Battery module where the fire-resistant coating layer peels off, opening up a vent hole

Abstract

A battery module according to the present invention includes a cell assembly including a plurality of stacked battery cells; a module case that houses the cell assembly in an internal space and has a vent hole formed therein; and a cover member that covers the vent hole and is disposed on an outer surface of the module case, the cover member having a fire-resistant coating layer coated with a fire-resistant coating material that peels off due to the pressure of vent gas when vent gas is generated inside the module case.

Description

[Technical Field]

[0001] The present invention relates to a battery module, and more particularly to a battery module in which a fire-resistant coating layer applied to the inside of a mesh plate on the upper part of the module can be partially peeled off to open a vent hole.

[0002] This application claims priority based on Korean Patent Application No. 10-2023-0030912, filed on March 9, 2023, the entire contents of which are incorporated herein by reference in their entirety in the specification and drawings thereof. [Background technology]

[0003] Semi-permanent batteries that convert electrical energy into chemical energy and can be repeatedly charged and discharged are called secondary batteries, in distinction from primary batteries, which cannot be reused once used.

[0004] Secondary batteries include lithium secondary batteries, nickel-cadmium (Ni-Cd) batteries, lead-acid batteries, nickel-metal hydride (Ni-MH) batteries, zinc-air batteries, alkaline manganese batteries, etc. Of these, lead-acid batteries and lithium secondary batteries are the most actively commercialized secondary batteries.

[0005] In particular, lithium secondary batteries have recently been actively used as batteries for electric vehicles due to their advantages of high energy storage density, light weight and miniaturization, excellent safety, low discharge rate, long life, etc. For reference, lithium secondary batteries are generally classified into cylindrical, prismatic, and pouch types depending on the manufacturing form, and are used not only for electric vehicle batteries but also for ESS batteries and other electrical devices.

[0006] Currently, the operating voltage of a single lithium secondary battery cell is approximately 2.5 V to 4.5 V. Therefore, in order to use a secondary battery as an energy source for an electric vehicle, a battery module is constructed by connecting multiple lithium ion battery cells in series and / or in parallel, and a battery pack is constructed by connecting the battery modules in series and / or in parallel.

[0007] On the other hand, secondary batteries undergo chemical reactions during charging and discharging, so their performance may deteriorate if they are used in an environment higher than the appropriate temperature, and if they are not thermally controlled to the appropriate temperature, they may unexpectedly catch fire or explode. Also, battery modules have a structure in which such secondary batteries are collectively housed inside a module housing, and if one secondary battery experiences thermal runaway and becomes a trigger cell, heat and flames are quickly transmitted to surrounding secondary batteries, making them more susceptible to chain fires.

[0008] In particular, in terms of integration, it is necessary to accommodate as many battery modules as possible within a limited space, and therefore there is not enough empty space inside the battery module. For example, in a battery pack including one or more battery modules, the space between the module case and the pack case may be very narrow.

[0009] Therefore, even in such a narrow space, it is necessary to quickly exhaust the vent gas and prevent the exhausted vent gas from flowing into other modules, thereby delaying or suppressing TP (thermal propagation). Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention has been made in consideration of the above problems, and an object of the present invention is to provide a battery module with an improved structure that can release internal pressure by discharging vent gas generated inside the battery module and prevent the inflow of flames discharged from other surrounding battery modules.

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

[0012] A battery module according to the present invention may include a cell assembly including a plurality of stacked battery cells; a module case that houses the cell assembly in an internal space and has a vent hole formed therein; and a cover member that covers the vent hole and is disposed on an outer surface of the module case, the cover member having a fire-resistant coating layer coated with a fire-resistant coating material that peels off due to pressure of vent gas when vent gas is generated inside the module case.

[0013] The vent hole may be formed on an upper side of the module case.

[0014] The cover member may further include a base layer coupled to face the upper surface of the module case and to which the fire-resistant coating layer is coupled.

[0015] The fire-resistant coating layer may be provided over the entire surface of the base layer and may be bonded to a portion or the entire thickness of the base layer.

[0016] The base layer may include at least one mesh plate having a plurality of mesh nets and voids, and a support frame disposed on an edge of the mesh plate and supporting the mesh plate.

[0017] The fire-resistant coating layer may be provided such that the fire-resistant coating material is bonded to the mesh net to block the gap.

[0018] The fire-resistant coating layer may include one or more inorganic materials selected from ceramic, silicon, silica aerogel, and silica-based inorganic fibers.

[0019] The particle size of the inorganic material may be relatively smaller than the voids.

[0020] The base layer may include a guide recess provided opposite the vent hole to guide the intake of the vent gas.

[0021] The guide recess may have a tapered surface that tapered toward the thickness direction of the base layer when viewed from the vent hole upward.

[0022] The fire-resistant coating layer may be partially provided on the plate surface of the base layer, and may be formed at a position of the base layer facing the vent hole.

[0023] According to another aspect of the present invention, there is provided a battery pack including one or more of the battery modules described above. [Effects of the Invention]

[0024] According to one aspect of the present invention, it is possible to provide a battery module having an improved structure that, when vent gas is generated in the internal space of a battery module, the vent gas can be discharged to the outside to relieve internal pressure and prevent flames, etc., emitted from other surrounding battery modules from flowing into the battery module.

[0025] In particular, even if the space between the battery module and the pack case is narrow when the battery module is housed inside the pack case, the fire-resistant coating layer peels off due to gas pressure, opening the vent hole, thereby ensuring a sufficient discharge path for the vent gas. Therefore, the vent gas is quickly discharged to the outside, effectively preventing heat accumulation and thermal explosion of the battery module.

[0026] In addition, since there is no need to form a separate gap or space to open the vent hole, it is possible to prevent a decrease in the energy density of the battery pack.

[0027] According to one aspect of the present invention, the vent holes of adjacent modules are kept closed by a fire-resistant coating layer that maintains heat resistance, thereby preventing external foreign objects, vent gas discharged to the outside of the battery module, or flames or sparks contained in the vent gas from entering other vent holes. Therefore, it is possible to delay as much as possible the occurrence of chain fires or thermal runaway in normal battery cells or battery modules due to vent gas or flames. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a schematic perspective view of a battery module according to an embodiment of the present invention; [Figure 2] FIG. 2 is an exploded perspective view of the main components of the battery module of FIG. 1. [Figure 3] FIG. 2 is a cross-sectional view of a cover member according to an embodiment of the present invention. [Figure 4] FIG. 2 is a cross-sectional view of a cover member according to an embodiment of the present invention. [Figure 5] 10 is a view illustrating a modified example of a cover member of a battery module according to an embodiment of the present invention, in which a fire-resistant coating layer is bonded to another section of the base layer in the thickness direction. FIG. [Figure 6]1 is a cross-sectional view of a structure of a battery pack including a battery module according to an embodiment of the present invention. [Figure 7] FIG. 7 is a partially enlarged view of FIG. [Figure 8] 10 is a cross-sectional view of a cover member of a battery module according to another embodiment of the present invention. [Figure 9] 10 is a view schematically illustrating a path through which vent gas is discharged through a cover member in a battery module according to another embodiment of the present invention. FIG. [Figure 10] FIG. 10 is a perspective view of a cover member of a battery module according to still another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0029] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms and phrases used in the specification and claims should not be construed as being limited to their ordinary and dictionary meanings, but should be construed as having meanings and concepts corresponding to the technical ideas of the present invention, in accordance with the principle that the inventors themselves can appropriately define the concepts of terms in order to best describe the invention.

[0030] Therefore, it should be understood that the configurations shown in the embodiments described in this specification are merely the most desirable 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.

[0031] In the drawings, the size of each component or specific parts constituting the component may be exaggerated, omitted, or schematically shown for convenience and clarity of description. Therefore, the size of each component may not completely reflect the actual size. If a detailed description of related well-known functions or configurations is deemed to unnecessarily obscure the gist of the present invention, such description will be omitted.

[0032] FIG. 1 is a schematic perspective view of a battery module according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view of the main components of the battery module of FIG.

[0033] 1 and 2, a battery module 10 according to the present invention includes a cell assembly 100, a module case 200, and a cover member 300.

[0034] The cell assembly 100 may include one or more battery cells 110. Here, each battery cell 110 may represent a secondary battery. Referring mainly to FIG. 2 , the battery cell 110 includes an electrode assembly, a case that houses the electrode assembly, and a pair of electrode leads 112 that are connected to the electrode assembly and extend outside the case to function as electrode terminals. The pair of electrode leads 112 extend from both ends of the battery cell 110, i.e., in the length direction.

[0035] If necessary, the battery cell 110 may have a shape in which the electrode lead 112 is located only at one end of the battery cell 110. Meanwhile, the present invention is not limited to a specific type or shape of the battery cell 110, and various battery cells 110 known at the time of filing of the present invention may be used to configure the cell assembly 100 of the present invention. While the present embodiment focuses on a pouch-type secondary battery that has high energy density and is easy to stack, it goes without saying that cylindrical or prismatic secondary batteries may also be applied to the battery cell 110.

[0036] The battery cells 110 may be stacked and arranged in at least one direction. In this embodiment, referring mainly to FIG. 2, the battery cells 110 may be stacked and arranged in a horizontal direction (the width direction of the battery module 10) with each battery cell standing upright.

[0037] The cell assembly 100 is an assembly of battery cells 110 formed by stacking a plurality of battery cells 110. That is, the cell assembly 100 may be a group of a plurality of pouch-type battery cells 110 stacked in one direction with their wide surfaces standing up, as shown in FIG.

[0038] The module case 200 may have an internal space formed therein, and may be configured to accommodate the battery cells 110. The module case 200 of the present embodiment may include a case body 210 and end plates 220 disposed on the front and rear surfaces of the case body 210.

[0039] The case body 210 may be configured in the shape of a rectangular tube having a hollow structure with open ends O at both ends in the length direction. For example, the case body 210 may be configured in the shape of a tube having an upper surface, a lower surface, a left side surface, and a right side surface, with openings formed at the front and rear ends, respectively.

[0040] The case body 210 may be configured to allow the battery cell 110 to be inserted into the case body 210 along the length direction. That is, the case body 210 may be configured to allow the battery cell 110 to be inserted therein by sliding or tight fit. For tight fit, there may be little gaps between the upper and lower surfaces of the case body 210 and between the upper and lower ends of the battery cell 110, and there may also be little gaps between both side surfaces of the case body 210 and both sides of the battery cell 110. The case body 210 may be made of a metal material having rigidity and heat resistance to physically and chemically protect the housed battery cell 110.

[0041] The end plate 220 may be provided to face one side of the cell assembly 100 and be coupled to the open end O of the case body 210 so as to prevent one side of the cell assembly 100, where the electrode leads 112 of the battery cells 110 are located, i.e., a portion where the electrode leads 112 are connected to be fixed to the bus bars on the bus bar frame, from being exposed to the outside. The end plate 220 may be configured, for example, so that the inside is made of an insulating material and the outside is made of a metallic material and is fixedly coupled to the case body 210 by welding. Meanwhile, although not shown for convenience of illustration, the end plate 220 may partially have holes or slits for exposing components that need to be exposed to the outside, such as the positive and negative terminals or connectors of the battery module 10.

[0042] The module case 200 configured as described above may have a vent hole H1 formed on at least one side. As shown in FIG. 2, a plurality of vent holes H1 may be formed on the upper side of the module case 200, offset to the left and right. The vent holes 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 module case 200 may be configured to be sealed except for the vent hole H1. Alternatively, the vent hole H1 may be formed to be completely open so as to penetrate the module case 200 in an internal to external direction.

[0043] The cover member 300 is disposed on the outer surface of the module case 200 and may be configured to close the vent hole H1 formed in the module case 200 in a normal state. In this embodiment, as shown in Figures 2 and 3, the cover member 300 may be provided on the upper side of the module case 200. As a result, the cover member 300 may be configured to cover the vent hole H1 formed in the upper surface of the module case 200.

[0044] The cover member 300 may be configured to selectively open the vent hole H1 when vent gas is generated from at least one battery cell 110 among the cell assemblies 100 housed inside the module case 200.

[0045] 3 and 4 are cross-sectional views of a cover member according to an embodiment of the present invention, and FIG. 5 is a view showing a modified example of the cover member of the battery module 10 according to an embodiment of the present invention, in which a fire-resistant coating layer is bonded to another section in the thickness direction of the base layer.

[0046] 3 and 4, the cover member 300 includes a base layer 310 coupled to face the upper surface of the module case 200, and a fire-resistant coating layer 320 coated with a fire-resistant coating material 321 that peels off due to the pressure of vent gas when vent gas is generated inside the module case 200.

[0047] The base layer 310 is coupled to face the upper surface of the module case 200 and may be provided with a size substantially the same as that of the upper surface of the module case 200 .

[0048] The base layer 310 may be at least one mesh plate 311 having a plurality of mesh nets 312 and gaps 313. The base layer 310 may be configured to block high-temperature flames and sparks that may travel with the vent gas. The base layer 310 is disposed to completely cover the vent hole H1 and can block the entry and exit of flames and sparks generated at the vent hole H1. This allows the base layer 310 to sufficiently filter and block flames and sparks associated with the discharge of vent gas and prevent them from being discharged outside the battery pack, thereby minimizing the risk of fire to structures around the battery pack or other battery packs.

[0049] In addition, the base layer 310 may include a support frame 314 disposed on the edge of the mesh plate 311 and supporting the mesh plate 311. The support frame 314 firmly holds the mesh plate 311 even when exposed to high temperatures, preventing warping, deformation, and damage to the plate surface.

[0050] Meanwhile, a vent structure is required to quickly and effectively exhaust the vent gas discharged from inside the battery module 10. In particular, the vent hole H1 is required to have an open / close structure that is normally kept closed and selectively opens the vent hole H1 when a thermal event occurs and vent gas is generated.

[0051] Therefore, in this embodiment, when vent gas is generated inside the module case 200, a fire-resistant coating layer 320 can be provided, which is coated with a fire-resistant coating material 321 that peels off due to the pressure of the vent gas.

[0052] Referring to FIGS. 2 and 3, the fire-resistant coating layer 320 may be provided over the entire surface of the base layer 310.

[0053] 4, the fire-resistant coating layer 320 may be provided such that the fire-resistant coating material 321 is bonded to the mesh net 312 to block the voids 313. Here, the fire-resistant coating layer 320 may include one or more inorganic materials selected from ceramic, silicon, silica aerogel, and silica-based inorganic fibers. In addition, the particle size of the inorganic material may be relatively smaller than the voids 313.

[0054] The fire-resistant coating layer 320 may further include a binder 322 that binds the fire-resistant coating material 321 to the mesh net 312, and various additives. The binder 322 may be a metal-affinity resin, such as polyvinyl acetal resin, acrylic resin, polyvinyl chloride resin, polyolefin resin, or epoxy resin. The binder 322 includes the fire-resistant coating material 321 and facilitates adhesion to the mesh net 312. The additives may include an adhesion promoter, a dispersant, a release agent, a heat stabilizer, an antioxidant, etc.

[0055] The fire-resistant coating layer 320 may be bonded to a portion of the base layer 310 in the thickness direction. For example, as shown in Figures 2 to 4, the fire-resistant coating layer 320 may be formed on an upper portion (approximately a predetermined thickness) of the base layer 310 in the thickness direction of the base layer 310.

[0056] Alternatively, as another modification, as shown in Fig. 5(a), the fire-resistant coating layer 320 may be provided over the entire thickness of the base layer 310. In this case, compared to Fig. 4 or Fig. 5(b), since the fire-resistant coating layer 320 is provided to a thickness approximately equal to the thickness of the base layer 310, the fire-resistant coating layer 320 may peel off if the vent gas ejected from the vent hole H1 has a higher pressure. In other words, the pressure range of the vent gas at which the vent hole H1 is fully opened can be increased.

[0057] 5(b), a fire-resistant coating layer 320 may be provided on the lower part of the base layer 310. In this case, the fire-resistant coating layer 320 can tightly cover the vent hole H1 of the module case 200, thereby improving the sealing performance of the vent hole H1 compared to FIG. 4, and further preventing the inflow of foreign matter, flames, and sparks. In this way, the position of the fire-resistant coating layer 320 on the base layer 310 may be varied depending on the pressure level of the vent gas, the sealing performance, or other design factors.

[0058] There are various methods for applying the fire-resistant coating layer 320 to the base layer 310. For example, a coating solution may be prepared by dissolving the fire-resistant coating material 321 in a viscous solvent, followed by a spray application process. The number of sprays may vary depending on the viscosity of the coating solution, and the time and temperature of subsequent processes such as drying may also be adjusted. Forming the fire-resistant coating layer 320 using such a spray process is advantageous for applying the fire-resistant coating layer 320 as shown in Figures 4 and 5(b).

[0059] Alternatively, the coating process can be performed by immersing the base layer 310 in a bath of the coating liquid. In this case, it is efficient to form the fire-resistant coating layer 320 over the entire thickness of the base layer 310, as shown in Figure 5(a).

[0060] FIG. 6 is a structural cross-sectional view of a battery pack including a battery module according to one embodiment of the present invention, and FIG. 7 is a partially enlarged view of FIG.

[0061] Hereinafter, the venting operation configuration will be described based on a state in which the fire-resistant coating layer 320 is provided over the entire section of the base layer 310 in the thickness direction, as shown in FIG. 5(a).

[0062] Normally, the vent hole H1 is covered with the fire-resistant coating layer 320 and maintained closed.

[0063] When a specific event cell ignites and a large amount of vent gas is generated, it is ejected into the vent hole H1 formed at the top.

[0064] 6 and 7, the pressure (high pressure state) of the vent gas causes the fire-resistant coating layer 320 to separate from the mesh net 312 and peel upward. At the same time, the mesh plate 311 in which the gaps 313 are formed is exposed. The vent gas is discharged to the outside of the case body along the gaps 313 of the mesh plate 311. Meanwhile, flames and sparks are blocked by the mesh net 312 of the mesh plate 311 and cannot escape to the outside of the case body.

[0065] As shown in FIG. 6 , vent gas discharged from an event-occurring battery module may travel along the internal space 430 of the pack case and pass over the adjacent battery modules 10. The other battery modules 10 may not be thermally damaged by the vent gas because the fire-resistant coating layer 320 of the cover member 300 remains unpeeled from the base layer 310. Furthermore, the vent gas traveling along the internal space 430 passes over the other battery modules at a relatively lower pressure than when discharged from the event battery module, and therefore the fire-resistant coating layer 320 of the other battery modules is not peeled off from the base layer 310 by the vent gas. This prevents the vent gas from entering the battery module 10.

[0066] According to this embodiment, when an event occurs, the fire-resistant coating layer 320 blocking the vent hole H1 is peeled off by the pressure of the vent gas, opening the vent hole H1, thereby ensuring a sufficient exhaust path for the vent gas to be exhausted from the inside of the battery module to the outside. As a result, the vent gas is quickly exhausted to the outside, effectively preventing heat accumulation and thermal explosion of the battery module 10.

[0067] In addition, with this configuration, the vent holes H1 of the adjacent battery modules remain closed by the fire-resistant coating layer 320, which maintains heat resistance, and therefore, it is possible to prevent vent gas discharged to the outside of the battery module 10 due to an external foreign object or an event, or flames or sparks contained in such vent gas, from flowing into other vent holes H1. Therefore, it is possible to delay as much as possible the occurrence of chain fires or thermal runaway phenomena in normal battery cells 110 or battery modules 10 due to vent gas or flames.

[0068] In addition, since a large internal space 430 for discharging vent gas, flames, etc. is secured, it is possible to prevent a decrease in the energy density of the battery module 10 or the battery pack.

[0069] Next, another embodiment of the battery module of the present invention will be briefly described with reference to FIGS.

[0070] FIG. 8 is a cross-sectional view of a cover member of a battery module according to another embodiment of the present invention, and FIG. 9 is a diagram schematically showing a path through which vent gas is discharged through the cover member in a battery module according to another embodiment of the present invention.

[0071] The same reference numerals as in the previous drawings indicate the same components, and a duplicated description of the same components will be omitted, with the focus being on the differences from the above-described embodiment.

[0072] In a battery module according to another embodiment of the present invention, compared to the above-described embodiment, an additional configuration is provided in the base layer 310 of the cover member 300A. That is, the base layer 310 may include a guide recess 330 that is provided opposite the vent hole H1 and guides the intake of the vent gas.

[0073] 8 and 9, the guide recess 330 may be provided on the bottom surface of the base layer 310. The guide recess 330 may be disposed so as to be in direct contact with the vent hole H1. The guide recess 330 may be provided by partially pressing or partially cutting the bottom surface of the base layer 310.

[0074] In addition, the guide recess 330 may have a tapered inclined surface 331 tapered toward the thickness direction of the base layer 310 when viewed from the vent hole H1 upward.

[0075] The narrowing inclined surface 331 is connected to the vent hole H1 but is narrowed so that the inner diameter is smaller, thereby guiding the vent gas to easily enter the cover member 300. In particular, the vent gas that has entered the vent hole H1 can easily enter upward in the thickness direction of the base layer 310 along the narrowing inclined surface 331.

[0076] In addition, the reduced inner diameter due to the contraction inclined surface 331 can increase the flow rate of the vent gas, locally increasing the pressure of the vent gas and assisting in the peeling off of the fire-resistant coating layer 320.

[0077] Furthermore, the guide recesses 330 are provided, so that the thickness of the fire-resistant coating layer 320 can be made thinner than that of the first embodiment, and the ratio of the fire-resistant coating layer 320 to the base layer 310 can be adjusted by adjusting the recess depth of the guide recesses 330. Furthermore, the fire-resistant coating layer 320 can be configured to be relatively easily peeled off depending on the pressure of the vent gas.

[0078] According to this embodiment, even if the space between the battery module and the module case 200 is narrow, the fire-resistant coating layer 320 is peeled off by the gas pressure to open the vent hole H1, thereby ensuring a sufficient discharge path for the vent gas. Therefore, the vent gas is quickly discharged to the outside, effectively preventing heat accumulation and thermal explosion of the battery module.

[0079] In addition, with this configuration, the vent holes H1 of the adjacent modules remain closed by the fire-resistant coating layer 320, which maintains heat resistance, and therefore, it is possible to prevent external foreign objects, vent gas discharged to the outside of the battery module, or flames or sparks contained in such vent gas from entering other vent holes H1. Therefore, it is possible to delay as much as possible the occurrence of chain fires or thermal runaway phenomena in normal battery cells 110 or battery modules due to vent gas or flames.

[0080] FIG. 10 is a perspective view of a cover member of a battery module according to still another embodiment of the present invention.

[0081] Referring to FIG. 10, the fire-resistant coating layer 320 of the battery module according to another embodiment of the present invention may be partially provided on the plate surface of the base layer 310 and formed at a position of the base layer 310 facing the vent hole H1.

[0082] In such a case, the cover member 300B can be manufactured at relatively low cost and with little effort, while the function of the fire-resistant coating layer 320 to block the vent hole H1, i.e., faithfully performs the function of closing the vent hole H1 under normal circumstances, but peels off when vent gas is generated, can be realized, a so-called selective opening and closing configuration.

[0083] According to this embodiment, even if the space between the battery module and the module case 200 is narrow, the fire-resistant coating layer 320 is peeled off by the gas pressure to open the vent hole H1, thereby ensuring a sufficient discharge path for the vent gas. Therefore, the vent gas is quickly discharged to the outside, effectively preventing heat accumulation and thermal explosion of the battery module.

[0084] In addition, with this configuration, the vent holes H1 of the adjacent modules are kept closed by the fire-resistant coating layer 320, which maintains heat resistance, and it is possible to prevent external foreign objects or vent gas discharged to the outside of the battery module, or flames or sparks contained in such vent gas, from flowing into other vent holes H1. Therefore, it is possible to delay as much as possible the occurrence of chain fires or thermal runaway phenomena in normal battery cells 110 or battery modules due to vent gas or flames.

[0085] A battery pack according to the present invention may include one or more battery modules according to the present invention. In particular, to increase capacity and / or output, a battery pack according to the present invention may include a plurality of battery modules according to the present invention. In this case, the various configurations described above may be applied to each battery module. For example, each battery module may include a cell assembly 100, a module case 200, and a cover member 300. Furthermore, such a plurality of battery modules may be housed inside a pack case. Furthermore, in the case of a battery module according to an embodiment of the present invention, even if other battery modules are located in front or behind the battery module, thermal runaway propagation between the modules can be effectively prevented.

[0086] In addition to the battery module and pack case, the battery pack according to the present invention may further include various other components, for example, battery pack components known at the time of filing of the present invention, such as a BMS (Battery Management System), bus bars, relays, current sensors, and fuses, in the internal space of the pack case.

[0087] The battery module according to the present invention or the battery pack according to the present invention can be applied to automobiles such as electric automobiles and hybrid automobiles. That is, the automobile according to the present invention can 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 can 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 can further include a vehicle body, a motor, a control device such as an ECU (electronic control unit), etc. in addition to the battery module according to the present invention.

[0088] Furthermore, the battery module according to the present invention or the battery pack according to the present invention may be applied to an energy storage system (ESS), that is, the energy storage system according to the present invention may include the battery module according to the present invention or the battery pack according to the present invention.

[0089] Although the present invention has been described above using limited embodiments and drawings, it goes without saying that the present invention is not limited thereto, and 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 technical spirit of the present invention and the equivalent scope of the claims set forth below.

[0090] Meanwhile, when terms indicating directions such as up, down, left, right, front, and back are used in this specification, it will be apparent to those skilled in the art that such terms are used for the convenience of explanation and may vary depending on the position of the object in question, the position of the observer, etc. [Explanation of symbols]

[0091] 10 Battery Module 100 Cell Assembly 110 battery cells 112 Electrode Lead 200 Module Case 210 Case body 220 End Plate 300 Cover member 300A Cover material 300B Cover material 310 Base Layer 311 Mesh Plate 312 Mesh Net 313 void 314 Support Frame 320 fire-resistant coating layer 321 Fire-resistant coating materials 322 Binder 330 Guide recess 331 Constriction slope 430 Interior Space

Claims

1. a cell assembly including a plurality of battery cells stacked on one another; a module case that houses the cell assembly in its internal space and has a vent hole; a cover member that covers the vent hole, is disposed on an outer surface of the module case, and has a fire-resistant coating layer coated with a fire-resistant coating material that peels off due to pressure of vent gas when vent gas is generated inside the module case.

2. The battery module according to claim 1 , wherein the vent hole is formed on an upper side of the module case.

3. The battery module of claim 2 , wherein the cover member further comprises a base layer coupled to face the upper surface of the module case and to which the fire-resistant coating layer is coupled.

4. The battery module according to claim 3 , wherein the fire-resistant coating layer is provided over the entire area of ​​the plate surface of the base layer and is bonded to a portion or the entire area of ​​the base layer along a thickness direction.

5. the base layer includes at least one mesh plate having a plurality of mesh nets and voids; The battery module according to claim 3 , further comprising: a support frame disposed on an edge of the mesh plate and supporting the mesh plate.

6. The battery module according to claim 5 , wherein the fire-resistant coating layer is provided such that the fire-resistant coating material is bonded to the mesh net to block the gap.

7. The battery module according to claim 5 , wherein the fire-resistant coating layer includes one or more inorganic materials selected from the group consisting of ceramic, silicon, silica aerogel, and silica-based inorganic fibers.

8. The battery module according to claim 7 , wherein the particle size of the inorganic material is relatively smaller than that of the voids.

9. The battery module according to claim 4 , wherein the base layer includes a guide recess provided opposite the vent hole to guide the intake of the vent gas.

10. The battery module of claim 9 , wherein the guide recess has a tapered surface that tapered toward a thickness direction of the base layer when viewed from the vent hole upward.

11. The battery module according to claim 3 , wherein the fire-resistant coating layer is partially provided on a plate surface of the base layer, and is formed at a position of the base layer facing the vent hole.

12. A battery pack comprising the battery module according to any one of claims 1 to 11.

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