside of the module case 200, it is not difficult to accurately align the vent hole H1 of the module case 200 with the inlet of the vent unit 300, thereby improving the assembly and manufacturing process of the battery module. Furthermore, in this case, one vent unit 300 can be attached to various types of module cases 200, thereby improving the compatibility of the vent unit 300.

[0045] The vent unit 300 may be attached to the outer surface of the module case 200. In particular, the outer housing 320 of the vent unit 300 may be joined in a form in which at least a portion of the outer periphery is welded to the outer surface of the module case 200. This will be described in more detail with reference to FIG.

[0046] FIG. 5 is a diagram showing the configuration of a battery module according to one embodiment of the present invention as viewed from the side.

[0047] 5, when the vent unit 300 is attached to the module case 200, the portion of the vent unit 300 exposed to the outside can be referred to as the outer housing 320. Furthermore, the outer housing 320 may be configured such that at least a portion of its outer periphery, for example, the upper end, lower end, and front end (the end on the right side in the figure) as indicated by W in FIG. 5, are welded. In particular, the upper end, lower end, and front end of the outer housing 320 may be continuously welded. That is, in the configuration of FIG. 5, the welded portion may extend forward (in the +Y-axis direction) from the rear end of the upper end of the outer housing 320, bend downward (in the -Z-axis direction), and then bend backward (in the -Y-axis direction) to extend to the rear end.

[0048] In this case, the upper, lower, and front ends of vent unit 300 may be closed, and the rear end (the end on the left side in the drawing) of vent unit 300 may be open. Therefore, gas discharged from vent hole H1 of module case 200 may flow rearward of module case 200, i.e., in the -Y-axis direction in the drawing, and be discharged to the outside. Here, it can be said that the entire outer periphery of outer housing 320 is welded to module case 200 except for only the exhaust port portion through which vent gas is discharged.

[0049] According to this configuration of the present invention, the vent unit 300 and the module case 200 can be easily assembled and fixed, making it easy to form a vent flow path inside the vent unit 300 and also ensuring airtightness for parts other than the exhaust port.

[0050] 1 and 2, the vent units 300 may be located on both sides of the module case 200. For example, the vent units 300 may be attached to the left and right sides of the module case 200, respectively. In this case, the vent gas inside the module case 200 can be discharged to the outside through multiple vent paths, thereby further improving vent performance. In addition, in this case, the gas discharged from the inside of the module case 200 can be dispersed to multiple vent units 300, thereby reducing the ejection pressure of the vent gas flowing into each vent unit 300.

[0051] In the above-described embodiment, the plurality of vent units 300, i.e., the left vent unit 300 and the right vent unit 300, may be configured to generate vent gas flows in opposite directions. More specifically, referring to the configurations of FIGS. 1 and 2, the outlet of the left vent unit 300 may be formed on the front (+Y-axis direction) side of the battery module, and the outlet of the right vent unit 300 may be formed on the rear (-Y-axis direction) side of the battery module. In this case, the vent gas may be discharged forward from the left vent unit 300 and backward from the right vent unit 300, as shown by the arrows in FIG. 1.

[0052] According to this configuration of the present invention, the vent directions for the multiple vent units 300 are formed in opposite directions to each other, thereby preventing high-temperature gases and flames from concentrating in a specific location or position.

[0053] The outer housing 320 and the inner housing 310 may be made of different metal materials. Alternatively, the outer housing 320 and the inner housing 310 may be made of metal plates, with at least a portion of their surfaces bonded together. In particular, the vent unit 300 may be made of clad metal, in which metal plates of different materials are bonded together. That is, the vent unit 300 may be made of clad metal, in which a first metal plate constituting the inner housing 310 and a second metal plate constituting the outer housing 320 are bonded together. In this case, the vent unit 300 can be said to be made of two or more different metal layers. In this case, the metal layer located on the inside can be said to be the inner housing 310, and the metal layer located on the outside can be said to be the outer housing 320.

[0054] According to this configuration of the present invention, various performance characteristics can be ensured for the vent unit 300. In particular, the shape and position of the vent unit 300 must be stably maintained despite external shocks, vibrations, high-temperature gases, flames, etc. Furthermore, the easier the vent unit 300 is to assemble when attached to the module case 200, the better. In the above embodiment, since different metal materials are present in one vent unit 300, the vent unit 300 can combine these various characteristics.

[0055] The inner housing 310 may be made of a material having a higher melting point than the outer housing 320. In particular, the inner housing 310 and the outer housing 320 may both be made of metal materials and further bonded together to form a clad metal shape, or the inner housing 310 may be made of a metal material having a higher melting point than the outer housing 320. The inner housing 310 is a part that comes into direct contact with the vent gas, flames, sparks, etc. discharged from the vent unit 300. Therefore, it is preferable that the inner housing 310 be made of a material that is resistant to melting and can withstand high temperatures.

[0056] In contrast, outer housing 320 may be made of a material that has excellent structural rigidity and weldability, even if it has a melting point slightly lower than that of inner housing 310. In particular, as described above with reference to FIG. 5 etc., outer housing 320, which is located on the outer side of vent unit 300, may be welded to module case 200. For example, outer housing 320 may be welded to the outer surface of module case 200 by a method such as laser welding or brazing welding. Therefore, outer housing 320 may be made of a material that has at least a certain level of structural rigidity and corrosion resistance, and that has excellent weldability with module case 200.

[0057] For example, outer housing 320 may be made of aluminum. In this case, inner housing 310 may be made of a material with a higher melting point than the material of outer housing 320. For example, inner housing 310 may be made of a material with a higher melting point, such as iron (Fe) or stainless steel (SUS: Steel Use Stainless).

[0058] This configuration of the present invention ensures more stable venting performance of vent unit 300. That is, vent unit 300 can be strongly bonded to module case 200 by outer housing 320, and high-temperature stability against vent gases and flames can be ensured by inner housing 310. In particular, when an event such as thermal runaway occurs, the gases and flames expelled from the interior of module case 200 through vent hole H1 can reach extremely high temperatures. However, inner housing 310, which is directly exposed to such gases and flames, is made of a heat-resistant material, and therefore, the structure of vent unit 300 can be prevented from collapsing despite the high temperatures of the gases and flames.

[0059] Fig. 6 is a cross-sectional view schematically illustrating the configuration of a vent unit 300 according to one embodiment of the present invention. For example, Fig. 6 may be a view illustrating an example of a modified cross-sectional configuration of portion A1 of the vent unit 300 of Fig. 3 viewed from above.

[0060] Referring to Fig. 6, the inner housing 310 may be configured to have portions with different thicknesses. In particular, the inner housing 310 may be configured to have portions with different thicknesses along the flow direction of the vent gas. For example, in the configuration of Fig. 6, the flow direction of the vent gas is the -Y-axis direction as indicated by the arrow. In this case, the inner housing 310 may be configured to have different thicknesses along the flow direction of the vent gas.

[0061] As a more specific example, in the configuration of FIG. 6 , the thickness T1 of one portion of the inner housing 310 and the thickness T2 of the other portion of the inner housing 310 may be different from each other. Furthermore, in the configuration of FIG. 6 , the thickness T1 can be considered to be thicker than the thickness T2. Furthermore, in the internal space of the vent unit 300, the portion indicated by the thickness T1 can be considered to be located upstream of the portion indicated by the thickness T2 in terms of the flow of vent gas. Therefore, in the configuration of FIG. 6 , the thicknesses of the inner housing 310 are different from each other along the flow direction of the vent gas, and in particular, the thickness T1 on the upstream side can be considered to be thicker than the thickness T2 on the downstream side. The inner housing 310 may be configured so that its thickness gradually decreases toward the exhaust port, at least in part. In this case, the inner surface of the inner housing 310 may be formed with an inclined surface so that the flow path gradually widens toward the exhaust port, as shown in FIG. 6 .

[0062] According to this embodiment of the present invention, the structural stability of the vent unit 300 can be more reliably ensured even when high-temperature gas or flames flow into the vent unit 300. In particular, even within the same inner housing 310, the temperature and pressure applied may vary depending on its location. Furthermore, the upstream side of the vent flow path, i.e., the portion closest to the vent hole H1 of the module case 200, is first hit by the gas or flames ejected from the vent hole H1, and therefore the applied pressure and heat may be relatively greater than those of other portions of the inner housing 310. Therefore, when the inner housing 310 is formed thicker toward the upstream side of the vent flow path, as in the above embodiment, structural stability can be maintained despite high pressure and heat. Furthermore, in this case, the temperature inside the vent unit 300, i.e., the inner housing 310 side, may be higher in temperature upstream than in temperature downstream, but this heat from the upstream side may not be transmitted to the outside of the vent unit 300, i.e., the outer housing 320 side. Therefore, heat can be prevented from being transferred to other components located outside the battery module, such as other battery modules, on the upstream side of the vent unit 300, that is, in the portion where the vent hole H1 is formed.

[0063] Furthermore, the inner housing 310 may be formed so that the portion facing the vent hole H1 is thicker than the other portions. In the portion of the inner housing 310 facing the vent hole H1, the gas and flame ejected from the vent hole H1 can flow in a direction approximately perpendicular to the surface of the inner housing 310. In contrast, in other portions of the inner housing 310, i.e., not the portion facing the vent hole H1 but other portions, the gas and flame can flow in a direction generally parallel to the surface of the inner housing 310.

[0064] Therefore, when the thickness of the portion of the inner housing 310 facing the vent hole H1 is made the thickest, as in the above embodiment, it is not easily damaged or broken, and its shape can be stably maintained, despite the high temperature and high pressure injection force of gas and flame.

[0065] 7 is a cross-sectional view schematically showing the configuration of a vent unit 300 according to another embodiment of the present invention. For example, FIG. 7 can be said to be a modified embodiment of FIG.

[0066] Referring to FIG. 7 , the inner housing 310 may be configured with at least one end bent toward the outer housing 320, as indicated by P1. That is, in the configuration of FIG. 7 , the end of the portion of the inner housing 310 extending in the +Y-axis direction may be bent in the −X-axis direction to form a vent channel. Furthermore, the −X-axis direction end of the inner housing may be configured to be bent again in the +Y-axis direction. Furthermore, the outer housing 320 may be configured to accommodate the bent end of the inner housing 310 and may have a groove formed therein. For example, as indicated by P1 in FIG. 7 , the outer housing 320 may be configured with the end of the portion extending in the +Y-axis direction bent in the −X-axis direction, +Y-axis direction, and −X-axis direction in this order. The bent end of the inner housing 310 can be inserted into the groove at the end of the outer housing 320 formed in such a bent shape.

[0067] According to this embodiment of the present invention, the end of the inner housing 310 is configured to be inserted into the end of the outer housing 320, thereby improving the connection between the outer housing 320 and the inner housing 310. Furthermore, this embodiment can prevent the outer housing 320 from being damaged by vent gas. In particular, the portion indicated by arrow B1 in FIG. 7 can be said to be the portion that comes into contact with the module case 200. In this case, in the above embodiment, even if gas flows into B1, the path through which the flowing gas reaches the outer housing 320 is increased, thereby preventing the high-temperature gas from damaging the outer housing 320.

[0068] The vent hole H1 may also be formed on a side surface of the module case 200. Furthermore, the vent unit 300 may be attached to the side surface of the module case 200 in accordance with the position of such a vent hole. For example, the vent holes may be formed on the left and right sides of the module case 200 as shown in FIG. 2 . The vent unit 300 may also be attached to the left and right sides of the module case 200.

[0069] In particular, the vent unit 300 may be configured such that the inner housing 310 has portions with different thicknesses in the vertical direction, which will be described in more detail with reference to FIG.

[0070] 8 is a diagram showing the configuration of a vent unit 300 according to still another embodiment of the present invention, viewed from the front. FIG. 8 can be said to be another modified example of the view of FIG.

[0071] 8, the inner housing 310 may be formed so that the thickness of the upper side is thicker than the thickness of the lower side. More specifically, as shown in the figure, when the thickness of a portion of the upper part of the inner housing 310 is T3 and the thickness of a portion of the lower part of the inner housing 310 is T4, T3 may be configured to be larger than T4.

[0072] According to this configuration of the present invention, when vent gas flows inside the vent unit 300, the structural stability of the vent unit 300 can be more reliably maintained. In particular, when vent gas flows into the vent unit 300 from the vent hole of the module case 200, the vent gas may flow throughout the entire inner housing 310, from the top to the bottom. However, because the temperature of the vent gas is high, the vent gas that flows into the internal space of the vent unit 300 may tend to flow toward the upper side of the internal space of the vent unit 300, as shown by the arrows in FIG. 8 . Therefore, more thermal energy may be applied to the upper side of the internal space of the vent unit 300 than to the lower side. However, according to the above-described embodiment, the thickness of the upper side of the inner housing 310 is thicker than the thickness of the lower side, thereby effectively dealing with such thermal stress applied to the upper side. Therefore, with the above-described embodiment, stability against thermal stress can be ensured throughout the entire vent unit 300.

[0073] 9 is a cross-sectional view schematically showing the configuration of a vent unit 300 according to still another embodiment of the present invention. For example, FIG. 9 can be said to be another embodiment modified from FIG.

[0074] 9, at least a portion between outer housing 320 and inner housing 310 may be configured to be separated by a predetermined distance. For example, vent unit 300 may be configured to form an empty space between outer housing 320 and inner housing 310, as shown by C1 in the configuration of FIG. 9. In this case, a gas layer such as air may be formed in the empty space between outer housing 320 and inner housing 310. In particular, vent unit 300 may be configured so that a separation space exists between outer housing 320 and inner housing 310 in a portion facing the vent hole.

[0075] According to this embodiment of the present invention, the heat insulating performance is improved by the gas layer, or so-called air layer, located in the space between the outer housing 320 and the inner housing 310. That is, according to the above embodiment, it is possible to prevent heat from the inner housing 310 from being transferred to the outer housing 320. Therefore, it is possible to reduce the propagation of thermal runaway to other battery modules located outside the outer housing 320.

[0076] Furthermore, according to the above-described embodiment, the separated space between the outer housing 320 and the inner housing 310 can function as a buffer space against pressure and force. In particular, the vent gas ejected from the vent hole side can pressurize the inner housing 310. At this time, the empty space between the inner housing 310 and the outer housing 320 buffers the pressurizing force on the inner housing 310, reducing transmission of the pressure to the outer housing 320. Therefore, it is possible to prevent or reduce the release or damage of the bonding force between the outer housing 320 and the module case 200 due to the ejected pressure of the vent gas. Therefore, in this case, the structural stability of the vent unit 300 is further improved.

[0077] A battery pack according to the present invention may include one or more battery modules according to the present invention described above. In addition to the battery module, the battery pack according to the present invention may further include various other components, such as a battery management system (BMS), bus bars, a pack case, a relay, a current sensor, and other battery pack components that are already known at the time of filing of the present invention.

[0078] The battery module according to the present invention is applicable to automobiles such as electric automobiles and hybrid automobiles. That is, the automobile according to the present invention may include the battery module according to the present invention or the battery pack according to the present invention. Furthermore, the automobile according to the present invention may further include various other components included in the automobile in addition to the battery module or battery pack. For example, the automobile according to the present invention may further include a vehicle body, a motor, a control device such as an electronic control unit (ECU), etc. in addition to the battery module according to the present invention.

[0079] Meanwhile, although directional terms such as up, down, left, right, front, and rear are used in this specification, it will be obvious to those skilled in the art of the present invention that these terms are used merely for ease of explanation and may differ depending on the position of the object in question, the position of the observer, etc.

[0080] Although the present invention has been described above using limited embodiments and drawings, the technical concept of the present invention is not limited to these in any way, and it goes without saying that a person having ordinary knowledge in the technical field to which the present invention pertains can make various modifications and variations within the scope of the technical concept of the present invention and the equivalent scope of the claims. [Explanation of symbols]

[0081] 100 Cell Assembly 200 Module Case 300 Vent Unit 310 inner housing, 320 outer housing

Claims

1. a cell assembly comprising one or more battery cells; a module case that houses the cell assembly in an internal space and has a vent hole formed therein so that vent gas generated from the cell assembly can be discharged; a vent unit provided outside the module case, the vent unit including an outer housing and an inner housing made of different materials, and configured to allow vent gas discharged from the vent hole to flow along a surface of the inner housing and be discharged to the outside; Including, the inner housing entirely covers the surface of the module case on which the vent hole is formed, the inner housing is made of a material having a higher melting point than the outer housing, The outer housing is welded to the module case.

2. a cell assembly comprising one or more battery cells; a module case that houses the cell assembly in an internal space and has a vent hole formed therein so that vent gas generated from the cell assembly can be discharged; a vent unit provided outside the module case, the vent unit including an outer housing and an inner housing made of different materials, and configured to allow vent gas discharged from the vent hole to flow along a surface of the inner housing and be discharged to the outside; A battery module comprising: The outer housing is configured in a plate shape with at least one end bent, and the inner housing covers the inner surface of the outer housing. the inner housing is made of a material having a higher melting point than the outer housing, The outer housing is welded to the module case.

3. a cell assembly comprising one or more battery cells; a module case that houses the cell assembly in an internal space and has a vent hole formed therein so that vent gas generated from the cell assembly can be discharged; a vent unit provided outside the module case, the vent unit including an outer housing and an inner housing made of different materials, and configured to allow vent gas discharged from the vent hole to flow along a surface of the inner housing and be discharged to the outside; A battery module comprising: the outer housing is joined to the outer surface of the module case in a shape where at least a part of the outer periphery thereof is welded; The battery module, wherein the inner housing is made of a material having a higher melting point than the outer housing.

4. a cell assembly comprising one or more battery cells; a module case that houses the cell assembly in an internal space and has a vent hole formed therein so that vent gas generated from the cell assembly can be discharged; a vent unit provided outside the module case, the vent unit including an outer housing and an inner housing made of different materials, and configured to allow vent gas discharged from the vent hole to flow along a surface of the inner housing and be discharged to the outside; A battery module comprising: The outer housing and the inner housing are made of different metal materials and at least a portion of the outer housing and the inner housing are bonded together, The battery module, wherein the inner housing is made of a material having a higher melting point than the outer housing.

5. a cell assembly comprising one or more battery cells; a module case that houses the cell assembly in an internal space and has a vent hole formed therein so that vent gas generated from the cell assembly can be discharged; a vent unit provided outside the module case, the vent unit including an outer housing and an inner housing made of different materials, and configured to allow vent gas discharged from the vent hole to flow along a surface of the inner housing and be discharged to the outside; Including, the inner housing entirely covers the surface of the module case on which the vent hole is formed, The inner housing has portions having different thicknesses along a flow direction of the vent gas.

6. a cell assembly comprising one or more battery cells; a module case that houses the cell assembly in an internal space and has a vent hole formed therein so that vent gas generated from the cell assembly can be discharged; a vent unit provided outside the module case, the vent unit including an outer housing and an inner housing made of different materials, and configured to allow vent gas discharged from the vent hole to flow along a surface of the inner housing and be discharged to the outside; A battery module comprising: The outer housing is configured in a plate shape with at least one end bent, and the inner housing covers the inner surface of the outer housing. The inner housing has portions having different thicknesses along a flow direction of the vent gas.

7. a cell assembly comprising one or more battery cells; a module case that houses the cell assembly in an internal space and has a vent hole formed therein so that vent gas generated from the cell assembly can be discharged; a vent unit provided outside the module case, the vent unit including an outer housing and an inner housing made of different materials, and configured to allow vent gas discharged from the vent hole to flow along a surface of the inner housing and be discharged to the outside; A battery module comprising: the outer housing is joined to the outer surface of the module case in a shape where at least a part of the outer periphery thereof is welded; The inner housing has portions having different thicknesses along a flow direction of the vent gas.

8. a cell assembly comprising one or more battery cells; a module case that houses the cell assembly in an internal space and has a vent hole formed therein so that vent gas generated from the cell assembly can be discharged; a vent unit provided outside the module case, the vent unit including an outer housing and an inner housing made of different materials, and configured to allow vent gas discharged from the vent hole to flow along a surface of the inner housing and be discharged to the outside; A battery module comprising: The outer housing and the inner housing are made of different metal materials and at least a portion of the outer housing and the inner housing are bonded together, The inner housing has portions having different thicknesses along a flow direction of the vent gas.

9. a cell assembly comprising one or more battery cells; a module case that houses the cell assembly in an internal space and has a vent hole formed therein so that vent gas generated from the cell assembly can be discharged; a vent unit provided outside the module case, the vent unit including an outer housing and an inner housing made of different materials, and configured to allow vent gas discharged from the vent hole to flow along a surface of the inner housing and be discharged to the outside; A battery module comprising: The vent hole is formed in a side surface of the module case, The vent unit is attached to a side surface of the module case, and the inner housing has portions whose thicknesses vary in a vertical direction.

10. a cell assembly comprising one or more battery cells; a module case that houses the cell assembly in an internal space and has a vent hole formed therein so that vent gas generated from the cell assembly can be discharged; a vent unit provided outside the module case, the vent unit including an outer housing and an inner housing made of different materials, and configured to allow vent gas discharged from the vent hole to flow along a surface of the inner housing and be discharged to the outside; Including, the inner housing entirely covers the surface of the module case on which the vent hole is formed, The battery module, wherein a portion between the outer housing and the inner housing is spaced apart by a predetermined distance.

11. a cell assembly comprising one or more battery cells; a module case that houses the cell assembly in an internal space and has a vent hole formed therein so that vent gas generated from the cell assembly can be discharged; a vent unit provided outside the module case, the vent unit including an outer housing and an inner housing made of different materials, and configured to allow vent gas discharged from the vent hole to flow along a surface of the inner housing and be discharged to the outside; A battery module comprising: The outer housing is configured in a plate shape with at least one end bent, and the inner housing covers the inner surface of the outer housing. The battery module, wherein a portion between the outer housing and the inner housing is spaced apart by a predetermined distance.

12. a cell assembly comprising one or more battery cells; a module case that houses the cell assembly in an internal space and has a vent hole formed therein so that vent gas generated from the cell assembly can be discharged; a vent unit provided outside the module case, the vent unit including an outer housing and an inner housing made of different materials, and configured to allow vent gas discharged from the vent hole to flow along a surface of the inner housing and be discharged to the outside; A battery module comprising: the outer housing is joined to the outer surface of the module case in a shape where at least a part of the outer periphery thereof is welded; The battery module, wherein a portion between the outer housing and the inner housing is spaced apart by a predetermined distance.

13. a cell assembly comprising one or more battery cells; a module case that houses the cell assembly in an internal space and has a vent hole formed therein so that vent gas generated from the cell assembly can be discharged; a vent unit provided outside the module case, the vent unit including an outer housing and an inner housing made of different materials, and configured to allow vent gas discharged from the vent hole to flow along a surface of the inner housing and be discharged to the outside; A battery module comprising: The outer housing and the inner housing are made of different metal materials and at least a portion of the outer housing and the inner housing are bonded together, The battery module, wherein a portion between the outer housing and the inner housing is spaced apart by a predetermined distance.

14. A battery pack comprising the battery module according to any one of claims 1 to 13.

15. A motor vehicle comprising a battery module according to any one of claims 1 to 13.

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