Battery module and battery pack including same

Abstract

A battery module according to the present invention comprises: a cell stack consisting of stacked battery cells; a module case accommodating the cell stack and having a vent hole provided in a bottom plate at the bottom of the cell stack; and an exhaust guide unit having a needle member protruding from the exhaust hole to form a hole in the battery cell, and a needle stop member that can prevent the needle member from protruding when deformation does not occur due to heat or an external force.

Description

Technical Field

[0001] The present disclosure relates to a battery module and a battery pack including the same, and more particularly, to a battery module having excellent safety against thermal events and a battery pack including the same.

[0002] This application claims priority from Korean Patent Application No. 10-2023-0125887 filed in Korea on September 20, 2023, the disclosure of which is incorporated herein by reference. Background Art

[0003] With the development of technology and the significant increase in demand for various mobile devices, electric vehicles, energy storage systems (ESS), etc., interest in and demand for secondary batteries as energy sources are also rapidly increasing. Although nickel-cadmium batteries or nickel-metal hydride batteries are commonly used as secondary batteries, lithium secondary batteries are now widely used because they have the advantages of free charge and discharge due to almost no memory effect, very low self-discharge rate, and high energy density compared to nickel-based secondary batteries.

[0004] These lithium secondary batteries typically use lithium-based oxides and carbon materials as positive and negative electrode active materials, respectively. A lithium secondary battery comprises an electrode assembly, in which positive and negative plates coated with positive and negative electrode active materials, respectively, and with a separator therebetween, are disposed, and an outer casing (i.e., a battery case) seals and stores the electrode assembly and electrolyte.

[0005] Generally, secondary batteries may be classified into can-type secondary batteries in which an electrode assembly is accommodated in a metal can and pouch-type secondary batteries in which an electrode assembly is accommodated in a pouch of an aluminum laminate sheet, according to the shape of an outer case.

[0006] Currently, widely used lithium secondary batteries have an operating voltage of approximately 2.5V to 4.5V. Therefore, in the case of electric vehicles or power storage devices that require large capacity and high output, a battery module or battery pack is configured by connecting multiple lithium secondary batteries in series and / or parallel, and used as an energy source. In particular, to meet the output or capacity required for electric vehicles, the battery module or battery pack includes a large number of lithium secondary batteries.

[0007] Therefore, battery modules or battery packs require measures to prevent fire or reduce the spread of fire in the event of a thermal event.

[0008] For example, if a thermal event occurs in a battery module, if gas or flames are generated and heat continues to accumulate inside, the heat may spread rapidly between the battery cells (heat propagation). As a result, multiple battery cells may catch fire simultaneously, making the thermal event difficult to extinguish, and the battery module may explode, potentially further expanding the damage.

[0009] Therefore, when a thermal event occurs in a battery module, a method is needed to effectively discharge the heat energy inside the battery module so as to delay the thermal runaway propagation and fire between battery cells as much as possible. Summary of the Invention

[0010] Technical issues

[0011] The present disclosure has been designed to solve the problems of the related art, and thus the present disclosure aims to provide a battery module that can effectively release heat and pressure inside the battery module when a thermal event occurs in the battery module.

[0012] The technical problems that the present disclosure seeks to solve are not limited to the above-mentioned problems, and other problems not mentioned above will be clearly understood by those skilled in the art from the following description of the present invention.

[0013] Technical Solution

[0014] In one aspect of the present disclosure, a battery module is provided, comprising: a cell stack including stacked battery cells; a module housing configured to accommodate the cell stack and having an exhaust hole formed in a bottom plate located at a lower portion of the cell stack; and an exhaust guide unit including a needle member and a needle stop member, the needle member being configured to pop out from the exhaust hole to form a hole in the battery cell, and the needle stop member being configured to prevent the needle member from popping out when deformation due to heat or external force does not occur.

[0015] The needle stopping member may be made of a material that is heat-meltable at a predetermined temperature.

[0016] The needle stop member may have a notch line that breaks at a predetermined pressure.

[0017] The needle member may include an elastic member vertically disposed in the vent hole, a needle portion coupled to a top end of the elastic member, and an elastic body fixing portion coupled to a bottom end of the elastic member and fixed to a bottom plate of the module case.

[0018] The needle stopper member may include a blocking portion configured to block the needle portion at an upper portion of the exhaust hole; and a stopper fixing portion connected to the blocking portion and fixed to a bottom plate of the module case.

[0019] A notch line may be provided at a boundary of the blocking portion and the stopper fixing portion.

[0020] At least one of the blocking portion and the stopper fixing portion may be made of a heat-fusible resin material.

[0021] The needle part may include: a needle plate coupled to a top end of the elastic member and located at a lower portion of the blocking part; and at least one needle configured to protrude from the needle plate.

[0022] The at least one needle may be configured to penetrate the barrier.

[0023] The battery cell may be a pouch-type battery cell, the vent holes may be arranged in plurality at predetermined intervals along the width direction of the bottom plate, and the vent holes may be arranged at positions perpendicularly corresponding to the cell steps formed by heat-sealing the bag sheets in the pouch-type battery cell.

[0024] An exhaust guide unit may be provided in each of the exhaust holes, and the exhaust holes and the exhaust guide unit may be provided at the front and rear sides of the bottom plate of the module case.

[0025] The module housing may include: a top plate configured to cover an upper portion of the battery cell stack; a bottom plate configured to cover a lower portion of the battery cell stack; a pair of side plates configured to respectively cover both sides of the battery cell stack; and a pair of end covers configured to respectively cover the front and rear sides of the battery cell stack.

[0026] The battery module may also include: a bus bar electrically connected to the electrode leads provided to the battery cells; and a bus bar frame configured to support the bus bar and having lead grooves through which the electrode leads pass, the bus bar frame being mounted to the front or rear of the battery cell stack, and the bus bar may include a first bus bar and a second bus bar arranged to overlap each other with the electrode leads inserted therebetween, and the electrode leads may be compressively fixed between the first bus bar and the second bus bar.

[0027] The battery cells may be pouch-type battery cells that are stacked in one direction with their wider surfaces standing upright, and the cell stack may include a plurality of partitions inserted between the battery cells at predetermined intervals along the one direction to limit the movement of heat or gas between the battery cells, and each of the plurality of partitions may have an end that fits into a busbar frame to separate the battery cells and the exhaust holes into a predetermined number.

[0028] According to one aspect of the present disclosure, a battery pack including the battery module may be provided.

[0029] Beneficial effects

[0030] According to one aspect of the present disclosure, a battery module capable of effectively releasing heat and pressure inside the battery module when a thermal event occurs in the battery module may be provided.

[0031] In particular, the exhaust guide unit of the present disclosure can form holes in triggered battery cells showing signs of thermal anomalies, allowing high-temperature gases, particles, and the like from the triggered battery cells to be discharged to the outside of the module housing at an early stage under low pressure. This can reduce thermal damage to adjacent battery cells.

[0032] Furthermore, the present disclosure may have various other effects, and these effects will be described in each embodiment, or description of effects that can be easily inferred by those skilled in the art will be omitted. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a perspective view schematically illustrating a battery module according to an embodiment of the present disclosure.

[0034] Figure 2 yes Figure 1 Exploded perspective view of the battery module.

[0035] Figure 3 It shows Figure 2 A three-dimensional diagram of a battery cell stack.

[0036] Figure 4 is a perspective view illustrating a portion of a module case according to an embodiment of the present disclosure.

[0037] Figure 5 yes Figure 4 A partial enlarged view of .

[0038] Figure 6 is a perspective view illustrating an exhaust guide unit according to an embodiment of the present disclosure.

[0039] Figure 7 is a diagram illustrating an example in which an exhaust guide unit is applied to an exhaust hole in a battery module according to an embodiment of the present disclosure.

[0040] Figure 8 is a schematic cross-sectional view illustrating a battery module according to an embodiment of the present disclosure.

[0041] Figure 9 It shows Figure 8 Magnified view of area A.

[0042] Figure 10 corresponds to Figure 9 Also shown is an example in which the needle pops out of the vent hole when the needle stopper member breaks.

[0043] Figure 11 FIG. 1 is a diagram illustrating an example of assembling a cell stack and a bus bar frame according to an embodiment of the present disclosure.

[0044] Figure 12 It shows Figure 11 FIG. 1 is a diagram of a frame cover and a busbar frame to which a compression busbar is coupled.

[0045] Figure 13 is a schematic cross-sectional view showing that a cell stack and a bus bar frame are assembled with each other according to an embodiment of the present disclosure.

[0046] Figure 14 is a diagram schematically showing a vehicle including a battery pack according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0047] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. It should be understood that the terms used in the specification and the appended claims should not be interpreted as limited to general meanings and dictionary meanings, but should be interpreted based on the meanings and concepts corresponding to the technical aspects of the present disclosure, based on the principle of allowing the inventor to appropriately define the terms for the best description. Therefore, the configurations proposed in the embodiments of this specification and the drawings only indicate the most preferred embodiments of the present disclosure and do not represent all technical concepts of the present disclosure. Therefore, it should be understood that various equivalents and modifications may be made thereto when filing an application.

[0048] For the sake of convenience and clarity of explanation, the dimensions of various elements or specific parts of each element shown in the drawings are exaggerated, omitted, or simplified. Therefore, the dimensions of various elements do not fully reflect their actual dimensions. Descriptions of related known functions or configurations that may obscure the subject matter of this disclosure will be omitted.

[0049] Figure 1 is a perspective view schematically showing a battery module according to an embodiment of the present disclosure, Figure 2 yes Figure 1 Exploded perspective view of the battery module. Figure 3 It shows Figure 2 A three-dimensional diagram of the battery cell stack, and Figure 4 is a perspective view illustrating a portion of a module case according to an embodiment of the present disclosure.

[0050] Reference Figures 1 to 4 , a battery module 10 according to an embodiment of the present disclosure includes a cell stack 100 having stacked battery cells 110, a module housing 200 configured to accommodate the cell stack 100 and having exhaust holes 201 formed in a bottom plate 220, and an exhaust guide unit 300 disposed in the exhaust holes 201.

[0051] like Figure 2 and Figure 3As shown, a battery cell stack 100 is prepared by stacking a plurality of battery cells 110 horizontally in an upright position. The battery cells 110 according to this embodiment are pouch-type battery cells 110. The pouch-type battery cells 110 can be stacked in one direction with their wider surfaces upright. The pouch-type battery cells 110 include electrode leads 111, an electrode assembly, an electrolyte, and a pouch-shaped case for sealing the electrode assembly and the electrolyte.

[0052] The pouch-type shell may include two pouch sheets, at least one of which may have a recess formed therein. The electrode assembly and the electrolyte are contained inside the recess, and the edges of the two pouch sheets are heat-fused. In the pouch-type battery cell 110, the portion where the pouch sheet is heat-fused for sealing is called a sealing portion. One end of the electrode lead 111 is connected to the electrode assembly inside the pouch-shaped shell and the other end protrudes to the outside of the pouch-shaped shell, and when the pouch sheet is heat-fused, the portion between the one end and the other end is fixed to the sealing portion. The portion of the electrode lead 111 exposed to the outside of the pouch-shaped shell can be used as an electrode terminal of the pouch-type battery cell 110.

[0053] For reference, a pouch-type battery cell 110 that encapsulates an electrode assembly with two pouch sheets has four seals. Here, the four seals refer to the front and rear seals from which the electrode leads 111 protrude, as well as two side seals extending in the longitudinal direction of the electrode assembly. Meanwhile, a pouch-type battery cell 110 that encapsulates an electrode assembly by folding a single pouch sheet has three seals. Here, the three seals refer to one side seal and the front and rear seals from which the electrode leads 111 protrude. In particular, in the pouch-type battery cell 110, the front and rear seals are referred to as cell terraces 112.

[0054] Meanwhile, the battery cell stack 100 according to the present embodiment further includes battery cells 110 and separators 120 for separating the battery cells 110. For convenience of explanation, the separators 120 will be described later.

[0055] like Figure 1 and 2 As shown, the module housing 200 may include a housing body and a pair of end caps 250 , 260 .

[0056] The case body may include a top plate 210 covering an upper portion of the battery cell stack 100 , a bottom plate 220 covering a lower portion of the battery cell stack 100 , and a pair of side plates 230 , 240 respectively covering both sides of the battery cell stack 100 .

[0057] The bottom plate 220 and the pair of side plates 230, 240 can be integrally formed. The integral bottom plate 220 and the pair of side plates 230, 240 are also referred to as a U-shaped frame. The U-shaped frame and the top plate 210 can be connected by bolting, welding, bonding, or other methods. Furthermore, unlike the present embodiment, the top plate 210, the bottom plate 220, and the pair of side plates 230, 240 can be integrally formed into a rectangular tubular shape. End caps 250, 260 can be coupled to the open front and rear sides of the housing body.

[0058] Reference Figure 1 and Figure 2 In this embodiment, the top plate 210 may have a terminal through-hole through which the terminal busbars of the battery module 10 can be drawn upward. The terminal busbars include a positive terminal busbar 410a and a negative terminal busbar 410b. However, unlike this embodiment, the terminal busbars may be designed to face forward by penetrating, for example, the end cap 250.

[0059] Thermal resin (TR) may be applied to the base plate 220. The thermal resin (TR) promotes heat exchange between the battery cells 110 and the base plate 220 and enhances the fixation of the battery cells 110 to the base plate 220. The battery cells 110 are stacked along the width of the base plate 220 with their wider surfaces upright. In this case, the lower edge surfaces of all battery cells 110 may contact the thermal resin (TR). Therefore, heat from each battery cell 110 is transferred to the base plate 220 via the thermal resin (TR), allowing the heat of the battery cells 110 to be effectively dissipated to the outside during charging and discharging.

[0060] Refer again Figure 2 or Figure 4 The bottom plate 220 has vent holes 201. Vent holes 201 prevent a pressure difference between the inside and outside of the module housing 200 under normal circumstances and prevent excessive heat accumulation within the battery module 10 by discharging high-temperature gases emitted from the battery cells 110 during a thermal event. Furthermore, since gases can be discharged to the outside through vent holes 201, the battery module 10 can be prevented from collapsing or exploding due to a rapid increase in internal pressure.

[0061] The vent holes 201 may be provided in a lower region of the cell terrace 112 of the battery cell 110 .

[0062] Specifically, if Figure 2As shown, the exhaust holes 201 according to the present embodiment can be arranged in a plurality at predetermined intervals along the width direction of the bottom plate 220. When the battery cell stack 100 is accommodated in the module housing 200, the exhaust holes 201 can be arranged at positions perpendicular to the cell steps 112 of the pouch-type battery cells 110. The pouch-type battery cells 110 of the present embodiment have two cell steps 112 at the front and rear sides. Corresponding to the structure of the pouch-type battery cells 110, the exhaust holes 201 according to the present embodiment can be respectively arranged at the front and rear sides of the bottom plate 220 of the module housing 200.

[0063] That is, a plurality of vent holes 201 may be provided in the bottom plate 220 to correspond to the number and position of the cell terraces 112 of the pouch-type battery cells 110. The number of vent holes 201 is plural, and the vent holes 201 may be provided at regular intervals in the width direction (X direction) at positions near both ends along the longitudinal direction (Y direction) of the bottom plate 220.

[0064] In addition, if Figure 2 As shown, the thermal resin may be configured to be distributed only to positions adjacent to the exhaust holes 201 on the bottom plate 220 so that the exhaust holes 201 are not blocked.

[0065] Preferably, the vent holes 201 may be provided at positions vertically corresponding to the cell terraces 112 in the pouch-type battery cells 110 .

[0066] Secondary batteries may generate gas due to side reactions during charge and discharge. In particular, if a large amount of gas is generated during excessive charge and discharge, the internal pressure increases significantly, leading to a swelling phenomenon. If this situation worsens, the bonding strength of the heat-fused seal may decrease, causing the corresponding portion to rupture and gas to escape. At this time, in the sealed portion of the pouch-type battery cell 110, the cell terrace 112 has the electrode lead 111 inserted therein, so compared with other parts, the cell terrace 112 generates relatively more heat and has a lower bonding strength. Therefore, when the internal pressure increases, the cell terrace 112 of the pouch-type battery cell 110 is most likely to be damaged.

[0067] Therefore, in the battery module 10 according to an embodiment of the present disclosure, the exhaust holes 201 are formed at two edge areas of the bottom plate 220 corresponding vertically to the battery cell ladder 112, so that the gas emitted when the battery cell ladder 112 is damaged can be immediately discharged to the outside of the battery module 10.

[0068] According to the above configuration, for example, when high-temperature gas or the like is ejected from a triggering battery cell 110 that has experienced a thermal event among the battery cells 110, the high-temperature gas or the like is easily discharged downwardly from the module housing 200 through the exhaust holes 201. In this case, significant damage to the other battery cells 110 adjacent to the triggering battery cell 110 due to heat can be prevented. Furthermore, a large amount of gas can be quickly discharged to the outside of the battery module 10, thereby preventing a rapid increase in the internal pressure of the battery module 10.

[0069] Meanwhile, the battery module 10 according to an embodiment of the present disclosure may include an exhaust guide unit 300 having a needle member 310 and a needle stop member 320, the needle member 310 being configured to pop out from the exhaust hole 201 to form a hole in the battery cell 110, and the needle stop member 320 being configured to prevent the needle member 310 from popping out without deformation due to heat or external force.

[0070] like Figure 2 and Figure 4 As shown, an exhaust guide unit 300 may be provided for each exhaust hole 201. In addition, the exhaust holes 201 and the exhaust guide units 300 may be provided at the front and rear sides of the bottom plate 220 of the module case 200.

[0071] As described in detail below, in the battery module 10 according to the present disclosure, since the exhaust guide unit 300 is installed in the exhaust hole 201, when a thermal event occurs, a hole is formed in the cell terrace 112 of the battery cell 110, and heat energy can be released earlier from the interior of the battery cell 110 through the hole.

[0072] Main reference Figures 4 to 7 , main components of the exhaust guide unit 300 will be described. The exhaust guide unit 300 includes a needle member 310 and a needle stopping member 320.

[0073] First, the needle member 310 is a component that causes cracks or forms holes in the pouch-shaped casing of the battery cell 110 that overheats during charge and discharge, thereby inducing the discharge of gas and the like inside the battery cell 110. In particular, the battery module 10 of the present disclosure is configured so that when a thermal event occurs, the needle member 310 damages a specific portion of the battery cell 110 to allow high-temperature gas and the like inside the battery cell 110 to be discharged in a specific direction.

[0074] For example, the battery module 10 of the present disclosure may be configured such that, when a thermal event occurs, the needle member 310 may be ejected from the vent hole 201, puncturing or otherwise damaging the cell terrace 112 of the battery cell 110. With this configuration, for example, if the needle member 310 is ejected from the lower portion of the cell terrace 112 while gas is trapped within the cell terrace 112, a hole is formed in the cell terrace 112, allowing gas to escape from the interior of the battery cell 110 and be directionally discharged toward the lower portion of the bottom plate 220 through the vent hole 201. Furthermore, even if the needle member 310 is ejected while the cell terrace 112 is not expanded, if the cell terrace 112 subsequently expands, the cell terrace 112 may be torn or cracks may become larger due to the needle member 310, allowing gas to be strongly discharged to the outside of the cell terrace 112.

[0075] Specifically, the needle member 310 may include an elastic member 311 vertically arranged in the exhaust hole 201, a needle portion 312 connected to the top end of the elastic member 311, and an elastomer fixing portion 313 connected to the bottom end of the elastic member 311 and fixed to the bottom plate 220 of the module housing 200.

[0076] In the present embodiment, a compression spring is used as the elastic member 311. However, as an alternative to the compression spring, any compressible and stretchable structure (eg, elastic rubber or a bellows) may be used as the elastic member 311.

[0077] The needle part 312 may include a needle plate 312 a coupled to a top end of the elastic member 311 and at least one needle 312 b protruding from the needle plate 312 a .

[0078] The needle plate 312a is preferably made of a material having excellent heat resistance and may be provided in a plate shape.The needle plate 312a and the compression spring may be coupled by, for example, welding or bonding.

[0079] Needle 312b has a pointed end. For example, needle 312b may have a tapered, rod-shaped, or pin-shaped shape, as long as it has a pointed end capable of forming a hole in the bag-shaped housing. Needle 312b may be integrally formed with needle plate 312a, or may be provided in a structure that can be attached to and detached from needle plate 312a.

[0080] One or more needles 312b may be provided. For example, when multiple needles 312b are provided as in the present embodiment, multiple holes may be formed in the cell terraces 112. Furthermore, when the battery stack 100 includes multiple battery cells 110 stacked horizontally as in the present embodiment, the cell terraces 112 of adjacent battery cells 110 may expand simultaneously due to heat transfer. In this case, when the cell terraces 112 of adjacent battery cells 110 are located above the multiple needles 312b, holes may be formed in all of the cell terraces 112.

[0081] The elastic body fixing portion 313 is preferably made of a material having excellent heat resistance and can be provided in a plate shape. For example, the elastic body fixing portion 313 and the compression spring can be coupled by welding or bonding.

[0082] The elastic body fixing portion 313 according to the present embodiment may be attached to the lower surface of the bottom plate 220. For example, Figure 7 As shown, the elastic body fixing portion 313 may be located at the lower portion of the exhaust hole 201 and may have both ends welded or adhesively coupled to the bottom plate 220 of the module housing 200. In this case, the compression spring may be configured to be vertically arranged inside the exhaust hole 201 at the center of the elastic body fixing portion 313. At the same time, unlike this embodiment, the elastic body fixing portion 313 may be formed integrally with the bottom plate 220 of the module housing 200.

[0083] The compression spring may be positioned within the vent hole 201 by the elastomeric fixing portion 313 and may be compressed by the needle stop member 320 .

[0084] Reference Figure 5 and Figure 6 The needle stopping member 320 may include a blocking portion 321 that blocks the needle portion 312 at an upper portion of the exhaust hole 201 and a stopper fixing portion 323 connected to the blocking portion 321 and fixed to the bottom plate 220 of the module housing 200 .

[0085] At least one end of the stopper fixing portion 323 may be fixedly coupled to the upper surface of the bottom plate 220 of the module housing 200. For example, in this embodiment, the stopper fixing portion 323 may be provided in a form extending from one side and the other side of the blocking portion 321 and may be attached to the upper surface of the module housing 200. The stopper fixing portion 323 may be fixed to the bottom plate 220 of the module housing 200 using various methods such as welding, bonding, and hooking.

[0086] Blocking portion 321 may be arranged vertically above needle plate 312a. For example, blocking portion 321 may be arranged facing needle plate 312a to prevent needle plate 312a from being ejected by the compressed spring. At this time, at least one needle 312b may be configured to penetrate blocking portion 321. Although not shown in detail in the drawings, blocking portion 321 may have a hole through which needle 312b can be inserted.

[0087] Furthermore, the blocking portion 321 is integrally formed with the stopper fixing portion 323 fixed to the upper surface of the bottom plate 220 of the module housing 200. Therefore, even if the blocking portion 321 receives an external force through the compression spring, a reaction force is generated in the blocking portion 321 so that the needle plate 312a does not pop out.

[0088] The needle stopping member 320 including the blocking portion 321 and the stopper fixing portion 323 as described above may be made of a material that is heat-meltable at a predetermined temperature. In addition, the needle stopping member 320 may have a notch line 322 to be broken by a predetermined pressure.

[0089] With this configuration, the needle portion 312 may not eject from the vent 201 because it is normally blocked by the needle stop member 320. However, if the needle stop member 320 is damaged by external pressure or melted by heat, detaching from the bottom plate 220 of the module housing 200 or partially melting and disappearing, the needle portion 312 may eject from the vent 201. In this case, the needle portion 312 may form a crack or hole in the pouch-shaped housing of the battery cell 110. Gas or heat energy within the battery cell 110 can then be quickly discharged to the outside through the vent 201. In other words, high-temperature gas or high-temperature particles generated in the battery cell 110 that has experienced a thermal event are allowed to escape from the module housing 200 to the outside through the vent 201 via the shortest path, thereby minimizing heat accumulation within the module housing 200 and the propagation of thermal runaway between the battery cells 110.

[0090] At least one of the blocking portion 321 and the stopper fixing portion 323 constituting the needle stopper member 320 may be made of a heat-meltable resin material, while the other may be made of a metal material having excellent heat resistance. For example, the blocking portion 321 may be made of foamed polystyrene, rubber, or a plastic material, and the stopper fixing portion 323 may be made of a metal material such as aluminum, copper, or steel.

[0091] If the needle stopper member 320 is configured in this manner, heat generated from the battery cell 110 can be absorbed into the stopper fixing portion 323 through the heat pad and / or the bottom plate 220 of the module housing 200, and the heat absorbed into the stopper fixing portion 323 can be transferred to the blocking portion 321. As a result, the blocking portion 321 melts and detaches from the stopper fixing portion 323, at which time the needle portion 312 can be ejected from the vent hole 201 due to the elastic force of the compression spring.

[0092] The needle stop member 320 can be configured so that the boundary between the blocking portion 321 and the stopper fixing portion 323 can be broken when a force of a certain strength or greater is applied in combination with heat. To this end, the needle stop member 320 according to this embodiment has a notch line 322 at the boundary between the blocking portion 321 and the stopper fixing portion 323. The notch line 322 can be provided in the form of a groove recessed from the surface of the needle stop member 320 to a predetermined depth and extending intermittently or continuously along the width direction. The notch line 322 of the needle stop member 320 can be broken by an increase in the internal pressure of the module housing 200 or by wind pressure from gas escaping through the exhaust hole 201, thereby separating the blocking portion 321 from the stopper fixing portion 323. In other words, the needle stop member 320 can be separated from the blocking portion 321 by pressure rather than heat.

[0093] Figure 8 is a schematic cross-sectional view showing a battery module 10 according to an embodiment of the present disclosure, Figure 9 It shows Figure 8 A magnified view of region A, and Figure 10 corresponds to Figure 9 Also, an example is shown in which the needle portion 312 pops out from the exhaust hole 201 when the needle stopping member 320 is damaged.

[0094] In the following, reference is made to Figures 8 to 10 An operation example of the exhaust guide unit 300 according to an embodiment of the present disclosure is briefly described.

[0095] like Figure 8 As shown, in the battery module 10 according to the embodiment of the present disclosure, exhaust holes 201 are formed at the front and rear sides of the bottom plate 220 of the module housing 200. Here, the front and rear sides of the bottom plate 220 of the module housing 200 refer to positions corresponding to the lower portion of the front cell terrace 112 of the battery cell 110 and the lower portion of the rear cell terrace 112 of the battery cell 110.

[0096] In addition, if Figure 9As shown, battery module 10 includes exhaust guide unit 300 installed in exhaust hole 201. As described above, when needle stopper 320 is not deformed by heat or external force, needle member 310 is blocked by needle stopper 320 and does not eject from exhaust hole 201. In other words, when there is no thermal event within battery module 10, needle portion 312 does not eject from exhaust hole 201, thereby preventing damage to battery cell 110.

[0097] However, if the temperature of the battery cell 110 increases rapidly due to, for example, a short circuit problem of the battery cell 110, thermal deformation may occur in the needle stopper member 320. At this time, the path for heat to be transferred from the battery cell 110 to the needle stopper member 320 may be various. For example, Figure 9 As shown at "H1" in FIG. 1 , heat may be transferred from the battery cell 110 to the stopper fixing portion 323 through the thermal resin TR or the bottom plate 220 of the module case 200. Furthermore, if gas is generated inside the battery cell 110, causing the cell step 112 to expand, and if the blocking portion 321 of the needle stopper member 320 receives heat and pressure from the expanded cell step 112 as shown at "H2", the blocking portion 321 may melt or the notch line 322 may be severed.

[0098] In this way, when deformation occurs in the needle stop member 320 due to heat or external force, as shown in FIG. Figure 10 As shown, the elastic force of the compression spring 311 becomes greater than the reaction force of the blocking portion 321, so that the compression spring 311 pushes the needle portion 312 upward to above the exhaust hole 201. As a result, a hole or crack can be generated in the battery cell ladder 112 by the needle 312b that pops up above the exhaust hole 201. As a result, high-temperature gas, particles, etc. in the battery cell 110 can be effectively and directionally discharged to the outside through the exhaust hole 201 of the module housing 200 at an early stage. Therefore, the exhaust guide unit 300 of the present disclosure can prevent the accumulation of heat and pressure inside the battery module 10, thereby significantly delaying the thermal runaway of the battery module 10.

[0099] Figure 11 1 is a diagram showing an example of assembling the battery cell stack 100 and the busbar frame 400 according to an embodiment of the present disclosure. Figure 12 It shows Figure 11 FIG. 5 shows a frame cover 500 and a bus bar frame 400 to which a compression bus bar is coupled, and Figure 13 is a schematic cross-sectional view showing that the battery cell stack 100 and the bus bar frame 400 are assembled with each other according to an embodiment of the present disclosure.

[0100] Reference Figure 2 and Figures 11 to 13The battery module 10 according to the embodiment of the disclosure can further include a plurality of bus bars 410 and 600 electrically connected to the electrode lead 111 provided in the battery cell 110, a bus bar frame 400, a frame cover 500, and a tight contact cover 700.

[0101] The bus bars 410 and 600 can be made of a metal having electrical conductivity such as copper or aluminum, and are provided in the form of a bar.

[0102] The bus bar frame 400 can be provided in a plate shape to support the bus bars 410 and 600, and can cover the front and rear of the cell stack 100, respectively. Here, the bus bar frame 400 can be made of an electrically insulating material such as plastic. In addition, the bus bar frame 400 can have a lead slot 420 through which the electrode lead 111 can pass. The electrode lead 111 of the battery cell 110 can pass through the lead slot 420 and be attached to the bus bar in a predetermined pattern.

[0103] In particular, the battery module 10 of the present embodiment is configured so that the electrode lead 111 can be fixed to the bus bar by being compressed onto the bus bar rather than being welded. Accordingly, the assembly time of the battery module 10 can be shortened, and the assembly process can be more easily performed.

[0104] In detail, the bus bar according to the embodiment of the disclosure includes a first bus bar 410 and a second bus bar 600. Referring to Figure 11 and Figure 12 , the first bus bar 410 and the second bus bar 600 can be overlapped, and the electrode lead 111 is interposed therebetween. In addition, the electrode lead 111 can be fixed between the first bus bar 410 and the second bus bar 600 in a compressed state. At this time, by fastening the first bus bar 410 and the second bus bar 600 using a fastening member 800 such as a bolt, the electrode lead 111 can be stably maintained in a compressed state between the first bus bar 410 and the second bus bar 600.

[0105] As shown in Figure 12 , the frame cover 500 is provided in the form of a pad made of a material having low thermal conductivity and excellent heat resistance (for example, silicone, aerogel, or mica), and can be coupled to face the bus bar frame 400. The frame cover 500 can include a plurality of cover plates 510. The cover plates 510 can be provided to correspond to the partition surfaces of the bus bar frame 400 partitioned by the partitions 430 protruding from the bus bar frame 400 and the ends 121 of the partition plates 120, which will be explained later, respectively. Here, the partitions 430 and the ends 121 of the partition plates 120 can function to prevent short circuiting between the electrode leads 111.

[0106] When the frame cover 500 is attached to the busbar frame 400, the lead grooves 420 of the busbar frame 400 can be covered. In this configuration, when a thermal event occurs, high temperature gas or flames do not leak out to the front or rear side of the cell stack 100 through the lead grooves 420.

[0107] The electrode lead 111 may be bent according to a predetermined pattern and arranged at the front surface of the corresponding first bus bar 410, and then the frame cover 500 may be attached to the bus bar frame 400. Here, the frame cover 500 has a bus bar insertion hole H. The second bus bar 600 may be configured to be coupled to the first bus bar 410 through the bus bar insertion hole H, with the electrode lead 111 interposed between the second bus bar 600 and the first bus bar 410.

[0108] The close contact cover 700 is a component for bringing the frame cover 500 into close contact with the bus bar frame 400 and also for bringing the second bus bar 600 into close contact toward the electrode lead 111 and the first bus bar 410 .

[0109] like Figure 12 As shown, the close contact cover 700 may include a plurality of close contact plates 710. The close contact plates 710 are provided in a number corresponding to the number of bus bars, and the close contact plates 710 may be coupled to each other by each corresponding bus bar and the fastening member 800. In addition, the close contact plate 710 may be attached between the end 121 of the partition 120 passing through the bus bar frame 400 and the partition 430 protruding from the bus bar frame 400. The close contact plate 710 may be made of a material having high mechanical rigidity and flame retardant properties. For example, the close contact plate 710 may be made of an insulating rigid material having a high melting point (e.g., SUS) or a rigid material having fire resistance and insulating properties.

[0110] As described above, the battery cell stack 100 according to an embodiment of the present disclosure may include a plurality of separators 120 interposed between the battery cells 110 at predetermined intervals in one direction to restrict movement of heat or gas between the battery cells 110 .

[0111] like Figure 12 and Figure 13 As shown, an end 121 of each of the plurality of separators 120 may be fitted into the bus bar frame 400 , thereby partitioning the battery cells 110 and the vent holes 201 into a predetermined number.

[0112] The spacer 120 may be provided in the form of a compressible pad made of a material having excellent heat resistance and / or fire resistance (eg, silicone, aerogel, mica, etc.).

[0113] like Figure 13As shown, the separator 120 can perform a heat insulation function, which prevents heat (e.g., flames) generated from the burning battery cells 110 from spreading along the stacking direction of the battery cells 110. Therefore, the heat propagation to adjacent battery cells 110 can be minimized. The separator 120 can not only block heat, but also block high-temperature gases, flames, exhaust, etc. generated from the battery cells 110. As a result, the barrier member can separate or isolate the battery cells 110 to prevent the spread of flames, etc. between the battery cells 110.

[0114] Meanwhile, a battery pack (not shown) according to the present disclosure may include one or more of the above-mentioned battery modules 10. The battery pack according to the present disclosure may further include a main battery management system (BMS) for integrated control of charge and discharge of at least one battery module 10, a current sensor, a fuse, and a battery pack housing for accommodating the above-mentioned components.

[0115] Reference Figure 14 The battery pack according to the present disclosure can be used as a driving energy source for an electric vehicle. That is, the battery pack can be used as an electrical energy source to provide driving force to the motor to operate the vehicle. The battery pack can be charged or discharged via an inverter according to the operation of the motor and / or internal combustion engine. The battery pack can be charged by a regenerative charging device combined with a brake. The battery pack can be electrically connected to the vehicle's motor via an inverter.

[0116] As described above, although the present disclosure has been described with reference to limited embodiments and drawings, the present disclosure is not limited thereto, and those skilled in the art to which the present disclosure pertains may make various modifications and changes within the technical concept of the present disclosure and the equivalent scope of the claims to be described.

[0117] In addition, although terms indicating directions such as up, down, left, and right are used in this specification, it is obvious to those skilled in the art that these terms are only for convenience of description and may vary depending on the position of the target object or the position of the observer.

Claims

1. A battery module, comprising: A battery cell stack comprising stacked battery cells; a module case configured to accommodate the battery cell stack and having a vent hole formed in a bottom plate located at a lower portion of the battery cell stack; as well as A vent guide unit includes a needle member configured to pop out from the vent hole to form a hole in the battery cell, and a needle stopper member configured to prevent the needle member from popping out when deformation due to heat or external force does not occur.

2. The battery module according to claim 1, in, The needle stopping member is made of a material that can be thermally melted at a predetermined temperature.

3. The battery module according to claim 1, in, The needle stop member has a notch line to rupture at a predetermined pressure.

4. The battery module according to claim 1, in, The needle member comprises: an elastic member, the elastic member being vertically disposed in the exhaust hole; a needle portion coupled to a tip end of the elastic member; and An elastic body fixing portion is coupled to a bottom end of the elastic member and fixed to the bottom plate of the module housing.

5. The battery module according to claim 4, in, The needle stop member comprises: a blocking portion configured to block the needle portion at an upper portion of the exhaust hole; and A stopper fixing portion is connected to the blocking portion and fixed to the bottom plate of the module housing.

6. The battery module according to claim 5, in, A notch line is provided at a boundary of the blocking portion and the stopper fixing portion.

7. The battery module according to claim 5, in, At least one of the blocking portion and the stopper fixing portion is made of a heat-meltable resin material.

8. The battery module according to claim 5, in, The needle portion comprises: a needle plate coupled to a top end of the elastic member and located at a lower portion of the blocking portion; and At least one needle is configured to protrude from the needle plate.

9. The battery module according to claim 8, in, The at least one needle is configured to penetrate into the barrier.

10. The battery module according to claim 1, in, The battery cell is a pouch-type battery cell, The exhaust holes are arranged in a plurality at predetermined intervals along the width direction of the bottom plate, and The exhaust hole is provided at a position vertically corresponding to a cell step formed by heat-fusion of the bag sheet in the pouch-type battery cell.

11. The battery module according to claim 10, in, The exhaust guide unit is provided in each of the exhaust holes, and The exhaust hole and the exhaust guide unit are provided at the front and rear sides of the bottom plate of the module housing.

12. The battery module according to claim 1, in, The module housing comprises: a top plate configured to cover an upper portion of the battery cell stack; The bottom plate is configured to cover a lower portion of the battery cell stack; a pair of side plates, the pair of side plates being configured to cover two sides of the battery cell stack, respectively; and A pair of end covers are configured to cover the front side and the rear side of the battery cell stack, respectively.

13. The battery module according to claim 1, further comprising: a bus bar electrically connected to electrode leads provided to the battery cell; as well as a bus bar frame configured to support the bus bar and having a lead groove through which the electrode lead passes, the bus bar frame being mounted to the front or rear of the battery cell stack, The bus bar includes a first bus bar and a second bus bar that are arranged to overlap each other with the electrode lead interposed therebetween, and the electrode lead is compressively fixed between the first bus bar and the second bus bar.

14. The battery module according to claim 13, in, The battery cells are pouch-type battery cells stacked in one direction with their wider surfaces standing upright. The battery cell stack includes a plurality of partitions interposed between the battery cells at predetermined intervals along the one direction to limit the movement of heat or gas between the battery cells, and Each of the plurality of separators has an end assembled into the bus bar frame, thereby partitioning the battery cells and the exhaust holes into a predetermined number. 15 . A battery pack comprising the battery module according to claim 1 .

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