Battery module, battery pack including same, and automobile

Abstract

The present invention relates to a battery module comprising: a cell stack including a plurality of battery cells; a module case configured to house the cell stack; and a protective layer disposed on an outer surface of the module case to prevent heat conduction and heat radiation to the outside of the module case.

Description

[Technical Field]

[0001] The present invention relates to a battery module, a battery pack including the same, and a vehicle.

[0002] This application claims priority based on Korean Patent Application No. 10-2023-0091921, filed on July 14, 2023, the entire contents of which are incorporated herein by reference in their entirety in the specification and drawings thereof. [Background technology]

[0003] Highly applicable to a variety of products and possessing electrical properties such as high energy density, secondary batteries are widely used not only in portable devices but also in electric vehicles (EVs) and hybrid electric vehicles (HEVs) powered by electrical sources. These secondary batteries not only have the temporary advantage of dramatically reducing the use of fossil fuels, but also have the advantage of producing no by-products associated with energy use, and are therefore attracting attention as a new energy source that is environmentally friendly and improves energy efficiency.

[0004] Currently widely used types of secondary batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. When a high output voltage is required, a battery module or a battery pack may be configured by connecting multiple battery cells in series. To increase the charge / discharge capacity, a battery module or a battery pack may be configured by connecting multiple battery cells in parallel. Therefore, the number of battery cells included in the battery module or battery pack may be varied depending on the required output voltage and / or charge / discharge capacity.

[0005] However, because battery cells undergo chemical reactions during charging and discharging, their performance may deteriorate if they are used in environments that are higher than their optimum temperature. Failure to control the heat at an appropriate temperature could result in unexpected fires or explosions. Furthermore, battery modules house these battery cells in a concentrated manner inside a module case. Therefore, if a thermal event occurs in one battery cell, the emitted high-temperature gases and flames could spread to adjacent battery cells, potentially causing a chain reaction of battery cell explosions, creating a significant risk.

[0006] In addition, since the module case is made of a metal material with relatively high thermal conductivity, such as aluminum, when a thermal event occurs in the battery cell, there is a high possibility that heat will be conducted to the outside or inside of the battery module, causing thermal runaway.

[0007] Therefore, efforts must be made to develop a mechanism that can prevent the accumulation of heat inside the battery module due to high-temperature gases and flames generated inside the battery module when thermal runaway occurs, thereby suppressing and delaying the propagation of heat within the battery module.

[0008] In addition, in a battery pack in which battery modules are integrated, efforts must be made to develop a mechanism that can suppress and delay the propagation of heat between battery modules by minimizing heat conduction and heat radiation to other adjacent battery modules, even if a thermal event occurs within one battery module. Summary of the Invention [Problem to be solved by the invention]

[0009] Therefore, the problem to be solved by the present invention is to provide a battery module that can effectively prevent or delay the propagation of thermal runaway within the battery module by preventing heat accumulation inside the battery module due to gas or flame generated inside the battery module when thermal runaway occurs in the battery module.

[0010] Another problem to be solved by the present invention is to provide a battery module that can effectively prevent or delay the propagation of thermal runaway between battery modules by minimizing heat conduction and heat radiation to adjacent battery modules when thermal runaway occurs in the battery module.

[0011] Therefore, another problem to be solved by the present invention is to provide a battery module with improved safety and reliability.

[0012] Still another problem to be solved by the present invention is to provide a battery pack and a vehicle including such a battery module.

[0013] 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 description of the invention given below. [Means for solving the problem]

[0014] In order to solve the above problems, the present invention provides a battery module comprising: a cell stack including a plurality of battery cells; a module case configured to house the cell stack; and a protective layer disposed on an outer surface of the module case to prevent heat conduction and heat radiation to the outside of the module case.

[0015] At least one vent hole through which vent gas discharged from the battery cell is discharged may be formed in an upper surface of the module case, and the protective layer may be disposed on the upper surface of the module case and an inner peripheral surface of the vent hole.

[0016] A plurality of the vent holes may be provided, and the protective layer may be provided individually for each of the plurality of vent holes.

[0017] The protective layer may be provided on all surfaces of the module case, including the top surface.

[0018] The protective layer may be made of a material including at least one of polyurethane and silicone.

[0019] The protective layer may be provided as a coating layer rated UL 94 V-0 or higher.

[0020] The protective layer may be a foam coating layer conformally coated along the outer surface of the module case.

[0021] The thickness of the protective layer may be set to be 5% or more and 50% or less of the thickness of the module case.

[0022] The battery module may further include a top cover configured to be attached to an upper surface of the module case by an adhesive member.

[0023] The top cover may be configured to be attached to the protective layer by the adhesive member.

[0024] The battery module may further include a primer layer disposed between the protective layer and the adhesive member to improve bonding strength between the module case and the top cover.

[0025] The module case may include a U-frame having an open top surface and front and rear surfaces configured to accommodate the cell stack, and a top plate covering the open top surface of the U-frame.

[0026] Alternatively, the modular case may include a monoframe configured with a front and back opening to accommodate the cell stack.

[0027] The present invention also provides a battery pack including the battery module according to the present invention.

[0028] The battery pack may further include a pack case that accommodates the battery module and has a cooling member disposed on a bottom surface thereof, and the protective layer may be formed on both side surfaces and an upper surface of the module case.

[0029] The present invention also provides a vehicle comprising a battery pack according to the present invention. [Effects of the Invention]

[0030] According to one aspect of the present invention, when thermal runaway occurs in a battery module, heat accumulation inside the battery module due to gas or flame generated inside the battery module can be prevented, thereby effectively preventing or delaying the propagation of thermal runaway inside the battery module, thereby ensuring the safety and reliability of the battery module.

[0031] Furthermore, according to another aspect of the present invention, when thermal runaway occurs in a battery module, it is possible to effectively prevent or delay the propagation of thermal runaway between battery modules by minimizing heat conduction and heat radiation to adjacent battery modules.

[0032] Furthermore, according to yet another aspect of the present invention, when the top cover is attached to the outside of the battery module, the adhesive strength between the adhesive member for adhering the top cover and the battery module can be improved.

[0033] Furthermore, according to yet another aspect of the present invention, it is possible to prevent or delay events associated with thermal runaway phenomena in battery packs including multiple battery modules and devices to which they are attached, such as fires and explosions.

[0034] In addition to these, the present invention can have various other effects, which will be explained in the sections for each embodiment, and explanations of effects that can be easily inferred by those skilled in the art will be omitted.

[0035] The drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further understand the technical concepts of the present invention as well as the content of the invention, and therefore the present invention should not be interpreted as being limited to only the matters depicted in the drawings. [Brief explanation of the drawings]

[0036] [Figure 1] 1 is an overall perspective view of a battery module according to an embodiment of the present invention; [Figure 2] 1 is an exploded perspective view of a battery module according to an embodiment of the present invention; [Figure 3] 1 is a cross-sectional view of a battery module according to an embodiment of the present invention; [Figure 4] FIG. 4 is an enlarged view of part A in FIG. 3. [Figure 5] FIG. 10 is an exploded perspective view of a battery module according to another embodiment of the present invention. [Figure 6] FIG. 10 is a cross-sectional view of a battery module according to another embodiment of the present invention. [Figure 7] FIG. 7 is an enlarged view of part B in FIG. 6. [Figure 8] FIG. 10 is an exploded perspective view of a battery module according to yet another embodiment of the present invention. [Figure 9] FIG. 10 is a cross-sectional view of a battery module according to yet another embodiment of the present invention. [Figure 10]FIG. 10 is a cross-sectional view of a battery module according to yet another embodiment of the present invention. [Figure 11] 1 is a schematic perspective view of a battery pack including a battery module according to an embodiment of the present invention; [Figure 12] 1 is a schematic perspective view of a vehicle including a battery pack according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0037] 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 construed as being limited to their ordinary or 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 inventor can appropriately define the concepts of terms himself in order to best describe the invention.

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

[0039] The present invention includes a wide variety of embodiments, and the following description will focus on the differences and omit redundant explanations of configurations that are substantially the same or similar to each other.

[0040] On the other hand, although directional terms such as up, down, left, right, front, and back 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.

[0041] For example, in an embodiment of the present invention, the illustrated X-axis direction may refer to the left-right direction, the Y-axis direction may refer to the front-back direction that is perpendicular to the X-axis direction on a horizontal plane (XY plane), and the Z-axis direction may refer to the up-down direction (vertical direction) that is perpendicular to both the X-axis direction and the Y-axis direction.

[0042] Fig. 1 is an overall perspective view of a battery module according to an embodiment of the present invention, Fig. 2 is an exploded perspective view of the battery module according to an embodiment of the present invention, Fig. 3 is a cross-sectional view of the battery module according to an embodiment of the present invention, and Fig. 4 is an enlarged view of part A in Fig. 3.

[0043] 1 to 4, a battery module 10 according to an embodiment of the present invention may include a cell stack 100, a module case 200, and a protective layer 300.

[0044] The cell stack 100 may include a battery cell 110. The battery cell 110 may be provided in multiple numbers.

[0045] The plurality of battery cells 110 may be, for example, pouch-type secondary batteries. Each of the plurality of battery cells 110 may be provided with an electrode lead 112. Specifically, the plurality of battery cells 110 may include an electrode assembly, a cell case 111 that houses the electrode assembly, and an electrode lead 112 that is connected to the electrode assembly and extends to the outside of the cell case 111 to function as an electrode terminal. The cell case 111 may house the electrode assembly in a housing portion, and the periphery of the housing portion may be heat-sealed to form a seal portion.

[0046] The electrode leads 112 may be provided in pairs, and the pair of electrode leads 112 may be drawn out from both ends of the battery cell 110, i.e., in the longitudinal direction (±Y direction). In this case, the pair of electrode leads 112 may be a positive electrode lead and a negative electrode lead. If necessary, the battery cell 110 may have a shape in which the two electrode leads 112 are located only at one end in the Y-axis direction, for example, at the end in the +Y-axis direction.

[0047] 2, the battery cells 110 may be arranged so as to stand upright in the vertical direction (Z-axis direction) and line up in the left-right direction (X-axis direction). In this case, the sealed portion of each battery cell 110 may face the front-rear direction (Y-axis direction) and the up-down direction (Z-axis direction), and the housing portion may face the left-right direction (X-axis direction).

[0048] The present invention is not limited in any way by the specific type or form of such battery cells 110, and a wide variety of battery cells 110 known at the time of filing of the present invention can be used to configure the cell stack 100 of the present invention. In this embodiment, as shown in the drawing, a pouch-type secondary battery that has high energy density and is easy to stack is targeted, but it goes without saying that cylindrical or prismatic secondary batteries can also be used as the battery cells 110.

[0049] The cell stack 100 may further include a blocking member 120. The blocking member 120 may be disposed between the battery cells 110. In particular, a plurality of blocking members 120 may be included in one cell stack 100. The blocking member 120 may be provided in a shape that is disposed for at least one battery cell 110. In the present embodiment, the blocking member 120 may be disposed for every two battery cells 110. According to this embodiment of the present invention, the battery cells 110 are partitioned or separated by the blocking member 120, and gas, flame, etc. can be prevented from passing over the blocking member 120 and transferring to another blocking member 120 adjacent thereto.

[0050] The isolating member 120 may be made of a material having excellent heat resistance and / or fire resistance, such as silicone or aerogel. According to the embodiment of the present invention, the isolating member 120 can contribute to the structural rigidity of the battery cell 110 by compressing the battery cell 110 when swelling of the battery cell 110 occurs.

[0051] Meanwhile, referring to Fig. 2, the battery module 10 of the present invention may further include a bus bar frame assembly 700. The bus bar frame assembly 700 may be disposed inside the module case 200 and configured to cover at least one side of the cell stack 100. In this embodiment, as shown in Fig. 2, the bus bar frame assembly 700 may be coupled to the front and rear of the cell stack 100.

[0052] The bus bar frame assembly 700 may include a bus bar frame 710 and a plurality of bus bars 720. The bus bar frame 710 may be provided so as to be coupled to the front and rear of the cell stack 100. The bus bar frame 710 may have slits that allow the electrode leads 112 of the battery cells 110 to be drawn out in the +Y-axis or -Y-axis direction. The bus bar frame 710 may be formed, for example, from a plastic material having electrical insulation properties, and may be configured to allow the bus bars 720 to be attached to its outer surface.

[0053] In addition, the bus bar frame 710 may be coupled to the front or rear of the cell stack 100 by interference fit.

[0054] Meanwhile, the bus bars 720 are means for connecting the battery cells 110 in series and / or parallel, and may be made into a rod shape from a metal material such as copper, aluminum, or nickel. The electrode leads 112 of the battery cells 110 pass through slits in the bus bar frame 710 and are pulled out to the outside of the bus bar frame 710, and the pulled-out portions may be attached to the surface of the bus bar 720 by a method such as welding. By welding the electrode leads 112 of the battery cells 110 and the bus bar 720 to the front and rear of the cell stack 100 according to a predetermined pattern, the battery cells 110 can be connected in series and / or parallel.

[0055] 1 to 4, a battery module 10 according to an embodiment of the present invention may include a module case 200. The module case 200 may be configured to accommodate the cell stack 100. Specifically, an internal space may be formed in the module case 200, and the cell stack 100 and a bus bar frame assembly 700 may be accommodated in the internal space.

[0056] Meanwhile, the module case 200 may include a case body 210a or 210b. For example, as shown in FIGS. 1 to 4, the case body 210a or 210b may be provided as a U-frame 210a. The U-frame 210a may be provided to cover both side surfaces and a bottom surface of the cell stack 100. The U-frame 210a may include a left plate and a right plate covering both side surfaces of the cell stack 100, and a bottom plate covering the bottom surface of the cell stack 100. The left plate, the right plate, and the bottom plate may be configured as an integrated unit. In this case, the top surface, front surface, and rear surface of the U-frame 210a may be open. The U-frame 210a may be made of a metal material having rigidity and heat resistance to physically and chemically protect the accommodated battery cells 110.

[0057] When the case body 210a or 210b is configured as a U-frame 210a, the module case 200 may further include a top plate 220. The top plate 220 may be configured to form the upper surface of the U-frame 210a. The top plate 220 may be coupled to the open upper surface of the U-frame 210a. The top plate 220 may be coupled to the U-frame 210a by welding. In this case, the combined shape of the top plate 220 and the U-frame 210a may be a rectangular tube shape with open front and back sides.

[0058] The case body 210a or 210b may be configured to allow the battery cell 110 to be inserted therein in one direction. For example, the battery cell 110 may be inserted therein in the front-rear direction (Y-axis direction). When the case body 210a or 210b is configured as a U-frame 210a, the U-frame 210a may be configured to allow the battery cell 110 to be inserted therein in a sliding manner.

[0059] FIG. 5 is an exploded perspective view of a battery module according to another embodiment of the present invention, FIG. 6 is a cross-sectional view of a battery module according to another embodiment of the present invention, and FIG. 7 is an enlarged view of part B in FIG. 6.

[0060] Alternatively, as shown in FIGS. 5 to 7, the case body 210a or 210b may be provided as a monoframe 210b. The monoframe 210b may have an upper surface, a lower surface, a left side surface, and a right side surface, and may be configured as a rectangular tube with an open front and rear surface. The upper surface, lower surface, left side surface, and right side surface may be configured as an integrated shape. The monoframe 210b may be made of a metal material having rigidity and heat resistance to physically and chemically protect the housed battery cells 110.

[0061] When the case body 210a or 210b is arranged as a monoframe 210b, the cell stack 100 may be combined with the bus bar frame assembly 700 and inserted into the monoframe 210b by an interference fit. Due to the interference fit, there may be little gaps between the upper and lower surfaces of the monoframe 210b and the battery cells 110, and there may also be little gaps between both side surfaces of the monoframe 210b and both sides of the battery cells 110.

[0062] In addition, the module case 200 may be formed in a variety of other shapes. For example, the module case 200 may include a box-shaped lower case having an open upper end and an upper cover that closes the open upper end of the lower case. In this case, the lower case may be provided with a left panel and a right panel that cover both sides of the cell stack 100, and a front panel and a rear panel that cover the front and rear of the cell stack 100, all of which are integrated into one piece.

[0063] 2 and 5, the module case 200 may include end plates 230 disposed on the open front and rear sides of the case body 210a or 210b. The end plates 230 may be welded to the case body 210a or 210b. Although not shown for ease of explanation, the end plates 230 may be made of an insulating material on the inside and a metal material on the outside. The end plates 230 may also have holes or slits partially formed thereon to expose components that require external exposure, such as the positive and negative terminals or connectors of the battery module 10.

[0064] 1 to 7, a vent hole H1 may be formed in the module case 200. The vent hole H1 may be configured to allow vent gas generated in the battery cells 110 to be discharged to the outside of the module case 200. The vent hole H1 may be formed on one side of the module case 200, allowing directional venting in one direction. For example, the vent hole H1 may be formed on an upper surface of the module case 200.

[0065] 1 to 4, when the case body 210 is configured as a U-frame 210a, a vent hole H1 is formed in the top plate 220, and directional venting of the battery module 10 upward can be performed through the vent hole H1. A plurality of the vent holes H1 may be provided, and may be spaced apart from one another in the horizontal direction (X-axis and Y-axis directions).

[0066] In this manner, the vent hole H1 provided on the upper surface of the module case 200 can be arranged to exhaust gases and flames generated inside the battery module 10 to the outside of the battery module 10 when thermal runaway occurs in the battery module 10. The remaining parts of the module case 200 except for the vent hole H1 are sealed, allowing the gases and flames to be exhausted in a straight line toward the vent hole H1.

[0067] According to the above-described embodiment of the present invention, even if a thermal event occurs at any one position of the battery cell 110, the gas or flame generated in the battery cell 110 is discharged to the outside of the battery module 10 through a specific vent hole H1 provided at the top of the battery cell 110, thereby enabling smooth venting.

[0068] 1 to 7, the battery module 10 according to the embodiment of the present invention may further include a protective layer 300. The protective layer 300 may be disposed on the outer surface of the module case 200.

[0069] The module case 200 may cover both side surfaces, the top surface, and the bottom surface of the cell stack 100 via a U-frame 210a and a top plate 220, or may cover both side surfaces, the top surface, and the bottom surface of the cell stack 100 via a mono-frame 210b. The module case 200 may cover the front and back surfaces of the cell stack 100 via end plates 230. In this manner, the module case 200 can cover a total of six surfaces of the cell stack 100, including both side surfaces, the top surface, the bottom surface, the front surface, and the back surface. The protective layer 300 may be provided on at least one of the six surfaces of the module case 200. The protective layer 300 may be provided on the outer surface of the module case 200.

[0070] The protective layer 300 may be configured to prevent heat conduction and heat radiation to the outside of the module case 200. To this end, the protective layer 300 may be made of a material having lower thermal conductivity than the module case 200. For example, the protective layer 300 may be made of a material containing at least one of polyurethane and silicone. Furthermore, the protective layer 300 may be provided as a coating layer with a rating of UL 94 V-0 or higher, thereby providing flame retardancy. The protective layer 300 may have fire resistance.

[0071] The module case 200 may be made of a metal material such as aluminum, which has high thermal conductivity. Due to the thermal conductivity of metal materials, heat from high-temperature gases or flames may be transferred to adjacent battery modules. However, according to the embodiment of the present invention, the protective layer 300 is provided on the outer surface of the module case 200, thereby preventing heat conduction and heat radiation to the outside of the module case 200. Therefore, according to the embodiment of the present invention, the propagation of thermal runaway between battery modules can be effectively prevented or delayed, thereby ensuring the safety and reliability of the battery modules.

[0072] Furthermore, according to the above-described embodiment of the present invention, when thermal runaway occurs in a battery module, it is possible to prevent heat accumulation inside the battery module due to gas or flame generated inside the battery module, thereby effectively preventing or delaying the propagation of thermal runaway within the battery module.

[0073] 3, 4, 6, and 7, the protective layer 300 may be provided on the upper surface of the module case 200 and the inner surface of the vent hole H1. For example, the protective layer 300 may be provided on the upper surface of the top plate 220 or the monoframe 210b. Also, the protective layer 300 may be provided individually for each of the plurality of vent holes H1.

[0074] When high-temperature gas or flame is discharged through the vent hole H1, there is a high possibility that heat will accumulate on the upper surface of the module case 200 where the vent hole H1 is formed or that the heat will be conducted to the outside. However, according to the embodiment of the present invention, a fire-resistant protective layer 300 is provided not only on the surface of the upper surface of the module case 200 where the vent hole H1 is provided but also on the inner surface of the vent hole H1, thereby preventing heat conduction due to even a portion of the metal material of the module case 200 being exposed to the outside. As a result, according to the embodiment of the present invention, it is possible to prevent heat from being conducted to adjacent battery cells 110 or the vent hole H1 due to high-temperature gas or flame discharged through the vent hole H1.

[0075] 3, 4, 6, and 7, the protective layer 300 may be provided on all surfaces including the top surface of the module case 200. For example, the protective layer 300 may also be provided on the bottom surface of the module case 200. According to the above-described embodiment of the present invention, in a battery pack including battery modules 10, heat transfer between battery modules 10 can be prevented regardless of the arrangement or position of the battery modules 10, thereby improving the heat transfer performance of the battery pack unit.

[0076] Meanwhile, the protective layer 300 may be a coating layer formed by foaming directly on the outer surface of the module case 200. According to the above embodiment of the present invention, the inner circumferential surface of the vent hole H1 can be easily covered compared to attaching a separate sheet-shaped fireproof member to the module case 200. In addition, the process of separately manufacturing a fireproof member according to the size of the outer surface of the module case 200 is omitted, thereby reducing the cost and time required to manufacture the battery module.

[0077] The protective layer 300 may be a conformal coated layer formed along the outer surface of the module case 200. In particular, the protective layer 300 may be a conformal foam coating layer. Here, conformal coating refers to applying a coating agent in a thin layer to prevent corrosion, etc. As described above, polyurethane or silicone may be used as the conformal coating material. Such a material can be easily formed as a coating layer on the outer surface of the module case 200 of the assembled battery module 10 using a foam coating method.

[0078] Furthermore, by using a conformal coating method, the protective layer 300 can be coated with a uniform thickness along the curve of the outer surface of the module case 200. For example, the thickness of the protective layer 300 on the upper surface of the module case 200 and the thickness of the protective layer 300 on the inner surface of the vent hole H1 become uniform.

[0079] According to the above-described embodiment of the present invention, the drying time can be shortened, thereby reducing manufacturing time, and the presence or absence of coating can be easily inspected, thereby improving productivity. Furthermore, since the coating can be applied to a uniform thickness along the curved outer surface of the module case 200, the metal material of the module case 200 can be prevented from being directly exposed to the outside at any part, and the effect of preventing heat conduction and heat radiation over the entire area of ​​the module case 200 can be clearly maintained.

[0080] 4 and 7, the thickness t of the protective layer 300 may be set to be 5% or more and 50% or less of the thickness t of the module case 200. For example, when the thickness t of the wall of the top plate 220 and the case body 210 is set to 2 mm, the thickness t of the protective layer 300 may be set to be 0.1 mm or more and 1.0 mm or less. According to this embodiment of the present invention, even if the protective layer 300 is foamed on the outer surface of the module case 200, it does not significantly increase the height of the battery module 10, and therefore does not increase the volume of the battery module 10, thereby not significantly affecting the energy density.

[0081] FIG. 8 is an exploded perspective view of a battery module according to yet another embodiment of the present invention, FIG. 9 is a cross-sectional view of a battery module according to yet another embodiment of the present invention, and FIG. 10 is a cross-sectional view of a battery module according to yet another embodiment of the present invention.

[0082] Meanwhile, referring to FIGS. 8 to 10, the battery module 10 according to the embodiment of the present invention may further include a top cover 400.

[0083] The top cover 400 may be made of a material with excellent heat resistance and / or fire resistance, such as mica or a fire-resistant barrier (FRB) and a silicone-containing pad, etc. The FRB may include an inorganic material that is easily converted and may be made of a material with very high flame retardancy and fire resistance.

[0084] Therefore, even if high-temperature heat is generated, shrinkage does not occur and shape stability can be maintained, thereby stably blocking high-temperature gas, flames, etc. generated in the battery cells 110. Furthermore, by providing the top cover 400, even if a thermal event occurs inside the battery module 10, the heat of high-temperature gas, flames, etc. can be prevented from being transmitted to the outside.

[0085] The top cover 400 may be coupled to one side of the module case 200. The top cover 400 may be configured to cover the top surface of the module case 200. Specifically, the top cover 400 may be coupled to the top surface of the top plate 220 or the monoframe 210b.

[0086] The top cover 400 may have a cover hole H2 formed therein. A plurality of cover holes H2 may be provided, and the cover holes H2 may be provided to correspond to the vent holes H1. That is, the cover holes H2 may be provided at positions where the vent holes H1 are formed, and have the same shape and size as the vent holes H1. The cover holes H2 may be configured to be detachable from the module case 200 by the pressure of vent gas discharged from the battery cells 110. Specifically, when gas is discharged from the vent holes H1 corresponding to the cover holes H2, only the cover holes H2 provided above the vented battery cells 110 may be configured to break in the top cover 400. To this end, notched grooves may be formed following the shape of the cover holes H2.

[0087] In other words, in a normal state, the top cover 400 covers all vent holes H1 provided on the upper surface of the module case 200 to protect the cell stack 100 inside the module case 200. However, when a thermal event occurs in which vent gas or flames are generated in some of the battery cells 110, at least one of the cover holes H2 of the top cover 400 is detached from the module case 200, allowing the vent gas or flames, which are discharged in a straight line through the vent hole H1, to be smoothly discharged to the outside of the battery module 10 without interfering with the path of the vent gas or flames. In addition, the cover hole H2 that remains in the module case 200 can block not only heat but also high-temperature gas, flames, and discharged material generated in the battery cells 110.

[0088] According to the above-described embodiment of the present invention, at least a portion of the cover hole H2 can be completely removed from the module case 200, so that the vent hole H1 is exposed to the outside of the battery module 10, and as a result, the vent hole H1 is not blocked, and gas, flames, etc. can be completely discharged to the outside of the battery module 10.

[0089] Since the module case 200 is made of a metal material such as aluminum, it may be difficult to combine with the top cover 400 made of a material such as mica. Therefore, the battery module 10 according to another embodiment of the present invention may further include an adhesive member 500. The top cover 400 may be attached to the upper surface of the module case 200 by the adhesive member 500. Examples of the adhesive member 500 include an adhesive agent and an adhesive tape. All portions of the top cover 400 except for the cover hole H2 may be attached to the upper surface of the module case 200 by the adhesive member 500.

[0090] 9, a protective layer 300 may be provided on the upper surface of the module case 200, and the top cover 400 may be attached to the protective layer 300. That is, the top cover 400 may be configured to be attached to the protective layer 300 by an adhesive member 500. This allows the module case 200 / protective layer 300 / adhesive member 500 / top cover 400 to be provided in this order from the bottom up. When the adhesive member 500 is formed on the protective layer 300, the matching performance between the protective layer 300 and the adhesive member 500 can be further improved compared to when the adhesive member 500 is formed directly on the module case 200 made of a metal material.

[0091] When thermal runaway occurs in the battery module 10, the adhesive member 500 may melt due to the pressure of gas emitted from the battery cells 110 and / or the high heat of dust, flames, etc., weakening the adhesive strength between the module case 200 and the top cover 400. As a result, the exhaust pressure of the vent gas acts between the module case 200 and the top cover 400, whose adhesive strength has been weakened, and the top cover 400 is pushed in the direction of the vent gas exhaust, allowing it to be removed from the module case 200. If the top cover 400 remains on the module case 200 with the adhesive strength of the adhesive member weakened, it not only hinders the exhaust of the vent gas and flame, but also there is a risk that the vent gas and flame may flow back into the interior of the battery module 10 through the raised interface between the top cover 400 and the module case 200.

[0092] In contrast, according to the above-described embodiment of the present invention, the protective layer 300 is provided when adhering the top cover 400 to the module case 200, thereby improving the adhesive strength between the protective layer 300 and the adhesive member 500, and thus preventing the top cover 400 from lifting off the module case 200 due to high-temperature gases or flames when a thermal event occurs. This makes it possible to prevent gases or flames discharged to the outside from flowing back into the battery module 10. This ensures the safety and reliability of the battery module 10.

[0093] 10 , a battery module 10 according to another embodiment of the present invention may further include a primer layer 600. The primer layer 600 may be made of a specially treated material having a primer function. The primer layer 600 may be applied to the protective layer 300 to improve the adhesive strength of the adhesive member 500. That is, the primer layer 600 may be disposed between the protective layer 300 and the adhesive member 500, and the module case 200 / protective layer 300 / primer layer 600 / adhesive member 500 / top cover 400 may be disposed in this order from the bottom.

[0094] According to the above-described embodiment of the present invention, the protective layer 300 functions as a base layer for forming the primer layer 600, making it easy to form the primer layer 600. Furthermore, since the protective layer 300 has good compatibility with the primer layer 600, it helps to prevent the primer layer 600 from coming off and to hold the primer layer 600 in place. Therefore, by applying a special treatment to the protective layer 300, the bonding strength between the module case 200 and the top cover 400 can be further improved.

[0095] FIG. 11 is a schematic perspective view of a battery pack including a battery module according to an embodiment of the present invention.

[0096] 11 , a battery pack 1 according to an embodiment of the present invention may include one or more battery modules 10 according to an embodiment of the present invention as described above. The battery pack 1 according to the present invention may further include a pack case 2 for accommodating a battery management system (BMS) for collectively controlling the charging and discharging of one or more battery modules 10, a current sensor, a fuse, and the like, as well as the above-mentioned components. A cooling member for cooling the battery module 10 may be provided on the bottom of the pack case 2. In this case, the protective layer 300 may be formed on both side surfaces and the top surface of the module case 200, excluding the bottom surface of the module case 200. As a result, the bottom surface on which the protective layer 300 is not formed may directly and quickly cool the battery module 10 through thermal contact between the cooling member and the battery module 10, and heat conduction and heat radiation may be prevented via the protective layer 300 formed on the remaining surfaces of the module case 200.

[0097] FIG. 12 is a schematic perspective view of a vehicle including a battery pack according to one embodiment of the present invention.

[0098] 12, an automobile 3 according to an embodiment of the present invention may include one or more of the battery pack 1 according to an embodiment of the present invention or the battery module 10 according to an embodiment of the present invention. The automobile 3 according to the present invention may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The automobile 3 includes a four-wheeled vehicle and a two-wheeled vehicle. The automobile 3 operates by receiving power from the battery pack 1 or the battery module 10 according to an embodiment of the present invention.

[0099] Although the present invention has been described above using limited embodiments and drawings, the present invention is not limited thereto 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 technical spirit of the present invention and the equivalent scope of the appended claims. [Explanation of symbols]

[0100] 1 battery pack 2-pack case 3. Automobiles 10 Battery Module 100 cell stack 110 battery cells 111 Cell Case 112 Electrode Lead 120 Blocking member 200 Module Case 210 Case body 220 Top Plate 230 End Plate 300 protective layer 400 top cover 500 adhesive material 600 primer layer 700 Busbar frame assembly 710 Busbar Frame 720 Busbar H1 vent hole H2 cover hole

Claims

1. a cell stack including a plurality of battery cells; a module case configured to house the cell stack; a protective layer disposed on an outer surface of the module case to prevent heat conduction and heat radiation to the outside of the module case; Including a battery module.

2. At least one vent hole is formed in an upper surface of the module case through which vent gas discharged from the battery cell is discharged, The battery module according to claim 1 , wherein the protective layer is disposed on an upper surface of the module case and an inner peripheral surface of the vent hole.

3. The vent holes are provided in a plurality of holes, The battery module according to claim 2 , wherein the protective layer is provided individually for each of the plurality of vent holes.

4. The battery module according to claim 2 , wherein the protective layer is provided on all surfaces of the module case, including the top surface.

5. The battery module according to claim 1 , wherein the protective layer is made of a material including at least one of polyurethane and silicone.

6. The battery module according to claim 1 , wherein the protective layer is provided as a coating layer rated at or above UL 94 V-0.

7. The battery module according to claim 1 , wherein the protective layer is a foam coating layer conformally coated along the outer surface of the module case.

8. The battery module according to claim 1 , wherein the thickness of the protective layer is set to be 5% or more and 50% or less of the thickness of the module case.

9. The battery module of claim 1 , further comprising a top cover configured to be attached to an upper surface of the module case by an adhesive member.

10. The battery module according to claim 9 , wherein the top cover is configured to be attached to the protective layer by the adhesive member.

11. The battery module of claim 10 , further comprising a primer layer disposed between the protective layer and the adhesive member to improve bonding strength between the module case and the top cover.

12. The module case includes: a U-frame having an open top surface and a front and rear surface configured to accommodate the cell stack; a top plate covering the open top surface of the U-frame; The battery module of claim 1 , comprising:

13. The module case includes: The battery module according to claim 1 , comprising a monoframe configured to receive the cell stack with its front and back sides open.

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

15. a pack case that houses the battery module and has a cooling member disposed on a bottom surface thereof; The battery pack according to claim 14 , wherein the protective layer is formed on both side surfaces and an upper surface of the module case.

16. A motor vehicle comprising the battery pack of claim 14.

Images