Safety-enhanced battery modules and battery packs

Abstract

The present invention discloses a battery module and the like having an improved structure to improve safety when a thermal event occurs inside the battery module.A battery module according to one aspect of the present invention includes a cell assembly having one or more battery cells, a module case that houses the cell assembly in its internal space, and an expansion member located inside the module case, the expansion member configured to expand in volume when heat is supplied thereto to fill at least a portion of the empty space inside the module case.

Description

[Technical field]

[0001] This application claims priority to Korean Patent Application No. 10-2021-0150114, filed on November 3, 2021, the entire contents of which are incorporated herein by reference in their entirety in the specification and drawings.

[0002] The present invention relates to a battery, and more particularly to a battery module and a battery pack having enhanced safety, and a vehicle including the same. [Background technology]

[0003] In recent years, as the demand for portable electronic products such as notebook computers, video cameras, and mobile phones has increased dramatically and robots, electric vehicles, and the like have been commercialized in earnest, active research has been conducted on high-performance secondary batteries that can be repeatedly charged and discharged.

[0004] Currently, commercially available secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium secondary batteries. Among them, lithium secondary batteries are attracting attention due to their advantages of being freely chargeable and dischargeable since they hardly have a memory effect compared to nickel-based secondary batteries, as well as their extremely low self-discharge rate and high energy density.

[0005] This type of lithium secondary battery mainly uses a lithium-based oxide and a carbon material as the positive and negative active materials, respectively, and includes an electrode assembly in which a positive electrode plate and a negative electrode plate coated with the positive and negative active materials are arranged with a separator sandwiched therebetween, and an exterior material, i.e., a battery case, that encloses the electrode assembly together with an electrolyte.

[0006] In general, lithium secondary batteries can be broadly classified into can-type secondary batteries, in which the electrode assembly is housed in a metal can, and pouch-type secondary batteries, in which the electrode assembly is housed in a pouch made of an aluminum laminate sheet, depending on the shape of the exterior material.

[0007] Recently, secondary batteries are widely used for driving and storing energy not only in small devices such as portable electronic devices but also in medium- to large-sized devices such as electric vehicles and energy storage systems (ESS). A battery module can be configured in such a form that a plurality of such secondary batteries are electrically connected and housed together inside a module case. A battery pack can be configured by connecting a plurality of such battery modules.

[0008] However, when multiple secondary batteries (battery cells) or multiple battery modules are densely packed in a small space, they may be vulnerable to thermal events. In particular, when an event such as thermal runaway occurs inside a battery module, high-temperature gas, flames, heat, etc. may be generated. If such gas, flame, heat, etc. cannot be properly controlled, fire or explosion may occur in the battery module, and fire or explosion may occur in other battery modules. Furthermore, in the case of a medium- to large-sized battery pack such as an electric vehicle, many battery cells and battery modules may be included in order to increase output and / or capacity. Furthermore, in the case of a battery pack mounted on an electric vehicle, etc., there may be people such as a driver around. Therefore, if a thermal event occurring in a specific battery module cannot be properly controlled and a chain reaction such as thermal propagation occurs, it may cause serious damage to property as well as damage to human life. Summary of the Invention [Problem to be solved by the invention]

[0009] Therefore, the present invention has been devised to solve the above problems, and aims to provide a battery module having an improved structure to improve safety when a thermal event occurs inside the battery module, and a battery pack, automobile, etc. including the same.

[0010] However, the technical problems that the present invention aims to solve 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. [Means for solving the problem]

[0011] In order to achieve the above object, a battery module according to one aspect of the present invention includes a cell assembly having one or more battery cells, a module case that houses the cell assembly in its internal space, and an expansion member located inside the module case, the expansion member configured to expand in volume when heat is supplied to the expansion member to fill at least a portion of the empty space inside the module case.

[0012] Here, the expansion member may comprise a phase change material.

[0013] In addition, the battery module according to one aspect of the present invention may further include a fire-extinguishing member configured to hold a fire-extinguishing material and to release the fire-extinguishing material therein upon expansion of the expansion member.

[0014] Additionally, the expansion member may be interposed between the cell assembly and the fire suppression member.

[0015] Furthermore, the fire suppression member may be located at an upper portion of the cell assembly.

[0016] Furthermore, a vent hole may be formed in the module case, and the expansion member may be configured to close at least a portion of the vent hole by expanding.

[0017] Furthermore, the expansion member may be configured so that the degree of expansion varies partially.

[0018] Furthermore, the expansion member may include a plurality of expansion sections each having a different reaction temperature for expansion.

[0019] In order to achieve the above object, a battery pack according to another aspect of the present invention includes a battery module according to the present invention.

[0020] Furthermore, in order to achieve the above-mentioned object, a battery pack according to yet another aspect of the present invention includes a cell assembly having one or more battery cells, a pack case that houses the cell assembly in its internal space, and an expansion member located inside the pack case, the expansion member being configured to expand in volume when heat is supplied to fill at least a portion of the empty space inside the pack case.

[0021] Furthermore, in order to achieve the above object, a vehicle according to yet another aspect of the present invention includes a battery module or a battery pack according to the present invention. Effect of the Invention

[0022] According to the present invention, even if a thermal event occurs inside a battery module, safety against the thermal event can be improved.

[0023] In particular, according to one aspect of the present invention, in the event of a thermal event occurring inside the battery module, a fire suppression effect is achieved by filling the empty space.

[0024] Furthermore, according to one embodiment of the present invention, the inflow of oxygen from the outside can be blocked or suppressed, thereby preventing the outbreak of a fire.

[0025] Furthermore, according to one embodiment of the present invention, by preventing flames and the like from escaping to the outside, it is possible to prevent the thermal runaway condition from spreading to other battery modules and the fire from spreading.

[0026] In addition to these, the present invention can have various other effects, which will be described in the sections for each embodiment, and descriptions of effects that can be easily inferred by a person skilled in the art will be omitted.

[0027] The drawings attached to this specification are intended to illustrate preferred embodiments of the present invention and serve to facilitate a further understanding of the technical ideas of the present invention as well as the content of the invention, and therefore the present invention should not be interpreted as being limited to only the matters depicted in the drawings. [Brief description of the drawings]

[0028] [Figure 1] 1 is a perspective view showing a schematic configuration of a battery module in an assembled state according to an embodiment of the present invention; [Diagram 2] FIG. 2 is an exploded perspective view of the battery module of FIG. 1. [Diagram 3] 2 is a cross-sectional view taken along the line A1-A1' in FIG. [Figure 4] 4 is a cross-sectional view showing a schematic configuration in which an expansion member in the configuration shown in FIG. 3 has expanded due to heat. FIG. [Diagram 5] FIG. 11 is an exploded perspective view illustrating a schematic configuration of a battery module according to another embodiment of the present invention. [Figure 6] FIG. 6 is a cross-sectional view of the battery module shown in FIG. 5. [Figure 7] 13 is a perspective view illustrating a schematic configuration of an expansion member included in a battery module according to still another embodiment of the present invention. FIG. [Figure 8] 13 is a perspective view illustrating a schematic configuration of a module case included in a battery module according to still another embodiment of the present invention. FIG. [Figure 9] 9 is a cross-sectional view taken along the line A3-A3' in FIG. 8. [Figure 10] 13 is a diagram illustrating a cross-sectional configuration of a battery module according to still another embodiment of the present invention. FIG. [Figure 11] FIG. 13 is a perspective view illustrating a schematic configuration of a battery module according to still another embodiment of the present invention. [Figure 12] 12 is a cross-sectional view taken along the line A4-A4' in FIG. 11. [Figure 13] FIG. 13 is an enlarged view of a portion A5 in FIG. [Figure 14] 14 is a diagram illustrating a schematic view of the expansion member in the configuration of FIG. 13 in an expanded state. FIG. [Figure 15] 13 is an enlarged view illustrating a schematic configuration of a portion of a battery module according to still another embodiment of the present invention. FIG. [Figure 16] 13 is an enlarged view illustrating a schematic configuration of a portion of a battery module according to still another embodiment of the present invention. FIG. [Figure 17] 13 is a perspective view illustrating a schematic configuration of a portion of a battery module according to still another embodiment of the present invention. FIG. [Figure 18] 18 is a diagram illustrating the battery module of FIG. 17 in a state where a part of the expansion member is expanded. FIG. [Figure 19] FIG. 13 is a perspective view illustrating a schematic configuration of a battery pack according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms and words used in the specification and claims are not to be construed as being limited to their ordinary or dictionary meanings, but are to be construed as being in accordance with the meanings and concepts of the technical ideas of the present invention, in accordance with the principle that the inventors themselves can appropriately define the concepts of terms in order to best describe the invention.

[0030] Therefore, it should be understood that the embodiment described in this specification and the configurations shown in the drawings are merely the most preferred embodiment of the present invention and do not represent the entire technical idea of ​​the present invention, and therefore there may be various equivalents and modifications that can be substituted therefor at the time of this application.

[0031] Fig. 1 is a perspective view of an assembled state that illustrates a configuration of a battery module according to one embodiment of the present invention, and Fig. 2 is an exploded perspective view of the battery module of Fig. 1. Fig. 3 is a cross-sectional view taken along the line A1-A1' in Fig. 1.

[0032] 1 to 3, a battery module according to one embodiment of the present invention includes a cell assembly 100, a module case 200, and an expansion member 300.

[0033] The cell assembly 100 may include one or more battery cells 110. Here, each battery cell 110 may refer to a secondary battery. The secondary battery may include an electrode assembly, an electrolyte, and a battery case. In particular, the battery cell 110 disposed in the cell assembly 100 may be a pouch-type secondary battery. However, other forms of secondary batteries, such as cylindrical batteries and prismatic batteries, may also be adopted in the cell assembly 100 of the present invention.

[0034] A plurality of secondary batteries may be stacked together to form the cell assembly 100. For example, a plurality of secondary batteries may be stacked in a shape in which they are arranged in a horizontal direction (Y-axis direction in the figure) while standing vertically (Z-axis direction in the figure). Each battery cell 110 may have an electrode lead, and such an electrode lead may be located at both ends of each battery cell 110 or at one end. A secondary battery having electrode leads protruding in both directions may be called a bidirectional cell, and a secondary battery having electrode leads protruding in one direction may be called a unidirectional cell. The present invention is not limited in any way by the specific type or form of such a secondary battery, and various forms of secondary batteries already known at the time of filing of the present invention may be adopted in the cell assembly 100 of the present invention.

[0035] 2, the module case 200 may include a top plate 210, a base plate 220, and a side plate 230. The module case 200 may define an internal space by these components, i.e., the top plate 210, the base plate 220, and the side plate 230. The top plate 210 may be located at an upper portion of the module case 200, and the base plate 220 may be disposed below the top plate 210 and spaced a predetermined distance from the top plate 210. The side plate 230 may be disposed between the top plate 210 and the base plate 220, with the upper end and the lower end connected to each other.

[0036] The top plate 210, the base plate 220, and / or the side plate 230 may be configured in a thin sheet shape, i.e., a plate shape, but may also be configured in a polyhedral, i.e., rectangular parallelepiped shape having a thickness equal to or greater than a certain level. Furthermore, the side plate 230 may include a left plate 231, a right plate 232, a front plate 233, and a rear plate 234. The top plate 210, the base plate 220, and / or the side plate 230 may be entirely or partially made of a metal material. Also, at least a part of these may be made of a plastic material. For example, the left plate 231, the right plate 232, the top plate 210, and the base plate 220 may be made of a steel material. The front plate 233 and the rear plate 234 may be made of a plastic material.

[0037] At least some of the top plate 210, the base plate 220, and the side plate 230 may be configured to be integrated with each other. For example, as shown in FIG. 2, among the four side plates 230, the left plate 231 and the right plate 232 may be configured to be integrated with the base plate 220. In this case, the left plate 231, the right plate 232, and the base plate 220, which are integrated with each other, may be referred to as a U-frame due to their shapes. In this case, the front plate 233 and the rear plate 234 are end plates, and may be coupled to the front end opening and the rear end opening of the U-frame, respectively. The top plate 210 may be coupled to the upper end opening of the U-frame.

[0038] However, in addition to this, the module case 200 may be configured in various other shapes. For example, the base plate 220 and the four side plates 230 may be integrated with each other to form a lower case in a box shape. In this case, the top plate 210 may be coupled to an opening at the top end of the box-shaped lower case. As another example, the base plate 220, the left plate 231, the right plate 232, and the top plate 210 may be integrated with each other to form a tubular shape. In this case, the tubular case may be referred to as a monoframe.

[0039] Meanwhile, various joining methods may be adopted for a configuration in which the components are joined during the assembly of the battery module without being manufactured in an integrated shape in the module case 200. For example, the top plate 210, the front plate 233, and the rear plate 234 may be joined to the U-frame by a laser welding method, an ultrasonic welding method, or the like. Alternatively, each component of the module case 200 may be joined to each other by a bolt fastening method, or the like.

[0040] The module case 200 can thus accommodate the cell assembly 100 in an internal space defined by the top plate 210 , the base plate 220 and the side plate 230 .

[0041] The expansion member 300 may be located inside the module case 200. Furthermore, one or more expansion members 300 may be included inside the module case 200. The expansion member 300 may be configured to expand in volume when heat is supplied thereto. In particular, the expansion member 300 may include a material whose volume expands when heat is supplied thereto and the temperature exceeds a certain level. The expansion member 300 may be configured to fill at least a portion of the empty space inside the module case 200 by such volume expansion. The configuration of such volume expansion will be described in more detail with further reference to FIG. 4.

[0042] FIG. 4 is a cross-sectional view that illustrates a schematic configuration in which the expansion member 300 in the configuration of FIG. 3 has expanded due to heat.

[0043] 3 and 4 in combination, the expansion member 300 can expand in volume due to heat, thereby filling the empty space inside the module case 200. First, as shown in FIG. 3, the cell assembly 100 and the expansion member 300 can be accommodated in the internal space of the module case 200. At this time, the cell assembly 100 and the expansion member 300 can occupy a part of the internal space of the module case 200, and the space not occupied by the cell assembly 100 and the expansion member 300 can be left as empty space. In particular, in a normal battery module state, for example, in a state where no thermal runaway is occurring in the battery module, such empty space may exist inside the module case 200.

[0044] For example, as shown by the symbol A2 in FIG. 3, there may be empty spaces between the upper part of the cell assembly 100 and the lower surface of the top plate 210, and between the side part of the cell assembly 100 and the side plate 230. Furthermore, an expansion member 300 may be interposed between the side part of the cell assembly 100 and the side plate 230, but the height of the expansion member 300 may be configured to be lower than the height of the cell assembly 100. The expansion member 300 may be located in the center part of the side of the cell assembly 100 in the vertical direction. In this case, there may be empty spaces on the upper and lower sides of the expansion member 300. The expansion member 300 may be interposed in the center part of the cell assembly 100 as shown in FIG. 2 and FIG. 3. In this case, there may be empty spaces on the upper and lower sides of the expansion member 300.

[0045] In this configuration, the empty space indicated by the symbol A2 can ensure tolerance during assembly and provide a thermal insulation space. In particular, the battery cells 110 can generate and release heat during normal use as well as during thermal runaway. At this time, the empty space inside the module case 200 can perform a thermal insulation function between the battery cells 110 or between the module case 200 and the cell assembly 100. In addition, such empty space A2 can also provide a path for vent gas to be discharged in an initial emergency situation in which vent gas is discharged from the battery cells 110.

[0046] When heat is generated and released in at least some of the battery cells 110 arranged in the cell assembly 100 due to a thermal event such as thermal runaway, the heat can be supplied to the expansion member 300. Then, the expansion member 300 can change its shape by expanding in volume due to the supplied heat, as shown in FIG 4, so as to fill a part or the whole of the empty space indicated by the reference symbol A2 in FIG 3.

[0047] According to this aspect of the present invention, the empty space existing inside the module case 200 is filled, thereby eliminating or reducing the space through which oxygen can flow into the inside of the battery module. Therefore, it is possible to prevent a fire from starting or spreading inside the battery module in an emergency situation such as thermal runaway. Even if a fire does start inside the battery module, the fire can be shut off or quickly put out.

[0048] The expansion member 300 may be formed in a plate shape as shown in Figures 2 and 3. In particular, at least some of the multiple expansion members 300 may be formed in a plate shape and arranged to face a wide surface of the pouch-type cell. That is, the expansion member 300 may be configured to be upright in the vertical direction, and at least one of the two wide surfaces may be configured to face or directly contact the containing portion of the pouch-type cell.

[0049] The expansion member 300 may also include a phase change material. In particular, the expansion member 300 may include a material that changes state, such as solid, liquid, and gas, depending on temperature, and has a property that the higher the temperature, the larger the volume of the material expands. For example, the phase change material used in the expansion member 300 may be a material that changes state from solid to liquid when heat is applied, and expands in volume. Alternatively, the phase change material may include a material that changes state from liquid to gas, solid to gas, or solid to gel, sol, etc., when heat is applied, and expands in volume. The present invention is not limited by the specific type of the expansion member 300, i.e., the specific type of the phase change material.

[0050] The expansion member 300 may be configured in such a way that a thermally expandable material, particularly a phase-change material, is accommodated inside a packaging. In this case, when an event such as thermal runaway occurs inside the battery module, the expansion member 300 may be configured in such a way that the internal phase-change material expands and flows out of the packaging. In this case, the packaging of the expansion member 300 may be configured to be burstable by the expansion of the internal phase-change material, or may be configured in such a way that an opening is pre-formed. In particular, in the case of an embodiment in which an opening is pre-formed in the packaging of the expansion member 300, a plug may be provided in the opening, and the plug may be configured in such a way that it opens when the internal pressure becomes higher than a certain level. Alternatively, the expansion member 300 may be configured such that the packaging itself can expand together with the internal expansion material. In this case, the expansion member 300 may fill the internal space of the module case 200 by expanding the internal expansion material and the packaging together. Alternatively, the expansion member 300 may be made of only a thermally expandable material, i.e., a phase-change material, without a separate packaging.

[0051] The expansion member 300 may include a polyurethane foam (PU foam) composite material or a porous foam (e.g., Si foam) composite material. The expansion member 300 may include a composite material in which foamed polypropylene or liquid hydrocarbon is wrapped in a granular (capsule) pouch and bonded to polyurethane foam or porous foam. Here, the pouch-type capsule may be made of a material such as acrylonitrile copolymer. In addition, in the configuration of the expansion member 300, when heat is applied, the pouch-type capsule and the foam may expand. In addition, in the above configuration, when heat is applied and a certain temperature is reached, foaming of the foam material may start, and at this time, the foaming start temperature may be appropriately configured according to the structure, type, shape, and form of the battery module or secondary battery. That is, the foaming start temperature may be 160° C. or more. Alternatively, the expansion member 300 may include a porous expansion glass. In the case of such a porous expansion glass, it can even perform a role of extinguishing a fire. However, the present invention is not necessarily limited to a specific material, type, shape, or configuration of the expansion member 300.

[0052] Fig. 5 is a partial perspective view illustrating a configuration of a battery module according to another embodiment of the present invention, and Fig. 6 is a cross-sectional view of the battery module illustrated in Fig. 5. Fig. 6 can be said to be a modified example of the configuration of Fig. 4.

[0053] On the other hand, with regard to the various embodiments contained in this specification, including this embodiment, detailed descriptions will be omitted for parts to which the descriptions of other embodiments can be applied in the same or similar manner, and the description will focus on the parts in which there are differences between each embodiment.

[0054] 5 and 6, the battery module according to the present invention may further include a fire extinguishing member 400. The fire extinguishing member 400 may hold a fire extinguishing material. In particular, the fire extinguishing member 400 may include an exterior material having an internal space formed therein and configured in a sealed form. The fire extinguishing member 400 may be configured to accommodate a fire extinguishing material in the internal space of the exterior material. Here, as the fire extinguishing material held in the fire extinguishing member 400, a wide variety of materials already known at the time of the advent of the present invention may be adopted. The fire extinguishing material may be in a solid state, i.e., a powder state, or may have other various states or properties, such as a liquid or gas.

[0055] In particular, the fire extinguishing member 400 may be configured to release the internal fire extinguishing material when the expansion member 300 expands. Furthermore, the fire extinguishing member 400 may be configured to be pressed by the expanding pressure when the expansion member 300 expands due to heat. In addition, the fire extinguishing member 400 may be configured to release the internal fire extinguishing material by damaging or bursting the exterior material when a pressure of a certain level or more is applied.

[0056] For example, the extinguishing member 400 may be configured in a form in which an extinguishing agent is sealed inside, and may have a generally sheet-like shape as shown in FIG. 5. In this case, the extinguishing member 400 may be accommodated inside the module case 200 in a form in which at least one side faces the expansion member 300. In particular, when a plurality of expansion members 300 are included, a plurality of extinguishing members 400 may also be included inside the module case 200. Here, one or more extinguishing members 400 may be configured to face each expansion member 300. As a more specific example, as shown in FIG. 5 and FIG. 6, the expansion members 300 may be located at three points, the left side, the right side, and the center, with the cell assembly 100 as the center. In particular, the expansion members 300 located in the center may be arranged in two positions spaced apart from each other, as shown by reference numerals 300C1 and 300C2. At this time, the extinguishing member 400 may be configured in a form in which it is in contact with the left expanding member 300 indicated by reference numeral 300L, the right expanding member 300 indicated by reference numeral 300R, and the central expanding member 300 indicated by reference numerals 300C1 and 300C2, with their surfaces facing each other. In particular, the extinguishing member 400 located in the center indicated by reference numeral 400C may be interposed between the two central expanding members 300C1 and 300C2.

[0057] According to this embodiment, when thermal runaway occurs in at least one battery cell 110 and heat or flame is emitted, the expansion member 300 expands, which allows the fire-extinguishing member 400 to release a fire-extinguishing substance into the interior of the module case 200. Then, the fire-extinguishing substance released from the fire-extinguishing member 400 can block the flame or effectively suppress the fire inside the module case 200.

[0058] For example, in the embodiment of FIG. 6, when the left-side expanding member 300 indicated by reference symbol 300L expands, it can press the left-side extinguishing member 400 indicated by reference symbol 400L. Also, in the embodiment of FIG. 6, when the right-side expanding member 300 indicated by reference symbol 300R expands, it can press the right-side extinguishing member 400 indicated by reference symbol 400R. And, when the central expanding members 300 indicated by reference symbols 300C1 and 300C expand, it can press the central extinguishing member 400 indicated by reference symbol 400C interposed therebetween. When the extinguishing members 400 are pressed in this way and the pressing force exceeds a certain level, each extinguishing member 400 is broken and the extinguishing material inside can be discharged.

[0059] A wide variety of extinguishing materials already known at the time of filing of the present invention may be used as the extinguishing member 400. For example, the extinguishing member 400 may include an extinguishing material such as sodium bicarbonate, potassium bicarbonate, ammonium phosphate, etc. In addition, the extinguishing member 400 may include a powdered or granular extinguishing material such as porous expanded glass.

[0060] In the above-described embodiment, the inflatable member 300 may be interposed between the cell assembly 100 and the extinguishing member 400. That is, the inflatable member 300 may be located closer to the cell assembly 100 than the extinguishing member 400. For example, referring to the embodiment of FIG. 6, the left inflatable member 300 indicated by reference numeral 300L may be interposed between the left inflatable member 400 indicated by reference numeral 400L and the left side of the cell assembly 100. In addition, in the embodiment of FIG. 6, the right inflatable member 300 indicated by reference numeral 300R may be interposed between the right inflatable member 400 indicated by reference numeral 400R and the right side of the cell assembly 100. In this case, it can be said that the extinguishing member 400 is located on the outer side of the cell assembly 100 than the inflatable member 300. Also, the central inflatable member 300, designated by reference numeral 300C1, may be interposed between the cell assemblies 100, particularly the left group of cell assemblies 100, and the central extinguishing member 400, designated by reference numeral 400C. And, the central inflatable member 300, designated by reference numeral 300C2, may be interposed between the right group of cell assemblies 100 and the central extinguishing member 400, designated by reference numeral 400C.

[0061] According to the above embodiment, when heat generated in the cell assembly 100 is applied to the expansion member 300, the heat does not pass through the fire extinguishing member 400. Therefore, when heat is generated in the cell assembly 100, the generated heat is directly transferred to the expansion member 300, and the operation of expanding the expansion member 300 due to the heat can be smoothly performed. In other words, according to the above embodiment, the heat of the cell assembly 100 can be well transferred to the expansion member 300 without being hindered by the fire extinguishing member 400.

[0062] 7 is a perspective view illustrating a schematic configuration of an expansion member 300 included in a battery module according to another embodiment of the present invention. This embodiment will also be described focusing on differences from the above-described embodiment.

[0063] Referring to FIG. 7, the expansion member 300 may have a through hole formed in a shape penetrating inward and outward directions, as indicated by the symbol O. For example, the expansion member 300 shown in FIG. 7 may be used as the expansion member 300 of the battery module shown in FIG. 5 and FIG. 6. In this case, the expansion member 300 may be configured in a sheet shape standing in the vertical direction, and may have a wide surface on the left and right sides, and the through hole O may be formed in a shape penetrating in the left and right directions. In particular, such through holes O may be formed in a large number in the expansion member 300 in a form spaced apart from each other. That is, the large number of through holes O may be widely distributed on the surface of the expansion member 300. Furthermore, such through holes O may be formed in a state in which the expansion member 300 is expanded. That is, the through holes O are not formed when the expansion member 300 is not expanded, and may be formed only in the expanded state. Alternatively, the through hole O may be pre-formed even when the expansion member 300 is not expanded, and may be configured to maintain such a through state or to have an even larger hole diameter even when the expansion member 300 is expanded.

[0064] According to this embodiment of the present invention, the extinguishing material of the extinguishing member 400 can contact the cell assembly 100 more smoothly. In particular, when the extinguishing member 400 discharges the extinguishing material in a state where the expanding member 300 is interposed between the extinguishing member 400 and the cell assembly 100 as in the above embodiment, the discharged extinguishing material can flow into the cell assembly 100 through the through hole O of the expanding member 300. Therefore, the extinguishing action of the cell assembly 100 by the extinguishing material can be performed well. For example, when the expanding member 300 of FIG. 7 is applied to the embodiment of FIG. 6, when the left extinguishing member 400 indicated by reference numeral 400L discharges the extinguishing material, the extinguishing material can be easily applied to the left surface of the cell assembly 100 through the through hole O of the left expanding member 300 indicated by reference numeral 300L.

[0065] 8 is a perspective view illustrating a schematic configuration of a module case 200 included in a battery module according to still another embodiment of the present invention, and FIG 9 is a cross-sectional view taken along line A3-A3' in FIG 8.

[0066] 8 and 9, the inner surface of the module case 200 may have a circulation groove formed thereon that is recessed outward, as indicated by the reference symbol G. In particular, the side plate 230 may have a plurality of circulation grooves G formed therein and spaced apart from each other by a predetermined distance in the front-rear direction. Each circulation groove G may be formed to extend elongatedly in the up-down direction. In particular, the circulation grooves G formed in the side plate 230 may extend downward to the base plate 220.

[0067] In addition, a plurality of circulation grooves G may be formed in the base plate 220 and may be arranged to be spaced apart from each other by a predetermined distance in the front-rear direction. In particular, the circulation grooves G formed in the base plate 220 may be configured to communicate with the circulation grooves formed in the side plate 230. The circulation grooves G formed in the base plate 220 may extend elongatedly in the left-right direction. At this time, a plurality of battery cells 110 may be stacked in the left-right direction on the upper surface of the base plate 220. Therefore, it can be said that the circulation grooves G of the base plate 220 are configured to be elongated in the stacking direction of the battery cells 110. Furthermore, in the embodiment of FIG. 8 and FIG. 9, the circulation grooves G of the base plate 220 may extend elongatedly in the left-right direction (Y-axis direction), and the left end portion may be connected to the circulation groove G of the left plate 231, and the right end portion may be connected to the circulation groove G of the right plate 232.

[0068] According to such an embodiment of the present invention, the extinguishing material discharged from the extinguishing member 400 can be smoothly supplied to a plurality of battery cells 110. For example, referring to Fig. 9, when the extinguishing material is discharged from the extinguishing member 400, the extinguishing material can flow into the flow groove G as shown by the dotted arrow. Therefore, the extinguishing material can be provided not only to the battery cells 110 adjacent to the extinguishing member 400, but also to battery cells 110 far away.

[0069] 5 and 6, each extinguishing member 400 may be present only at a predetermined position on the outside of the cell assembly 100 or in the central portion of the cell assembly 100. In addition, the battery cells 110 may be in contact with the inner surface of the module case 200 or the space therebetween may be very narrow, which may hinder the movement of the extinguishing material. However, when the flow groove G is formed elongated in the stacking direction of the cells as in the above embodiment, the extinguishing material can be moved through the flow groove G. Therefore, when a plurality of battery cells 110 are stacked, the extinguishing material can be smoothly supplied to all the stacked battery cells 110, thereby improving the fire prevention or suppression ability of the entire battery module.

[0070] 10 is a schematic diagram illustrating a cross-sectional configuration of a battery module according to another embodiment of the present invention, particularly, FIG. 10 is another modified example of the embodiment of FIG.

[0071] Referring to FIG. 10, the extinguishing member 400 may be located at the top of the cell assembly 100. In particular, the extinguishing member 400 may be interposed between the cell assembly 100 and the top plate 210. In this embodiment, the expansion member 300 may cause an extinguishing material to be ejected from the extinguishing member 400 located at the top of the cell assembly 100 when the expansion member 300 is expanded. For example, the extinguishing member 400 may be located at the bottom of the top plate 210, and the expansion member 300 may be located at the bottom of the extinguishing member 400. When the expansion member 300 expands, the extinguishing member 400 is pressed to allow the extinguishing material inside to be ejected. The ejected extinguishing material is then provided to the top of the cell assembly 100, thereby preventing the cell assembly 100 from catching fire or causing a fire.

[0072] According to the above embodiment, since the extinguishing material is supplied from the upper side of the cell assembly 100, the entire cell assembly 100 can come into contact with the extinguishing material from the top to the bottom. Therefore, the fire suppression or extinguishing ability of the cell assembly 100 can be further improved. In particular, the cell assemblies 100 can be stacked horizontally, i.e., in the left-right direction (Y-axis direction), with each battery cell 110 standing upright. With such a configuration of the cell assembly 100, when the extinguishing member 400 is located on the upper part of the cell assembly 100 as in the above embodiment, the extinguishing material can be smoothly applied to the entire battery cell 110.

[0073] 10, a plurality of the expansion members 300 may be arranged on the upper portion of the cell assembly 100 and spaced apart from each other by a predetermined distance. In particular, the expansion members 300 may be configured to ensure a certain level of separation space when expanded by heat. In this case, the extinguishing material discharged from the extinguishing member 400 may be provided to the cell assembly 100 through the separation space between the expansion members 300. According to this embodiment, even if the expansion member 300 is located between the extinguishing member 400 and the cell assembly 100, the extinguishing material discharged from the extinguishing member 400 may be smoothly supplied to the cell assembly 100.

[0074] 7 may be adopted for the expansion member 300 shown in Fig. 10. In this case, the fire extinguishing material discharged from the fire extinguishing member 400 passes through the expansion member 300 via the through hole O, moves downward, and can be supplied to the cell assembly 100 side.

[0075] Fig. 11 is a perspective view showing a schematic configuration of a battery module according to still another embodiment of the present invention. Fig. 12 is a cross-sectional view taken along line A4-A4' in Fig. 11. Fig. 13 is an enlarged view of a portion A5 in Fig. 12, and Fig. 14 is a schematic view showing a state in which the expansion member 300 in the configuration of Fig. 13 is expanded. This embodiment will also be described with an emphasis on the differences from the above-described embodiment.

[0076] 11 to 14, a vent hole may be formed in the module case 200, as indicated by the symbol H. For example, a vent hole H that communicates between the inside and outside of the module case 200 may be formed in the right plate 232 of the module case 200. In this configuration, when vent gas is generated and ejected from the cell assembly 100 housed in the internal space of the module case 200, the generated vent gas can be discharged to the outside through the vent hole H.

[0077] In such an embodiment, the expansion member 300 may be configured to close at least a part of the vent hole H by expanding. For example, as shown in FIG. 14, the expansion member 300 fills the internal space of the module case 200 while expanding due to heat, and at this time, the expanded expansion member 300 may block a part or all of the vent hole H. In particular, such an expansion member 300 may be configured to block the vent hole H by expanding in response to the supply of heat during the process in which the vent gas is discharged to the outside through the vent hole H. The configuration for closing the vent hole H by the expansion member 300 may be appropriately designed in consideration of various circumstances, such as the size of the expansion member 300, the distance to the vent hole H, the temperature that rises when the vent gas is discharged, and the internal space of the module case 200.

[0078] According to such an embodiment of the present invention, it is possible to effectively block the flow of outside air, particularly oxygen, into the interior of the module case 200 through the vent hole H. When vent gas is generated inside the module case 200, the vent gas can be discharged to the outside through the vent hole H. However, after the vent gas is discharged, there is a possibility that oxygen will flow into the interior of the module case 200 through the vent hole H. However, according to the above embodiment, since the vent hole H can be closed by the expansion member 300 after the vent gas is discharged, it is possible to block the flow of oxygen through the vent hole H. Therefore, in this case, while ensuring the exhaust ability through the vent hole H, it is possible to prevent a fire from starting or spreading through such a vent hole H as much as possible.

[0079] 15 is an enlarged view showing a schematic configuration of a portion of a battery module according to another embodiment of the present invention. In particular, FIG. 15 can be said to be a modified example of the configuration of FIG.

[0080] Referring to FIG. 15, the module case 200 may have a sliding part around the vent hole H, as indicated by the symbol S. Such a sliding part S may be configured to be movable as indicated by the arrow B1. In particular, in a normal state, such a sliding part S may be positioned so as to open the vent hole H without closing it. However, when the expansion member 300 expands as indicated by the arrow B2 due to thermal runaway or the like occurring inside the battery module, the expansion of such an expansion member 300 may cause the sliding part S to slide in the direction of the arrow B1. Then, the vent hole H may be partially or entirely closed by the sliding action of such a sliding part S. Furthermore, in such an embodiment, in order for the sliding part S to smoothly close the vent hole H, a guide rail may be provided on the module case 200, as indicated by the symbol E in the figure. Such a guide rail E is a component that guides the sliding direction or movement distance of the sliding part S, and allows the sliding part S to successfully close the vent hole H by the expansion of the expansion member 300.

[0081] According to this embodiment, it is easier to realize a configuration in which the expansion member 300 expands to block the vent hole H. Therefore, in an emergency situation such as thermal runaway, the effect of blocking the inflow of oxygen through the vent hole H can be more reliably achieved. Also, in the above embodiment, a material that is resistant to flames or high temperatures can be used for the sliding part S. Therefore, even if a flame occurs inside the battery module, the flame can be reliably prevented from escaping to the outside through the vent hole H.

[0082] Meanwhile, as described in the above embodiment, the battery module according to the present invention may include the fire extinguishing member 400. In the above description, the fire extinguishing material of the fire extinguishing member 400 is discharged by the expansion member 300 directly pressing the fire extinguishing member 400, but the present invention is not necessarily limited to this embodiment. For example, the fire extinguishing member 400 may be configured to be broken by a component such as a sharp needle-shaped body when the expansion member 300 expands, thereby discharging the fire extinguishing material therein.

[0083] In particular, as shown in Fig. 15, when the sliding part S is provided on the module case 200, the movement of the sliding part S may damage the fire extinguishing member 400, causing the fire extinguishing material inside to be ejected. As a more specific example, as shown in Fig. 15, the sliding part S may move in the direction of B1, i.e., toward the rear of the battery module, due to the expansion of the expansion member 300. At this time, the fire extinguishing member 400 may be provided behind the sliding part S. Note that a needle-shaped protrusion may be formed on the rear end of the sliding part S, i.e., the end facing the fire extinguishing member 400, as shown by the symbol C.

[0084] In this configuration, when the sliding part S moves in the direction of symbol B1, i.e., rearward, due to the expansion of the expansion member 300, the vent hole H may be closed. Then, together with the closure of the vent hole H, the needle-like projection C disposed at the rear end of the sliding part S may cause the fire extinguishing member 400 to burst. Then, it becomes possible to eject the fire extinguishing material into the interior of the module case 200 through the burst part of the fire extinguishing member 400.

[0085] Particularly, in the above embodiment, the sliding part S may be configured to rupture the extinguishing member 400 after closing the vent hole H. For this purpose, the position of the extinguishing member 400 and the shape or size of the needle-like protrusion C may be configured to contact the extinguishing member 400 after the sliding part S closes the vent hole H.

[0086] According to such an embodiment of the present invention, the extinguishing substance is sprayed into the interior of the module case 200 after the module case 200 is sealed, so that the extinguishing effect of the extinguishing substance can be further improved. That is, the extinguishing substance is sprayed with the interior of the module case 200 sealed by the sliding portion S, so that the extinguishing substance is not discharged to the outside through the vent hole H, and can remain mainly only inside the module case. Therefore, in this case, the extinguishing effect (fire suppression effect) of the extinguishing substance can be increased.

[0087] 16 is an enlarged view showing a schematic configuration of a portion of a battery module according to another embodiment of the present invention, in particular, FIG. 16 shows yet another modified example of the configuration of FIG.

[0088] 16, the module case 200 may have a blocking portion formed on the inner surface thereof, as indicated by the symbol R, protruding toward the cell assembly 100. For example, in the embodiment of FIG. 16, the inner surface of the right plate 232 may be provided with a blocking portion R protruding toward the cell assembly 100, i.e., toward the left side. In particular, such a blocking portion R may be located between the expansion member 300 and the vent hole H. Furthermore, the blocking portion R may be provided around the vent hole H.

[0089] According to such an embodiment of the present invention, when vent gas is generated inside the battery module, the vent gas can be easily discharged through the vent hole H formed in the module case 200, while preventing leakage of the expansion member 300. In particular, when the expansion member 300 changes to a fluid state such as liquid, gas, gel, etc., during the process of expanding due to the supply of heat, it may leak out of the module case 200 through the vent hole H. However, according to the above embodiment, the blocking portion R can prevent such leakage of the expansion member 300. For example, in the configuration of FIG. 16, when the expansion member 300 expands in the direction of B3 due to heat, the blocking portion R provided around the vent hole H can prevent the expansion member 300 from flowing out to the vent hole H. Therefore, the effect of the expansion member 300 filling the inside of the module case 200 can be more firmly realized.

[0090] The expansion member 300 may be configured to have different degrees of expansion in different parts. In particular, for such a configuration, the expansion member 300 may include a plurality of expansion sections. This will be described in more detail with reference to Figures 17 and 18.

[0091] Figure 17 is an oblique view showing a schematic configuration of a portion of a battery module according to yet another embodiment of the present invention, and Figure 18 is a diagram showing a schematic configuration of the battery module configuration of Figure 17 in a state where a portion of the expansion member 300 is expanded.

[0092] 17 and 18, the expansion member 300 may be disposed so that one surface, i.e., the left surface, faces the cell assembly 100. Although not shown, the right surface of the expansion member 300 may face the inner surface of the module case 200. In this configuration, when heat is generated on the cell assembly 100 side and the expansion member 300 is heated, the front end portion of the expansion member 300 may expand first. That is, when the expansion member 300 is heated and reaches a predetermined temperature first, the front end portion of the expansion member 300 may expand as shown by the arrow in FIG. 17. Note that, until this point, the rear end portion of the expansion member 300 may not expand or may expand to a smaller extent than the front end portion. In this case, the expansion member 300 may be configured to be only partially expanded as shown in FIG. 18.

[0093] According to such a configuration of the present invention, the effect of discharging vent gas from the inside to the outside of the module case 200 can be further improved. For example, as shown in FIG. 18, when only the front end portion of the expansion member 300 is inflated and the rear end portion is not inflated, an empty space may exist on the right side surface behind the expansion member 300, such as the portion indicated by reference symbol A6. Therefore, in such a state, the vent gas inside the module case 200 can be guided to the portion indicated by reference symbol A6. The vent gas accumulated in the space indicated by reference symbol A6 can be discharged to the outside of the module case 200.

[0094] 11, when a vent hole H is formed in the module case 200, the expansion member 300 may be configured so that the empty space indicated by the symbol A6 is located on the side of the vent hole H. That is, the expansion member 300 may be configured so that as the temperature increases, the portion farther from the vent hole H expands first, and the portion closer to the vent hole H expands relatively later.

[0095] According to this embodiment, the vent gas inside the module case 200 is guided to the space A6 side where the expansion member 300 has not yet expanded, and such vent gas can be discharged to the outside through the vent hole H. Therefore, according to the above embodiment, when vent gas exists inside the module case 200, such vent gas can be smoothly discharged to the outside of the module case 200 when the expansion member 300 expands.

[0096] In particular, the expansion member 300 may include a plurality of expansion parts having different reaction temperatures for expansion. For example, as shown in Fig. 17 and Fig. 18, the expansion member 300 may include a first expansion part 310 and a second expansion part 320. In this case, the first expansion part 310 and the second expansion part 320 may both be configured in a sheet shape and may be arranged in a form in which the edge parts face each other on one plane.

[0097] Furthermore, the first expansion section 310 and the second expansion section 320 may be configured to have different degrees of expansion depending on temperature. In particular, the first expansion section 310 may be configured to have a maximum degree of expansion at a temperature (T1), and the second expansion section 320 may be configured to have a maximum degree of expansion at a temperature (T2) different from the temperature (T1). Such a difference in the degree of expansion between the first expansion section 310 and the second expansion section 320 may be realized by differences in the constituent materials and shapes of the expansion sections.

[0098] 17 and 18, when the vent hole H is located on the second expansion section 320 side, the maximum expansion temperature (T2) of the second expansion section 320 can be configured to be higher than the maximum expansion temperature (T1) of the first expansion section 310. Therefore, when heated to a predetermined temperature, i.e., the maximum expansion temperature (T1) of the first expansion section 310, the expansion member 300 only partially expands to the form shown in Fig. 18, so that the vent gas can move to the side closer to the vent hole H. This improves the discharge ability of the vent gas.

[0099] Furthermore, when the internal temperature of the battery module further rises and reaches a higher temperature, i.e., temperature T2, the second expansion portion 320 also expands, and the empty space indicated by reference symbol A6 may be filled by the second expansion portion 320. Therefore, the empty space in the internal space of the module case 200 becomes further narrow, and in particular, the vent hole H may also become closable. Therefore, the possibility of oxygen flowing into the inside of the module case 200 becomes even lower.

[0100] A battery pack according to an aspect of the present invention may include one or more battery modules according to the present invention. The battery pack according to the present invention may further include various other components, i.e., a battery management system (BMS), in addition to the battery module. Here, the BMS may be mounted in an internal space of a pack case and configured to generally control the charging and discharging operation of the cell assembly, the data transmission and reception operation, etc. The BMS may be arranged in pack units, not in module units. More specifically, the BMS may be configured to control or predict the charging and discharging state, power state, performance state, etc. of the cell assembly using the pack voltage and the pack current, etc. Such a BMS is already known at the time of filing of the present invention, and therefore a detailed description thereof will be omitted. The battery pack according to the present invention may further include various other components of a battery pack already known at the time of filing of the present invention, such as a bus bar, a pack case, a relay, a current sensor, etc.

[0101] Meanwhile, a battery pack according to another aspect of the present invention may not include the module case 200. This will be described with reference to FIG.

[0102] FIG. 19 is a perspective view illustrating a schematic configuration of a battery pack according to another embodiment of the present invention.

[0103] 19, a battery pack according to an embodiment of the present invention may include a cell assembly 100, a pack case PC, and an expansion member 300. In this case, the cell assembly 100 and the expansion member 300 may be directly accommodated in the internal space of the pack case PC without being accommodated inside the module case 200. In this embodiment, it can be said that the multiple battery cells 110 are directly mounted in the pack case PC in a cell-to-pack form without being modularized. In addition to the cell assembly 100, a BMS as indicated by the symbol M and other electrical components may be accommodated together in the internal space of the pack case PC.

[0104] The only difference in this type of battery pack is that the cell assembly 100, the expansion member 300, the fire extinguishing member 400, etc. are mounted inside the pack case PC instead of the module case 200, and the description of the other parts can be applied in the same or similar manner. For example, in the case of the contents described in the embodiments of Figures 3 to 18, etc., most of the contents can be applied as they are, with only the module case 200 being replaced with the pack case PC.

[0105] For example, although not shown in Fig. 19, the fire extinguishing member 400 described in Fig. 5 and Fig. 6 may be housed inside the pack case PC. As another example, the components related to the flow groove G formed in the module case 200 described in the embodiment of Fig. 8 and Fig. 9 may be formed in the pack case PC. As yet another example, the contents related to the vent hole H formed in the module case 200 described with reference to Figs. 11 to 14 may be replaced with a configuration in which a vent hole is formed in the pack case PC. Therefore, further detailed description of the battery pack in these various aspects will be omitted.

[0106] The battery module or battery pack according to the present invention may be applied to automobiles such as electric automobiles and hybrid automobiles. That is, the automobile according to the present invention may include the battery module according to the present invention or the battery pack according to the present invention. Furthermore, the automobile according to the present invention may further include various other components included in the automobile, in addition to the battery module or battery pack. For example, the automobile according to the present invention may further include a vehicle body, a motor, a control device such as an electronic control unit (ECU), in addition to the battery module according to the present invention.

[0107] Furthermore, the battery module or the 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 according to the present invention or the battery pack according to the present invention.

[0108] Meanwhile, although directional terms such as up, down, left, right, front, and back are used in this specification, it will be obvious to those skilled in the art of the present invention that these terms are used merely for ease of explanation and may vary depending on the position of the object in question, the position of the observer, etc.

[0109] Although the present invention has been described above using limited embodiments and drawings, the present invention is not limited thereto, and it goes without saying that various modifications and variations can be made by a person having ordinary knowledge in the technical field to which the present invention pertains within the scope of the technical concept of the present invention and the scope of the claims. [Explanation of symbols]

[0110] 100 Cell Assembly 110 Battery Cell 200 module case 210 Top Plate 220 Base Plate 230 Side Plate 231 Left side plate 232 Right side plate 233 Front Plate 234 Rear plate 300 Expansion member 310 First expansion section 320 Second expansion section 400 Fire extinguishing materials O Through hole G Flow groove S Sliding part E Guide rail C Acicular process R blocking part PC Pack Case M BMS

Claims

1. a cell assembly comprising one or more battery cells; a module case that houses the cell assembly in an internal space; an expansion member located inside the module case, the expansion member expanding in volume when heat is supplied thereto to fill at least a portion of the empty space inside the module case; A fire extinguishing member for holding a fire extinguishing substance, the fire extinguishing member being pressed by the pressure of the expansion member when the expansion member expands to release the fire extinguishing substance therein; a battery module.

2. 10. The battery module of claim 1, wherein the expansion member comprises a phase change material.

3. A cell assembly comprising one or more battery cells; a module case that houses the cell assembly in an internal space; an expansion member located inside the module case, the expansion member expanding in volume when heat is supplied thereto to fill at least a portion of the empty space inside the module case; a fire extinguishing member for holding a fire extinguishing material, the fire extinguishing member releasing the fire extinguishing material therein upon expansion of the inflatable member; Including, The expansion member is interposed between the cell assembly and the fire extinguishing member.

4. The battery module according to claim 1 , wherein the fire-extinguishing member is located on an upper portion of the cell assembly.

5. The module case has a vent hole formed therein, The battery module according to claim 1 , wherein the expansion member closes at least a portion of the vent hole by expanding.

6. The battery module according to claim 1 , wherein the expansion member has a degree of expansion that varies partially.

7. A cell assembly comprising one or more battery cells; a module case that houses the cell assembly in an internal space; an expansion member located inside the module case, the expansion member expanding in volume when heat is supplied thereto to fill at least a portion of the empty space inside the module case; Including, The expansion member includes a plurality of expansion sections each having a different reaction temperature for expansion.

8. A battery pack comprising the battery module according to any one of claims 1 to 7.

9. a cell assembly comprising one or more battery cells; a pack case that houses the cell assembly in an internal space thereof; an expansion member located inside the pack case, the expansion member expanding in volume when heat is supplied thereto to fill at least a portion of an empty space inside the pack case; A fire extinguishing member for holding a fire extinguishing substance, the fire extinguishing member being pressed by the pressure of the expansion member when the expansion member expands to release the fire extinguishing substance therein; Including the battery pack.

10. A motor vehicle comprising a battery module according to any one of claims 1 to 7 or a battery pack according to claim 9.

Images