A battery module in which the width of a gas discharge passage is variably adjusted according to the pressure of vent gas, and a battery pack including the same

Abstract

A battery module according to the present invention includes a plurality of battery cells, a module case that houses the plurality of battery cells and has a gas vent hole on at least one side, and a gas vent panel that is coupled to the outside of the module case and has a gas exhaust passage that communicates with the gas vent hole and guides a gas flow to the outside along a predetermined path, and the gas vent panel may include a flow path width adjustment unit that variably adjusts a width of the gas exhaust passage in response to gas pressure.

Description

Technical Field

[0001] The present invention relates to a battery module, and more specifically, to a battery module in which the width of a gas discharge passage is significantly increased according to the amount of gas generated during internal ignition of the battery module, and a battery pack including the same.

[0002] This application claims priority based on Korean Patent Application No. 10-2022-0020960 filed on February 17, 2022, and all of the contents disclosed in the specification and drawings of the application are incorporated herein.

Background Art

[0003] Secondary batteries have not only the temporary advantage of significantly reducing the use of fossil fuels, but also the advantage of producing no by-products associated with energy use, and thus are attracting attention as a new energy source for environmental friendliness and improved energy efficiency.

[0004] For this reason, the application of secondary batteries to a wide variety of devices is increasing. For example, it is widely used not only as an energy source for wireless mobile devices or wearable devices, which are multifunctional small products, but also as an energy source or energy storage system (ESS) for electric vehicles and hybrid electric vehicles proposed as alternatives to existing gasoline vehicles and diesel vehicles.

[0005] The most commonly used lithium secondary battery recently has an operating voltage of about 2.5V to 4.5V per cell. Therefore, in the case of electric vehicles and energy storage systems that require high capacity and high output, a battery module in which a plurality of secondary batteries are connected in series and / or in parallel, and a battery pack in which the battery modules are connected in series and / or in parallel are configured and used as an energy source.

[0006] Depending on the output and capacity of the battery pack required for an electric vehicle, the number of lithium secondary batteries in one battery module may increase, or the number of battery modules in one battery pack may increase.

[0007] However, a battery pack containing a large number of lithium secondary batteries like this will inevitably cause even greater damage in the event of a fire in the battery module.

[0008] For example, when events such as a short circuit between lithium secondary batteries or an abnormal rise in temperature occur in some battery modules, there is a risk that a large amount of vent gas will be generated in the lithium secondary batteries. If the degradation becomes more severe, there is a risk that high-temperature sparks containing flames, electrode active materials, aluminum particles, etc. will be generated. There is concern that the flames and high-temperature particles will be ejected outside the battery module together with the vent gas. The flames and high-temperature sparks ejected in this way will cause thermal damage to other battery modules adjacent to the ignited battery module and promote the ignition of other battery modules.

[0009] Therefore, in order to prevent or delay the risk of chain ignition or explosion of battery modules to the maximum extent, flames, high-temperature sparks, etc. generated in the first ignited battery module should not be discharged from the inside to the outside of the battery module, and only gas should be discharged to the outside so that the internal pressure of the battery module does not continue to rise. It is necessary to design the battery module.

[0010] However, if the width of the gas discharge passage is enlarged to quickly discharge a large amount of gas, oxygen is likely to flow into the battery module from the outside. The oxygen flowing in like this may cause the flames and high-temperature sparks inside the battery module to come into contact with each other, which may cause the ignition of the battery module to be promoted more quickly and significantly.

[0011] For this reason, when a large amount of vent gas is generated inside the battery module, a solution that can discharge a large amount of vent gas to the outside while reducing the inflow of oxygen is required.

Summary of the Invention

Problems to be Solved by the Invention

[0012] The present invention has been devised to solve the above-described technical problems, and an object thereof is to provide a battery module that can effectively discharge a large amount of vent gas to the outside while reducing the inflow of oxygen when a large amount of vent gas is generated inside the battery module, and a battery pack including the same.

[0013] The technical problems to be solved by the present invention are not limited to the above-described technical problems at all, and other technical problems not mentioned should be clearly understood by those skilled in the art from the description of the invention described below.

Means for Solving the Problems

[0014] The battery module according to the present invention includes a plurality of battery cells, a module case that houses the plurality of battery cells therein and has gas vent holes on at least one side, a gas discharge passage that communicates with the gas vent holes and guides the flow of gas to the outside along a predetermined path, and a gas vent panel that is coupled to the outside of the module case, and the gas vent panel may include a flow path width adjustment unit that variably adjusts the width of the gas discharge passage according to the pressure of the gas.

[0015] The gas discharge passage may include a fixed-type passage section having a constant width and a variable-type passage section whose width is variably adjusted by the flow path width adjustment unit.

[0016] The flow path width adjustment unit is provided to close the variable passage section, but when gas is generated, the variable passage section is opened in proportion to the pressure of the gas, and the flow path can be configured to widen.

[0017] The flow path width adjustment unit is initially positioned at a closing point which is a point on the variable passage section, and includes a flow path blocking film provided to be able to close the variable passage section, and a position adjusting member that moves the flow path blocking film away from the closing point in a direction in which the width of the flow path of the variable passage section through which gas can pass expands in proportion to the pressure of the gas when gas is generated.

[0018] The position adjusting member may be composed of a spring whose one side is fixed inside the gas vent panel and the other side is coupled to the flow path blocking film, and whose length is compressed in proportion to the pressure.

[0019] The position adjusting member may be composed of a screw spring that rotates the flow path blocking film in proportion to the pressure of the gas.

[0020] The position adjusting member may include an actuator including a cylinder fixed inside the gas vent panel and a piston rod connected to the flow path blocking film in the cylinder.

[0021] The gas vent panel includes a cover plate disposed at a predetermined distance from one surface of the module case where the gas vent hole is located, and a frame edge portion provided along the periphery of the edge portion of the cover plate and surrounding the space between one surface of the module case and the cover plate. The gas discharge passage may be provided in an internal space surrounded by one surface of the module case, the cover plate, and the frame edge portion.

[0022] The frame edge portion includes a first frame edge portion extending along the longitudinal direction of the module case, a second frame edge portion facing the first frame edge portion and extending along the longitudinal direction of the module case, and a third frame edge portion extending so as to intersect the first frame edge portion and having both ends connected to one end of the first frame edge portion and one end of the second frame edge portion. The terminal portion of the gas vent panel facing the third frame edge portion can be opened so that gas can be discharged to the outside.

[0023] The gas vent panel may be shorter than the straight-line distance between the first frame edge portion and the second frame edge portion, and may include a first protruding plate protruding from the first frame edge portion toward the second frame edge portion and a second protruding plate protruding from the second frame edge portion toward the first frame edge portion.

[0024] There are a plurality of the first protruding plates, and the plurality of first protruding plates are separated from each other by a predetermined interval along the longitudinal direction of the gas vent panel. There are a plurality of the second protruding plates, and the plurality of second protruding plates may be arranged alternately with the first protruding plates and separated from each other by a predetermined interval along the longitudinal direction of the gas vent panel.

[0025] The gas vent panel may include a third protruding plate that does not contact the first frame edge portion and the second frame edge portion and protrudes so as to contact one surface of the module case on the surface of the cover plate.

[0026] The module case is provided with gas vent holes on one side surface and the other side surface along the longitudinal direction, and there are two gas vent panels, which may be provided so as to cover one side surface and the other side surface of the module case respectively.

[0027] The module case is provided with a gas vent hole at the upper end, and the gas vent panel may be provided so as to cover the upper end of the module case.

[0028] According to another aspect of the present invention, a battery pack including one or more of the battery modules according to the present invention described above may be provided.

Advantages of the Invention

[0029] According to one aspect of the present invention, when a large amount of vent gas is generated inside the battery module, it becomes possible to provide a battery module that can effectively discharge a large amount of vent gas to the outside while reducing the inflow of oxygen.

[0030] More specifically, in the battery module according to the present invention, a plate-shaped gas vent panel having a gas discharge passage is coupled to the outside of the module case. Normally, the gas discharge passage is closed so that oxygen does not flow in, and when an event occurs, the gas discharge passage is opened and vent gas is discharged to the outside. In particular, the gas discharge passage is configured to variably expand according to the strength of the gas pressure, so that a large amount of rapidly increasing gas can be discharged more smoothly.

[0031] The effects of the present invention are not limited to the above-described effects at all, and other effects not mentioned will be clearly understood by those having ordinary knowledge in the technical field to which the present invention pertains from this specification and the accompanying drawings.

Brief Description of the Drawings

[0032]

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Figure 9a

Figure 9b

Figure 10a

Figure 10b

Figure 11a

Figure 11b

Figure 12a

Figure 12b

Embodiments for Carrying Out the Invention

[0033] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms and words used in this specification and the claims are not to be construed as being limited to ordinary or dictionary meanings. The inventor himself interprets them in accordance with the meaning and concept corresponding to the technical idea of the present invention in accordance with the principle that he can appropriately define the concept of the terms in order to explain the invention in the best way. Therefore, it should be understood that the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. At the time of this application, there can be various equivalents and modifications that can replace them.

[0034] FIG. 1 is a schematic perspective view of a battery module according to a first embodiment of the present invention, FIG. 2 is an exploded perspective view of the main components of the battery module of FIG. 1, FIG. 3 is a view showing a state in which a gas vent panel is removed from the battery module of FIG. 1, and FIG. 4 is a perspective view schematically showing the configuration of the gas vent panel according to the first embodiment of the present invention.

[0035] Referring to these drawings, a battery module 10 according to the present invention includes a cell assembly 100 including battery cells 111, a module case 200 for housing and protecting the cell assembly 100, and a gas vent panel 300 for discharging gas when the battery cells 111 ignite.

[0036] If a large amount of gas is generated inside the battery module 10 and cannot be properly discharged to the outside, there is a risk that the battery module 10 will explode due to high pressure. For example, generally, a battery pack for an electric vehicle includes a plurality of battery modules 10. If a part of the battery cells 111 belonging to a certain battery module 10 undergoes thermal runaway and a large amount of gas is generated, the battery module 10 may explode due to a rapid increase in pressure. Thus, if the battery module 10 explodes, there is a concern that other surrounding battery modules 10 will also be severely damaged thermally and cause a chain explosion, or that a fire will quickly and extensively spread or transfer.

[0037] Therefore, the battery module 10 according to the present invention includes the gas vent panel 300 as a means for discharging a large amount of gas to the outside under the condition that the battery cell 111 undergoes thermal runaway and relieving the pressure inside the battery module 10.

[0038] In particular, the gas vent panel 300 according to the present invention is configured such that a flame or a high-temperature spark inside the battery module 10 is difficult to escape to the outside, and air (oxygen) outside the battery module 10 is also difficult to enter the inside of the battery module 10 and come into contact with the flame or the high-temperature spark (here, the spark means an electrode active material or aluminum particles detached from an electrode when the battery cell 111 ignites).

[0039] Hereinafter, the main components of the battery module 10 according to the present invention will be described in detail.

[0040] First, as shown in FIG. 2, the cell assembly 100 of the battery module 10 according to the first embodiment of the present invention includes a cell stack 110, a bus bar frame 120, and a plurality of bus bars 130.

[0041] The cell stack 110 is an assembly of a plurality of battery cells 111 formed by stacking the battery cells 111. That is, the cell stack 110 may be composed of a plurality of pouch-type battery cells 111 that are widely laid out and stacked in one direction (X direction).

[0042] The pouch-type battery cell 111 includes an electrode assembly, a pouch case that houses the electrode assembly, and a pair of electrode leads 112 that are connected to the electrode assembly and drawn out to the outside of the pouch case to function as electrode terminals. The pair of electrode leads 112 are drawn out in opposite directions to each other in the longitudinal direction (±Y direction) of the battery cell 111.

[0043] If necessary, the pouch-type battery cell 111 may have a form in which the electrode lead 112 is located only at one end in the Y-axis direction, for example, the end in the +Y-axis direction. On the other hand, the present invention is not limited by such specific types and forms of the battery cell 111, and various battery cells 111 known at the time of filing the present invention can be adopted in constructing the cell stack 110 of the present invention.

[0044] The bus bar frame 120 can be injection-molded from an electrically insulating material and is provided in the shape of a plate-like body sized to cover the front (+Y direction) or the rear (-Y direction) of the cell stack 110.

[0045] In addition, the bus bar frame 120 includes a plurality of lead slots through which the electrode leads 112 of the pouch-type battery cell 111 can pass in the +Y axis or -Y axis direction. The plurality of lead slots can be provided along the stacking direction (X direction) of the battery cells 111.

[0046] The bus bar frame 120 of this embodiment is configured to be able to fix a plurality of bus bars 130. Although not shown, additional components such as connectors and other printed circuit boards (PCBs) can be arranged in the upper space of the bus bar 130, and the bus bar frame 120 can be configured to have a support plate for supporting and fixing the additional components.

[0047] The plurality of bus bars 130 are made of an electrically conductive material, such as a metal like copper, aluminum, nickel, etc., and the electrode leads 112 of a defined number of battery cells 111 are welded and fixed to the surface of the defined bus bar 130 and electrically connected. The bus bar 130 of this embodiment is provided in a rectangular rod shape with a perforation in the middle so that the electrode lead 112 can pass through it, and is arranged in the bus bar frame 120 so that the perforated part communicates with the lead slot of the bus bar frame 120.

[0048] Also, the bus bar 130 is arranged in the bus bar frame 120 along the same direction as the stacking direction of the battery cells 111. For a predetermined battery cell 111, the electrode leads 112 overlap and pass through the bus bar frame 120 back and forth through the corresponding lead slots, and the portion thus drawn out can be welded so as to be bent and fixed to the surface of the bus bar 130.

[0049] The module case 200 is a component for protecting the cell assembly 100 from external impacts, etc., and preferably can be made of a material with excellent mechanical rigidity. The module case 200 according to this embodiment includes a case body 210 and a case cover 220 as shown in FIGS. 1 and 2.

[0050] The case body 210 includes a top plate 211, a bottom plate 212, both side plates 213, 214, and an open end O with both ends in the longitudinal direction open, presenting a rectangular tube with an empty interior, and can be provided so that the cell assembly 100 can be inserted into it along the longitudinal direction (Y direction). That is, the case body 210 can be configured so that the cell assembly 100 can be inserted into it by a sliding or interference fit method.

[0051] The battery module 10 to which such a case body 210 is applied can be configured such that there is almost no gap between the top plate 211 of the case body 210 and the upper end of the cell stack 110, and there is also almost no gap between the bottom plate of the case body 210 and the lower end of the cell stack 110, and there is also almost no gap between both side plates 213, 214 of the case body 210 and both sides of the cell stack 110.

[0052] The case cover 220 can be provided so as to shield the portion where the electrode lead 112 and the bus bar 130 are electrically connected, cover the open end O of the case body 210, and be coupled to the case body 210. The case cover 220 can be provided, for example, with an inner side made of an insulating material and an outer side made of a metal material, and can be provided so as to be weldable to the open end O of the case body 210.

[0053] Returning to FIGS. 2 and 3, the case body 210 is provided with a gas vent hole 215. The gas vent hole 215 is a portion where gas escapes from the module case 200 when ignition occurs inside the battery module 10.

[0054] The gas vent hole 215 is provided in a region on the opposite side of the discharge port 340 with respect to the closing point C of the gas vent channel when the gas vent panel 300 is mounted. Preferably, in order to prevent the outflow of flame or spark to the outside, it is effective to configure the gas vent hole 215 to be located as far as possible from the discharge port 340 of the gas vent panel 300.

[0055] Therefore, as shown in FIG. 3, one gas vent hole 215 can be provided at each of the -Y direction end portions of both side plates 213, 214 of the case body 210, and is covered by the gas vent panel 300 to prevent exposure to the outside. In this way, by covering the gas vent hole 215 with the gas vent panel 300, when gas is discharged from the gas vent hole 215, it is possible to prevent the exposure of flame or spark to the outside.

[0056] That is, although it will be described in detail later, the gas vent panel 300 covers the outside of the gas vent hole 215 and is configured to allow only gas to easily escape, restricting the movement of flames and high-temperature sparks. Although not shown, a metal mesh may be further applied to the gas vent hole 215 so that flames and coarse particles cannot easily pass through.

[0057] The gas vent panel 300 guides and discharges the gas generated in the battery cell 111 to the outside along a predetermined path, and covers the gas vent hole 215 in a generally plate-like shape so that flames and high-temperature sparks are not easily discharged to the outside. It is coupled to the outside of the module case 200 and provided with a gas discharge passage P inside.

[0058] In particular, the gas vent panel 300 according to the present invention includes a flow path width adjustment unit 330 that variably adjusts the width of the gas discharge passage P. The flow path width adjustment unit 330 can be configured to act so as to discharge gas to the outside while reducing the inflow of oxygen when gas is generated in the battery module 10.

[0059] That is, the flow path width adjustment unit 330 can be said to be a component that plays a role in discharging a large amount of gas to the outside of the battery module 10 while reducing the contact between the ignition source inside the battery module and the oxygen outside the battery module among the three elements of a fire (combustible, ignition source, oxygen).

[0060] Hereinafter, the configuration of the gas vent panel 300 according to the present invention will be described in more detail.

[0061] As shown in FIGS. 3 to 4, the gas vent panel 300 according to this embodiment includes a cover plate 310, a frame edge portion 320, a flow path width adjustment unit 330, and a discharge port 340.

[0062] The cover plate 310 can be provided as a plate-shaped body made of a metal material having an area corresponding to one surface of the module case 200 with a gas vent hole 215.

[0063] When the gas vent panel is attached to the module case, the cover plate is arranged to be separated by an amount corresponding to the height (X direction) of the frame edge portion 320 from one surface of the module case 200 with the gas vent hole 215.

[0064] The frame edge portion 320 is provided along the periphery of the edge portion of the cover plate 310, and can be provided so as to surround the space between one surface of the module case 200 and the cover plate 310 except for the discharge port 340.

[0065] The frame edge portion 320 includes a first frame edge portion 321 extending along the longitudinal direction of the module case 200, a second frame edge portion 322 facing the first frame edge portion 321 and extending along the longitudinal direction of the module case 200, and a third frame edge portion 323 extending so as to intersect the first frame edge portion 321 and having both ends connected to one end of the first frame edge portion 321 and one end of the second frame edge portion 322.

[0066] By welding the first to third frame edge portions 321, 322, 323 to the periphery of one surface of the module case 200, the gas vent panel 300 can be fixedly coupled to the outside of the module case 200 with good airtightness, and an internal space communicating with the gas vent hole 215 and surrounded by one surface of the module case 200, the cover plate 310, and the frame edge portion 320, that is, a gas discharge passage P can be provided.

[0067] Further, a discharge port 340 can be provided at the terminal portion of the gas vent panel 300 facing the third frame edge portion 323 by reducing or omitting the frame edge portion 320. The discharge port 340 has a structure that is opened so that gas can be discharged to the outside when the gas vent panel 300 is coupled to one surface of the module case 200.

[0068] Therefore, according to the above configuration, when ignition occurs inside the battery module 10, gas exits from the gas vent hole 215 of the module case 200 (on the end side in the -Y direction), enters the gas vent panel 300, and can move in the direction (+Y direction) from the third frame edge portion 323 side toward the discharge port 340 and be discharged to the outside of the battery module 10.

[0069] Also, the gas discharge passage P inside the gas vent panel 300 can be configured to guide the gas flow into a zigzag or meandering shape. A zigzag or meandering flow path makes it difficult for flames and sparks to move, and since many vortices are generated during the process of the gas passing through, there is a risk that the flames and sparks will frequently collide with the module case 200 or the gas vent panel 300 due to the vortices, and at this time, heat exchange will occur and the flames will extinguish, and the temperature of the sparks will drop significantly.

[0070] As an example of forming the above-described zigzag or meandering flow path, the gas vent panel 300 according to this embodiment includes a first protruding plate 351 and a second protruding plate 352 inside the gas discharge passage P.

[0071] As shown in FIG. 4, the first protruding plate 351 has a height corresponding to the height (X direction) of the frame edge portion 320, is shorter than the shortest straight-line distance between the first frame edge portion 321 and the second frame edge portion 322, and can be configured to protrude from the first frame edge portion 321 toward the second frame edge portion 322.

[0072] And the second protruding plate 352 has a height corresponding to the height (X direction) of the frame edge portion 320, is shorter than the shortest straight-line distance between the second frame edge portion 322 and the first frame edge portion 321, and may be configured to protrude from the second frame edge portion 322 toward the first frame edge portion 321. Also, a plurality of first protruding plates 351 may be configured to be arranged at predetermined intervals from each other along the longitudinal direction (Y direction) of the gas vent panel 300, and a plurality of second protruding plates 352 may also be configured to be arranged at predetermined intervals from each other along the longitudinal direction (Y direction) of the gas vent panel 300. The first protruding plate 351 and the second protruding plate 352 may be arranged alternately with each other, or may be provided so as not to contact each other even if they are at the same position in the Y direction.

[0073] According to such first protruding plates 351 and second protruding plates 352, as shown in FIGS. 5 to 6, the gas flow can be guided from one end of the gas vent panel 300 to the discharge port 340 in a zigzag or tortuous shape.

[0074] On the other hand, as shown in FIGS. 4 to 6, the gas discharge passage P according to this embodiment includes a fixed-type passage section P1 and a variable-type passage section P2.

[0075] The fixed-type passage section P1 means a section where the width of the flow path through which the gas can move does not change, and the variable-type passage section P2 means a section where the width of the flow path is variably changed by the flow path width adjustment unit 330 according to the gas pressure.

[0076] The flow path width adjustment unit 330 is normally provided so as to be able to close the variable-type passage section P2, and when gas is generated, the variable-type passage section P2 is opened, and the higher the gas pressure, the more the flow path can be configured to expand.

[0077] Specifically, the channel width adjustment unit 330 according to this embodiment is initially positioned at a closing point C which is a point on the variable channel section P2, and is provided with a channel blocking film 331 capable of closing the variable channel section P2, and a position adjusting member 332 for moving the channel blocking film 331 away from the closing point C in a direction in which the width of the channel of the variable channel section P2 through which gas can pass expands when gas is generated.

[0078] For example, as shown in FIG. 4, the channel blocking film 331 can be initially positioned at a closing point C which is a point on the variable channel section P2, and can be disposed in the shape of a plate-like body capable of closing the variable channel section P2. According to such a channel blocking film 331, normally, that is, under the condition that no gas is generated, the air (oxygen) outside the battery module 10 does not flow into the gas vent hole 215 through the gas vent panel 300. Therefore, it is possible to prevent the contact between air (oxygen) and an ignition source at the initial stage when ignition starts to occur.

[0079] The position adjusting member 332 can be realized by a coil spring. For the sake of easy illustration, the shape of the coil spring is simply shown in FIG. 4, but the number, shape and material of the coil spring can be selected so as to have a spring constant whose length can be appropriately compressed in proportion to the gas pressure.

[0080] One side of the coil spring can be fixed inside the gas vent panel 300, and the other side can be fixedly coupled to the channel blocking film 331.

[0081] For example, as in the implementation configuration of FIG. 4, one end of the coil spring is coupled to a first protruding plate 351 which is located at a predetermined interval in the direction (-Y direction) from the closing point C toward the discharge port 340, and the other end of the coil spring can be coupled to the back surface of the channel blocking film 331.

[0082] At the closing point C, a stopper which is on the same line in the Z direction as the second protruding plate 352 and protrudes relatively very short from the first frame edge portion 321 can be provided.

[0083] In a state where the elastic force of the coil spring acts in the -Y direction, by configuring the edge portion on the front surface of the flow path blocking film 331 to contact the second protruding plate 352 and the stopper, the flow path between the second protruding plate 352 and the stopper is blocked by the flow path blocking film 331 and closed. Therefore, normally, the flow path blocking film 331 adheres to the second protruding plate 352 and the stopper, and the elastic force of the coil spring continues to act in the direction of pushing the flow path blocking film 331 (the -Y direction), and the variable passage section P2 is held in a closed state.

[0084] However, when ignition occurs inside the battery module 10, when gas exits from the gas vent hole 215 and flows into the gas vent panel 300, the gas pressure acts on the flow path blocking film 331 (in the +Y direction). At this time, when the gas pressure becomes greater than the elastic force of the coil spring, while the coil spring is compressed, the flow path blocking film 331 moves (in the +Y direction) and the variable passage section P2 is opened. Then, as shown by the arrows in FIGS. 5 to 6, the gas can move along the gas discharge passage P and be discharged to the outside through the discharge port 340.

[0085] More specifically, the implementation configuration in FIG. 5 is the state of the gas vent panel 300 when ignition of the battery module 10 starts, and the implementation configuration in FIG. 6 can be said to be the state of the gas vent panel 300 when ignition of the battery module 10 intensifies and a large amount of gas is generated.

[0086] In the initial stage when the ignition of the battery module 10 starts, the amount of gas generated inside the battery module 10 is not large. Therefore, rather than relieving the pressure inside the battery module 10, it is even more important to prevent external air (oxygen) from flowing into the battery module 10 so that the flame or spark, which is the ignition source, does not come into contact with the air (oxygen). And when the ignition of the battery module 10 intensifies, since the amount of gas inside the battery module 10 increases rapidly, it can be said that it is even more important to quickly discharge a large amount of gas to the outside of the battery module 10 to relieve the internal pressure.

[0087] It can be said that the gas vent panel 300 according to the present invention is configured to discharge gas step by step when ignition occurs inside the battery module as described above.

[0088] That is, when the amount of gas is small, the gas vent panel 300 according to the present invention is adjusted by the flow path width adjustment unit 330 so that the width of the flow path in the variable passage section P2 becomes relatively narrow as shown by F1 in FIG. 5, thereby reducing the inflow of air (oxygen) as much as possible while allowing gas to be discharged. When the amount of gas is large, as shown by F2 in FIG. 6, the width of the flow path in the variable passage section P2 is adjusted to be wider than when the amount of gas is small, so that a large amount of gas can be discharged to the outside of the battery module 10 more quickly.

[0089] Therefore, the battery module 10 according to the first embodiment of the present invention includes the gas vent panel 300 having the above-described configuration and operation. When an event occurs, the width of the gas discharge passage P variably expands and contracts according to the strength of the gas pressure, so that the gas can be effectively discharged to the outside while reducing the contact between the air (oxygen) and the ignition source.

[0090] On the other hand, in the case of the battery module 10 according to the first embodiment, a total of two gas vent holes 215 are provided, one each on one side surface portion and the other side surface portion of the module case 200 along the longitudinal direction of the module case 200, and the gas vent panel 300 is configured to cover one side surface portion and the other side surface portion of the module case 200, respectively.

[0091] However, it should be clarified in advance that the scope of the present invention is not limited in any way by the fact that the gas vent panel 300 is located on the side surface portion of the module case as in the battery module 10 of the first embodiment. For example, the gas vent panel 300 may be located on the upper portion of the module case 200.

[0092] That is, as a modification of the battery module according to the first embodiment, as in the implementation configurations of FIGS. 7 and 8, the gas vent hole 215 may be applied to the top plate 211 of the case body 210, and the gas vent panel 300 may be configured to communicate with the gas vent hole 215 and cover the top plate 211 of the case body 210.

[0093] In this case, it becomes possible to provide a battery module 20 having a narrower width in the side surface direction than in the first embodiment, and such a battery module 20 has the advantage that when a plurality of them are arranged inside a battery pack (not shown), they can be arranged more efficiently in the horizontal direction than the battery module 10 according to the first embodiment.

[0094] Next, with reference to FIGS. 9a to 12b, the battery module 10 according to the second to fifth embodiments of the present invention will be briefly described.

[0095] The same member numbers as in the previous drawings indicate the same members, and duplicate explanations of the same members are omitted, and the description will focus on the differences from the above-described embodiments.

[0096] When comparing the battery module according to the second to fifth embodiments with the battery module 10 according to the first embodiment described above, there are differences in the structure of the gas discharge passage P inside the gas vent panel 300 and the configuration of the flow path width adjustment unit 330, and the other configurations are substantially the same.

[0097] First, as shown in FIGS. 9A and 9B, the gas vent panel 300A of the battery module according to the second embodiment of the present invention further includes a third protruding plate 353 that does not contact the first frame edge portion 321 and the second frame edge portion 322 and protrudes so as to contact one surface of the module case 200 on the surface of the cover plate 310. And the position adjusting member 332A in the second embodiment can be realized by a leaf spring.

[0098] That is, as shown in the enlarged view of FIG. 9A, the flow path width adjustment unit 330a includes a flow path blocking film 331a and a leaf spring-like position adjustment member 332a.

[0099] The flow path width adjustment unit 330a is configured such that the front edge portion of the flow path blocking film 331a is in contact with the first protruding plate 351 and the second protruding plate 352 which are located on the same axis in the Z direction in a state where the elastic force of the leaf spring acts in the -Y direction, so that the flow path between the first protruding plate 351 and the second protruding plate 352 can be closed by the flow path blocking film 331a.

[0100] When ignition occurs inside the battery module and gas flows into the inside of the gas vent panel 300A, as shown in FIG. 9B, the leaf spring-like position adjustment member 332a is compressed by the pressure of the gas and the flow path blocking film 331a moves in the +Y direction, and the flow path of the variable-type passage section P2 can be opened. At this time, similar to the first embodiment described above, as the leaf spring-like position adjustment member 332a is compressed in proportion to the pressure of the gas, the width of the flow path can be variably expanded and contracted according to the amount of gas.

[0101] As shown in FIGS. 10a and 10b, the flow path width adjustment unit 330b of the gas vent panel 300b according to the third embodiment of the present invention includes a flow path blocking film 331b and a screw spring-shaped position adjustment member 332b that rotates the flow path blocking film 331b in proportion to the gas pressure.

[0102] The third embodiment minimizes the number of the first protruding plate 351 and the second protruding plate 352 so that gas discharge can be performed more smoothly. That is, the first protruding plate 351 and the second protruding plate 352 are located on the same line in the Z direction and are provided only at the closing point. Here, the second protruding plate 352 can be realized in substantially the same shape as the stopper of the first embodiment.

[0103] As shown in FIG. 10a, the flow path blocking film 331B can be rotatably coupled to one end of the first protruding plate 351 by a screw spring. One arm of the screw spring is fixedly coupled to the flow path blocking film 331, and the other arm is fixedly coupled to the first protruding plate 351. With the elastic force of the screw spring acting in the clockwise direction, one end of the flow path blocking film 331 is brought into contact with the second protruding plate 352. According to this, the flow path between the first protruding plate 351 and the second protruding plate 352 can be closed by the flow path blocking film 331b. When gas is generated, as shown in FIG. 10b, the flow path blocking film 331 rotates counterclockwise by an angle Θ corresponding to the gas pressure, and the flow path can be opened.

[0104] Similar to the first and second embodiments described above, since the screw spring rotates in proportion to the gas pressure, the width of the flow path can be variably expanded and contracted according to the gas amount.

[0105] Referring to FIGS. 11a and 11b, the flow path width adjustment unit 330c of the gas vent panel according to the fourth embodiment of the present invention includes a flow path blocking film 331c and a screw spring-shaped position adjustment member 332c that rotates the flow path blocking film 331c in proportion to the gas pressure, similar to the third embodiment. However, it can be said that the fourth embodiment is an embodiment in which the range of change in the width of the flow path of the gas discharge passage P is significantly widened compared to the first to third embodiments so that a large amount of gas can be discharged to the outside more quickly.

[0106] For example, in the gas vent panel 300C of this embodiment, the first protruding plate 351 and the second protruding plate 352 may be omitted, and a third protruding plate 353 that serves as a stopper may be provided. And two flow path width adjustment units 330 may be provided. As shown in FIG. 11a, two flow path blocking films 331c contact the third protruding plate 353 with the third protruding plate 353 interposed therebetween, and as shown in FIG. 11b, when gas is generated and the pressure of the gas is received, they may be configured to rotate in the direction in which the flow paths widen, respectively.

[0107] Finally, the flow path width adjustment unit 330D of the gas vent panel 300D according to the fifth embodiment of the present invention includes a flow path blocking film 331d and a position adjustment member 332d realized by an actuator, as shown in FIGS. 12a and 12b. Here, the actuator may be a hydraulic or pneumatic device including a cylinder fixed inside the gas vent panel 300d and a piston rod connected to the flow path blocking film 331d in the cylinder.

[0108] And the gas vent panel 300D of the fifth embodiment may include any of the first protruding plate 351, the second protruding plate 352, and the third protruding plate 353 inside thereof.

[0109] As shown in FIG. 12a, a flow path blocking film 331d is disposed so as to be able to block the flow path between the first protruding plate 351 and the second protruding plate 352 that are located on the same line in the Z direction. The cylinder can be fixed to a third protruding plate 353 that is disposed at a predetermined interval in the +y direction from the first and second protruding plates 352. The flow path blocking film 331d and the cylinder are connected to a piston rod that can linearly reciprocate with respect to the cylinder.

[0110] The hydraulic pressure or pneumatic pressure of the actuator acts on the flow path blocking film 331 in the -Y direction so that the flow path between the first protruding plate 351 and the second protruding plate 352 is normally closed. As shown in FIG. 12b, when gas is generated, the piston rod can move in the +Y direction in proportion to the pressure of the gas so that the flow path expands variably.

[0111] As described above, also with the configurations according to the second to fifth embodiments, when ignition occurs inside the battery module, while variably expanding and contracting the width of the flow path of the gas discharge passage P to reduce the contact between the air (oxygen) outside the battery module and the ignition source inside the battery module, the vent gas can be effectively discharged to the outside.

[0112] On the other hand, a battery pack (not shown) according to the present invention may include one or more of the above-described battery modules. The battery pack according to the present invention may further include a master for collectively controlling the charging and discharging of one or more battery modules, for example, a Battery Management System (BMS), a current sensor, a fuse, etc., and a pack case for accommodating the above-described components.

[0113] The battery pack according to the present invention may be applied to an energy storage device, or may be applied to an automobile such as an electric scooter, an electric vehicle, or a hybrid vehicle.

[0114] As described above, the present invention has been explained by way of limited embodiments and drawings. However, the present invention is not limited thereto, and it goes without saying that various modifications and variations can be made within the scope equivalent to the technical idea of the present invention and the scope of the claims by those having ordinary knowledge in the technical field to which the present invention pertains.

[0115] In this specification, directional indicators such as up, down, left, right, front, and back have been used. However, these terms are merely used for ease of explanation and it is obvious to those skilled in the art of the present invention that they may vary depending on the position of the object in question and the position of the observer.

Description of Reference Numerals

[0116] 10, 20 Battery Modules 100 Cell Assembly 110 Cell Stack 111 Pouch-Type Battery Cell 112 Electrode Lead 120 Busbar Frame 130 Busbar 200 Module Case 210 Case Body 211 Top Plate 212 Bottom Plate 213, 214 Side Plates 215 Gas Vent Hole 220 Case Cover 300, 300A, 300b, 300C, 300d, 300D Gas Vent Panels 310 Cover Plate 320 Frame Edge 321 First Frame Edge 322 Second Frame Edge 323 Third Frame Edge 330, 330a, 330b, 330c, 330D Flow Path Width Adjustment Units 331, 331a, 331b, 331B, 331c, 331d Flow Path Shutoff Films 332, 332a, 332A, 332b, 332c, 332d Position Adjustment Members 340 Discharge Port 351 First protruding plate 352 Second protruding plate 353 Third protruding plate C Closing point ESS Energy storage system O Open end P Gas discharge passage P1 Fixed passage section P2 Variable passage section PCB Printed circuit board

Claims

1. A plurality of battery cells, a module case that houses the plurality of battery cells therein and has a gas vent hole on at least one side, a gas vent panel that is coupled to the outside of the module case and includes a gas discharge passage that communicates with the gas vent hole and guides the flow of gas to the outside along a predetermined path, comprising, wherein the gas vent panel, includes a flow path width adjustment unit that variably adjusts the width of the gas discharge passage according to the pressure of the gas, the gas discharge passage includes a fixed type passage section having a constant width and a variable type passage section whose width is variably adjusted by the flow path width adjustment unit, the flow path width adjustment unit, initially is positioned at a closing point that is one point on the variable type passage section, and includes a flow path blocking film that is provided to be able to close the variable type passage section, a position adjustment member that moves the flow path blocking film away from the closing point in a direction in which the width of the flow path of the variable type passage section through which gas can pass expands in proportion to the pressure of the gas when gas is generated, comprising, the position adjustment member, one side is fixed inside the gas vent panel, the other side is coupled to the flow path blocking film, and is composed of a spring whose length is compressed in proportion to the pressure, a battery module.

2. A plurality of battery cells, a module case that houses the plurality of battery cells therein and has a gas vent hole on at least one side, a gas vent panel that is coupled to the outside of the module case and includes a gas discharge passage that communicates with the gas vent hole and guides the flow of gas to the outside along a predetermined path, comprising, wherein the gas vent panel, includes a flow path width adjustment unit that variably adjusts the width of the gas discharge passage according to the pressure of the gas, the gas discharge passage includes a fixed type passage section having a constant width and a variable type passage section whose width is variably adjusted by the flow path width adjustment unit, the flow path width adjustment unit, initially is positioned at a closing point that is one point on the variable type passage section, and includes a flow path blocking film that is provided to be able to close the variable type passage section, a position adjustment member that moves the flow path blocking film away from the closing point in a direction in which the width of the flow path of the variable type passage section through which gas can pass expands in proportion to the pressure of the gas when gas is generated, comprising, the position adjustment member, A battery module including an actuator including a cylinder fixed within the gas vent panel and a piston rod connected to the flow path blocking film in the cylinder.

3. The flow path width adjustment unit is provided to close the variable passage section, but when gas is generated, the variable passage section is opened in proportion to the pressure of the gas, and the flow path is configured to expand. The battery module according to claim 2.

4. The gas vent panel includes a cover plate disposed at a predetermined interval from one surface of the module case where the gas vent hole is located, and a frame edge portion provided along the periphery of the edge portion of the cover plate and surrounding the space between one surface of the module case and the cover plate. including The gas discharge passage is provided in an internal space surrounded by one surface of the module case, the cover plate, and the frame edge portion. The battery module according to claim 1.

5. The frame edge portion includes a first frame edge portion extending along the longitudinal direction of the module case, a second frame edge portion facing the first frame edge portion and extending along the longitudinal direction of the module case, and a third frame edge portion extending so as to intersect the first frame edge portion and having both ends connected to one end of the first frame edge portion and one end of the second frame edge portion. including The end portion of the gas vent panel facing the third frame edge portion is open so that gas can be discharged to the outside. The battery module according to claim 4.

6. The gas vent panel includes a first protruding plate shorter than the linear distance between the first frame edge portion and the second frame edge portion and protruding from the first frame edge portion toward the second frame edge portion, and a second protruding plate protruding from the second frame edge portion toward the first frame edge portion. The battery module according to claim 5.

7. There are a plurality of the first protruding plates, and the plurality of the first protruding plates are separated from each other at a predetermined interval along the longitudinal direction of the gas vent panel. There are a plurality of the second protruding plates, and the plurality of the second protruding plates are alternately arranged at a predetermined interval along the longitudinal direction of the gas vent panel with respect to the first protruding plates. The battery module according to claim 6.

8. The gas vent panel The battery module according to claim 5, further comprising a third protruding plate that does not contact the first frame edge portion and the second frame edge portion and protrudes so as to contact one surface of the module case on the surface of the cover plate.

9. The module case is provided with gas vent holes on one side surface and the other side surface along the longitudinal direction, The battery module according to claim 1, wherein there are two gas vent panels, which are provided so as to cover one side surface and the other side surface of the module case respectively.

10. The module case is provided with a gas vent hole at the upper part, The battery module according to claim 1, wherein the gas vent panel is provided so as to cover the upper part of the module case.

11. A battery pack including the battery module according to any one of claims 1 to 10.

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