Battery module and battery pack with reinforced safety

Abstract

A battery module according to the present invention comprises: a cell assembly having a plurality of battery cells stacked on each other; a module case in which a cell assembly is accommodated in the inner space thereof, and in which a venting hole is formed; and a cover member which includes a plurality of refractory layers each having a discharge slit, and which is coupled to the outer surface of the module case so that the venting hole and the plurality of discharge slits communicate, wherein the discharge slit of any one refractory layer can be ruptured, and the discharge slit of another neighboring refractory layer can be opened by the rupture of any one refractory layer so as to be selectively opened only in one direction from the inside to the outside of the module case.

Description

Battery modules and battery packs with enhanced safety

[0001] The present invention relates to a battery module and a battery pack, and more particularly, to a battery module and a battery pack in which discharged matter generated inside a module can be easily discharged through discharge slits having different patterns formed in each of the double refractory layers on the upper portion of the module, while preventing re-inflow into an adjacent module, thereby delaying thermal runaway. This application claims priority to Korean Patent Application No. 10-2023-0107851, filed on August 17, 2023, and all contents disclosed in the specification and drawings of that application are incorporated by reference herein.

[0002] A semi-permanent battery that converts electrical energy into chemical energy and can be repeatedly charged and discharged is called a secondary battery, distinguishing it from a primary battery that cannot be reused after a single use.

[0003] Secondary batteries include lithium-ion batteries, nickel-cadmium (Ni-Cd) batteries, lead-acid batteries, nickel-metal hydride (Ni-MH) batteries, zinc-air batteries, and alkaline manganese batteries. Of these, lead-acid batteries and lithium secondary batteries are the most widely commercialized types.

[0004] Lithium-ion secondary batteries, in particular, are actively used as batteries for electric vehicles due to their high energy storage density, lightweight and compact design, excellent safety, low discharge rate, and long lifespan. Lithium-ion secondary batteries are generally classified into cylindrical, prismatic, and pouch types depending on their manufacturing form, and their applications extend beyond electric vehicle batteries to include ESS batteries and other electrical devices.

[0005] Currently, the operating voltage of a single lithium-ion secondary battery cell is approximately 2.5 V to 4.5 V. Therefore, in order to apply a secondary battery as an energy source for an electric vehicle, a battery module is formed by connecting multiple lithium-ion battery cells in series and / or parallel, and a battery pack is formed by connecting the battery modules in series and / or parallel.

[0006] Meanwhile, since secondary batteries involve chemical reactions during charging and discharging, their performance may deteriorate if used in environments higher than the appropriate temperature, and if thermal control is not achieved at the appropriate temperature, there is always a risk of unexpected fire or explosion. Furthermore, battery modules are structured to house these secondary batteries closely within the module housing, so if any one secondary battery experiences heat runaway and becomes a trigger cell, the heat and flames will quickly spread to surrounding secondary batteries (thermal propagation), making it easier for the secondary batteries to catch fire in a chain reaction.

[0007] In particular, due to the need to accommodate as many battery modules as possible within a limited space, the internal empty space of a battery pack is insufficient. For example, in a battery pack containing one or more battery modules, the space between the module case and the pack case may be narrow.

[0008] Therefore, in addition to quickly discharging the venting gas in such a narrow space, it is necessary to delay or suppress heat propagation by preventing the discharged venting gas from re-entering other modules.

[0009] The present invention was created in consideration of the above problems, and the problem that the present invention seeks to solve is to provide a battery module in which high-temperature particles and venting gases, etc., generated in one battery module due to a thermal event can be quickly discharged from the battery module, while the discharge can be minimized from re-introducing into another adjacent battery module.

[0010] Another problem that the present invention seeks to solve is to provide a battery pack with enhanced safety by including such a battery module.

[0011] The technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention described below.

[0012] According to the present invention for solving the above problem, a battery module comprises: a cell assembly having a plurality of battery cells that are mutually stacked; a module case that houses the cell assembly in an internal space and has a venting hole formed therein; and a cover member that is coupled to an outer surface of the module case so that the venting hole and the plurality of discharge slits are in communication with each other, and wherein the discharge slit of one of the fire-resistant layers is ruptured and the discharge slit of another adjacent fire-resistant layer is opened by the rupture of one of the fire-resistant layers, so that the module case can be selectively opened in only one direction from the inside to the outside.

[0013] The plurality of fire-resistant layers may be two layers, and the fire-resistant layers may include a first fire-resistant layer portion provided with a first discharge slit formed in the width direction of the module case or formed to correspond to the shape of the venting hole; and a second fire-resistant layer portion provided with a second discharge slit formed in the length direction of the module case.

[0014] The second fire-resistant layer may be provided to overlap the first fire-resistant layer.

[0015] The above first refractory layer may be provided to cover the upper surface of the module case, or may be provided to cover the upper surface of the module case and both side surfaces in the longitudinal direction of the module case.

[0016] The second refractory layer may be provided to cover the upper surface of the module case and both side surfaces in the longitudinal direction of the module case.

[0017] The first discharge slit and the second discharge slit are arranged to overlap in the vertical direction on the venting hole, and an imaginary boundary circle connecting the ends of the first discharge slit formed in the width direction and an imaginary ellipse connecting the ends of the second discharge slit can be arranged to overlap the opening shape of the venting hole.

[0018] The first discharge slit is formed by a partially cut rupture line and is opened by the rupture line being ruptured by a gaseous discharge or a solid discharge generated in one of the module cases where a thermal event has occurred, and the second discharge slit is formed by at least one continuously cut slit portion and the slit portion can be opened by the rupture of the first discharge slit.

[0019] The second exhaust slit of one of the module cases adjacent to the other module case where the thermal event occurred is configured to block the re-inflow of the gaseous discharge or the solid discharge, and the first exhaust slit adjacent to the second exhaust slit can support the second exhaust slit to limit deformation in the thickness direction of the second exhaust slit.

[0020] The above rupture lines may be formed to extend in the width direction of the module case, but may be arranged to be spaced apart at predetermined intervals along the length direction of the module case.

[0021] The above rupture line is formed on the edge of the rupture membrane corresponding to the opening shape of the venting hole, and a bridge portion connecting the first refractory layer and the rupture membrane may be provided at regular intervals.

[0022] The above-mentioned cut portion may be a cut line formed parallel to the longitudinal direction of the module case.

[0023] The above-mentioned cut portions may be plural, and the above-mentioned cut portions may include a first cut line formed parallel to the longitudinal direction of the module case; and a second cut line formed diagonally at each end of the first cut line.

[0024] The above-mentioned cut portion includes a first cut line formed parallel to the longitudinal direction of the module case; and a second cut line formed diagonally at each end of the first cut line, and an orthogonal projection of the second cut line onto the venting hole may not overlap with an orthogonal projection of the bridge portion onto the venting hole.

[0025] The above cover member can be made of an inorganic material, a MICA material, a refractory plastic, or a combination thereof.

[0026] The first refractory layer may be made of an inorganic material or a MICA material, and the second refractory layer may be made of an inorganic material, a MICA material, or a refractory plastic.

[0027] Additionally, according to the present invention, a battery pack including one or more of the above-described battery modules can be provided.

[0028] According to one aspect of the present invention, high-temperature particles and venting gases generated from a battery module during a thermal event can be quickly discharged from the battery module through different patterns of discharge slits formed in the dual refractory layers on the upper portion of the module. This significantly reduces the risk of battery module deterioration or explosion.

[0029] Furthermore, according to one aspect of the present invention, discharged material discharged outside of a battery module can be blocked by the double refractory layer of an adjacent battery module, thereby minimizing re-inflow. As a result, thermal runaway occurring from a single trigger cell can be delayed in spreading heat to surrounding secondary batteries.

[0030] Thus, according to the present invention, a trigger module including a trigger cell smoothly discharges high-temperature particles and venting gas, thereby reducing heat accumulation within the battery module, and preventing externally discharged particles and flames from flowing into adjacent battery modules, thereby delaying heat transmission between battery modules, thereby enhancing the safety of the battery module.

[0031] In addition, the battery pack of the present invention has enhanced safety by including such a battery module.

[0032] The following drawings attached to this specification illustrate preferred embodiments of the present invention, and together with the detailed description of the invention described below, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0033] FIG. 1 is a schematic perspective view of a battery module according to one embodiment of the present invention.

[0034] Figure 2 is an exploded perspective view of the main components of the battery module of Figure 1.

[0035] FIG. 3 is a perspective view of a first refractory layer in a cover member of a battery module according to one embodiment of the present invention.

[0036] Figure 4 is a drawing showing a modified example of the first refractory layer of Figure 3.

[0037] FIG. 5 is a perspective view of a second refractory layer in a cover member of a battery module according to one embodiment of the present invention.

[0038] FIG. 6 is a top view of a battery module according to one embodiment of the present invention, with a cover member coupled to a module case.

[0039] Figure 7 is a cross-sectional view taken along line A-A' of Figure 6.

[0040] FIG. 8 is a schematic cross-sectional view of a structure of a battery pack including a battery module according to one embodiment of the present invention.

[0041] FIGS. 9 and 10 are top views of the first fire-resistant layer and the second fire-resistant layer in the cover member of the battery module according to another embodiment of the present invention.

[0042] FIG. 11 is a top view of a battery module according to another embodiment of the present invention, with a cover member coupled to a module case.

[0043] FIG. 12 is a drawing for explaining a battery pack and a vehicle according to one embodiment of the present invention.

[0044] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, it should be noted that the terms and words used in this specification and claims should not be construed as limited to their conventional or dictionary meanings. Based on the principle that the inventor can appropriately define the concepts of terms to best explain his or her invention, they should be interpreted in a way that conforms to the technical spirit of the present invention.

[0045] Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are only some of the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention, so it should be understood that there may be various equivalents and modified examples that can replace them at the time of this application.

[0046]

[0047] FIG. 1 is a schematic perspective view of a battery module according to one embodiment of the present invention, and FIG. 2 is an exploded perspective view of the main components of the battery module of FIG. 1.

[0048] Referring to FIGS. 1 and 2, a battery module (10) according to the present invention includes a cell assembly (100), a module case (200), and a cover member (300).

[0049] The above cell assembly (100) may include one or more battery cells (110). Here, each battery cell (110) may refer to a secondary battery. The battery cell (110) refers to a secondary battery including an electrode assembly, an electrolyte, and a pouch case that accommodates the electrode assembly. In the present embodiment, a pouch-type battery cell (110) having a high energy density and easy stacking is used, but it is obvious that a cylindrical or square secondary battery may be applied as a battery cell.

[0050] The above pouch-type battery cell (110) includes an electrode assembly, a case that accommodates the electrode assembly, and a pair of electrode leads that are connected to the electrode assembly and extend outward from the case to function as electrode terminals. The pair of electrode leads may extend forward and backward (±Y direction) along the longitudinal direction of the battery cell (110). Alternatively, if necessary, the electrode leads may have a form in which they are positioned only at one end in the Y-axis direction, for example, at an end in the -Y-axis direction. Although not shown, electrical components such as a busbar, a busbar frame, and a module connector may be mounted adjacent to the pair of electrode leads of the battery cell (110).

[0051] These battery cells (110) can be stacked and arranged in at least one direction. In the present embodiment, referring mainly to FIG. 2, the battery cells (110) can be stacked in a form arranged along a horizontal direction (the width direction of the battery module (10), the X-axis direction) while standing upright in the vertical direction (Z-axis direction).

[0052] The above cell assembly (100) is an assembly of battery cells (110) formed by stacking a plurality of battery cells (110). That is, as illustrated in FIG. 2, the cell assembly (100) may be an assembly of a plurality of pouch-type battery cells (110) in which the wide surfaces of the battery cells (110) are upright and stacked in one direction (X-axis direction).

[0053]

[0054] The above module case (200) may be configured to have an internal space and accommodate battery cells (110) in the internal space. The module case (200) may be preferably manufactured from a material having excellent mechanical strength as a component for protecting the cell assembly (100) from external impacts, etc. The module case (200) of the present embodiment may include a case body (210) and end plates (220) arranged on the front and rear sides of the case body (210).

[0055] The case body (210) may be configured in a square tube shape having an open end (O) with both ends in the longitudinal direction (Y-axis direction) open and a hollow structure with an empty interior. For example, the case body (210) may be configured in a tube shape having an upper surface, a lower surface, a left surface, and a right surface, and having openings formed at the front and rear ends, respectively.

[0056] In addition, the module case (200) may be formed in various other shapes. For example, the case body (210) may be configured in a form in which the left plate, the right plate, and the lower plate are integrated with each other. In this case, the integrated case portion may be referred to as a U-frame. The U-frame may be configured in a tubular shape by welding a top plate to the upper surface. Alternatively, the module case (200) may be provided with a box-shaped lower case in which the left plate, the right plate, the front plate, and the rear plate are integrated, and an upper cover that closes the upper open end of the lower case.

[0057] The case body (210) may be configured to allow the cell assembly (100) to be inserted therein along the longitudinal direction. That is, the case body (210) may be configured to allow multi-layered battery cells (110) to be inserted therein in a sliding or force-fit manner. For force-fitting, there may be almost no gap between the upper and lower surfaces of the case body (210) and the upper and lower portions of the battery cells (110), and there may also be almost no gap between both side surfaces of the case body (210) and both side portions of the battery cells (110). The case body (210) may be configured to be made of a metal material having rigidity and heat resistance in order to physically or chemically protect the battery cells (110) contained therein.

[0058] The end plate (220) is arranged at both ends in the longitudinal direction of the cell assembly (100) where the electrode leads of the battery cells (110) are located, i.e., at the front and rear, and may be provided so as to be coupled to the open end (O) of the case body (210). The end plate (220) is provided so as to cover the bus bar frame, in which the electrode leads of the battery cells (110) are fixedly connected to the bus bar frame, and the connection portions between the electrode leads and the bus bar frame, so as not to be exposed to the outside. The end plate (220) may be configured so that the inside is made of an insulating material and the outside is made of a metal material, for example, and may be configured to be fixedly connected to the case body (210) by welding. Meanwhile, although not illustrated for the sake of convenience of the drawing, the end plate (220) may be partially provided with holes or slits to expose components that need to be exposed to the outside, such as the positive terminal and negative terminal of the battery module (10) or the connector.

[0059] The module case (200) having such a configuration may have a venting hole (H) formed on at least one side. The venting hole (H) may be configured so that, when a discharged substance such as a venting gas is generated and ejected from a cell assembly (100) housed in the internal space, the discharged substance can be discharged from the internal space of the module case (200) to the outside. For example, the module case (200) may be configured in a sealed form except for the venting hole (H). In addition, the venting hole (H) may be formed in a completely open form so as to penetrate the module case (200) in an inward and outward direction.

[0060] In the present embodiment, the venting hole (H) may be provided in a kind of long hole shape that has a predetermined width in the width direction of the module case (200) and is formed long in the length direction of the module case (200). In addition, a plurality of the venting holes (H) may be formed on the upper side of the module case (200), as indicated by H in Fig. 2. Meanwhile, the number and shape of the venting holes (H) may vary, and the arrangement position of the venting holes (H) may also be changed as needed.

[0061]

[0062] The cover member (300) may be arranged on the outer surface of the module case (200). Referring mainly to FIG. 2, the cover member (300) may be provided on the upper side of the module case (200). Accordingly, the cover member (300) may be configured to cover a venting hole (H) formed on the upper surface of the module case (200). In addition, one configuration of the cover member (300) may be provided to cover both sides in the width direction (X-axis direction) (or both sides in the length direction (Y-axis direction)) of the module case (200).

[0063] The above-described cover member (300) may include a fire-resistant layer. Here, the fire-resistant layer may be provided with a material that ensures fire resistance or heat resistance. Preferably, the fire-resistant layer may have a VO rating or higher in the UL 94 test. The fire-resistant layer may be manufactured from an inorganic material (e.g., FRB (Fire Retardant Barrier) material, etc.), a MICA material, a fire-resistant plastic, or a combination thereof. Accordingly, heat resistance against high-temperature ejected substances such as venting gas, flames, and sparks generated when a thermal event occurs is secured, so that the material can withstand high-temperature heat without melting, and can suppress heat transmission to adjacent modules. Meanwhile, the material of the fire-resistant layer may be applied without significant limitations as long as it is a material that ensures fire resistance or heat resistance in addition to the materials described above.

[0064] The cover member (300) in the present embodiment may be composed of a plurality of fire-resistant layers. Specifically, the plurality of fire-resistant layers may be composed of two layers, and the fire-resistant layers may include a first fire-resistant layer portion (310) provided with a first discharge slit (313), and a second fire-resistant layer portion (320) provided with a second discharge slit (323), as will be described in detail later.

[0065] The first refractory layer (310) and the second refractory layer (320) may be provided with a first discharge slit (313) and a second discharge slit (323), respectively. The first discharge slit (313) and the second discharge slit (323) may be provided to overlap vertically on the venting hole (H). In addition, the first discharge slit (313) and the second discharge slit (323) may be provided to be in communication with the venting hole (H). Accordingly, discharged matter generated within the module case (200) due to a thermal event may pass through the first discharge slit (313) of the first refractory layer (310) through the venting hole (H) and the second discharge slit (323) of the second refractory layer (320) to be discharged outside the battery module (10).

[0066] The first discharge slit (313) and the second discharge slit (323) are processed into different shapes.

[0067] And, the discharge slit of one of the refractory layers (in this embodiment, the first discharge slit (313) of the first refractory layer portion (310)) is configured to be ruptured, and the discharge slit of another adjacent refractory layer (in this embodiment, the second discharge slit (323) of the second refractory layer portion (320)) is configured to be opened by the rupture of one of the refractory layers (in this embodiment, the first refractory layer portion (310)), so that the module case (200) can be configured to be selectively opened only in one direction from the inside to the outside.

[0068] To explain this in more detail, the discharge generated by the thermal event is formed at high temperature and high pressure, and when the pressure is higher than a predetermined level, the first discharge slit (313) adjacent to the venting hole (H) may be ruptured and opened. In addition, the second discharge slit (323) may be opened by the rupture of the first refractory layer (310). Accordingly, the discharge inside the battery module (10) may be discharged in one direction from the inside of the module case (200) to the outside. Accordingly, the discharge, such as high-temperature particles and venting gas generated in one of the battery modules (10), may be quickly discharged outside the battery module (10). Therefore, the high-temperature particles and venting gas from the trigger cell may be smoothly discharged, thereby reducing heat accumulation inside the battery module (10). As a result, the possibility of deterioration or explosion of the battery module (10) may be reduced.

[0069] On the other hand, since the discharged discharged matter is in a state of relatively lower temperature or pressure, the reverse re-inflow of the discharged matter into the module case (200) by penetrating the cover member (300) of the adjacent other battery module (10) can be blocked. From the standpoint of particles and flames outside the other battery module (10), the second fire-resistant layer (320) is provided with a structure in which the second fire-resistant layer (320) blocks them first and the first fire-resistant layer (310) holds them second, so that particles and flames discharged from the trigger module including the trigger cell can be prevented from re-inflowing into the adjacent other battery module (10).

[0070] Accordingly, the cover member (300) in the present embodiment can be selectively opened only in one direction from the inside of the module case (200) to the outside. Accordingly, the heat propagation that causes a thermal runaway phenomenon occurring from one trigger cell or triggered battery module (10) to be serially transmitted to surrounding secondary batteries can be delayed, and the battery module (10) including such a cover member (300) is a battery module with enhanced safety.

[0071] In addition, in the case of the existing single cover member, the discharge hole was prepared through slitting processing, but there was an aspect that the slitting processability was not precise and discharge uniformity was not secured due to processing deviation and material deviation. On the other hand, in the case of the present embodiment, there is an advantage that the processing deviation and material deviation can be reduced because the double refractory layer parts (310, 320) and the discharge slits (313, 323) are applied in duplicate to each refractory layer parts (310, 320).

[0072] A battery module (10) may be housed in a pack case to form a battery pack (reference numeral 1 in FIG. 12). At this time, the pack case may include a lower case with an open upper surface in which the battery module (10) is mounted, and a pack cover (reference numeral 60 in FIG. 8) coupled to the open upper surface of the lower case. The lower case may include a plurality of partitions, so that the battery modules (10) housed in the pack case may be separated by the partitions. Since such a battery pack includes a battery module (10) with enhanced safety, the safety of the battery pack may also be enhanced.

[0073] Hereinafter, the cover member (300) will be described in detail.

[0074] FIG. 3 is a perspective view of a first fire-resistant layer in a cover member of a battery module according to one embodiment of the present invention, FIG. 4 is a drawing showing a modified example of the first fire-resistant layer of FIG. 3, FIG. 5 is a perspective view of a second fire-resistant layer in a cover member of a battery module according to one embodiment of the present invention, and FIG. 6 is a top view of a state in which a cover member is coupled to a module case in a battery module according to one embodiment of the present invention.

[0075] Referring to FIGS. 3 to 6 and the preceding FIGS. 1 and 2, the cover member (300) includes two layers of fire-resistant layers. The fire-resistant layers may include a first fire-resistant layer portion (310) in which a first discharge slit (313) is formed, and a second fire-resistant layer portion (320) in which a second discharge slit (323) is formed.

[0076] Referring again to FIG. 2, the first refractory layer (310) may be arranged directly above the module case (200). As illustrated in FIG. 3, the first refractory layer (310) may be provided in a flat type to cover the upper surface of the module case (200). The first refractory layer (310) may be arranged to be in contact with the upper surface of the module case (200) to cover the venting hole (H).

[0077] As a variation, referring mainly to FIG. 4, the first refractory layer (310) may be provided to cover the upper surface of the module case (200) and both side surfaces in the longitudinal direction of the module case (200). The first refractory layer (310) may be provided with a side plate (311). In this case, the side plate (311) covers both side surfaces of the module case (200), thereby blocking discharged substances from being discharged in the width direction of the module case (200), and efficiently blocking deterioration or heat propagation from battery modules (10) arranged adjacently in the width direction.

[0078] In addition, by integrating battery modules including the first refractory layer (310) into a pack case including a plurality of bulkheads (not shown) to form a battery pack, heat energy dissipation to the bulkheads within the pack case can be minimized, thereby improving the heat resistance and durability of the entire pack case.

[0079] The first refractory layer (310) may be provided with a first discharge slit (313) formed in the width direction of the module case (200). The first discharge slit (313) may be formed in the width direction (X-axis direction) of the module case (200) and may be provided in multiple numbers spaced apart at predetermined intervals along the length direction (Y-axis direction). In addition, the first discharge slit (313) may be arranged within the orthogonal projection area of ​​the venting hole (H) in the up-down direction (Z-axis direction).

[0080] The first discharge slit (313) may be formed with a rupture line (314). The rupture line (314) refers to a type of cut line that is provided to be partially cut, and may be provided to be cut at regular intervals. That is, the rupture line (314) may be torn and opened when a predetermined pressure is exceeded.

[0081] The first refractory layer (310) may be manufactured from a refractory material, and may also be manufactured by laminating a silicone pad to an inorganic material or MICA material. Since the first refractory layer (310) has a refractory surface, it does not melt from heat such as venting gas or flames generated from an adjacent module, and can serve to protect the battery module (10).

[0082] The second refractory layer (320) may be provided on top of the first refractory layer (310). The second refractory layer (320) may be coupled to face the upper surface of the first refractory layer (310). The second refractory layer (320), like the first refractory layer (310), may be made of a refractory material, and is preferably made of an inorganic material, a MICA material, or a refractory plastic. The second refractory layer (320) may also be made by laminating a silicone pad to an inorganic material or a MICA material. Here, the refractory plastic may be a material containing a refractory enhancing agent such as a silicate, an aluminum salt, or a titanium salt in a plastic material such as polystyrene or polyurethane.

[0083] Referring mainly to FIG. 5, the second fire-resistant layer (320) is provided to cover the upper surface of the module case (200), and side plates (321) may be provided to cover both side surfaces in the longitudinal direction (Y-axis) of the module case (200). The second fire-resistant layer (320) can protect the upper surface and side surfaces of the module case (200) from external heat. In particular, when a modified example of the first fire-resistant layer (310) is applied, the both side surfaces in the longitudinal direction of the module case (200) are formed with a double fire-resistant layer (two side plates (311, 321)), so that heat resistance can be further improved.

[0084] A second discharge slit (323) may be provided in the second refractory layer (320). The second discharge slit (323) may be formed in the longitudinal direction of the module case (200) so as to vertically intersect the first discharge slit (313) when viewed from above. The second discharge slit (323) may have at least one continuously cut portion formed. The cut portion may be a cut line (324) formed parallel to the longitudinal direction of the module case (200). In addition, the cut line (324) may be a continuously cut cutting line. The cut line (324) may be arranged within an orthogonal projection area of ​​the venting hole (H) in the vertical direction.

[0085] Referring mainly to FIG. 6, the first discharge slit (313) of the first refractory layer (310) and the second discharge slit (323) of the second refractory layer (320) may be provided to overlap vertically on the venting hole (H). Specifically, the rupture line (314) of the first discharge slit (313) may be formed in the width direction of the battery module (10), and may be formed to correspond to the opening shape of the venting hole (H). In addition, the cut line (324) of the second discharge slit (323) may be formed in the length direction of the battery module (10), and may be formed up to a point that matches the opening shape of the venting hole (H) in the length direction (Y-axis direction).

[0086] In other words, a virtual boundary circle connecting the ends of the first discharge slits (313) formed in the width direction and a virtual ellipse connecting the ends of the second discharge slits (323) may be arranged to overlap the opening shape of the venting hole (H). Accordingly, the venting hole (H), the first discharge slit (313), and the second discharge slit (323) may be connected in the vertical direction, which will be described later.

[0087]

[0088] Hereinafter, the operating mechanism of the cover member (300) will be described.

[0089] FIG. 7 is a cross-sectional view taken along line A-A' of FIG. 6, and FIG. 8 is a schematic cross-sectional view of a structure of a battery pack including a battery module according to one embodiment of the present invention.

[0090] Referring to FIGS. 6 and 7, the discharged matter generated inside the module case (200) can be discharged to the outside (for example, inside the pack outside the module) through the venting hole (H) and the first discharge slit (313) and the second discharge slit (323) which are connected in the vertical direction as needed.

[0091] Specifically, when a thermal event occurs due to ignition in a trigger cell, etc., the discharged material is discharged through the venting hole (H) of the triggered battery module (10).

[0092] At this time, due to the high temperature and high pressure of the discharged material, when a predetermined temperature and pressure are applied, the rupture line (314) of the first discharge slit (313) is partially or completely ruptured and opened.

[0093] Next, the ruptured first refractory layer (310) is directed toward the outside of the module case (200), and the second discharge slit (323), which has already been cut, is naturally opened. Here, the second discharge slit (323) is formed with a continuously cut cut line (324), so that it can be naturally opened and does not provide resistance to the discharged material.

[0094] In addition, when the first discharge slit (313) and the second discharge slit (323) are opened, they can be opened in substantially the same shape as the opening of the venting hole (H), so that discharge resistance can be minimized.

[0095] According to one aspect of the present invention, high-temperature particles and venting gases generated from the trigger module can be quickly discharged from the battery module (10). As a result, the possibility of deterioration or explosion of the battery module (10) can be significantly reduced.

[0096] Referring to FIG. 8, when an event occurs in any one of the battery modules included in the battery pack, the discharged matter from the battery cell (110) is discharged through the venting hole (H) while opening the first discharge slit (313) (see the arrow indicating the Z-axis direction on the left side of the drawing), and hits the pack cover (60) and flows back. At this time, the discharged matter may be configured to be blocked from re-introducing into the adjacent battery module (10) (see the arrow indicating that it is bounced off the second refractory layer (320) on the right side of the drawing). That is, the second discharge slit (323) of another module case (200) adjacent to any one of the module cases (200) where the thermal event has occurred may be configured to block the re-introduction of the gaseous discharged matter or solid discharged matter. This is because the discharged matter, especially the venting gas, which has already been discharged out of the battery module (10) may be in a relatively low pressure state, and the high temperature of the flame or solid discharged matter may also be in a relatively low state. These discharges are primarily blocked by the second refractory layer (320). The second discharge slit (323) can block the discharge from re-entering the module.

[0097] In addition, the first refractory layer (310) secondarily blocks the re-inflow of the discharged material. That is, the first discharge slit (313) positioned facing the lower portion of the second discharge slit (323) can support the second discharge slit (323). In particular, although there is a possibility of deformation in the thickness direction of the second discharge slit (323) due to the pressure of the discharged material, the first discharge slit (313) can firmly support it from below. With this configuration, the re-inflow of the gaseous discharged material or the solid discharged material can be blocked. At this time, the rupture line (314) of the first discharge slit (313) can be provided to withstand the pressure of the discharged material during the re-inflow process.

[0098] According to this embodiment, the discharged material discharged outside the battery module (10) can be blocked by the double refractory layer (310, 320) of the adjacent battery module (10), thereby minimizing re-inflow. As a result, the heat propagation that causes the thermal runaway phenomenon generated from one trigger cell or triggered battery module (10) to be serially transmitted to the surrounding secondary batteries can be delayed. Therefore, in a battery pack including such a battery module (10), the heat propagation between the battery modules (10) can be delayed, thereby enhancing safety.

[0099]

[0100] Next, other embodiments of the battery module (10) of the present invention will be briefly described with reference to FIGS. 9 to 11.

[0101] FIG. 9 and FIG. 10 are top views of the first fire-resistant layer and the second fire-resistant layer in the cover member of the battery module according to another embodiment of the present invention, and FIG. 11 is a top view of the cover member coupled to the module case in the battery module according to another embodiment of the present invention.

[0102] The same reference numerals as in the previous drawings indicate the same reference parts, and duplicate descriptions of the same reference parts will be omitted, and the differences from the previously described embodiment will be mainly explained.

[0103] Referring to FIGS. 9 to 11, the cover member (300) may include a first refractory layer (310a) provided with a first discharge slit (313a) formed to correspond to the shape of the venting hole (H), and a second refractory layer (320a) provided with a second discharge slit (323a) formed in the longitudinal direction of the module case (200).

[0104] Referring mainly to FIG. 9, the first discharge slit (313a) is formed with a partially cut rupture line (314a), and the rupture line (314a) is formed on the edge of the rupture film (315) corresponding to the opening shape of the venting hole (H), and a bridge portion (316) connecting the first refractory layer (310) and the rupture film (315) may be provided at regular intervals. The bridge portion (316) supports the rupture film (315).

[0105] Referring mainly to FIG. 10, the second discharge slit (323a) may include a plurality of continuously cut sections, and the cut sections may include a first cut line (324a) formed parallel to the longitudinal direction of the module case (200); and a second cut line (324b) formed in a diagonal shape at both ends of the first cut line (324a). The second cut line (324b) may be formed at the upper and lower ends of the first cut line (324a) in the Y-axis direction, respectively.

[0106] Referring mainly to FIG. 11, the orthogonal projection of the second cutting line (324b) onto the venting hole (H) may not overlap with the orthogonal projection of the bridge portion (316) onto the venting hole (H).

[0107] The first discharge slit (3113a) of the first refractory layer (310a) can discharge the discharged matter more quickly. In particular, the bridge portion (316) is ruptured by the discharged matter, and the rupture film (315) having the same size as the opening area of ​​the venting hole (H) is opened, thereby allowing the discharged matter inside to be discharged quickly.

[0108] In addition, since the second incision line (324b) is provided to be larger than the opening of the venting hole (H), the size of the second discharge slit (323a) opening to open the rupture membrane (315) to the outside can be larger, thereby improving discharge efficiency.

[0109] In addition, the projection of the second cut line (324b) onto the vent hole (H) may be made so as not to overlap with the projection of the bridge portion (316) onto the vent hole (H), so that the bridge portion (316) may be positioned at a position that is misaligned with the second cut line (324b). Accordingly, the bridge portion (316) may be supported below the weak second cut line (324b) that may be naturally cut open, thereby ensuring the robustness of the cover member (300) of the corresponding portion, thereby more reliably preventing the re-inflow of discharged matter from the outside.

[0110] According to the present embodiment, high-temperature particles and venting gases, etc., generated from one battery module (10) due to a thermal event can be quickly discharged out of the battery module (10) through different patterns of discharge slits formed in the double refractory layers on the upper portion of the module. As a result, the possibility of deterioration or explosion of the battery module (10) can be significantly reduced.

[0111] In addition, the discharged material discharged outside the battery module (10) can be blocked by the double refractory layer (310a, 320a) of the adjacent battery module (10) to minimize re-inflow. As a result, the heat propagation that causes a thermal runaway phenomenon occurring from one trigger cell or triggered battery module (10) to be serially transmitted to surrounding secondary batteries can be delayed.

[0112]

[0113] FIG. 12 is a drawing for explaining a battery pack and a vehicle including the same according to one embodiment of the present invention.

[0114] The battery pack (1) according to the present invention may include one or more battery modules (10) according to the present invention described above. In particular, in order to increase capacity and / or output, the battery pack (1) according to the present invention may include multiple battery modules (10) according to the present invention. At this time, various configurations described above may be applied to each battery module (10). For example, each battery module (10) may include a cell assembly (100), a module case (200), and a cover member (300). In addition, these multiple battery modules (10) may be accommodated inside the pack case as described above. Furthermore, in the case of the battery module (10) according to one embodiment of the present invention, even if another battery module (10) is positioned on the front or rear side, thermal runaway propagation between modules can be effectively prevented.

[0115] The battery pack (1) according to the present invention may further include, in addition to the battery module (10) or the pack case, various other components, such as a BMS (Battery Management System), a bus bar, a relay, a current sensor, a fuse, and other components of a battery pack known at the time of filing of the present invention, in the internal space of the pack case, etc.

[0116] The battery module (10) according to the present invention or the battery pack (1) according to the present invention can be applied to a vehicle (V) such as an electric vehicle or a hybrid vehicle. That is, the vehicle (V) according to the present invention can include the battery module (10) according to the present invention or the battery pack (1) according to the present invention. In addition, the vehicle (V) according to the present invention can further include various other components included in the vehicle (V) in addition to the battery module (10) or the battery pack (1). For example, the vehicle (V) according to the present invention can further include a body, a motor, a control device such as an ECU (electronic control unit), etc. in addition to the battery module (10) according to the present invention.

[0117] In addition, the battery module (10) according to the present invention or the battery pack (1) according to the present invention can be applied to an energy storage system (ESS). That is, the energy storage system according to the present invention can include the battery module (10) according to the present invention or the battery pack (1) according to the present invention.

[0118] As described above, although the present invention has been described by limited embodiments and drawings, the present invention is not limited thereto, and various modifications and variations are possible by a person having ordinary skill in the art to which the present invention pertains within the scope of the technical idea of ​​the present invention and the equivalent scope of the patent claims to be described below.

[0119] Meanwhile, when terms indicating directions such as up, down, left, right, front, and back are used in this specification, it is obvious to those skilled in the art that these terms are only for the convenience of explanation and may vary depending on the position of the target object or the position of the observer.

[0120] [Explanation of symbols]

[0121] 1: Battery Pack V: Car

[0122] 10: Battery module 100: Cell assembly

[0123] 110: Battery cell 200: Module case

[0124] 210: Case body H: Venting hole

[0125] 220: End plate 300: Cover member

[0126] 310,310a: First refractory layer 313, 313a: First discharge slit

[0127] 314, 314a: Rupture line 315: Rupture membrane

[0128] 316: Bridge section 320,320a: Second fireproof layer section

[0129] 311, 321: Side plate 323,323a: Second discharge slit

[0130] 324: Incision line 324a: First incision line

[0131] 324b: Second incision line

Claims

1. A cell assembly comprising a plurality of battery cells stacked one on top of the other; A module case that houses the cell assembly in an internal space and has a venting hole formed therein; and It includes a cover member having a plurality of refractory layers, each of which has a discharge slit formed therein, and is joined to the outer surface of the module case so that the venting hole and the plurality of discharge slits are in communication with each other. A battery module characterized in that the discharge slit of one of the refractory layers is ruptured, and the discharge slit of another adjacent refractory layer is opened by the rupture of one of the refractory layers, so as to be selectively opened only in one direction from the inside of the module case to the outside.

2. In paragraph 1, The above multiple refractory layers are two layers, The above refractory layer is, A first refractory layer provided with a first discharge slit formed in the width direction of the module case or formed corresponding to the shape of the venting hole; and A battery module characterized by including a second refractory layer having a second discharge slit formed in the longitudinal direction of the module case.

3. In paragraph 2, A battery module characterized in that the second refractory layer is provided to overlap the first refractory layer.

4. In paragraph 3, A battery module characterized in that the first refractory layer is provided to cover the upper surface of the module case, or to cover the upper surface of the module case and both side surfaces in the longitudinal direction of the module case.

5. In paragraph 3, A battery module characterized in that the second refractory layer is provided to cover the upper surface of the module case and both side surfaces in the longitudinal direction of the module case.

6. In paragraph 3, The first exhaust slit and the second exhaust slit are arranged to overlap in the vertical direction on the venting hole, A battery module characterized in that a virtual boundary circle connecting the ends of the first discharge slits formed in the width direction and a virtual ellipse connecting the ends of the second discharge slits are arranged to cover the opening shape of the venting hole.

7. In paragraph 3, The above first discharge slit is opened by the rupture line being ruptured by a gaseous discharge or a solid discharge generated in one of the module cases where a thermal event has occurred, forming a partially cut rupture line. A battery module characterized in that the second discharge slit is formed with at least one continuously cut portion, and the cut portion is opened due to rupture of the first discharge slit.

8. In paragraph 7, The second exhaust slit of one of the above module cases adjacent to the one above module case where the thermal event occurred is configured to block the re-introduction of the gaseous discharge or solid discharge, A battery module characterized in that the first discharge slit adjacent to the second discharge slit supports the second discharge slit to limit deformation in the thickness direction of the second discharge slit.

9. In paragraph 7, A battery module characterized in that the above rupture lines are formed to extend in the width direction of the module case, but are arranged to be spaced apart at predetermined intervals along the length direction of the module case.

10. In paragraph 7, A battery module characterized in that the above rupture line is formed on the edge of the rupture membrane corresponding to the opening shape of the venting hole, and a bridge portion is provided to connect the first refractory layer portion and the rupture membrane at regular intervals.

11. In paragraph 7, A battery module characterized in that the above-mentioned cut portion is a cut line formed parallel to the longitudinal direction of the module case.

12. In paragraph 11, The above incisions are plural, The above incision is, A first cutting line formed parallel to the longitudinal direction of the above module case; and A battery module characterized by including a second cutting line formed in a diagonal shape at each end of the first cutting line.

13. In paragraph 10, The above incision is, A first cutting line formed parallel to the longitudinal direction of the above module case; and Including a second cutting line formed in a diagonal shape at each end of the first cutting line, A battery module, characterized in that the orthogonal projection of the second cutting line onto the venting hole does not overlap with the orthogonal projection of the bridge portion onto the venting hole.

14. In paragraph 1, A battery module characterized in that the above cover member is manufactured from an inorganic material, a MICA material, a refractory plastic, or a combination thereof.

15. In paragraph 2, The above first refractory layer is made of an inorganic material or a MICA material, A battery module characterized in that the second refractory layer is made of an inorganic material, a MICA material, or a refractory plastic.

16. A battery pack comprising a battery module according to any one of claims 1 to 15.

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