Battery modules, battery packs containing them, and automobiles

Abstract

The battery module according to the present invention includes a cell stack comprising a plurality of battery cells; a module case provided to house the cell stack and having vent holes in an upper plate covering the upper end of the cell stack; and a vent channel forming sheet coupled to the upper plate and having folded portions folded once or more at positions corresponding to the vent holes, wherein the folded portions may be provided to be expanded upward above the vent holes by a predetermined pressure to form a gas transfer passage on the upper part of the upper plate.

Description

Technical Field

[0001] The present invention relates to a battery module, a battery pack including the same, and a vehicle, and more particularly, to a battery module capable of suppressing heat transfer between battery cells when a thermal event occurs in the battery module, a battery pack including the same, and a vehicle.

[0002] This application claims priority based on Korean Patent Application No. 10-2024-0053175 filed on April 22, 2024, and all the contents disclosed in the specification and drawings of the application are incorporated into this application.

Background Art

[0003] Secondary batteries with high applicability according to product groups and having electrical characteristics such as high energy density are widely applied not only to portable devices but also to electric vehicles (EVs) or hybrid electric vehicles (HEVs) driven by an electric drive source.

[0004] Such secondary batteries not only have the primary advantage of significantly reducing the use of fossil fuels but also are environmentally friendly in that they do not produce any by-products associated with energy use and are attracting attention as a new energy source for improving energy efficiency.

[0005] Currently, widely used types of secondary batteries include lithium-ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel metal hydride batteries, nickel zinc batteries, etc. When a high output voltage is required, a plurality of battery cells can be connected in series to form a battery module or a battery pack. Also, in order to increase the charge / discharge capacity, a plurality of battery cells can be connected in parallel to form a battery module or a battery pack. Therefore, the number of battery cells included in a battery module or a battery pack can be variously set according to the required output voltage or charge / discharge capacity.

[0006] On the other hand, because battery cells undergo chemical reactions during charging and discharging, their performance may degrade if used in environments with temperatures higher than the appropriate temperature. Furthermore, if the heat is not controlled to the appropriate temperature, there is a risk of unexpected ignition or explosion. In addition, since battery modules consist of a structure in which such battery cells are densely housed inside a module housing, if a thermal event occurs in any one battery cell, the emitted high-temperature gases and flames can transfer to adjacent battery cells, potentially causing a chain reaction of battery cell explosions, making them extremely dangerous.

[0007] Therefore, there is a need for a battery module that has a structure to suppress and delay heat propagation so that even if a thermal event occurs in some of the battery cells within the battery module, high-temperature gases or flames are not transferred to other battery cells within the battery module, preventing thermal runaway. [Overview of the project] [Problems that the invention aims to solve]

[0008] The present invention aims to provide a battery module that prevents the propagation of vent gases and other substances to other battery cells when a thermal event occurs in a battery cell, and that can guide and discharge them in a specific direction.

[0009] However, the technical problems that this invention aims to solve are not limited to those described above, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention below. [Means for solving the problem]

[0010] According to the present invention, a battery module may be provided that includes a cell stack comprising a plurality of battery cells; a module case provided to house the cell stack and having vent holes in an upper plate covering the upper end of the cell stack; and a vent channel forming sheet coupled to the upper plate and having folded portions folded once or more at positions corresponding to the vent holes, wherein the folded portions are provided to be expanded upward above the vent holes by a predetermined pressure to form a gas transport passage on the upper part of the upper plate.

[0011] The vent channel forming sheet may be positioned opposite the cell laminate and on the lower surface of the upper plate.

[0012] The vent channel forming sheet may be made of an electrically insulating and fire-resistant material.

[0013] The vent channel forming sheet may include a first fixing portion and a second fixing portion that are fixed to the lower surface of the upper plate between the folded portions.

[0014] The first and second fixing parts can be bonded to or bolted to the lower surface of the upper plate.

[0015] Each may include a first sheet fixing member that protrudes downward from the upper plate and is connected to the first fixing portion, and a second sheet fixing member that is connected to the second fixing portion.

[0016] The first sheet fixing member and the second sheet fixing member have the same structure, and the first sheet fixing member may include a main body that penetrates the first fixing portion and a support portion formed at the lower end of the main body so as to support the lower surface of the first fixing portion.

[0017] The upper plate may include N vent holes that are spaced apart along the stacking direction of the battery cells.

[0018] The vent channel forming sheet may include folding portions that correspond one-to-one to the N vent holes.

[0019] It may further include a flameproof cover coupled to the upper part of the module case, and the flameproof cover may include an opening / closing part configured to burst by a predetermined pressure or heat or at least partially separate in a region corresponding to the vent hole of the upper plate.

[0020] The opening / closing part may be provided in a form in which a notch line or a shredding line is formed in the flameproof cover.

[0021] The module case may include a case body having at least an open upper surface, and an upper plate covering the upper surface of the case body and coupled to the case body.

[0022] The battery cell is a pouch-type battery cell, and the pouch-type battery cells may be stacked in one direction.

[0023] According to another aspect of the present invention, a battery pack including the battery module described above may be provided.

[0024] According to another aspect of the present invention, an automobile including the battery pack may be provided.

Advantages of the Invention

[0025] The battery module according to the present invention includes a vent channel forming sheet, so that when a thermal event occurs in the battery cell, vent gas or the like is not propagated to other battery cells and can be induced and discharged in a specific direction.

[0026] However, the effects of the present invention are not limited to the effects described above, and effects not mentioned will be clearly understood by those having ordinary knowledge in the technical field to which the present invention pertains from the present specification and the accompanying drawings.

Brief Description of the Drawings

[0027] [Figure 1] It is a perspective view of a battery module according to an embodiment of the present invention. [Figure 2] It is an exploded perspective view of the battery module of FIG. 1. [Figure 3] It is a view showing the lower surface of the upper plate to which a vent channel forming sheet according to an embodiment of the present invention is attached. [Figure 4] It is a cross-sectional view of the battery module taken along A-A' of FIG. 1. [Figure 5] It is a partially enlarged view of FIG. 4. [Figure 6] In the battery module of FIG. 4, it is a view showing a state where the folding part is expanded during thermal runaway of the battery cell in the outermost region. [Figure 7] It is a perspective view of a battery module in which a gas movement passage corresponding to FIG. 6 is formed. [Figure 8] In the battery module of FIG. 4, it is a view showing a state where the folding part is expanded during thermal runaway of the battery cell in the outermost region and the battery cell in the central region. [Figure 9] It is a perspective view of a battery module in which a gas movement passage corresponding to FIG. 8 is formed. [Figure 10] It is a partial cross-sectional view of a battery module according to another embodiment of the present invention. [Figure 11] It is a view showing a state where the folding part of FIG. 10 is expanded. [Figure 12] It is a partial cross-sectional view of a battery module according to still another embodiment of the present invention. [Figure 13] It is a view showing a state where the folding part of FIG. 12 is expanded. [Figure 14] It is a perspective view of still another battery module of the present invention. [Figure 15] It is a perspective view showing a state where the flameproof cover is removed from the battery module of FIG. 14. [Figure 16] This diagram schematically shows a battery pack according to one embodiment of the present invention. [Figure 17] This diagram schematically shows an automobile according to one embodiment of the present invention. [Modes for carrying out the invention]

[0028] Preferred embodiments of the present invention will now be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and in the claims should not be interpreted in a manner limited to their ordinary or dictionary meanings, but rather in a manner consistent with the technical idea of ​​the present invention, in accordance with the principle that the inventor himself may appropriately define the concepts of terms in order to best describe the invention. Accordingly, it should be understood that the embodiments described herein and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent the entirety of the technical idea of ​​the present invention, and that there may be a variety of equivalents and modifications that can be substituted therein at the time of this application.

[0029] Furthermore, in describing the present invention, if it is determined that a specific description of a related known configuration or function would obscure the gist of the present invention, such description will be omitted.

[0030] Since embodiments of the present invention are provided to give a more complete explanation to an ordinary person of the art, the shapes and sizes of components in the drawings may be exaggerated or omitted, or illustrated schematically, for the sake of clearer explanation. Accordingly, the sizes and proportions of each component do not fully reflect their actual sizes and proportions.

[0031] Figure 1 is a perspective view of a battery module according to one embodiment of the present invention, Figure 2 is an exploded perspective view of the battery module of Figure 1, Figure 3 is a view showing the lower surface of the upper plate to which a vent channel forming sheet is attached according to one embodiment of the present invention, and Figure 4 is a cross-sectional view of the battery module along line A-A' in Figure 1.

[0032] Referring to Figures 1 to 4, a battery module 10 according to one embodiment of the present invention includes a cell stack 100, a module case 200, and a vent channel forming sheet 300.

[0033] The cell assembly is a collection of multiple battery cells 110. The battery cells 110 may be pouch-type battery cells 110.

[0034] The pouch-type battery cell 110 may include an electrode assembly and a pouch case that houses the electrode assembly. The pouch case houses the electrode assembly in a storage section, and the peripheral edges around the storage section may be sealed by heat welding. The sealing section may be provided on three of the four sides of the pouch case.

[0035] The pouch-type battery cell 110 can be installed in an upright position with the side not containing the sealing portion facing downwards. As shown in Figure 2, multiple pouch-type battery cells 110 can 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, each battery cell 110 may have its sealing portion facing in the front-back direction (Y-axis direction) and upward (+Z-axis direction), and its storage portion facing in the left-right direction (X-axis direction). Arranging the battery cells 110 in this way makes it easier to control the venting direction to one side, and allows for edge cooling on the side not containing the sealing portion to ensure cooling performance.

[0036] Furthermore, the pouch-type battery cell 110 includes a pair of electrode leads 111 that connect to an electrode assembly inside the pouch case and are drawn out to the outside of the pouch case to function as electrode terminals. The pair of electrode leads 111 may be arranged in opposite directions to each other in the longitudinal direction (±Y direction) of the pouch-type battery cell 110. If necessary, the pouch-type battery cell 110 may have a configuration in which the two electrode leads 111 are located only at one end in the Y-axis direction, for example, at the end in the +Y-axis direction.

[0037] The present invention is not limited by the specific type or form of the battery cell 110, and a variety of known battery cells 110 at the time of filing the present invention may be used. In this embodiment, a pouch-type battery cell 110 with high energy density and easy stacking is targeted as shown in the drawings, but cylindrical or prismatic secondary batteries may also be used as the battery cell 110.

[0038] The cell laminate 100 according to this embodiment may include a barrier member 120. The barrier member 120 may be provided in the form of a plate-like body with a thickness thinner than the battery cell 110. For example, the barrier member 120 may be provided in the form of a pad that has excellent heat resistance and / or fire resistance and is compressible. Materials such as silicone or aerogel may be used as the material for the barrier member 120.

[0039] Multiple barrier members 120 can be arranged between a predetermined number of battery cells 110 along the direction in which the battery cells 110 are arranged. In particular, the barrier members 120 can be configured to partition the battery cells 110 into groups of a predetermined number. For example, as shown in Figure 4, barrier members 120 can be arranged for every four battery cells 110, thus grouping the battery cells 110 into groups of four.

[0040] According to the above-described embodiment of the present invention, when the battery cell 110 experiences thermal runaway, the barrier member 120 can block the propagation of flames and heat. Furthermore, when the battery cell 110 swells, the battery member can absorb the expansion force of the battery cell 110, thereby contributing to the suppression of structural deformation of the module case 200.

[0041] On the other hand, referring to Figure 2, a battery module 10 according to one embodiment of the present invention may include a busbar frame assembly 400. The busbar frame assembly 400 includes a busbar frame 410 and a plurality of busbars 420, and may be positioned in front of and behind the cell stack 100.

[0042] The busbar frame 410 is injection molded from an electrically insulating material, has a size that covers the front (+Y direction) or rear (-Y direction) of the cell stack 100, and may be provided in a substantially plate-like form. The busbar frame 410 may also have a plurality of lead slots for passing the electrode leads 111 of the battery cells 110 in the front-rear direction. The plurality of lead slots may be provided along the stacking direction of the battery cells 110. The busbar frame 410 may also be configured to have a plurality of busbars 420 attached to its outer surface.

[0043] The plurality of busbars 420 are means for connecting battery cells 110 in series and / or parallel, and may be made of an electrically conductive material, such as a metal such as copper, aluminum, or nickel. The busbars 420 may be arranged on the busbar frame 410 along the same direction as the stacking direction of the battery cells 110. For example, the electrode leads 111 of the battery cells 110 may be led out of the busbar frame 410 through lead slots and welded to a designated busbar 420.

[0044] The module case 200 is a component for protecting the cell laminate 100 from external impacts and the like, and is preferably made of a material with excellent mechanical rigidity.

[0045] The module case 200 may include a case body 210 and an upper plate 220. The case body 210 may be configured so that at least its top surface is open. For example, the case body 210 may be configured so that its top, front, and rear surfaces are open. The case body 210 may be provided in the form of a so-called U-frame, in which a lower plate 211, a left side plate 212, and a right side plate 213 are integrally formed.

[0046] The upper plate 220 is configured to cover the upper end of the cell laminate 100 and can be provided so as to be connectable to the case body 210. For example, the upper plate 220 can be connected by welding both longitudinal edges to the upper ends of a pair of side plates 212 and 213. In this case, the connected form of the upper plate 220 and the case body 210 may be a rectangular tubular shape with open front and rear surfaces.

[0047] The module case 200 may include end covers 230, 240 provided on the open front and rear surfaces of the case body 210. The end covers 230, 240 may be welded to the case body 210. On the other hand, although not shown for convenience, the end covers 230, 240 may be made of an insulating material on the inside and a metal material on the outside, for example. The end covers 230, 240 may also be partially provided with holes or slits 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.

[0048] On the other hand, the upper plate 220 may be provided with vent holes 221 for discharging vent gas to the outside of the module case 200 when the battery cell 110 ignites.

[0049] The upper plate 220 may include N vent holes 221 that are spaced apart in the stacking direction of the battery cells 110. As shown in Figure 2, the vent holes 221 may be provided at predetermined intervals in the width direction (X direction) of the upper plate 220. Preferably, the vent holes 221 may be provided in the form of elongated holes with a larger diameter in the longitudinal direction of the upper plate 220. The vent holes 221 may be provided at predetermined intervals in the longitudinal direction of the upper plate 220.

[0050] The upper plate 220 may be provided with vent holes 221 arranged in a substantially matrix configuration. For example, the upper plate 220 of this embodiment can be said to have 6 rows and 3 columns of vent holes 221. However, the vent holes 221 according to the present invention only need to be configured to be spaced apart in the width direction (X direction) of the upper plate 220. That is, the vent holes 221 do not necessarily need to be divided in the longitudinal direction (Y direction) of the upper plate 220. In other words, the upper plate 220 can have an N row and 1 column structure. As will be described in detail later, the configuration in which vent holes 221 are provided at predetermined intervals in the width direction of the upper plate 220 is intended to prevent gas generated in any battery cell 110 inside the module case 200 from propagating to other battery cells 110 inside the module case 200, and to guide the gas to be discharged upwards from the module case 200 via the shortest path.

[0051] Referring further to Figures 2 to 4, the vent channel forming sheet 300 may be positioned opposite the cell stack 100 and on the lower surface of the upper plate 220. The vent channel forming sheet 300 may be configured to form a gas transfer passage on the upper part of the upper plate 220 when a thermal event occurs in the battery module 10.

[0052] The vent channel forming sheet 300 may have at least a portion attached to the upper plate 220 and include a folded portion 310 that is folded once or more at a position corresponding to the vent hole 221. The folded portion 310 may be configured to expand upward of the vent hole 221 by a predetermined pressure to form a gas transport passage on the upper part of the upper plate 220. For example, a folded portion 310 located above or below a battery cell 110 where thermal runaway has occurred may expand due to the pressure of the vent gas generated in the battery cell 110, and bulge upward of the vent hole 221, thereby forming a predetermined gas transport passage. The gas transport passage formed at this time may be in the form of a tunnel with the front and rear ends open so that the vent gas flows in the front-rear direction (Y direction) of the battery module 10.

[0053] The vent channel forming sheet 300 may be made of an electrically insulating and fire-resistant material. For example, the vent channel forming sheet 300 may be made of a material with excellent electrical insulation and flame-retardant properties, such as graphite or silicone. Under normal circumstances, such a vent channel forming sheet 300 can serve to electrically insulate the battery cell 110 from the upper plate 220.

[0054] Specifically, the vent channel forming sheet 300 may include a plurality of unit vent channel forming sheets 300A, 300B, and 300C. For example, as shown in the embodiment of Figure 2, vent holes 221 arranged in 6 rows and 3 columns on the upper plate 220 may be covered by three unit vent channel forming sheets 300A, 300B, and 300C. That is, in Figure 2, six vent holes 221 in the first row may be covered by the first unit vent channel forming sheet 300A, six vent holes 221 in the second row may be covered by the second unit vent channel forming sheet 300B, and six vent holes 221 in the third row may be covered by the third unit vent channel forming sheet 300C.

[0055] The vent channel forming sheet 300 may have folding portions 310 that correspond one-to-one with the N vent holes 221. For example, the vent channel forming sheet 300 may have 18 folding portions 310 that correspond one-to-one with the total of 18 vent holes 221 of the upper plate 220 shown in Figure 2.

[0056] Referring to Figure 5, the vent channel forming sheet 300 may include a first fixing portion 320 and a second fixing portion 330 that are fixed to the lower surface of the upper plate 220 between the folded portions 310.

[0057] The first fixing portion 320 and the second fixing portion 330 may be configured to be fixed to the lower surface of the upper plate 220 by adhesive or bolting. However, other methods besides adhesive or bolting are acceptable as long as the first fixing portion 320 and the second fixing portion 330 can be installed on the lower surface of the upper plate 220.

[0058] When the first fixing portion 320 and the second fixing portion 330 are fixed, if a heat event occurs and gas pressure acts on the vent channel forming sheet 300, the first fixing portion 320 and the second fixing portion 330 will not move, and only the folding portion 310 will be unfolded, allowing it to protrude above the upper plate 220 from the vent hole 221. In this case, a tunnel-shaped gas passage having a circumference corresponding to the folded length of the folding portion 310 may be formed on the upper part of the upper plate 220.

[0059] For reference, the vent channel forming sheet 300 according to this embodiment has a plurality of vent holes 221 and a plurality of corresponding folding portions 310 in the width direction (X direction) of the upper plate 220, and two adjacent folding portions 310 share a fixing portion. The first fixing portion 320 and the second fixing portion 330 are fixed portions located to the left and right of one folding portion 310 as a reference. That is, the second fixing portion 330 to the right of any folding portion 310 can become the first fixing portion 320 for any other folding portion 310 adjacent to the right of any of the aforementioned folding portions 310.

[0060] Figure 6 shows how the folding portion 310A is unfolded when thermal runaway occurs in the battery cell 110 in the outermost region of the battery module 10 of Figure 4; Figure 7 is a perspective view of the battery module 10 with the gas transfer passage corresponding to Figure 6 formed therein; Figure 8 shows how the folding portions 310A and 310D are unfolded when thermal runaway occurs in the battery cell 110 in the outermost region and the battery cell 110 in the central region of the battery module 10 of Figure 4; and Figure 9 is a perspective view of the battery module 10 with the gas transfer passage corresponding to Figure 8 formed therein.

[0061] Referring to Figures 6 to 9, an example of gas discharge and directional vent channel formation in a battery module 10 according to one embodiment of the present invention when a thermal event occurs will be briefly described.

[0062] As shown in Figure 6, the battery module 10 according to this embodiment may have battery cells 110 partitioned into predetermined numbers by barrier members 120, and vent holes 221 provided in the upper regions of the partitioned battery cells 110. For example, when a thermal event occurs in the rightmost outermost battery cell 110 of the battery cells 110, the folded portion 310A, which was folded due to the pressure of discharged material (such as fragments detached from the current collector or electrode active material) and vent gas near the battery cell 110 where the thermal event occurred, expands and bulges upward above the vent hole 221. As a result, a gas transfer passage may be formed on the upper part of the upper plate 220, as shown in Figure 7. In this case, the gas transfer passage may be in the form of a tunnel with the front and rear ends open.

[0063] With this configuration, discharges and vent gases ejected from the outermost battery cells 110 are discharged upwards from the upper plate 220 through the open vent holes 221 and guided along the gas transport passage in the front-to-back direction (Y direction) of the battery module 10. At this time, the transfer of heat to the sides of the upper plate 220 is restricted, so that thermal damage to other battery cells 110 is minimized. In addition, as the internal pressure of the module case 200 is relieved, the folding sections 310 adjacent to other battery cells 110 where no thermal events have occurred remain folded. That is, as shown in Figure 7, the remaining vent holes 221, excluding the vent hole 221 located on the outermost edge, remain covered by their corresponding folding sections 310B, 310C, 310D, 310E, and 310F, so that discharges or vent gases do not flow from the outside to the inside of the upper plate 220.

[0064] In another example, as shown in Figure 8, when a thermal event occurs in the battery cell 110 in the outermost right region and the battery cell 110 in the central region of the battery cell 110, the folding portions 310A and 310D corresponding to those battery cells 110 are unfolded, and an isolated gas transfer passage can be formed on the upper part of the upper plate 220, as shown in Figure 9.

[0065] According to the above configuration, the discharge and vent gas generated in the battery cell 110 where a thermal event occurs are immediately discharged from the inside of the module case 200 upwards to the outside of the module case 200, preventing them from spreading to other battery cells 110. In addition, the remaining vent holes 221, excluding the outermost vent hole 221 and the vent hole 221 located in the central region, are covered by the corresponding folding parts 310B, 310C, 310E, and 310F, so that the discharge and vent gas do not flow back into the inside of the module case 200.

[0066] Furthermore, the discharged material and vent gas can be guided to flow in the front-to-back direction of the battery module 10 along the gas flow passage outside the module case 200. In this way, by controlling the flow of the discharged material and vent gas in the intended direction when a thermal event occurs, thermal damage to other battery modules 10 arranged laterally (X direction) in the battery pack can be minimized.

[0067] Figure 10 is a cross-sectional view of a part of a battery module 10 according to another embodiment of the present invention, Figure 11 shows the folded portion 310 of Figure 10 in an unfolded state, Figure 12 is a cross-sectional view of a part of a battery module 10 according to yet another embodiment of the present invention, and Figure 13 shows the folded portion 310 of Figure 12 in an unfolded state.

[0068] The same part numbers as in the aforementioned drawings refer to the same parts, and redundant explanations of the same parts will be omitted. The explanation will focus on the differences from the previously described embodiments.

[0069] The embodiment of the present invention shown in Figures 10 to 13 differs from the previously described embodiment in the bonding structure between the upper plate 220 and the vent channel forming sheet 300.

[0070] First, a battery module 10 according to another embodiment of the present invention may include, as shown in Figure 10, a first sheet fixing member 223 that protrudes downward from the upper plate 220 and connects to the first fixing portion 320, and a second sheet fixing member 224 that connects to the second fixing portion 330. The first sheet fixing member 223 and the second sheet fixing member 224 have the same structure, and the first sheet fixing member 223 may include a main body 225 that penetrates the first fixing portion 320, and a support portion 226 formed at the lower end of the main body 225 so as to support the lower surface of the first fixing portion 320.

[0071] The first sheet fixing member 223 and the second sheet fixing member 224 may be means for mechanically fixing the first fixing portion 320 and the second fixing portion 330 to the upper plate 220, such as rivets. With the first sheet fixing member 223 and the second sheet fixing member 224, the fixing force can be increased compared to when the first fixing portion 320 and the second fixing portion 330 are bonded to the upper plate 220.

[0072] With this embodiment configuration, compared to the previously described embodiment, even if the folding portion 310 is opened very forcefully by gas pressure as shown in Figure 11, there is less risk of the first fixing portion 320 and the second fixing portion 330 separating from the upper plate 220, thus the gas flow passage is maintained more stably.

[0073] In yet another embodiment of the present invention, as shown in Figure 12, the battery module 10 may have the same structure as the first sheet fixing member 223A and the second sheet fixing member 224, each configured to be vertically aligned with the barrier member 120. The main body 225A may be provided in a form that protrudes more downward from the upper plate 220 than in the previously described embodiment, so that the barrier member 120 and the support portion 226 come into contact. In particular, compared with the embodiment of Figure 10, the embodiment of Figure 12 may be configured such that the vertical upper part of the barrier member is separated on the left and right sides by the first sheet fixing member 223A or the second sheet fixing member 224.

[0074] Therefore, according to yet another embodiment of the present invention, discharges and vent gases from the battery cell 110 experiencing thermal runaway are more concentratedly guided towards the upper vent hole 221 and discharged to the outside. Furthermore, the heat and gases from the thermally runaway battery cell 110 are less likely to pass through the barrier member 120, the first sheet fixing member 223, and the second sheet fixing member 224 and propagate to other adjacent battery cells 110.

[0075] Figure 14 is a perspective view of yet another battery module 10 of the present invention, and Figure 15 is a perspective view showing the battery module 10A of Figure 14 with the flame-retardant cover 500 removed.

[0076] Referring to Figures 14 and 15, a battery module 10A according to yet another embodiment of the present invention may further include a flame-retardant cover 500 compared to the battery module 10 of the embodiment described above.

[0077] The flame-retardant cover 500 may be configured to suppress the transfer of vent gases, flames, etc., to other battery modules 10 when a thermal event occurs in the battery module 10A. For this purpose, the flame-retardant cover 500 may be made of a material with excellent heat resistance and / or fire resistance, such as mica sheet or silicone composite material.

[0078] Because this flame-retardant cover 500 is resistant to deformation even when high temperatures are generated, its dimensional stability is maintained, allowing it to reliably block high-temperature gases and flames generated in the battery cell 110.

[0079] The flame-retardant cover 500 may include an opening / closing section 510 configured to burst or at least partially separate completely when a pressure exceeding the allowable pressure is applied to the area corresponding to the vent hole 221 of the upper plate 220, as in the embodiments shown in Figures 14 and 15.

[0080] For this purpose, the opening / closing section 510 may be provided in a form in which a notch line or shredding line 511 is formed. The opening / closing section 510 may burst or at least partially separate due to the pressure when the folding section 310 is unfolded.

[0081] A battery module 10 according to yet another embodiment of the present invention has a structure in which, from the top layer, the opening and closing portion 510 of the flame-retardant cover 500, the vent hole 221 of the upper plate 220, the folding portion 310 of the vent channel forming sheet 300, and the battery cell 110 are arranged in that order.

[0082] Therefore, according to the above-described embodiment of the present invention, when a thermal event occurs in a particular battery cell 110, the pressure of the discharge and gas causes the folding portion 310 located on the upper part of the particular battery cell 110 to expand and bulge above the vent hole 221, and at this time, the pressure may cause the opening and closing portion 510 to rupture or at least partially separate. As a result, as described above, a gas transport passage can be provided on the upper part of the flame-retardant cover 500 through which the discharge and vent gas can move in the front-rear direction of the battery module 10.

[0083] In this case, the flame-retardant cover 500 can more reliably block discharges and vent gases expelled to the outside of the module case 200 from further flowing into the inside of the module case 200. Therefore, the battery module 10A of the present invention, including the flame-retardant cover 500, can minimize heat transfer to adjacent battery cells 110 and other adjacent battery modules 10A, thereby more effectively preventing or delaying the propagation of thermal runaway.

[0084] Figure 16 is a schematic perspective view of a battery pack 20 including a battery module 10 according to one embodiment of the present invention.

[0085] Referring to Figure 16, a battery pack 20 according to one embodiment of the present invention may include one or more battery modules 10 according to one embodiment of the present invention as described above. The battery pack 20 according to the present invention may further include a BMS (Battery Management System) for integrated control of the charging and discharging of one or more battery modules 10, a current sensor, a fuse, etc., and a pack case for housing the aforementioned components.

[0086] The pack case may include a pack tray 21 for partitioning and housing the battery module 10, a pack lead 22 that is coupled to the pack tray 21 and covers the top of the battery module 10, and at least one gas outlet 23. Preferably, the gas outlet 23 may be provided on one side of the pack case located in front of or behind the battery module 10.

[0087] Figure 17 is a schematic perspective view of an automobile containing a battery pack 20 according to one embodiment of the present invention.

[0088] Referring to Figure 17, an automobile according to one embodiment of the present invention may include one or more battery packs 20 or battery modules 10 according to one embodiment of the present invention. The automobile 1 according to the present invention may be, for example, an electric vehicle, a hybrid vehicle or a plug-in hybrid vehicle. The automobile includes four-wheeled vehicles and two-wheeled vehicles. The automobile operates by receiving power from a battery pack or battery module 10 according to one embodiment of the present invention.

[0089] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and it goes without saying that various modifications and variations are possible within the equivalent scope of the technical concept and claims of the present invention by persons with ordinary skill in the art to which the present invention pertains.

[0090] In this specification, terms indicating direction such as up, down, left, right, front, and back are used. However, such terms indicate relative positions and are used only for the convenience of explanation. It is obvious to those skilled in the art that these positions can change depending on the position of the object in question, the observer's position, etc.

Claims

1. A cell stack comprising multiple battery cells, A module case provided to house the cell stack, with a vent hole in the upper plate covering the upper end of the cell stack, The sheet includes a vent channel forming sheet which is coupled to the upper plate and has folded portions that are folded once or more at positions corresponding to the vent holes, A battery module characterized in that the folding portion is provided to be expanded upward by a predetermined pressure to form a gas transfer passage on the upper part of the upper plate.

2. The vent channel forming sheet is The battery module according to claim 1, characterized in that it is positioned opposite the cell stack and on the lower surface of the upper plate.

3. The battery module according to claim 1, characterized in that the vent channel forming sheet is made of an electrically insulating and fire-resistant material.

4. The vent channel forming sheet is The battery module according to claim 1, characterized in that it includes a first fixing portion and a second fixing portion that are fixed to the lower surface of the upper plate between the folding portions.

5. The battery module according to claim 4, characterized in that the first fixing portion and the second fixing portion are bonded to or bolted to the lower surface of the upper plate.

6. The battery module according to claim 4, characterized in that it includes a first sheet fixing member that protrudes downward from the upper plate and is connected to the first fixing portion, and a second sheet fixing member that is connected to the second fixing portion.

7. The first sheet fixing member and the second sheet fixing member have the same structure. The battery module according to claim 6, characterized in that the first sheet fixing member includes a main body that penetrates the first fixing portion and a support portion formed at the lower end of the main body so as to support the lower surface of the first fixing portion.

8. The battery module according to claim 1, characterized in that the upper plate includes N vent holes arranged spaced apart along the stacking direction of the battery cells.

9. The vent channel forming sheet is The battery module according to claim 8, characterized in that it comprises a folding portion that corresponds one-to-one with N vent holes.

10. The module case further includes a flame-retardant cover that is coupled to the top of the module case, The battery module according to claim 1, characterized in that the flame-retardant cover is provided with an opening / closing section configured to rupture or at least partially separate upon predetermined pressure or heat in an area corresponding to the vent hole of the upper plate.

11. The battery module according to claim 10, characterized in that the opening and closing section is provided in a form in which a notch line or a crushing line is formed in the flame-retardant cover.

12. The aforementioned module case is The case body, with at least the top open, The battery module according to claim 1, characterized in that it includes an upper plate that covers the upper surface of the case body and is coupled to the case body.

13. The aforementioned battery cell is a pouch-type battery cell, The battery module according to claim 1, characterized in that the pouch-type battery cells are stacked in one direction.

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

15. An automobile comprising the battery pack described in claim 14.

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