Battery module with reinforced safety

Abstract

A battery module according to the present invention comprises: a cell assembly having a plurality of battery cells stacked together; a module case having a venting hole formed therein and housing the cell assembly in an internal space; and a cover member having a plurality of refractory layers spaced apart from each other, each having a discharge hole formed therein, and coupled to the outer surface of the module case so as to communicate with the venting hole and the discharge hole, wherein the discharge hole of any one of the refractory layers and the discharge hole of another refractory layer facing it may be arranged so as not to overlap each other.

Description

Technology Field

[0001] The present invention relates to a battery module, and more specifically, to a battery module in which gas generated inside the module is easily discharged through a unidirectional venting structure provided in a double fire-resistant material on the upper part of the module, while preventing re-entry into an adjacent module, thereby preventing chain ignition and explosion. Background Technology

[0002] Semi-permanent batteries that convert electrical energy into the form of chemical energy and can be repeatedly charged and discharged are referred to as secondary batteries to distinguish them from primary batteries, which cannot be reused after a single use.

[0003] Rechargeable batteries include lithium-ion batteries, nickel-cadmium (Ni-Cd) batteries, lead-acid batteries, nickel-hydrogen (Ni-MH) batteries, air-zinc batteries, and alkaline manganese batteries. Among these, lead-acid batteries and lithium-ion batteries are considered the most actively commercialized rechargeable batteries.

[0004] In particular, lithium-ion batteries are actively being utilized as electric vehicle batteries recently due to their high energy storage density, the ability to be lightweight and miniaturized, excellent safety, low discharge rate, and long lifespan. For reference, lithium-ion 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 secondary battery cell is approximately 2.5V to 4.5V. Therefore, in order to apply secondary batteries as an energy source for electric vehicles, a battery module is configured by connecting multiple lithium-ion battery cells in series and / or parallel, and a battery pack is configured by connecting the battery modules in series and / or parallel.

[0006] Meanwhile, since rechargeable batteries involve chemical reactions during charging and discharging, their performance may degrade if used in environments higher than the optimal temperature; furthermore, if thermal control is not maintained at the appropriate temperature, there is a constant risk of unexpected ignition or explosion. Additionally, battery modules are structured to intensively house these rechargeable batteries within a module housing; consequently, if even a single battery undergoes heat runaway and becomes a trigger cell, heat and flames rapidly propagate to surrounding batteries, making it easier for them to ignite in a chain reaction.

[0007] In particular, because as many battery modules as possible must be accommodated within a limited space in terms of density, sufficient empty space is not provided inside the battery pack. For example, in a battery pack containing one or more battery modules, the space between the module case and the pack case can be formed very narrowly.

[0008] Therefore, in addition to rapidly venting the venting gas even in such a narrow space, it is necessary to prevent the vented venting gas from flowing into other modules to delay or suppress TP (Thermal Pollution). The problem to be solved

[0009] The present invention was devised in consideration of the above-mentioned problems, and has the primary objective of providing a battery module with an improved structure that can relieve internal pressure by discharging venting gas generated inside the battery module and also prevents the ingress of flames discharged from other surrounding battery modules.

[0010] The technical problems that the present invention aims to solve are not limited to those described above, and other unmentioned problems will be clearly understood by those skilled in the art from the description of the invention below. means of solving the problem

[0011] A battery module according to the present invention comprises: a cell assembly having a plurality of battery cells stacked together; a module case having a venting hole formed therein and housing the cell assembly in an internal space; and a cover member having a plurality of refractory layers spaced apart from each other, each having a discharge hole formed therein, and coupled to the outer surface of the module case so as to communicate with the venting hole and the discharge hole, wherein the discharge hole of any one of the refractory layers and the other refractory layer facing it may be arranged so as not to overlap each other.

[0012] The above refractory layer is two layers, and the refractory layer may include a first refractory layer having a first discharge hole formed therein; and a second refractory layer having a second discharge hole formed therein.

[0013] The above cover member may further include a gap member provided between the first refractory layer and the second refractory layer to separate the first refractory layer and the second refractory layer by a mutually preset gap.

[0014] The second refractory layer is provided on top of the first refractory layer, and the first discharge hole and the second discharge hole can be interconnected.

[0015] At least one of the first refractory layer and the second refractory layer may be provided with a plurality of guide members disposed between the first discharge hole and the second discharge hole to guide the discharge of venting gas generated in the module case.

[0016] The above guide member may be inclined to spread out in the direction of the venting gas discharge.

[0017] The above cover member may further include a base layer; and a fireproof coating layer applied with a fireproof coating material that is provided over the entire surface area of ​​the base layer and is detached by the pressure of the venting gas when venting gas is generated inside the module case.

[0018] The above base layer can be disposed between the upper surface of the module case and the first refractory layer.

[0019] The base layer may include at least one mesh plate having a plurality of mesh bars and a void; and a support frame disposed at the edge of the mesh plate to support the mesh plate.

[0020] The above fire-resistant coating layer can be configured such that the fire-resistant coating material is bonded to the mesh bars to block the pores.

[0021] The above refractory coating layer may include one or more inorganic materials selected from ceramic, silicon, silica aerogel, and silica-based inorganic fibers.

[0022] The particle size of the above mineral material may be relatively smaller than the above pores.

[0023] According to another aspect of the present invention, a battery pack comprising one or more of the above-described battery modules may be provided. Effects of the invention

[0024] According to one aspect of the present invention, when a battery module is housed inside a pack case, even if the space between the battery module and the pack case is narrowly formed, the gas is discharged through a zigzag-shaped venting gas discharge path provided between the double refractory layers, thereby effectively preventing heat accumulation and thermal explosion of the battery module.

[0025] In addition, according to one aspect of the present invention, the phenomenon in which venting gas or foreign substances discharged out of the module flow into adjacent battery modules due to the zigzag discharge path can be prevented. Therefore, the phenomenon of chain ignition or thermal runaway to normal battery cells or battery modules caused by venting gas or flames can be delayed as much as possible.

[0026] In addition, a double refractory layer is placed on top of the module, so heat transfer to surrounding modules or resulting thermal runaway can be minimized.

[0027] In addition, the formation of a gap or space (such as an open space in an existing cover) for opening a separate venting hole is unnecessary, which can prevent a decrease in the energy density of the battery pack. Brief explanation of the drawing

[0028] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings. FIG. 1 is a schematic perspective view of a battery module according to one embodiment of the present invention. FIG. 2 is an exploded perspective view of the main components of the battery module of FIG. 1. FIG. 3 is a perspective view of a first refractory layer among cover members in a battery module according to one embodiment of the present invention. FIG. 4 is a perspective view of a battery module according to one embodiment of the present invention in which a second refractory layer is combined with a first refractory layer. FIG. 5 is a cross-sectional view of the structure of a battery pack including a battery module according to one embodiment of the present invention. Figure 6 is a partial enlarged view of Figure 5. Figures 7 and 8 are schematic diagrams illustrating the flow of venting gas on the upper surface of the battery module, respectively. FIG. 9 is a perspective view of a fire-resistant coating layer applied to a base layer and a plate surface in a battery module according to another embodiment of the present invention. FIG. 10 is a schematic diagram illustrating the path through which venting gas is discharged through a cover member in a battery module according to another embodiment of the present invention. Specific details for implementing the invention

[0029] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, and should be interpreted in a meaning and concept consistent with the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0030] Therefore, it should be understood that the embodiments described in this specification and the configurations illustrated in the drawings are merely some of the most preferred embodiments of the invention and do not represent all of the technical ideas of the invention, and that various equivalents and modifications that can replace them may exist at the time of filing this application.

[0031] In the drawings, the size of each component or specific part constituting the component is exaggerated, omitted, or schematically depicted for convenience and clarity of explanation. Accordingly, the size of each component does not entirely reflect its actual size. If it is determined that a detailed description of related known functions or configurations could unnecessarily obscure the essence of the invention, such description shall be omitted.

[0033] 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.

[0034] 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).

[0035] The cell assembly (100) may comprise one or more battery cells (110). Here, each battery cell (110) may represent a secondary battery. Referring mainly to FIG. 4, the battery cell (110) comprises an electrode assembly, a case housing the electrode assembly, and a pair of electrode leads (112) connected to the electrode assembly and drawn out to the outside of the case to function as electrode terminals. The pair of electrode leads (112) are drawn out at both ends of the battery cell (110), that is, in the longitudinal direction.

[0036] If necessary, the battery cell (110) may have a form in which the electrode lead (112) is located only at one end of the battery cell (110). Meanwhile, the present invention is not limited by the specific type or form of such battery cell (110), and various battery cells (110) known at the time of filing the present invention may be employed to constitute the cell assembly (100) of the present invention. In this embodiment, a pouch-type secondary battery with high energy density and easy stacking is used, but it is understood that cylindrical or prismatic secondary batteries may be applied as the battery cell (110).

[0037] These battery cells (110) can be stacked in at least one direction. In this embodiment, with reference mainly to FIG. 2, the battery cells (110) can be stacked in a form arranged along the horizontal direction (width direction of the battery module (10), Y-axis direction) while standing upright in the vertical direction (Z-axis direction).

[0038] The cell assembly (100) is a collection of battery cells (110) formed by stacking a plurality of battery cells (110). That is, the cell assembly (100) may be a group of a plurality of pouch-type battery cells (110) stacked in one direction with a wide surface facing upright, as shown in FIG. 2.

[0040] The module case (200) may be configured to have an internal space formed therein and to accommodate battery cells (110) in the internal space. The module case (200) of the present embodiment may include a case body (210) and end plates (220) disposed on the front and rear of the case body (210).

[0041] The case body (210) may be configured in the shape of a square tube with a hollow structure having open ends (O) that are open at both ends in the longitudinal direction (X-axis direction). For example, the case body (210) may be configured in the shape of a tube having an upper surface, a lower surface, a left side, and a right side, with openings formed at the front and rear ends, respectively.

[0042] In addition, the module case (200) may be formed in various other forms. For instance, the case body (210) may be configured such that the left plate, the right plate, and the bottom 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.

[0043] And the above case body may be configured to allow battery cells (110) to be inserted inside along the longitudinal direction. That is, the case body (210) may be configured to allow battery cells (110) to be inserted inside by sliding or press fitting. For press fitting, there may be almost no gap between the upper and lower surfaces of the case body (210) and the upper and lower surfaces of the battery cells (110), and there may also be almost no gap between both sides of the case body (210) and both sides of the battery cells (110). Such a case body (210) may be composed of a metal material having rigidity and heat resistance to physically or chemically protect the accommodated battery cells (110).

[0044] The end plate (220) may be provided to be coupled to the open end (O) of the case body (210) facing the side of the cell assembly (100) where the electrode leads (112) of the battery cells (110) are located, that is, the part where the electrode leads (112) are fixedly connected to the busbars on the busbar frame, so as not to be exposed to the outside. The end plate (220) may be configured such that, for example, the inside is made of an insulating material and the outside is made of a metal material, and may be configured to be fixedly coupled to the case body (210) by welding. Meanwhile, although not shown for convenience of drawing, the end plate (220) may be partially provided with holes or slits to expose parts that need to be exposed to the outside, such as the positive terminal and negative terminal or connector of the battery module (10).

[0045] The module case (200) with such a configuration may have a venting hole (H1) formed on at least one side. As indicated by H1 in FIG. 2, a plurality of venting holes (H1) may be formed on the upper side of the module case (200), offset to the left and right. These venting holes (H1) may be configured so that when venting gas is generated and ejected from the cell assembly (100) housed in the internal space, the generated venting gas can be discharged to the external space of the module case (200). For example, the module case (200) may be configured in a sealed form except for the venting hole (H1). Additionally, the venting hole (H1) may be formed in a completely open form to penetrate the module case (200) in an internal and external direction.

[0046] In this embodiment, the venting hole (H1) is provided in a circular shape, but it may be an elongated hole formed in the longitudinal direction, and any shape that allows for the smooth discharge of venting gas may be applied.

[0048] The cover member (300) is disposed on the outer surface of the module case (200), and in this embodiment, the cover member may be provided on the upper side of the module case (200) as shown in FIGS. 1 and 2. Accordingly, it may be configured to cover the venting hole (H1) formed on the upper surface of the module case (200).

[0049] The above-mentioned cover member (300) may include a plurality of refractory layers (301, 304) spaced apart from each other and each having a discharge hole (H2, H3) formed therein; and a gap member (307) spaced apart from each other the plurality of refractory layers (301, 304).

[0050] The above-mentioned fire-resistant layer may be provided with a size substantially identical to the upper surface of the battery module (10) and made of a material with fire-resistant properties. For example, MICA material may be adopted. Accordingly, it can withstand heat caused by venting gas, flames, sparks, etc., generated when a thermal event occurs, and can suppress TP such as propagation to adjacent modules.

[0051] Discharge holes (H2, H3) may be formed in the above refractory layers. The discharge holes (H2, H3) may be arranged to be connected to the venting hole (H1). That is, the venting hole (H1) of the module case and the plurality of discharge holes (H2, H3) formed in each of the plurality of refractory layers (301, 304) may be interconnected. In this way, the venting gas discharged through the venting hole (H1) can be easily discharged from the inside of the module through the venting structure provided between the plurality of refractory layers (301, 304).

[0052] In addition, the plurality of refractory layers (301, 304) may be arranged so that the discharge hole (H3) of another refractory layer (304) facing the discharge hole (H2) of one of the refractory layers (301) does not overlap with one another. That is, the discharge hole (H2) of one of the refractory layers (301) and the discharge hole (H2) of another refractory layer (304) adjacent to it may be positioned at an offset location from each other.

[0053] Accordingly, the phenomenon of venting gas or foreign substances discharged out of the module flowing into adjacent other battery modules (10) can be prevented. That is, the inflow into adjacent modules can be minimized due to the zigzag discharge path formed in the plurality of refractory layers (301, 304). This will be explained in detail in the description of the cover member.

[0055] FIG. 3 is a perspective view of a first refractory layer among cover members in a battery module according to one embodiment of the present invention, and FIG. 4 is a perspective view of a battery module according to one embodiment of the present invention in a state where a second refractory layer is coupled to the first refractory layer.

[0056] With reference mainly to FIGS. 2 to 4, the above cover member (300) may include a plurality of refractory layers (301, 304) and a gap member (307) provided between the refractory layers (301, 304) to separate the refractory layers (301, 304) from each other.

[0057] With reference mainly to FIG. 2, the above refractory layers (301, 304) are two layers, and the above refractory layers (301, 304) may include a first refractory layer (301) having a first discharge hole (H2) formed therein; and a second refractory layer (304) having a second discharge hole (H3) formed therein.

[0058] The first refractory layer (301) can be placed directly above the module case. A plurality of first discharge holes (H2) are provided on the plate surface of the first refractory layer (301), and the first discharge holes (H2) can be connected to the venting holes (H1) by being provided at positions corresponding to the positions of the venting holes (H1). The first refractory layer (301) can primarily serve to protect the module from heat generated by venting gas, flames, etc., from an adjacent module.

[0059] Additionally, a plurality of guide members (340) may be provided in at least one of the first refractory layer (301) and the second refractory layer (304). In this embodiment, the guide members (340) are provided on the plate surface of the first refractory layer (301) for convenience of explanation, but they may be provided on the bottom surface of the second refractory layer (304) as well as on the upper surface of the first refractory layer (301), or they may be formed at the same height on the first refractory layer (301) and the second refractory layer (304) and combined with each other.

[0060] Referring mainly to FIGS. 3 and 4, the guide member (340) may be positioned between the first discharge hole (H2) and the second discharge hole (H3) to guide the discharge of venting gas generated in the module case. Specifically, the guide member (340) may be inclined to spread out in the direction of the discharge of the venting gas. Referring to FIG. 3, a pair of guide members (340) may be arranged to spread out and expand along the X-axis and -X-axis directions centered on the first discharge hole (H2). Accordingly, the unidirectional venting flow of the venting gas may be induced or assisted, and the operational configuration will be described later. Meanwhile, the height of the guide member (340) is provided to be substantially the same as the height of the gap member (307), and accordingly, the upper end of the guide member (340) may be provided to be in contact with the bottom surface of the second refractory layer (304).

[0061] The second refractory layer (304) may be provided on top of the first refractory layer (301), as shown in FIGS. 2 and 4. The second refractory layer (304) may also be made of a refractory material, similar to the first refractory layer (301), and it is preferable that it be made of MICA material.

[0062] A plurality of second discharge holes (H3) are provided on the plate surface of the second refractory layer (304), and the second discharge holes (H3) may be provided on the path of the venting flow leading to the first discharge hole (H2) and the guide member (340). The size of these second discharge holes (H3) may be provided to be relatively larger than the size of the first discharge hole (H2), or alternatively, if necessary, the size may be the same as the first discharge hole (H2) or the diameter of the second discharge hole (H3) may be relatively smaller than that of the first discharge hole (H2).

[0063] The gap member (307) is provided between the first refractory layer (301) and the second refractory layer (304) to separate the first refractory layer (301) and the second refractory layer (304) by a mutually predetermined gap.

[0064] The gap member (307) is provided along the perimeter of the edge of the first refractory layer (301), and a number of them may also be provided in the width direction as shown in FIG. 3. Due to this gap member (307), a uniform gap can be secured between the first refractory layer (301) and the second refractory layer (304) across the entire plate surface. In addition, not only the gap member (307) but also the guide member (340) may be configured to maintain the gap.

[0065] Although the gap member (307) is not shown in the drawing, it may provide a joining position for joining the first and second refractory layers (304) to each other. The joining method may vary, such as bolting or welding. With the gap member (307) provided in this manner, the first refractory layer (301) and the second refractory layer (304) can form a strong structure even with pressure changes caused by venting gas, and structural rigidity against twisting or bending can also be secured.

[0066] With the cover member (300) of this configuration, heat caused by venting gas, flame, spark, etc. generated when a thermal event occurs can be withstood, and TP such as propagation to adjacent modules can be suppressed.

[0067] According to this embodiment, even if the space between the battery module (10) and the pack case is narrow while the battery module (10) is housed inside the pack case, the gas is discharged through a zigzag-shaped venting gas discharge path provided between the double refractory layers, thereby effectively preventing heat accumulation and thermal explosion of the battery module (10).

[0068] In addition, due to the zigzag discharge path, the phenomenon of venting gas or foreign substances discharged out of the module flowing into adjacent battery modules (10) can be prevented. Therefore, the phenomenon of chain ignition or thermal runaway to normal battery cells or battery modules (10) caused by venting gas or flames can be delayed as much as possible.

[0069] In addition, a double fire-resistant layer is placed on the upper part of the module, so heat transfer to surrounding modules or resulting thermal runaway can be minimized. Furthermore, since there is no need to form a gap or space (such as an open space in an existing cover) for opening a separate venting hole (H1), the energy density of the battery pack can be prevented from decreasing.

[0071] FIG. 5 is a cross-sectional view of the structure of a battery pack including a battery module according to one embodiment of the present invention, FIG. 6 is a partial enlarged view of FIG. 5, and FIG. 7 and FIG. 8 are schematic diagrams illustrating the flow of venting gas on the upper surface of the battery module, respectively.

[0072] A cover member (300) is disposed on the upper surface of the battery module (10), and a first fire-resistant layer (301) and a second fire-resistant layer (304) cover the upper surface of the battery module (10), so that it can withstand heat caused by venting gas, flames, sparks, etc., generated when a thermal event occurs, and suppress TP such as propagation to adjacent modules.

[0073] And with reference to FIGS. 5 and 6, the first discharge hole (H2) is positioned directly above the venting hole (H1) so that the venting hole (H1) is connected to the first discharge hole (H2) and is spaced apart by the distance between the first refractory layer (301) and the second refractory layer (304), and the second discharge hole (H3) is positioned at an offset location so as not to overlap with the first discharge hole (H2). Accordingly, although the venting hole (H1) is connected to the first discharge hole (H2) and the second discharge hole (H3) in sequence, the discharge path can be formed in a zigzag shape.

[0074] If a specific battery cell ignites and a large amount of venting gas is generated, it is ejected through the venting hole (H1) formed at the top, passes through the first discharge hole (H2) in succession, and strikes the bottom wall of the second refractory layer (304). Consequently, it turns to the left and right at a predetermined distance from the first discharge hole (H2) and is ejected into the second discharge hole (H3). Ultimately, the venting flow forms a zigzag venting path as shown in FIG. 6. Additionally, referring to FIG. 7, a plurality of guide members (340) positioned between the first discharge hole (H2) and the second discharge hole (H3) guide the venting gas in one direction and assist in easy discharge. In this way, the venting gas discharged through the venting hole (H1) can be easily discharged through a zigzag-shaped venting path provided between the first refractory layer (301) and the second refractory layer (304), thereby effectively preventing heat accumulation and thermal explosion of the battery module (10).

[0075] Meanwhile, the venting gas generated in the left battery module (10) of FIG. 5 may move to the right along the inside of the pack case. In this case, there is a risk that the venting gas may enter the inside of the right battery module (10).

[0076] In this case, as shown in FIG. 8, the second discharge hole (H3) and the first discharge hole (H2) are positioned at an offset location without overlapping each other, thereby blocking the inflow of venting gas. That is, although the second discharge hole (H3) of the second refractory layer (304) and the first discharge hole (H2) of the first refractory layer (301) are connected, they are spaced apart by a predetermined distance and are blocked by a plurality of guide members (340) on the flow path, so that inflow into the battery module (10) through the venting hole (H1) can be prevented.

[0077] In this way, even if the space between the battery module (10) and the pack case (pack tray (410) and pack cover (420)) is narrow while the battery module (10) is housed inside the pack case, the gas can be discharged through a zigzag-shaped venting gas discharge path provided between the double refractory layers, thereby effectively preventing heat accumulation and thermal explosion of the battery module (10).

[0078] In addition, due to the zigzag discharge path, the phenomenon of venting gas or foreign substances discharged out of the module flowing into adjacent battery modules (10) can be prevented. In particular, the flow path can be blocked by a plurality of guide members (340) to prevent inflow into the battery module (10) through the venting hole (H1). Accordingly, the phenomenon of chain ignition or thermal runaway to normal battery cells or battery modules (10) caused by venting gas or flames can be delayed as much as possible.

[0080] Next, other embodiments of the battery module (10) of the present invention will be briefly described with reference to FIGS. 9 and 10.

[0081] FIG. 9 is a perspective view of a fire-resistant coating layer applied to a base layer and a plate surface in a battery module according to another embodiment of the present invention, and FIG. 10 is a schematic diagram illustrating the path through which venting gas is discharged through a cover member in a battery module according to another embodiment of the present invention.

[0082] Reference numbers identical to those in previous drawings indicate identical components. Duplicate descriptions of identical components will be omitted, and the explanation will focus on the differences from the previously described embodiments.

[0083] With reference mainly to FIG. 10, the above cover member comprises a base layer (310) coupled to the upper surface of the module case (200) in addition to the first refractory layer (301) and the second refractory layer (304); and a refractory coating layer (320) coated with a refractory coating material (321) that is detached by the pressure of the venting gas when venting gas is generated inside the module case (200).

[0084] Here, the base layer (310) may be disposed between the upper surface of the module case and the first refractory layer (301). The base layer (310) is coupled facing the upper surface of the module case (200) and may be provided to be substantially the same size as the upper surface of the module case (200).

[0085] The above-mentioned base layer (310) may be at least one mesh plate having a plurality of mesh bars (312) and gaps (313). The above-mentioned base layer (310) may be configured to block high-temperature flames and sparks that may travel along with the venting gas. The above-mentioned base layer (310) is positioned to completely cover the venting hole (H1) to block the entry and exit of flames or sparks generated in the venting hole (H1). By doing so, flames or sparks accompanying the venting gas discharge are sufficiently filtered and blocked, preventing their discharge to the outside of the battery pack, thereby minimizing the risk of ignition of structures around the battery pack or other battery packs.

[0086] And, referring mainly to FIG. 9, the base layer (310) may include a support frame (314) that is positioned at the edge of the mesh plate and supports the mesh plate. Through the support frame (314), the mesh plate can be firmly held even when exposed to high temperatures, thereby preventing warping, deformation, or damage to the plate surface.

[0087] A fire-resistant coating layer (320) is provided on the base layer (310), and the fire-resistant coating layer (320) may be configured to have a fire-resistant coating material (321) applied thereto, which is detached by the pressure of the venting gas when venting gas is generated inside the module case (200).

[0088] The above fire-resistant coating layer (320) can be provided over the entire surface area of ​​the base layer (310).

[0089] Referring mainly to FIG. 10, the above-mentioned refractory coating layer (320) can be formed such that the refractory coating material (321) is bonded to the mesh (312) to block the pores (313). Here, the refractory coating layer (320) may include one or more inorganic materials selected from ceramic, silicon, silica aerogel, and silica-based inorganic fibers. The particle size of the inorganic material may be relatively smaller than the pores (313).

[0090] Additionally, the fire-resistant coating layer (320) may further include a binder that binds the fire-resistant coating material (321) to the mesh (312) and various additives. The binder may be a metal-friendly resin, such as polyvinyl acetal resin, acrylic resin, polyvinyl chloride resin, polyolefin resin, and epoxy resin. The binder includes the fire-resistant coating material (321) and facilitates attachment to the mesh (312). The additives may include an adhesion promoter, a dispersant, a release agent, a heat stabilizer, an antioxidant, etc.

[0091] The above fire-resistant coating layer (320) may be provided over the entire section in the thickness direction of the base layer (310), or the fire-resistant coating layer (320) may be bonded to a portion of the section along the thickness direction of the base layer (310).

[0092] Various methods may be considered for the process of applying such a fire-resistant coating layer (320) to the base layer (310). For example, a coating solution may be prepared by dissolving a fire-resistant coating material (321) in an adhesive solvent, and then a coating process may be performed by spraying it. Depending on the viscosity of the coating solution, the number of sprays may vary, and the time and temperature in subsequent processes such as drying may also be adjusted in various ways. Alternatively, the coating process may be performed by impregnating the base layer (310) in a tank of the coating solution.

[0093] According to this embodiment, in addition to the composition of the first refractory layer (301) and the second refractory layer (304) having a zigzag-shaped discharge path, the cover member may be provided with a refractory coating layer that closes (covers) the venting hole (H1). Furthermore, as the refractory coating layer (320) is detached due to gas pressure, the venting hole (H1) can be opened when necessary, thereby ensuring a sufficient discharge path for the venting gas. Thus, due to the structure in which the refractory coating layer (320) on the base layer (310) is opened and closed by detachment, even if the space between the battery module (10) and the pack cover (420) (the space between the pack cover and the top of the module) is formed narrowly, a sufficient discharge path for the venting gas can be ensured. Therefore, by rapidly discharging the venting gas to the outside, heat accumulation and thermal explosion of the battery module (10) can be effectively prevented.

[0094] In addition, according to this embodiment, the venting hole (H1) of an adjacent module can be maintained in a closed state more stably than in the first embodiment due to the heat-resistant fire-resistant coating layer (320). Accordingly, it is possible to prevent external foreign substances or venting gas discharged outside the battery module (10), or flames or sparks contained in such venting gas, from entering other venting holes (H1). This allows for the maximum delay in the phenomenon of chain ignition or thermal runaway to normal battery cells (110) or battery modules (10) caused by venting gas or flames.

[0096] A battery pack according to the present invention may include one or more battery modules according to the present invention as described above. In particular, to increase capacity and / or output, a battery pack according to the present invention may include a plurality of battery modules according to the present invention. At this time, various configurations described above may be applied to each battery module. For example, each battery module may include a cell assembly (100), a module case (200), and a cover member (300). And, such a plurality of battery modules (10) may be accommodated inside a pack case. Furthermore, in the case of a battery module according to one embodiment of the present invention, even if another battery module is located on the front or rear side, the propagation of thermal runaway between modules can be effectively prevented.

[0097] The battery pack according to the present invention may further include various other components in addition to the battery module or pack case, such as a Battery Management System (BMS), a busbar, a relay, a current sensor, a fuse, etc., components of a battery pack known at the time of filing the present invention, within the internal space of the pack case.

[0098] A battery module or a battery pack according to the present invention may be applied to a vehicle such as an electric vehicle or a hybrid vehicle. That is, a vehicle according to the present invention may include a battery module or a battery pack according to the present invention. In addition, a vehicle according to the present invention may further include various other components included in the vehicle in addition to such a battery module or battery pack. For example, a vehicle according to the present invention may further include, in addition to the battery module according to the present invention, a vehicle body, a motor, a control device such as an ECU (electronic control unit), etc.

[0099] In addition, the battery module or battery pack according to the present invention may be applied to an energy storage system (ESS). That is, the energy storage system according to the present invention may include the battery module or battery pack according to the present invention.

[0100] As described above, although the present invention has been explained by limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs.

[0101] Meanwhile, where terms indicating directions such as up, down, left, right, front, and back are used in this specification, these terms are used merely for convenience of explanation and may vary depending on the location of the object or the position of the observer, as is obvious to those skilled in the art of this invention. Explanation of the symbols

[0102] 10: Battery module 100: Cell assembly 110: Battery cell 112: Electrode Lead 200: Module Case 210 : Case body H1 : Venting hole 220: End plate 300: Cover member 301: First refractory layer H2: 1st discharge hole 304: 2nd refractory layer H3 : Second discharge hole 307 : Gap member 310 : Base layer 311 : Mesh Plate 312 : Mesh Mesh Bar 313 : Void 314 : Support frame 320 : Fireproof coating layer 321 : Fireproof coating material 340 : Guide member 420 : Pack cover

Claims

Claim 1 A battery module comprising: a cell assembly having a plurality of mutually stacked battery cells; a module case having a venting hole formed therein that accommodates the cell assembly in an internal space; and a cover member coupled to the outer surface of the module case so as to communicate between the venting hole and the venting hole, wherein one of the venting holes and the venting hole of another venting hole facing it are arranged so as not to overlap each other, and the venting holes of the venting holes are two layers, wherein the venting holes of the venting holes of one of the venting holes and the other venting holes facing it are arranged so as not to overlap each other, and the venting holes are two layers, wherein the venting holes include a first venting hole formed therein; and a second venting hole formed therein, and the first venting hole and the second venting hole are arranged at offset positions so as not to overlap each other, so as to divert the venting gas discharge path. Claim 2 delete Claim 3 A battery module according to claim 1, wherein the cover member further comprises a gap member provided between the first refractory layer and the second refractory layer to separate the first refractory layer and the second refractory layer by a mutually preset gap. Claim 4 A battery module according to claim 3, wherein the second refractory layer is provided on the first refractory layer, and the first discharge hole and the second discharge hole are interconnected. Claim 5 A battery module according to claim 1, characterized in that at least one of the first refractory layer and the second refractory layer is provided with a plurality of guide members disposed between the first discharge hole and the second discharge hole to guide the discharge of venting gas generated in the module case. Claim 6 A battery module according to claim 5, characterized in that the guide member is inclined to spread out in the direction of venting gas discharge. Claim 7 A battery module according to paragraph 3, wherein the cover member comprises: a base layer; and a fireproof coating layer provided over the entire surface area of ​​the base layer, wherein the fireproof coating material applied thereto detaches by the pressure of the venting gas when venting gas is generated inside the module case. Claim 8 A battery module according to claim 7, characterized in that the base layer is disposed between the upper surface of the module case and the first refractory layer. Claim 9 A battery module according to claim 7, wherein the base layer comprises at least one mesh plate having a plurality of mesh bars and a void; and a support frame disposed at the edge of the mesh plate to support the mesh plate. Claim 10 A battery module according to claim 9, characterized in that the fire-resistant coating layer is formed such that the fire-resistant coating material is bonded to the mesh bars to block the pores. Claim 11 A battery module according to claim 9, wherein the fire-resistant coating layer comprises one or more inorganic materials selected from ceramic, silicon, silica aerogel, and silica-based inorganic fibers. Claim 12 A battery module according to claim 11, characterized in that the particle size of the inorganic material is relatively smaller than the voids. Claim 13 A battery pack characterized by including a battery module according to any one of claims 1 and 3 through 12.

Images