Battery module, battery pack including same, and automobile

Abstract

The present invention relates to a battery module including: a cell stack including a plurality of battery cells; a module case configured to accommodate the cell stack and having at least one vent hole formed on one side through which vent gas discharged from the battery cells is discharged; a top cover coupled to one side of the module case and having at least one cover hole formed corresponding to the vent hole; and a vent sheet configured to cover each of the vent hole and the cover hole.

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. 10-2023-0091291, filed on July 13, 2023, the entire contents of which are incorporated herein by reference in their entirety in the specification and drawings thereof. [Background technology]

[0003] Secondary batteries, which are easy to apply to various products and have electrical properties such as high energy density, are commonly used not only in portable devices but also in electric vehicles (EVs) and hybrid electric vehicles (HEVs), which are powered by electrical sources. These secondary batteries are attracting attention as a new energy source that is environmentally friendly and improves energy efficiency because they do not produce any by-products from energy use, in addition to their main advantage of dramatically reducing the use of fossil fuels.

[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 pack may be varied depending on the required output voltage 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 an environment that is higher than the appropriate temperature. Furthermore, if the temperature is not thermally controlled to the appropriate level, there is a risk of unexpected fire or explosion. Furthermore, battery modules are constructed by integrating these battery cells into a module housing. Therefore, if a thermal event occurs in one battery cell, the emitted high-temperature gas and flames can spread to adjacent battery cells, potentially causing a chain reaction of battery cell explosions, creating a very dangerous situation.

[0006] Therefore, it is necessary to develop a structure that can exhaust high-temperature gases and flames generated inside the battery module to the outside when thermal runaway occurs in the battery module, preventing heat accumulation inside the battery module and preventing the exhausted gases and flames from re-entering the battery module.

[0007] In addition, it is necessary to develop a structure that can suppress and delay heat propagation by reliably separating the battery cells so that even if a thermal event occurs in some battery cells within a battery module, gas, flame, etc. can be prevented from propagating to other battery cells within the battery module and causing thermal runaway. Summary of the Invention [Problem to be solved by the invention]

[0008] Therefore, an object of the present invention is to provide a battery module that can effectively prevent or delay the propagation of thermal runaway between cells by smoothly discharging gases and flames generated inside the battery module to the outside of the battery module when thermal runaway occurs in the battery module.

[0009] Another problem to be solved by the present invention is to provide a battery module with improved safety and reliability by preventing gas or flames discharged to the outside of the battery module from re-entering the inside of 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 cells by reliably separating the battery cells into compartments.

[0011] Another problem to be solved by the present invention is to provide a battery pack and a vehicle including such a battery module.

[0012] However, the 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]

[0013] In order to solve the above problems, the present invention provides a battery module including: a cell stack including a plurality of battery cells; a module case configured to accommodate the cell stack and having at least one vent hole formed on one side through which vent gas discharged from the battery cells is discharged; a top cover coupled to one side of the module case and having at least one cover hole formed corresponding to the vent hole; and a vent sheet configured to cover each of the vent holes and the cover hole.

[0014] The vent sheet may include a score line configured to open in response to pressure of the vent gas.

[0015] The vent sheet may be provided in plurality, each provided for a respective vent hole, and configured such that when the battery cell is vented, only the incision line of the vent sheet provided above the vented battery cell is opened.

[0016] The vent sheet is open in only one direction, preventing the vent gas from flowing back.

[0017] The module case includes a case body having an open top surface and configured to accommodate the cell stack, and a top plate covering the open top surface of the case body and having the vent hole, and the top cover can be coupled to the top plate.

[0018] The top plate may include a seating portion that protrudes upward from the vent hole and is configured to seat the vent sheet.

[0019] The seating portion may be provided to protrude inward from the vent hole.

[0020] The vent sheet may be attached to the seat.

[0021] The cell stack may include at least one blocking member configured to separate the plurality of battery cells, and the top plate may further include a fixing portion protruding downward from a bottom surface of the top plate and configured to receive one end of the blocking member.

[0022] The blocking member may be provided in a plurality in one direction, and the vent hole may be located between adjacent blocking members.

[0023] At least one battery cell is positioned between the adjacent blocking members, and the blocking member extends further beyond the battery cell and is inserted into the fixing portion, thereby forming an airtight space between the adjacent blocking members and the fixing portion.

[0024] The fixing portion may include a first fixing portion and a second fixing portion disposed to face each other, and one end of the blocking member may be inserted between the first fixing portion and the second fixing portion.

[0025] The first fixing portion and the second fixing portion may each be provided in plural, and may be individually provided for each of the vent holes.

[0026] The seating portion and the fixing portion may be integrally formed and connected to the top plate.

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

[0028] The present invention also provides a vehicle including a battery pack according to the present invention. [Effects of the Invention]

[0029] According to one aspect of the present invention, when an abnormality occurs in a battery cell, high-temperature gas or flame generated in the battery cell can be smoothly discharged to the outside of the battery module, thereby effectively preventing or delaying the propagation of thermal runaway between cells, thereby ensuring the safety and reliability of the battery module.

[0030] According to another aspect of the present invention, it is possible to prevent high-temperature gas, flames, etc. generated in the battery cell when an abnormal condition occurs in the battery cell from re-entering the battery module.

[0031] According to yet another aspect of the present invention, by reliably separating and isolating the battery cells in the battery module, even if a thermal event occurs in some of the battery cells in the battery module, the propagation of gas, flame, etc. to other battery cells in the battery module can be effectively prevented or delayed.

[0032] According to another aspect of the present invention, it is possible to prevent or delay events, such as fires and explosions, caused by thermal runaway phenomena in battery packs including multiple battery modules or devices equipped with the battery packs.

[0033] In addition, the present invention has various other effects, which will be described in each embodiment, or effects that can be easily inferred by those skilled in the art will not be described.

[0034] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention, serve to further understand the technical concepts of the present invention. Therefore, the present invention should not be interpreted as being limited to only the matters described in the drawings. [Brief explanation of the drawings]

[0035] [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 plan view of a battery module according to an embodiment of the present invention; [Figure 4] 1 is an exploded perspective view of a main part of a battery module according to an embodiment of the present invention; [Figure 5] 1 is a cross-sectional view of a battery module according to an embodiment of the present invention; [Figure 6] FIG. 6 is an enlarged view of part A in FIG. 5. [Figure 7]10A and 10B are views illustrating that a portion of a vent sheet is opened when a thermal runaway occurs in a battery module according to an embodiment of the present invention. [Figure 8] FIG. 10 is a bottom perspective view of a top plate included in a battery module according to another embodiment of the present invention. [Figure 9] FIG. 4 is a cross-sectional view of a battery module according to another embodiment of the present invention. [Figure 10] FIG. 10 is a cross-sectional view taken along line II' of FIG. [Figure 11] FIG. 10 is an enlarged view of part B in FIG. 9. [Figure 12] FIG. 10 is an exploded perspective view of a main part of a battery module according to still another embodiment of the present invention. [Figure 13] 1 is a schematic perspective view of a battery pack including a battery module according to an embodiment of the present invention; [Figure 14] 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

[0036] 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.

[0037] 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.

[0038] The present invention includes many different embodiments, and the following description will focus on the differences and omit redundant explanations of substantially the same or similar configurations among the embodiments.

[0039] Meanwhile, in the present invention, terms indicating directions such as up, down, left, right, front, and back are used, but 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 target object, the position of the observer, etc.

[0040] For example, in an embodiment of the present invention, the X-axis direction shown in the drawings may refer to the left-right direction, the Y-axis direction may refer to the front-back direction 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) perpendicular to both the X-axis and Y-axis directions.

[0041] Fig. 1 is an overall perspective view of a battery module according to one embodiment of the present invention, Fig. 2 is an exploded perspective view of the battery module according to one embodiment of the present invention, Fig. 3 is a plan view of the battery module according to one embodiment of the present invention, and Fig. 4 is an exploded perspective view of a main part of the battery module according to one embodiment of the present invention.

[0042] 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, a top cover 300, and a vent sheet 400.

[0043] The cell stack 100 may include a battery cell 110. A plurality of the battery cells 110 may be provided.

[0044] 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 a frame surrounding the housing portion may be heat-sealed to form a seal portion.

[0045] The electrode leads 112 are 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 length 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 configuration in which the two electrode leads 112 are located only at one end in the Y-axis direction, for example, at an end in the +Y-axis direction.

[0046] 2, the battery cells 110 may be arranged side by side in the left-right direction (X-axis direction) while standing upright in the vertical direction (Z-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 storage portion may face the left-right direction (X-axis direction).

[0047] 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 can be used to configure the cell stack 100 of the present invention. In this embodiment, as shown in the drawings, a pouch-type secondary battery that has high energy density and is easy to stack is targeted, but it goes without saying that a cylindrical or prismatic secondary battery can also be used as the battery cell 110.

[0048] The cell stack 100 may further include a blocking member 120. The blocking member 120 may be provided 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 made of a material having excellent heat resistance and / or fire resistance, such as mica. In the present embodiment, a plurality of blocking members 120 may be provided so as to be disposed for at least two or more battery cells 110. According to the above-described embodiment of the present invention, the battery cells 110 are partitioned or separated, and it is possible to prevent gas, flame, etc. from spreading to other blocking members 120 adjacent to the blocking member 120.

[0049] Alternatively, the blocking member 120 may be formed in the form of a compressive pad made of a material such as silicon or aerogel. According to the above-described embodiment of the present invention, the blocking member 120 may contribute to the structural rigidity of the battery cell 110 by compressing the battery cell 110 when the battery cell 110 swells.

[0050] Meanwhile, referring to Fig. 2, the battery module 10 of the present invention may further include a bus bar frame assembly 500. The bus bar frame assembly 500 may be provided 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 500 may be coupled to the front and rear of the cell stack 100.

[0051] The bus bar frame assembly 500 may include a bus bar frame 510 and a plurality of bus bars 520. The bus bar frame 510 may be provided to be coupled to approximately the front and rear of the cell stack 100. The bus bar frame 510 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 510 may be formed of an electrically insulating material, such as a plastic material, and may be configured to allow the bus bars 520 to be attached to its outer surface.

[0052] In addition, the bus bar frame 510 can be connected to the front or rear of the cell stack 100 in a manner that allows for a tight fit.

[0053] Meanwhile, the plurality of bus bars 520 are means for connecting the battery cells 110 in series and / or parallel, and may be made of a metal material such as copper, aluminum, or nickel, and may be provided in a rod shape. The electrode leads 112 of the battery cells 110 pass through slits in the bus bar frame 510 and are pulled out to the outside of the bus bar frame 510, and the pulled-out portions may be attached to the surfaces of the bus bars 520 by welding or other methods. The battery cells 110 can be connected in series and / or parallel by welding the electrode leads 112 of the battery cells 110 to the bus bars 520 at the front and rear of the cell stack 100 according to a predetermined pattern.

[0054] 1 and 2, 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 500 may be accommodated in the internal space.

[0055] 2, the module case 200 may include a case body 210. For example, the case body 210 may be provided as a U-frame. When provided as a U-frame, the case body 210 may be provided to cover both side surfaces and a bottom surface of the cell stack 100. The case body 210 may include left and right plates that cover both side surfaces of the cell stack 100, and a bottom plate that covers the bottom surface of the cell stack 100. The left, right, and bottom plates may be integrally formed with one another. In this case, the top and front and rear surfaces of the case body 210 may be open. The case body 210 may be made of a metal material having rigidity and heat resistance to physically and chemically protect the accommodated battery cells 110.

[0056] The module case 200 may further include a top plate 220. The top plate 220 may be provided to form an upper surface of the module case 200. When the case body 210 is provided as a U-frame, the top plate 220 may be coupled to the open upper surface of the case body 210. The top plate 220 may be coupled to the case body 210 by welding. In this case, the coupled shape of the top plate 220 and the case body 210 may be a rectangular tube shape with open front and rear surfaces.

[0057] In addition, the case body 210 may be configured to allow the battery cell 110 to be inserted into the case body 210 in one direction. For example, the battery cell 110 may be inserted into the case body 210 in the front-rear direction (Y-axis direction). That is, the case body 210 may be configured to allow the battery cell 110 to be inserted into the case body 210 in a sliding manner.

[0058] Meanwhile, the module case 200 may include end plates 230 provided on the open front and rear surfaces of the case body 210. The end plates 230 may be welded to the case body 210. Although not shown for convenience, the end plates 230 may have, for example, an inner surface made of an insulating material and an outer surface made of a metal material. In addition, the end plates 230 may have holes or slits partially formed therein to expose components that need to be exposed to the outside, such as the positive and negative terminals or connectors of the battery module 10.

[0059] Alternatively, the module case 200 may be formed in various 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 in an integrated form with left and right plates that cover both sides of the cell stack 100, and front and rear plates that cover the front and rear of the cell stack 100.

[0060] Alternatively, the module case 200 may be provided as a monoframe. For example, the case body 210 may be configured as a rectangular tube having an upper side, a lower side, a left side, and a right side, with the front and rear sides open. Using such a module case 200 including a monoframe, the cell stack 100 and the bus bar frame assembly 500 may be assembled and inserted into the monoframe using an interference fit, and the battery module 10 may be assembled by connecting end plates 230 to both open ends of the monoframe. Due to the interference fit, there may be little gaps between the lower surface and top plate 220 of the case body 210 and the battery cells 110, and there may also be little gaps between both side surfaces of the case body 210 and both sides of the battery cells 110.

[0061] Meanwhile, 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 cell 110 to be discharged to the outside of the module case 200. The vent hole H1 is formed on one side of the module case 200, allowing directional venting in one direction.

[0062] 4, a vent hole H1 is formed in the upper portion of the module case 200, i.e., in the top plate 220, and directional venting of the battery module 10 upward is possible through the vent hole H1. A plurality of the vent holes H1 may be provided, and may be spaced apart at regular intervals in the horizontal direction (X-axis and Y-axis directions).

[0063] The plurality of vent holes H1 may be located between adjacent blocking members 120 among the plurality of blocking members 120 arranged in one direction.

[0064] In other words, the vent hole H1 may be provided on the top of at least one battery cell 110 provided between adjacent blocking members 120. For example, as shown in Fig. 2, in a battery module 10 according to an embodiment of the present invention, a blocking member 120 is disposed for every two battery cells 110, and a plurality of vent holes H1 may be formed in a row along the length direction (Y-axis direction) of the battery cells 110 on the top of the battery cells 110 provided between the blocking members 120.

[0065] In this manner, the vent hole H1 provided in the top plate 220 can be provided to allow gas or flame generated inside the battery module 10 to be discharged to the outside of the battery module 10 when thermal runaway occurs in the battery module 10. The remaining portion of the module case 200 excluding the vent hole H1 is sealed, and the gas or flame can be discharged in a straight line toward the vent hole H1.

[0066] According to the above-described embodiment of the present invention, even if a thermal event occurs at any position of the battery cell 110, 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.

[0067] Meanwhile, the battery module 10 according to an embodiment of the present invention may further include a top cover 300.

[0068] The top cover 300 may be provided as a pad made of a material having excellent heat resistance and / or fire resistance, such as mica or a combination of a fire-resistant barrier (FRB) and silicone. The FRB may be made of an inorganic material that is easily converted and has excellent flame retardancy and fire resistance. Therefore, when the top cover 300 is provided as a pad made of a fire-resistant barrier (FRB) and silicone, it does not shrink and maintains shape stability even when high-temperature heat is generated, thereby reliably blocking high-temperature gases and flames generated in the battery cells 110. Furthermore, the provision of the top cover 300 can prevent heat, such as high-temperature gases and flames, from being transmitted to the outside even when a thermal event occurs inside the battery module 10.

[0069] A cover hole H2 may be formed in the top cover 300. 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.

[0070] The top cover 300 may be coupled to one side of the module case 200. For example, the top cover 300 may be attached to the upper part of the module case 200. Specifically, the top cover 300 may be coupled to the top plate 220. That is, the top cover 300 may be coupled to the remaining part of the top plate 220 excluding the part where the cover hole H2 is formed. The top cover 300 may be attached to the top plate 220 by an adhesive member. The adhesive member may include an adhesive agent, an adhesive tape, etc.

[0071] The battery module 10 according to one embodiment of the present invention may be manufactured in the following order: housing the cell stack 100 in the case body 210; completing the exterior of the battery module 10 by welding the top plate 220 and the end plate 230 to the case body 210; applying an adhesive member to the top plate 220; and assembling the top cover 300 thereon. In this case, all portions of the top cover 300 except for the cover hole H2 may be attached to the top plate 220 by the adhesive member.

[0072] The battery module 10 according to an embodiment of the present invention may further include a vent sheet 400. The vent sheet 400 may be configured to cover each vent hole H1. At the same time, the vent sheet 400 may be configured to cover each cover hole H2. In other words, the vent sheet 400 may be configured to cover the vent hole H1, and the top cover 300 may be configured to cover the remaining portion of the top plate 220 except for the vent hole H1. The vent sheet 400 may be made of a flame-retardant material. For example, the vent sheet 400 may be made of a rigid material with a high melting point, such as stainless steel, or a rigid material with fire resistance and insulating properties. This prevents the vent sheet 400 from being easily deformed even when an external force is applied, thereby reducing the risk of the vent hole H1 being accidentally exposed.

[0073] When thermal runaway occurs within the battery module 10, the adhesive member may melt due to the pressure of gas discharged from the battery cells 110 and / or the high heat of dust, flames, etc., and the adhesive strength between the module case 200 and the top cover 300 may weaken. For example, if the top cover 300 and the vent sheet 400 are not separated and are configured as a single component so that the top cover 300 covers the vent hole H1, as in the present invention, the exhaust pressure of the vent gas may act between the module case 200 and the top cover 300, which has weakened adhesive strength, and the top cover 300 may be pushed in the direction of vent gas exhaust, causing it to separate from the module case 200. In this case, if the top cover 300 remains without being separated from the module case 200 with the adhesive strength of the adhesive member weakened, not only may the exhaust of vent gas and flame be hindered, but the vent gas and flame may also re-enter the interior of the battery module 10 through the raised interface between the top cover 300 and the module case 200.

[0074] In contrast, according to the above-described embodiment of the present invention, the top cover 300 and the vent sheet 400 are separated, the vent hole H1 is covered by the vent sheet 400, and the rest of the battery module 10 is covered by the top cover 300. This essentially prevents the top cover 300 from lifting up from the module case 200 due to high-temperature gas or fire when a thermal event occurs. That is, because the top cover 300 and the vent sheet 400 are separated as separate components, it is possible to prevent the portion of the top cover 300 adjacent to the vent hole H1 from lifting up, thereby preventing gas or fire from flowing into the adjacent vent hole H1. The provision of the vent sheet 400 separately prevents the portion of the top cover 300 adjacent to the vent hole H1 from lifting up. This prevents gas or fire discharged to the outside from re-entering the battery module 10. This ensures the safety and reliability of the battery module 10.

[0075] FIG. 5 is a cross-sectional view of a battery module according to one embodiment of the present invention, and FIG. 6 is an enlarged view of part A in FIG.

[0076] 5 and 6 in addition to FIG. 4, the top plate 220 may include a seating portion 221. The seating portion 221 may be configured to seat the vent sheet 400. The seating portion 221 may be provided to protrude upward from the vent hole H1. Specifically, the seating portion 221 may be provided to protrude upward along the outer periphery of the vent hole H1. In this case, the left-right length of the vent sheet 400 may be longer than the left-right diameter of the vent hole H1 and may be the same as the left-right diameter of the seating portion 221. As a result, the vent sheet 400 may be seated on the seating portion 221 to completely cover the vent hole H1.

[0077] In addition, the seating portion 221 may be provided to protrude into the vent hole H1, thereby increasing the contact area of ​​the vent sheet 400 with the seating portion 221, thereby enabling the vent sheet 400 to be more stably seated on the seating portion 221 and cover the vent hole H1.

[0078] The vent sheet 400 may be attached to the mounting portion 221. For example, the vent sheet 400 may be attached to the mounting portion 221 by an adhesive member such as double-sided tape. According to the above-described embodiment of the present invention, the vent sheet 400 is attached and fixed to the mounting portion 221, thereby stably covering the vent hole H1.

[0079] FIG. 7 is a view illustrating that a portion of the vent sheet is opened when thermal runaway occurs in a battery module according to an embodiment of the present invention.

[0080] 7, when a thermal event occurs, the vent sheet 400 may be configured to open in response to the pressure of vent gas or flame discharged from the battery cell 110. The thickness of the vent sheet 400 may be thin enough to open in response to the pressure of vent gas or flame.

[0081] 4 and 7, the vent sheet 400 may be provided with a cut line L. When gas is discharged from a vent hole H1, the cut line L of the vent sheet 400 covering the vent hole H1 may be broken, allowing the gas to be discharged to the outside (gas may be discharged in the direction of the dotted arrow in FIG. 7).

[0082] The incision line L may be formed so as to break in response to the pressure of the vent gas or flame and open in the direction in which the vent gas or flame is discharged. The incision line L may be formed as a dashed or solid line by forming a groove or notch in a portion of the vent sheet 400. For example, as shown in FIGS. 3 and 4, the incision line L may be formed in a fishbone shape. That is, the incision line L may be formed in a substantially straight line along the extension direction of the vent sheet 400, with the end portion in the extension direction configured to be branched. For example, the incision line L may include a center incision line extending elongately along the front-rear direction (Y-axis direction), which is the length direction of the vent sheet 400, and branch incision lines branching from both ends of the center incision line. More specifically, the branch incision line may include two front end incision lines formed in a shape branching from the front end of the center incision line at a predetermined angle with respect to the center incision line. In addition, the branch incision line may include two rear incision lines formed from the rear end of the center incision line at a predetermined angle to the center incision line. In particular, the front and rear incision lines may be formed at a right angle or an obtuse angle to the center incision line. According to the above-described embodiment of the present invention, the vent sheet 400 is reliably deployed along the incision lines L, allowing the vent sheet 400 to open the vent hole H1.

[0083] Alternatively, the incision line L may be weaker than adjacent areas and may be easily broken by the pressure of vent gas or flame. Alternatively, the incision line L may be formed in a shape that cuts a portion of the vent sheet 400 with a sharp object such as a knife. For example, the incision line L may be formed by cutting a linear line through the vent sheet 400 with a knife. Such an incision line L may also be referred to as a slit. In this case, the incision line L does not need to be broken, but rather expands due to the pressure of the vent gas, allowing the vent gas or flame to easily escape through the expanded portion.

[0084] According to the above-described embodiment of the present invention, when a thermal event occurs, the vent sheet 400 can be opened, exposing the vent hole H1 to the outside of the battery module 10, and since the vent sheet 400 does not block the vent hole H1, gases, flames, etc. can be completely discharged to the outside of the battery module 10.

[0085] Meanwhile, referring to FIG. 4 , a plurality of the vent sheets 400 may be provided. The vent sheets 400 may be individually provided for each of the plurality of vent holes H1. The vent sheets 400 may be configured to cover each of the plurality of vent holes H1 in a normal state. However, when a thermal event occurs inside the battery module 10, only some of the plurality of vent sheets 400 may be configured to open. When a battery cell 110 vents, only the cut line L of the vent sheet 400 provided above the vented battery cell 110 may be configured to open. Specifically, when gas is discharged from the vent hole H1 corresponding to the vented battery cell 110, only the cut line L provided on the vent sheet 400 covering the vent hole H1 may be broken. Furthermore, the remaining vent sheets 400 other than the opened vent sheet 400 may be configured to maintain a state of covering the vent hole H1.

[0086] In this case, the vent sheet 400 may be configured to open in only one direction, thereby preventing gas and flames discharged to the outside from re-entering the battery module 10. In addition, the vent sheet 400 that does not open and covers the vent hole H1 can block not only heat but also high-temperature gas, flames, and discharged matter generated from the battery cell 110.

[0087] In other words, in a normal state, the vent sheet 400 completely covers the vent holes H1 to protect the cell stack 100 inside the module case 200. However, in the event of a thermal event in which vent gas or flame is generated in some of the battery cells 110, the vent sheet 400 provided on the upper part of the vented battery cell 110 opens in one direction, allowing the vent gas or flame, which is discharged in a straight line through the vent holes H1, to be smoothly discharged to the outside of the battery module 10 without interfering with the path of the vent gas or flame.

[0088] According to the above-described embodiment of the present invention, not only can gases and flames present inside the module case 200 be efficiently vented through the opened vent sheet 400, but the vent sheet 400, which still maintains a state of covering the vent hole H1, can prevent the gases and flames discharged through the opened vent sheet 400 from re-entering the module case 200. Therefore, by minimizing heat propagation to adjacent battery modules 10, it is possible to effectively prevent or delay thermal runaway propagation, thereby ensuring the safety and reliability of the battery module 10.

[0089] Fig. 8 is a bottom perspective view of a top plate included in a battery module according to another embodiment of the present invention, Fig. 9 is a cross-sectional view of a battery module according to another embodiment of the present invention, Fig. 10 is a cross-sectional view taken along line II' in Fig. 9, and Fig. 11 is an enlarged view of portion B in Fig. 9.

[0090] Meanwhile, taking into consideration ease of assembly and assembly tolerances, one surface of the module case 200 and the blocking member 120 may be spaced apart by a predetermined distance. In this case, if a thermal event occurs in one battery cell 110, vent gas or flame may spread to another adjacent battery cell 110 through the gap formed between the blocking member 120 and the module case 200. Even if there is no gap between the blocking member 120 and one surface of the module case 200, if there is no additional device to fix the blocking member 120, the pressure of the vent gas or flame may cause bending deformation in the blocking member 120, causing the blocking member 120 to move left or right. As a result, a gap may form between the blocking member 120 and the module case 200, and vent gas may spread to another adjacent battery cell 110 through the gap.

[0091] 8 to 11, the battery module 10 according to an embodiment of the present invention may be provided with a fixing portion 222. The fixing portion 222 may be provided in the module case 200 and configured to fix the blocking member 120. The fixing portion 222 may be formed of a material with excellent heat resistance and / or fire resistance, and configured to maintain an airtight structure even under high heat and pressure. For example, the fixing portion 222 may be formed of a fire-resistant plastic material.

[0092] According to the above-described embodiment of the present invention, the battery cells 110 can be reliably separated by minimizing the space between the module case 200 and the blocking member 120. As a result, when a thermal event occurs in a battery cell 110, vent gas, flames, etc. are prevented from spreading to adjacent battery cells 110, thereby ensuring the safety and reliability of the battery module 10.

[0093] Furthermore, according to the above-described embodiment of the present invention, the blocking member 120 is fixed to the module case 200 by the fixing portion 222, thereby suppressing bending deformation of the blocking member 120. Even if a thermal event occurs, the possibility that the resulting high-temperature, high-pressure vent gas or flame will push out the blocking member 120 and propagate to other battery cells 110 can be reduced. As a result, when thermal runaway propagation occurs in the battery module 10, thermal runaway propagation between the battery cells 110 can be effectively prevented or delayed.

[0094] 8 and 9, the fixing portion 222 may be provided on the bottom surface of the top plate 220 and configured to fix the upper end of the blocking member 120. The fixing portion 222 is located inside the battery module 10, and therefore does not increase the height of the battery module 10 or change the appearance of the battery module 10. In addition, the fixing portion 222 may be disposed in an empty space within the battery module 10 so as not to affect the energy density of the battery module 10.

[0095] The fixing portion 222 may be configured to receive one end of the blocking member 120. The number of fixing portions 222 may correspond to the number of blocking members 120. In this case, the blocking member 120 may be provided to extend further in the vertical direction than the battery cells 110. That is, the vertical height of the blocking member 120 may be greater than the vertical height of the battery cells 110. According to the above-described embodiment of the present invention, since the blocking member 120 is inserted into the fixing portion 222 and supported on both sides, it is possible to prevent one end of the blocking member 120 from moving in the left-right direction. This allows for more reliable partitioning and separation between the plurality of battery cells 110.

[0096] 9, one surface of the module case 200, i.e., the top plate 220 and the blocking member 120 may be arranged to contact each other. The blocking member 120 may be arranged to extend above the battery cell 110, and the upper end of the blocking member 120 may be inserted into the fixing portion 222. According to the above-described embodiment of the present invention, the gap between the blocking member 120 and the top plate 220 is minimized, thereby reducing the space through which vent gas can flow and preventing thermal runaway propagation to other adjacent battery cells 110.

[0097] In this case, a plurality of fixing portions 222 may be provided along one direction. The one direction may be defined as a direction in which the blocking member 120 and the battery cell 110 are stacked, i.e., a left-right direction (X-axis direction).

[0098] According to the above-described embodiment of the present invention, gases, flames, etc. emitted from the battery cells 110 housed between adjacent blocking members 120 can be discharged to the outside of the module case 200 only through the vent hole H1 located between the adjacent blocking members 120 by the fixing portion 222.

[0099] 8 and 10, the fixing portions 222 may be provided in plurality, one for each vent hole H1, and may be configured to be spaced apart from one another along the length direction (Y-axis direction) of the blocking member 120. The length of the fixing portions 222 may be set to correspond to the length of the vent hole H1.

[0100] According to the above-described embodiment of the present invention, an airtight space S can be formed by adjacent blocking members 120 among the plurality of blocking members 120 and the fixing portion 222. Here, airtightness is a concept that means restricting the movement of vent gas between adjacent battery cells 110 in the left-right direction (X-axis direction) across one blocking member 120. That is, according to the above-described embodiment of the present invention, gas generated in a certain battery cell 110 can be guided to move in the length direction of the blocking member 120 (the direction of the thick arrow in FIG. 10 ) within the airtight space S containing the battery cell 110.

[0101] In addition, the airtight space S may be configured to communicate with the vent hole H1 so that gas generated in the battery cell 110 is guided and discharged only toward the vent hole H1 without moving toward other battery cells 110. This allows the vent gas to be discharged in a targeted direction, for example, in the direction of the vent hole H1 (the direction of the arrow in FIG. 9). That is, since the periphery of the vent hole H1 is completely sealed, the directional venting of gas toward the upper side can be more effectively guided.

[0102] If gas generated inside the battery module 10 were to be discharged in multiple directions, it would take a long time to discharge the vent gas, which could significantly reduce the safety of the battery module 10. However, according to this embodiment, the vent gas is quickly guided to the vent hole H1, preventing it from spreading in all directions from inside the module case 200.

[0103] The structure of the fixing portion 222 will be described in detail with reference to Fig. 11. The fixing portion 222 may include a first fixing portion 222a and a second fixing portion 222b that are disposed opposite to each other. The first fixing portion 222a and the second fixing portion 222b may each be provided to protrude from one surface of the module case 200. For example, as shown in Fig. 10, the first fixing portion 222a and the second fixing portion 222b may be provided to protrude downward from the bottom surface of the top plate 220. The protruding lengths of the first fixing portion 222a and the second fixing portion 222b may be the same.

[0104] According to the above-described embodiment of the present invention, the first fixing portion 222a and the second fixing portion 222b are not formed integrally, and the distance w1 between the first fixing portion 222a and the second fixing portion 222b near the top plate 220 is set to a predetermined size. Therefore, even if the first fixing portion 222a and the second fixing portion 222b deform, the entire structure does not distort, and the deformation stress can be absorbed to maintain structural robustness.

[0105] One end of the blocking member 120 may be inserted between the first fixing portion 222a and the second fixing portion 222b. At this time, the distance w1 between the first fixing portion 222a and the second fixing portion 222b may be set to be smaller than the thickness w2 of the blocking member 120 (w1 <w2)。

[0106] As a result, one end of the blocking member 120 can be configured to be tightly fitted between the first fixing portion 222a and the second fixing portion 222b. According to the above-described embodiment of the present invention, the movement of the blocking member 120 in the left-right direction is further suppressed, and the arrangement of the battery cell 110 and the blocking member 120 can be stably maintained.

[0107] 11, the distance w1 between the first fixing portion 222a and the second fixing portion 222b may be configured to increase along the direction of protrusion from the module case 200. According to the above-described embodiment of the present invention, one end of the blocking member 120 can be fixed below the first fixing portion 222a and the second fixing portion 222b. According to the above-described embodiment of the present invention, the distance w1 between the first fixing portion 222a and the second fixing portion 222b increases along the direction of protrusion from the module case 200, and the blocking member 120 can be stably inserted into the increasing distance by an interference fit.

[0108] The first and second fixing portions 222a and 222b may be formed in the shape of two processed block-shaped structures. For example, as shown in Fig. 10, the corners of the block faces where the first and second fixing portions 222a and 222b face each other may be rounded. Alternatively, the corners of the block faces where the first and second fixing portions 222a and 222b face each other may be chamfered.

[0109] The first fixing portion 222a and the second fixing portion 222b may be fabricated as separate structures from the top plate 220 and may be attached to the top plate 220 by bonding, inserting, or bolting.

[0110] Alternatively, the first and second fixing portions 222a and 222b may be integrally formed with the top plate 220. For example, the fixing portions 222 may be integrally formed on the bottom surface of the top plate 220.

[0111] According to the above-described embodiment of the present invention, since the fixing part 222 is integrally provided on the top plate 220, the process of joining the fixing part 222 to the top plate 220 is omitted, and defects at the joining portion between the fixing part 222 and the top plate 220 can be minimized.

[0112] In this case, the fixing portion 222 may be a groove formed by recessing at least a portion of the top plate 220. The blocking member 120 may be inserted into the groove. In this case, the upper end of the blocking member 120 may be tightly fitted into the groove without any gap.

[0113] According to this embodiment of the present invention, the end of the blocking member 120 is inserted into the groove of the top plate 220, thereby further improving the fixing force of the blocking member 120. In particular, when vent gas is generated from a specific battery cell 110, the blocking member 120 can be prevented from moving in the left-right direction due to the internal pressure of the vent gas.

[0114] Furthermore, in the above embodiment, a stable sealing force can be ensured between the end of the blocking member 120 and the fixing portion 222 of the top plate 220. Therefore, according to the above embodiment, the blocking member 120 can further improve the performance of preventing heat transfer between the cells, and the arrangement of the battery cells 110 and the blocking member 120 can be stably maintained.

[0115] FIG. 12 is an exploded perspective view of a main part of a battery module according to still another embodiment of the present invention.

[0116] According to another embodiment of the present invention, as shown in Fig. 12, the mounting portion 221 and the fixing portion 222 may be integrally formed and coupled to the top plate 220. For example, the mounting portion 221 and the fixing portion 222 may be formed by plastic injection molding and then inserted into the vent hole H1 of the top plate 220 for coupling. According to the above embodiment of the present invention, the mounting portion 221 and the fixing portion 222 are simultaneously manufactured and coupled to the top plate 220 at the same time, thereby eliminating the need to separately manufacture the mounting portion 221 and the fixing portion 222 and then couple them to the top plate 220. Furthermore, the need to separately form the mounting portion 221 and the fixing portion 222 when manufacturing the top plate 220 can be eliminated. This reduces the time and cost required for manufacturing the battery module 10 and improves productivity.

[0117] FIG. 13 is a schematic perspective view of a battery pack including a battery module according to an embodiment of the present invention.

[0118] 13, 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 battery management system (BMS) for integrally controlling the charging and discharging of the one or more battery modules, a current sensor, a fuse, etc., and a pack case 2 for accommodating the above-mentioned components.

[0119] FIG. 14 is a schematic perspective view of a vehicle including a battery pack according to one embodiment of the present invention.

[0120] 14, 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.

[0121] 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. [Explanation of symbols]

[0122] 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 221 Safe Place 222 Fixed part 222a 1st fixed part 222b Second fixed part 230 End Plate 300 top cover 400 vent seat 500 Busbar frame assembly 510 Busbar Frame 520 Busbar

Claims

1. a cell stack including a plurality of battery cells; a module case configured to accommodate the cell stack and having at least one vent hole formed on one side through which vent gas discharged from the battery cells is discharged; a top cover coupled to one side of the module case, the top cover having at least one cover hole corresponding to the vent hole; a vent sheet configured to cover each of the vent holes and the cover hole.

2. The battery module according to claim 1 , wherein the vent sheet includes a cut line configured to open in response to a pressure of the vent gas.

3. The vent sheet is provided in plurality, and is provided individually for each of the vent holes, The battery module according to claim 2 , wherein when the battery cell is vented, only the cut line of the vent sheet provided above the vented battery cell is opened.

4. The battery module according to claim 3 , wherein the vent sheet is open in only one direction to prevent the vent gas from flowing back.

5. The module case includes: a case body having an open upper surface and configured to accommodate the cell stack; a top plate that covers the open top surface of the case body and in which the vent hole is formed, The battery module according to claim 1 , wherein the top cover is coupled to the top plate.

6. The top plate is The battery module according to claim 5 , further comprising a seating portion protruding upward from the vent hole and configured to seat the vent sheet.

7. The battery module according to claim 6 , wherein the mounting portion is provided to protrude toward the inside of the vent hole.

8. The battery module according to claim 6 , wherein the vent sheet is attached to the mounting portion.

9. The cell stack is at least one blocking member configured to separate the plurality of battery cells; The top plate is The battery module according to claim 6 , further comprising a fixing portion protruding downward from a bottom surface of the top plate and configured to receive one end of the blocking member.

10. The blocking member is provided in a plurality of positions along one direction, The battery module according to claim 9 , wherein the vent hole is located between adjacent ones of the blocking members.

11. At least one battery cell is located between adjacent blocking members, The blocking member extends beyond the battery cell and is inserted into the fixing portion, The battery module according to claim 10 , wherein an airtight space is formed by the blocking member and the fixing portion adjacent to each other.

12. The fixing portion is The fixing device includes a first fixing portion and a second fixing portion that are provided to face each other, The battery module of claim 9 , wherein one end of the blocking member is inserted between the first fixing portion and the second fixing portion.

13. The battery module according to claim 12 , wherein a plurality of the first fixing portions and a plurality of the second fixing portions are provided, each of the first fixing portions being provided for each of the vent holes.

14. The battery module of claim 9 , wherein the mounting portion and the fixing portion are integrally formed and coupled to the top plate.

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

16. A motor vehicle comprising the battery pack of claim 15.

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