Battery module with structure to block oxygen inflow in case of thermal runaway

Abstract

A battery module according to the present invention includes a cell assembly having a plurality of battery cells, a module case configured to house the cell assembly and having an opening on at least one side, and an oxygen inflow blocking cover covering the opening, wherein the oxygen inflow blocking covers each have a vent hole, are arranged to overlap each other, and are configured to cover the opening, and may also include two or more partition walls configured to allow gas to be discharged to the outside of the module case through the vent hole when gas is generated in the cell assembly, and a hole closing member positioned between the partition walls and configured to deform when heat is applied to close the vent hole.

Description

[Technical field]

[0001] This application claims priority to Korean Patent Application No. 10-2021-0115112, filed on August 30, 2021, and all 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 capable of effectively preventing the occurrence or spread of a fire, a battery pack including the same, and an energy storage system. [Background technology]

[0003] In recent years, as the demand for portable electronic products such as notebook computers, video cameras, and mobile phones has increased dramatically and robots, electric vehicles, and the like have been commercialized in earnest, active research has been conducted on 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, lithium secondary batteries, etc. In particular, lithium secondary batteries are attracting attention due to their advantages of being freely chargeable and dischargeable since they have almost no memory effect compared to nickel-based secondary batteries, a very low self-discharge rate, and a high energy density.

[0005] Although a secondary battery may be used alone, it is generally configured in a form in which a plurality of secondary batteries are electrically connected to each other in series and / or parallel. In particular, a plurality of secondary batteries may be electrically connected to each other and housed inside one module case to configure one battery module. The battery module may be used alone, or two or more may be electrically connected to each other in series and / or parallel to configure a higher level device such as a battery pack.

[0006] Recently, as issues such as power shortages and environmentally friendly energy have been raised, energy storage systems (ESS) for storing generated electricity have been attracting more attention. Typically, the use of such energy storage systems makes it easy to build systems such as smart grid systems, making it possible to easily adjust the supply and demand of electricity in specific regions or cities.

[0007] A battery pack used in an energy storage system may require a significantly larger capacity than a small or medium-sized battery pack. Therefore, a battery pack may typically include a plurality of battery modules. In addition, in order to increase the energy density, the plurality of battery modules are often configured in a dense form in a very small space.

[0008] However, when multiple battery modules are densely packed in a small space, they may be vulnerable to fire. For example, a thermal runaway may occur in a battery module, causing hot gas to be discharged from at least one battery cell. Furthermore, hot sparks may be emitted when the gas is discharged, and the sparks may contain active material detached from electrodes inside the battery cells or molten aluminum particles. If the hot sparks and hot gas come into contact with oxygen, there is a risk of the battery pack starting a fire.

[0009] In particular, if a fire occurs in a particular battery cell or module, it may spread to other surrounding battery cells, battery modules, other battery packs, etc. In particular, since a large number of batteries are densely packed in a small space in an energy storage system, it is not easy to extinguish a fire if it occurs. Furthermore, considering the size and role of the energy storage system, the occurrence of a fire inside a battery pack may cause very serious damage to property and human life. Therefore, even if a thermal runaway situation occurs in a particular battery cell or module, it is important to prevent it from escalating into a fire. Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention has been devised to solve the above problems, and aims to provide a battery module configured to effectively prevent the occurrence of a fire even if high-temperature gas or sparks are generated inside due to thermal runaway, and a battery pack and energy storage system including the same.

[0011] However, the technical problems that the present invention aims to solve are not limited to the problems described above, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention described below. [Means for solving the problem]

[0012] In order to achieve the above technical objective, a battery module according to one aspect of the present invention includes a cell assembly having a plurality of battery cells, a module case configured to accommodate the cell assembly and having an opening on at least one side, and an oxygen inflow blocking cover covering the opening, wherein the oxygen inflow blocking cover may include two or more partition walls each having a vent hole, arranged to overlap each other and covering the opening, wherein when gas is generated in the cell assembly, the gas is discharged to the outside of the module case through the vent hole, and a hole closing member located between the partition walls, configured to close the vent hole by distorting a shape of the hole opening and closing member when heat is applied.

[0013] The hole blocking member may be a plastic injection molding and configured in the shape of a plate.

[0014] The two or more partition walls may include a first partition wall and a second partition wall, and the first partition wall and the second partition wall may be arranged to overlap with the hole blocking member sandwiched therebetween.

[0015] The hole blocking member may be formed in a plate-like shape and have gas passage holes through which gas can pass in the thickness direction, and the vent hole of the first partition wall, the gas passage hole, and the vent hole of the second partition wall may be configured to at least partially coincide with each other.

[0016] The gas passage hole may be formed to have a width narrower than a width of a vent hole of the first partition wall and a width of a vent hole of the second partition wall.

[0017] The width of the gas passage hole may be gradually narrowed toward the vent hole of the first partition wall.

[0018] The hole closing member may be made of a mesh that is meltable at a predetermined temperature.

[0019] The two or more partitions may include a first partition, a second partition and a third partition arranged facing each other in three layers, and the hole blocking member may include a first hole blocking member arranged between the first partition and the second partition, and a second hole blocking member arranged between the second partition and the third partition.

[0020] The vent hole of the first partition and the vent hole of the second partition are positioned offset from each other, the vent hole of the second partition and the vent hole of the third partition are positioned offset from each other, and the first hole blocking member and the second hole blocking member may be made of a porous structure.

[0021] The cell assembly may be configured in a shape in which a plurality of pouch-type battery cells are stacked on top of each other.

[0022] The plurality of pouch-type battery cells may have electrode leads positioned in a front-rear direction of the module case, and the module case may have the opening at at least one of a front and a rear.

[0023] Furthermore, a battery pack according to another aspect of the present invention for achieving the above technical object may include the battery module according to the present invention.

[0024] Furthermore, an energy storage system according to yet another aspect of the present invention for achieving the above technical object may include a battery module according to the present invention. Effect of the Invention

[0025] According to the present invention, the occurrence of a fire in a battery module can be effectively prevented.

[0026] In particular, according to one aspect of the present invention, even if high-temperature gas or sparks are generated due to a thermal runaway phenomenon or the like in a specific battery cell included in a battery module, it is possible to prevent the occurrence of a fire.

[0027] Furthermore, according to one embodiment of the present invention, it is possible to prevent oxygen from flowing into the battery module while discharging gas to the outside of the battery module. Therefore, by eliminating oxygen, which is one of the three elements of combustion, it is possible to prevent combustion, i.e., fire, from occurring inside the battery module at its source.

[0028] Furthermore, according to one aspect of the present invention, even if a fire breaks out inside the battery module, further flow of oxygen can be blocked, preventing the fire from spreading and allowing it to be quickly extinguished.

[0029] In addition to these, the present invention can have various other effects, which will be described in the sections for each embodiment, and descriptions of effects that can be easily inferred by a person skilled in the art will be omitted. [Brief description of the drawings]

[0030] [Figure 1] 1 is a schematic perspective view of a battery module according to an embodiment of the present invention; [Diagram 2] 2 is an exploded perspective view in which the module case and the oxygen inflow blocking cover in FIG. 1 are separated. FIG. [Diagram 3] FIG. 3 is an exploded perspective view of the oxygen inflow blocking cover of FIG. 2. [Figure 4] 1 is a diagram illustrating the effect of exhausting gas and blocking the inflow of oxygen when gas is generated inside a battery module according to an embodiment of the present invention; [Diagram 5] 1 is a diagram illustrating the effect of exhausting gas and blocking the inflow of oxygen when gas is generated inside a battery module according to an embodiment of the present invention; [Figure 6] FIG. 5 is a modified example of FIG. 4, showing an enlarged view of the main part. [Figure 7] 7 is a diagram showing an example in which the shape of the hole closing member in FIG. 6 is distorted by heat. [Figure 8] FIG. 3 corresponds to FIG. 2 and shows a modified example of the oxygen inflow blocking cover. [Figure 9] 1 is a schematic perspective view of a battery module according to another embodiment of the present invention; [Figure 10] FIG. 10 is an exploded perspective view of the oxygen inflow blocking cover of FIG. 9. [Figure 11] 11 is a diagram illustrating the effect of exhausting gas and blocking the inflow of oxygen when gas is generated inside a battery module according to another embodiment of the present invention. FIG. [Figure 12] 11 is a diagram illustrating the effect of exhausting gas and blocking the inflow of oxygen when gas is generated inside a battery module according to another embodiment of the present invention. FIG. [Figure 13] 1 is a schematic diagram of a battery pack according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] Hereinafter, a preferred embodiment 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 that correspond 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 describe the invention.

[0032] Therefore, it should be understood that the embodiment 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 therefor at the time of this application.

[0033] FIG. 1 is a schematic perspective view of a battery module according to one embodiment of the present invention, FIG. 2 is an exploded perspective view of the module case and the oxygen inflow blocking cover of FIG. 1 separated, and FIG. 3 is an exploded perspective view of the oxygen inflow blocking cover of FIG. 2.

[0034] Referring to the figure, a battery module 10 according to an embodiment of the present invention may include a cell assembly 100, a module case 200, and an oxygen inflow blocking cover 300.

[0035] The cell assembly 100 may include a plurality of battery cells 110. The battery cell 110 may include an electrode assembly, an electrolyte, and a battery case. As shown in Fig. 2, the cell assembly 100 may be composed of a pouch-type battery cell 110. Needless to say, the cell assembly 100 does not necessarily have to be composed of a pouch-type battery cell 110. For example, the cell assembly 100 may be composed of a cylindrical battery cell or a prismatic battery cell.

[0036] The pouch-type battery cells 110 may be stacked on one another to form the cell assembly 100. For example, as shown in Fig. 2, a plurality of pouch-type battery cells 110 may be stacked in the vertical direction (Z-axis direction). Each pouch-type battery cell 110 includes an electrode lead, and the electrode lead may be located at both ends or one end of each battery cell 110.

[0037] The battery cell 110 shown in Fig. 2 is a bidirectional cell, and electrode leads are located at both ends of the battery cell 110 in the longitudinal direction (X-axis direction). However, the pouch-type battery cell 110 may be replaced by one in which the electrode leads are located only at one end in the X-axis direction, for example, the end in the +X-axis direction. The present invention is not limited in any way by the specific type or shape of such a battery cell 110, and a wide variety of battery cells 110 known at the time of filing of the present invention may be adopted in the cell assembly 100 of the present invention.

[0038] The cell assembly 100 is accommodated in the module case 200 such that the electrode lead sides of the battery cells 110 face the front and rear of the module case 200, i.e., the openings 210 on both sides. Although not shown for convenience of drawing, bus bar assemblies (not shown) as means for electrical connection of the battery cells 110 may be assembled to both ends along the longitudinal direction of the cell assembly 100. Here, the bus bar assembly may be composed of an insulating plate having a slot through which the electrode lead can pass, and a bus bar attached to one side of the insulating plate and arranged in a rod shape made of a metal material such as copper. For example, the battery cells 110 may be connected in series and / or parallel in such a manner that the electrode leads of one or more battery cells 110 are pulled out to the front side of the insulating plate through the slot and welded to one side of a specific bus bar, and the electrode leads of one or more other battery cells 110 are pulled out to the front side of the insulating plate through another slot and welded to the specific bus bar.

[0039] The module case 200 may be configured to have an empty space therein so as to accommodate the cell assembly 100. The module case 200 may be configured to have a predetermined length (along the X-axis direction) and a generally rectangular parallelepiped shape with openings 210 disposed at the front and rear along the longitudinal direction.

[0040] For ease of explanation, in the following, in the module case 200, the portions covering the upper and lower portions of the cell assembly 100 will be referred to as the upper plate and the lower plate, respectively, and the portions covering both side portions of the cell assembly 100 will be referred to as the side plates (left plate and right plate).

[0041] For example, the upper plate and the side plates may be integrated to form a U-frame having a U-shaped cross section, and the lower plate may be disposed in a plate shape with peripheral lines on both sides bent upward so that it can be connected to the U-frame by a method such as bolting or welding. Alternatively, the module case 200 may be in the shape of a square tube, and the upper plate, lower plate, and side plates may all be integrated to form a seamless single frame (monoframe).

[0042] Such a module case 200 has a structure in which all four sides except for the open portion 210 are sealed, and when gas or sparks are generated in the cell assembly 100, the gas or sparks can move to the open portion 210 side of the module case 200.

[0043] The oxygen inflow blocking cover 300 is a component that prevents an explosion due to an increase in the internal pressure of the battery module 10 by sending the gas to the outside of the module case 200 when gas is generated inside the module case 200 due to thermal runaway of the battery cell 110, and blocks the flow of oxygen into the module case 200 after the gas is discharged, thereby minimizing the risk of fire.

[0044] Such oxygen inflow blocking covers 300 may be provided as a pair at the front and rear of the module case 200, i.e., at the openings 210 on both sides of the module case 200. The oxygen inflow blocking covers 300 may be configured to cover the entire opening 210 and be coupled to both ends of the module case 200. When combining the oxygen inflow blocking covers with the module case 200, various methods such as welding, bolting, hook fastening, and adhesive methods may be used, and a sealant such as an O-ring may be added to ensure airtightness.

[0045] Specifically, as shown in FIGS. 2 and 3, the oxygen inflow blocking cover 300 includes hole closing members 320 that are arranged to overlap each other and have vent holes H1 and H2, and are positioned between a first partition 310A and a second partition 310B that are provided to cover the opening 210, and between the first partition 310A and the second partition 310B, and that distort in shape when heat is applied to close the vent holes H1 and H2.

[0046] The first partition wall 310A and the second partition wall 310B may be made of a metal material having high mechanical rigidity or a material having excellent fire resistance, and the hole closing member 320 may be made of a material that can be melted by heat, such as a plastic (polymer) material. The hole closing member 320 may have a gas passage hole 321.

[0047] The first partition 310A is provided in a plate shape capable of covering the opening 210 of the module case 200, and serves to prevent sparks or flames from escaping to the outside in the event of thermal runaway of the battery cell 110. However, the first partition 310A has a plurality of vent holes H1 along a height direction (Z-axis direction) so that gas can pass through the first partition 310A.

[0048] The second partition wall 310B is a component disposed to overlap the first partition wall 310A with the hole blocking member 320 interposed therebetween, and may be provided substantially similarly to the first partition wall 310A. The vent hole H2 of the second partition wall 310B may be provided in the same shape as the vent hole H1 of the first partition wall 310A, and may be provided in a plurality of holes in the height direction (Z-axis direction) of the second partition wall 310B. The vent hole H1 of the first partition wall 310A and the vent hole H2 of the second partition wall 310B may be configured to match each other in the longitudinal direction (X-axis direction) of the battery module 10 so that gas can pass through the first partition wall 310A and the second partition wall 310B even when the first partition wall 310A and the second partition wall 310B are disposed to overlap each other.

[0049] The hole closing member 320 may be a plastic injection product, and may be configured in the shape of a plate having a predetermined thickness, and may be located between the first partition wall 310A and the second partition wall 310B such that one surface of the hole closing member 320 faces and contacts the first partition wall 310A, and the other surface of the hole closing member 320 faces and contacts the second partition wall 310B. The hole closing member 320 includes a plurality of gas passing holes 321 arranged along the height direction (Z-axis direction). Gas can pass through the hole closing member 320 through the plurality of gas passing holes 321.

[0050] The gas passing hole 321 is disposed at a height at which the vent hole H1 of the first partition wall 310A and the vent hole H2 of the second partition wall 310B are at least partially aligned with each other. That is, as shown in FIG. 2, the vent hole H1 of the first partition wall 310A, the gas passing hole 321, and the vent hole H2 of the second partition wall 310B may be at least partially aligned with each other in a state where the first partition wall 310A, the hole blocking member 320, and the second partition wall 310B are stacked in this order. Therefore, when gas is generated inside the module case 200, the gas can be discharged to the outside of the battery module 10 by passing through the vent hole H1 of the first partition wall 310A, the gas passing hole 321 of the hole blocking member 320, and the vent hole H2 of the second partition wall 310B in this order.

[0051] Meanwhile, since the hole blocking member 320 is made of a plastic injection molding, if heat generated due to a thermal runaway of the battery cell 110 is transferred to the hole blocking member 320 above a certain level, or if heat of the released gas is transferred to the hole blocking member 320 above a certain level, the hole blocking member 320 may melt down and become distorted in shape. Such distortion of the shape of the hole blocking member 320 may cause the vent hole H1 of the first partition 310A and the vent hole H2 of the second partition 310B to be blocked.

[0052] According to this configuration of the present invention, when a thermal runaway situation occurs inside the battery module 10 and gas is released, the released gas can be smoothly discharged to the outside of the battery module 10 through the vent holes H1 and H2 and the gas passage hole 321. Therefore, an explosion due to an increase in the internal pressure of the battery module 10 can be prevented. In addition, the hole closing member 320 melts down due to the heat transferred while the vent gas is being discharged, and the vent hole H1 of the first partition wall 310A and the vent hole H2 of the second partition wall 310B are closed, so that it is possible to effectively block the inflow of oxygen into the inside of the battery module 10 through the vent holes and the gas passage hole 321 after the vent gas is discharged.

[0053] This will be explained in more detail with reference to FIGS.

[0054] 4 and 5 are diagrams illustrating the effects of exhausting gas and blocking the inflow of oxygen when gas is generated inside the battery module 10 according to an embodiment of the present invention.

[0055] 4 under the condition of thermal runaway of one or more battery cells 110, when gas is emitted from the battery cell 110, the emitted gas may move to the opening 210 of the module case 200. The gas indicated by the symbol G may be discharged to the outside of the battery module 10 by passing through the vent hole H1 of the first partition 310A, the gas passing hole 321 of the hole closing member 320, and the vent hole H2 of the second partition 310B in this order.

[0056] As described above, the gas passage hole 321 of the hole blocking member 320 may be formed to have a narrower width than the vent hole H1 of the first partition wall 310A and the vent hole H2 of the second partition wall 310B so that heat can be effectively transferred to the surrounding area of ​​the gas passage hole 321 when the gas is discharged. With this configuration, heat is effectively transferred to the surrounding area of ​​the gas passage hole 321 of the hole blocking member 320, and the shape of the corresponding portion is easily distorted. Therefore, as shown in FIG. 5, the vent hole H1 of the first partition wall 310A and the vent hole H2 of the second partition wall 310B are blocked, and the inflow of oxygen from the outside to the inside of the battery module 10 can be blocked.

[0057] FIG. 6 is an enlarged view of the main portion of a modified example of FIG. 4, and FIG. 7 is a view showing an example in which the shape of the hole closing member 320 of FIG. 6 has been distorted by heat.

[0058] As a modification of FIG. 4, the gas passage hole 321 may be configured so that the width in the vertical direction gradually narrows as it approaches the vent hole H1 of the first partition wall 310A. According to the above configuration, the gas flow indicated by the reference symbol G0 in FIG. 6 has no obstacles on its path, but the gas flow indicated by the reference symbol G1, for example, is blocked by the area around the gas passage hole 321. This allows the temperature of the area around the gas passage hole 321 to increase more quickly, and the area can be effectively melted. However, since the gas exhaust pressure acts in the right direction in the gas passage hole 321, the melted part may be biased to the right direction in FIG. 6, that is, toward the vent hole H2 of the second partition wall 310B. If this bias phenomenon becomes more severe, the melted part may scatter outside the vent hole H2 of the second partition wall 310B together with the gas, making it difficult to block the vent hole. For this reason, in this modification, the width of the gas passing hole 321 is gradually narrowed toward the vent hole H1 side of the first partition wall 310A, so that the upper and lower sides of the gas passing hole 321 can be fused more quickly when the plastic area around it is melted. In this way, after the upper and lower sides of the gas passing hole 321 are fused, the viscosity of the molten part becomes strong and it does not easily scatter outside the vent hole H2 of the second partition wall 310B. Therefore, according to this modification, the vent hole can be blocked more effectively.

[0059] Meanwhile, as an alternative to the plastic injection type hole blocking member 320 having the gas passage holes 321, a mesh net hole blocking member 320A made of a material that can melt at a predetermined temperature may be used as shown in Fig. 8. The mesh net has better ventilation than the plastic injection type hole blocking member 320 described above, so that gas can be discharged more smoothly and the inflow or outflow of particulate sparks and foreign matter can be more effectively blocked.

[0060] As described above, according to the configuration of the battery module 10 according to an embodiment of the present invention and the operation of the configuration, gas generated in a thermal runaway situation of a specific battery cell 110 can be discharged to the outside of the battery module 10, thereby preventing the explosion of the battery module 10, and the inflow of oxygen can be blocked after the gas is discharged to prevent the spread of fire. That is, in a thermal runaway situation, a heat source such as a spark or a combustible material may exist inside the battery module 10, but as described above, if the inflow of oxygen, which is one of the three elements of combustion, is blocked, the spread of a fire inside the battery module 10 can be prevented or significantly delayed.

[0061] FIG. 9 is a schematic perspective view of a battery module 10A according to another embodiment of the present invention, and FIG. 10 is an exploded perspective view of the oxygen inflow blocking cover 400 of FIG.

[0062] Next, another embodiment of the present invention will be described with reference to the same figure.

[0063] The same component numbers as in the previously described embodiment indicate the same components, and duplicated descriptions of the same components will be omitted, with the focus being on the differences from the previously described embodiment.

[0064] Compared with the configuration of the above-described embodiment, the battery module 10A according to another embodiment of the present invention includes three partition walls 410A, 410B, 410C arranged to overlap each other in three layers, and two hole blocking members 420, 430 arranged between the three partition walls 410A, 410B, 410C. The two hole blocking members 420, 430 are formed to have a porous structure.

[0065] 10, the oxygen inflow blocking cover 400 of the present invention includes a first partition 410A, a second partition 410B, and a third partition 410C arranged to face each other in three layers. The oxygen inflow blocking cover 400 also includes a first hole closing member 420 arranged between the first partition 410A and the second partition 410B, and a second hole closing member 430 arranged between the second partition 410B and the third partition 410C.

[0066] The vent holes J1, J2 of the first partition 410A may be provided on both sides so as to extend elongatedly in the vertical direction (Z-axis direction), the vent hole K1 of the second partition 410B may be provided in a central portion so as to extend elongatedly in the vertical direction (Z-axis direction) so as to be shifted from the vent holes J1, J2 of the first partition 410A, and the vent holes Q1, Q2 of the third partition 410C may be provided on both sides so as to extend elongatedly in the vertical direction (Z-axis direction) so as to be shifted from the vent hole K1 of the second partition 410B.

[0067] The first hole blocking member 420 and the second hole blocking member 430 are made of a material that is heat-meltable, such as plastic resin, and can be realized in a form having a porous structure and a predetermined volume, for example, in the form of a porous sponge, porous foam, or web. The first hole blocking member 420 and the second hole blocking member 430 have ventilation not only in the thickness direction (X-axis direction) but also in the horizontal direction (Y-axis direction) and vertical direction (Z-axis direction).

[0068] According to the above-mentioned configuration of the oxygen inflow blocking cover 400, it is possible to prevent sparks and flames from being discharged to the outside under the condition of thermal runaway inside the battery module 10A, while allowing gas to be smoothly discharged to the outside. As in the above-mentioned embodiment, the first hole blocking member 420 and the second hole blocking member 430 are configured to be distorted by heat, and it is possible to block oxygen from flowing into the inside of the battery module 10A after the gas is discharged.

[0069] This will be further explained with reference to FIG. 11 and FIG.

[0070] 11 and 12 are diagrams illustrating the effect of exhausting gas and blocking the inflow of oxygen when gas is generated inside a battery module 10 according to another embodiment of the present invention.

[0071] When gas and sparks are ejected from the battery cell 110, the sparks shown by F in FIG. 11 are blocked by the first partition 410A, or even if they pass through the vent holes J1 and J2 of the first partition 410A, they can be blocked by the second partition 410B. Furthermore, since most sparks are particulate, they are difficult to flow into the porous first hole blocking member 420. In addition, since the present embodiment is made of a triple partition, sparks or flames are forced to take a complicated route to escape to the outside. Therefore, it is substantially very difficult for sparks or flames to escape to the outside.

[0072] However, in the case of the gas indicated by the symbol G in FIG. 11, the gas passes through the vent holes J1 and J2 of the first partition 410A to reach the first hole blocking member 420 having a porous structure, and then passes through the vent hole K1 of the second partition 410B to reach the second hole blocking member 430 having a porous structure, and finally passes through the vent holes Q1 and Q2 of the third partition 410C to be discharged to the outside of the battery module 10A.

[0073] After the gas is discharged, heat is transferred to the first hole blocking member 420 and the second hole blocking member 430 during the process of discharging the gas. As a result, at least one of the first hole blocking member 420 and the second hole blocking member 430 may be distorted in shape. That is, the first hole blocking member 420 or the second hole blocking member 430 may melt down, causing the porous structure to collapse, or the vent holes J1 and J2 of the first partition wall 410A, the vent hole K1 of the second partition wall 410B, and the vent holes Q1 and Q2 of the third partition wall 410C may be blocked. At this time, as shown by the symbol O in FIG. 12, it is possible to block oxygen from flowing into the battery module 10A.

[0074] As described above, the battery module 10A according to another embodiment of the present invention is composed of three partition walls 410A, 410B, and 410C, and the vent holes of the partition walls are alternately positioned to prevent sparks and flames from passing through and to allow only gas to be discharged to the outside. In addition, after gas is discharged, the hole blocking member is configured to be distorted by heat during the gas discharge process to block the vent hole, thereby preventing oxygen from flowing into the battery module 10A. As a result, the risk of fire spreading inside the battery module 10A and outside the battery module 10 can be significantly reduced.

[0075] Meanwhile, the battery pack 1 according to the present invention may include a plurality of the above-described battery modules according to the present invention. In addition to such battery modules, the battery pack 1 according to the present invention may further include various other components, such as a battery management system (BMS), bus bars, a pack case 20, a relay, a current sensor, and other components of the battery pack 1 that are publicly known at the time of filing of the present invention.

[0076] The energy storage system according to the present invention may include one or more battery modules according to the present invention. In particular, the energy storage system may include a plurality of battery modules according to the present invention, electrically connected to each other, in order to have a large energy capacity. Alternatively, a plurality of battery modules according to the present invention may constitute one battery pack 1, and the energy storage system may include a plurality of such battery packs. In addition, the energy storage system according to the present invention may further include various components of an energy storage system that are publicly known at the time of filing of the present invention. Furthermore, such an energy storage system may be used in a variety of locations and devices, such as a smart grid system or an electric charging station.

[0077] Although the present invention has been described above using limited embodiments and drawings, the present invention is not limited thereto, and it goes without saying that various modifications and variations can be made by a person having ordinary knowledge in the technical field to which the present invention pertains within the scope of the technical concept of the present invention and the scope of the claims.

[0078] Meanwhile, although directional terms such as up, down, left, and right 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 vary depending on the position of the object in question, the position of the observer, etc. [Explanation of symbols]

[0079] Code Name 1 Battery Pack 10 Battery Module 10A Battery Module 20 pack case 100 Cell Assembly 110 Battery cell (pouch type battery cell) 200 module case 210 Open area 300 Oxygen inflow cutoff cover 310A 1st bulkhead 310B 2nd bulkhead 320 Hole Closure Material 320A Hole Closure Material 321 Gas passage hole 400 Oxygen inflow cutoff cover 410A 1st bulkhead 410B 2nd bulkhead 410C 3rd bulkhead 420 First hole closing member 430 Second hole blocking member H1 Vent hole H2 vent hole J1 vent hole J2 vent hole K1 Vent hole Q1 Vent hole Q2 Vent hole

Claims

1. a cell assembly including a plurality of battery cells; a module case provided to house the cell assembly and having an opening on at least one side; an oxygen inflow blocking cover for covering the opening; Including, The oxygen inflow blocking cover is two or more partition walls each having a vent hole, the two or more partition walls being arranged to overlap each other and covering the opening, the two or more partition walls being configured such that when gas is generated in the cell assembly, the gas is discharged to the outside of the module case through the vent hole; a hole closing member disposed between the partition walls, the hole closing member being distorted in shape when heat is applied thereto, thereby closing the vent hole; A battery module comprising: The two or more partition walls include a first partition wall and a second partition wall, the first partition wall and the second partition wall are arranged to overlap with each other with the hole closing member sandwiched between the first partition wall and the second partition wall, the hole closing member is provided in a plate-like shape and has gas passage holes through which gas can pass in a thickness direction; the vent hole of the first partition wall, the gas passage hole, and the vent hole of the second partition wall at least partially coincide with each other; The gas passage hole is the vent hole of the first partition and the vent hole of the second partition are formed to have a width narrower than a width of each of the vent holes of the first partition and the second partition.

2. The battery module according to claim 1 , wherein the hole blocking member is a plastic injection molded member having a plate shape.

3. The battery module of claim 1 , wherein a width of the gas passage hole is gradually increased in a direction in which the gas flows out of the battery module.

4. The battery module according to claim 1 , wherein the hole closing member is made of a mesh net that can be melted at a predetermined temperature.

5. A cell assembly including a plurality of battery cells; a module case provided to house the cell assembly and having an opening on at least one side; an oxygen inflow blocking cover for covering the opening; Including, The oxygen inflow blocking cover is two or more partition walls each having a vent hole, the two or more partition walls being arranged to overlap each other and covering the opening, the two or more partition walls being configured such that when gas is generated in the cell assembly, the gas is discharged to the outside of the module case through the vent hole; a hole closing member disposed between the partition walls, the hole closing member being distorted in shape when heat is applied thereto, thereby closing the vent hole; A battery module comprising: The two or more partition walls are The insulating layer includes a first partition wall, a second partition wall, and a third partition wall that are arranged in three layers facing each other, the hole blocking member includes a first hole blocking member disposed between the first partition and the second partition, and a second hole blocking member disposed between the second partition and the third partition.

6. a vent hole of the first partition wall and a vent hole of the second partition wall are positioned so as to be shifted from each other, and a vent hole of the second partition wall and a vent hole of the third partition wall are positioned so as to be shifted from each other, The battery module of claim 5 , wherein the first hole blocking member and the second hole blocking member have a porous structure.

7. The battery module according to claim 1 , wherein the cell assembly is configured in a shape in which a plurality of pouch-type battery cells are stacked on one another.

8. The plurality of pouch-type battery cells have electrode leads positioned in a front-rear direction of the module case, The battery module according to claim 7 , wherein the module case has the opening at least at one of a front and a rear.

9. A battery pack comprising a plurality of battery modules according to any one of claims 1 to 8.

10. An energy storage system comprising a battery module according to any one of claims 1 to 8.

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