Battery module comprising housing part comprising flame-retardant composite material

Abstract

The present invention relates to a battery module capable of effectively suppressing propagation of heat or flame while improving structural rigidity, and more particularly, to a battery module which accommodates a plurality of secondary battery cells in a case member including an upper case, a lower case, and a side cover coupled to each other by a fastening portion, wherein the upper shell is made of a flame-retardant composite material comprising a thermal insulation layer, the thermal insulation layer comprising an inorganic long fiber network and an organic binder, the inorganic long fiber network is formed by weaving a plurality of first fibers (weft yarns) arranged in a first direction and second fibers (warp yarns) arranged in a second direction crossing the first direction.

Description

Technical Field

[0001] The invention relates to a battery module comprising a housing component comprising a flame-retardant composite material. Background Art

[0002] Secondary batteries are easy to use depending on the product group and have electrical characteristics such as high energy density, so they are widely used not only in portable devices but also in electric vehicles (EV) or hybrid electric vehicles (HEV) driven by an electric drive source.

[0003] When a higher output voltage is required, multiple battery cells can be connected in series or in parallel to form a battery pack. Generally, a battery module including at least one battery cell is first formed, and at least one such battery module and other components are added to form a battery pack or battery rack.

[0004] In addition, secondary batteries have the risk of catching fire when overheated, so ensuring safety is an important technical issue.

[0005] As an example, if abnormal heating occurs due to various reasons such as overcharging, overcurrent, short circuit or physical impact, it may cause flames or fire, and eventually cause the secondary battery to explode due to thermal runaway. When multiple secondary batteries such as a battery module or battery pack are included, its stability problem becomes more serious.

[0006] In the past, in order to prevent the spread of flames, a cooling component for cooling or a box containing a thermal conductive additive was installed in the battery module. However, this is for cooling the heat generated when the battery is driven, and has the limitation that it cannot be used in the case of thermal runaway such as battery cell explosion.

[0007] In particular, metals such as aluminum or heat-resistant plastics are used as materials for the casing member that accommodates a plurality of secondary battery cells. However, when a flame of 1000° C. or higher is generated, holes are locally generated through which the flame rapidly propagates, thereby accelerating the thermal runaway phenomenon.

[0008] Therefore, it is necessary to develop a battery module that can suppress the spread of flames when a fire occurs in the battery module and ensure long-term stability. Summary of the invention

[0009] Technical issues to be solved

[0010] According to one aspect of the present invention, there may be provided a battery module including a case member including a flame-retardant composite material, which may suppress the spread of heat or flame when a secondary battery cell catches fire.

[0011] According to another aspect of the present invention, there may be provided a battery module including a case member including a flame retardant composite material, the battery module having excellent structural rigidity to withstand stress concentratedly generated due to a swelling phenomenon of secondary battery cells within the battery module.

[0012] In addition, the technical problems to be solved by the present invention are not limited to the technical problems mentioned above, and those skilled in the art can clearly understand other technical problems not mentioned from the following description.

[0013] Technical Solution

[0014] The battery module according to the present invention is characterized in that the battery module accommodates a plurality of secondary battery cells in a shell component, the shell component includes an upper shell, a lower shell and a side cover coupled to each other by a fastening portion, the upper shell is made of a flame-retardant composite material including a heat-insulating layer, the heat-insulating layer contains an inorganic long fiber network and an organic adhesive, and the inorganic long fiber network is formed by weaving a plurality of first fibers (weft yarns) arranged in a first direction and second fibers (warp yarns) arranged in a second direction intersecting the first direction with each other.

[0015] In a specific embodiment, the upper housing may further include a metal component.

[0016] In a specific embodiment, the metal component may be located at the outermost side or the inner side of the upper shell.

[0017] In a specific embodiment, the metal component may be provided in a manner of being connected to one or more fastening portions located at both ends of the upper housing.

[0018] In a specific embodiment, two or more fastening parts located at one end of the upper shell can be provided in a manner of being continuously connected to the metal component.

[0019] In a specific embodiment, the metal component may be located on at least one side of the upper housing including the fastening portion.

[0020] In a specific embodiment, the thermal insulation layer may include a plurality of thermal insulation unit layers stacked together.

[0021] In a specific embodiment, directions of the first fibers (weft yarns) of each adjacent unit thermal insulation layer in the plurality of unit thermal insulation layers may be the same as or different from each other.

[0022] In a specific embodiment, 1 to 10 thermal insulation layers may be stacked in the thermal insulation layer.

[0023] In a specific embodiment, the unit thermal insulation layer may further include an inorganic filler.

[0024] In a specific embodiment, the inorganic filler may include any one or both selected from heat absorbing materials or heat expanding materials.

[0025] In a specific embodiment, the heat absorbing material may include one or more selected from aluminum hydroxide, talc, calcium carbonate, diatomaceous earth, titanium oxide, zeolite or white carbon black.

[0026] In a specific embodiment, the thermal expansion material may include any one or two or more selected from mica, biotite, muscovite, vermiculite, kaolin, thermal expansion graphite, perlite, and bentonite.

[0027] In a specific embodiment, the inorganic long fibers may include glass long fibers.

[0028] In a specific embodiment, the organic binder may include a curable polymer.

[0029] In a specific embodiment, the curable polymer may include an unsaturated polyester.

[0030] In addition, the battery pack according to the present invention includes a battery module, which is characterized in that the battery module accommodates a plurality of secondary battery cells in a shell component, the shell component includes an upper shell, a lower shell and a side cover coupled to each other by a fastening portion, the upper shell is made of a flame-retardant composite material including a thermal insulation layer, the thermal insulation layer contains an inorganic long fiber network and an organic adhesive, and the inorganic long fiber network is formed by weaving a plurality of first fibers (weft yarns) arranged in a first direction and second fibers (warp yarns) arranged in a second direction intersecting the first direction with each other.

[0031] Beneficial Effects

[0032] The battery module including the case member including the flame-retardant composite material according to the present invention also has structural stability without locally generating holes in a high-temperature flame, thereby effectively suppressing the spread of heat or flame.

[0033] Furthermore, the battery module including the case member including the flame-retardant composite material according to the present invention has excellent structural rigidity, thereby having an advantage of being able to withstand stress intensively generated due to a swelling phenomenon of secondary battery cells within the battery module. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a perspective view schematically showing a battery module according to a specific embodiment of the present invention, Figure 2 yes Figure 1An exploded perspective view of a battery module is shown in FIG.

[0035] Figure 3 is an enlarged view of an upper housing further comprising a metal component according to a specific embodiment of the present invention.

[0036] Figure 4 is an enlarged view of an upper housing further comprising a metal component according to another specific embodiment of the present invention.

[0037] Figure 5 is an enlarged view of an upper housing further comprising a metal component according to another specific embodiment of the present invention.

[0038] Figure 6 is an enlarged view of an upper housing further comprising a metal component according to another specific embodiment of the present invention.

[0039] Description of Reference Numerals

[0040] 100: Battery module 10: Secondary battery cell

[0041] 15: Electrode lead 1: Fastening part

[0042] 20: Insulation component 30: Housing

[0043] 40: Lower housing 42: First plate

[0044] 48: Side plate 50: Upper shell

[0045] 52: Terminal hole 60: Side cover

[0046] 70: Circuit part 72: Connection terminal

[0047] 80: Bus bar 90: Insulation board

[0048] 500: Metal component 501: First metal component

[0049] 502: Second metal component DETAILED DESCRIPTION

[0050] Unless otherwise specifically stated, the singular forms of the terms used in this specification may be construed as also including the plural forms.

[0051] The numerical range used in this specification includes the lower limit value and the upper limit value and all possible combinations of all values ​​within the range, all values ​​defined therein, and the upper and lower limits of the numerical range defined in different forms from each other. In this specification, unless otherwise specifically defined, values ​​outside the numerical range that may appear due to experimental errors or rounding of values ​​are also included in the defined numerical range.

[0052] The words “comprising” or “including” mentioned in this specification are open-ended statements with the same meaning as “having”, “containing”, “having”, “characterized by”, etc., and do not exclude elements, materials or processes not further listed.

[0053] The expressions "woven inorganic long fibers" or "woven inorganic long fiber network" mentioned in this specification refer to an inorganic long fiber network formed by weaving a plurality of first fibers (weft yarns) arranged in a first direction and second fibers (warp yarns) arranged in a second direction intersecting the first direction. In the angles mentioned in this specification, + refers to the angle in the clockwise direction, and - refers to the angle in the counterclockwise direction.

[0054] A specific embodiment of the present invention is a battery module, characterized in that the battery module accommodates a plurality of secondary battery cells in a shell component, the shell component includes an upper shell, a lower shell and a side cover connected to each other by a fastening portion, the upper shell is made of a flame retardant composite material including a thermal insulation layer, the thermal insulation layer contains an inorganic long fiber network and an organic adhesive, and the inorganic long fiber network is formed by weaving a plurality of first fibers (weft yarns) arranged in a first direction and second fibers (warp yarns) arranged in a second direction intersecting the first direction with each other.

[0055] By having the above-mentioned structural combination, the spread of heat or flame can be effectively suppressed when a fire occurs.

[0056] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings, however, this is merely exemplary and the present invention is not limited to the specific embodiments described exemplarily.

[0057] Figure 1 is a perspective view schematically showing a battery module according to a specific embodiment of the present invention, Figure 2 yes Figure 1 An exploded perspective view of a battery module is shown in FIG.

[0058] Reference Figure 1 and Figure 2 , a battery module 100 according to one embodiment of the present invention may include a case 30 , which may have a hexahedral shape and protect a plurality of secondary battery cells 10 from external influences.

[0059] At this time, the case 30 may include a lower case 40 accommodating a plurality of secondary battery cells 10 therein, an upper case 50 , and a side cover 60 , which may be coupled to each other through the fastening part 1 using fixing members such as bolts or screws.

[0060] The lower housing 40 may include a first plate 42 supporting the lower surface of the plurality of secondary battery cells 10 and a side plate 48 supporting the side surface. The first plate 42 and the side plate 48 may be integrally formed, or they may be formed of separate components as required.

[0061] Each secondary battery cell 10 having a structure in which an electrode lead 15 protrudes from the body to the outside may be disposed with the electrode lead 15 facing the side plate 48 , and a bus bar 80 electrically connected to the electrode lead 15 may be disposed between the side plate 48 and the secondary battery cell 10 .

[0062] In addition, in the lower shell 40, an insertion portion in the form of a through hole (not shown) can be located in the first plate 42 so that multiple secondary battery cells 10 can be easily inserted, and in order to prevent the internal components of the battery module 100 from being exposed to the outside of the first plate 42 through the insertion portion (not shown) while improving the adhesion with the multiple secondary battery cells 10, an insulating part 20 inserted into and disposed in the insertion portion (not shown) may be included.

[0063] The lower shell 40 can be made of a material with high thermal conductivity such as metal, for example, aluminum. However, even if it is not metal, various materials can be used as long as they have similar strength and thermal conductivity.

[0064] Side covers 60 may be respectively coupled to both ends of the tubular member formed by coupling the upper housing 50 and the lower housing 40 .

[0065] The side cover 60 is respectively coupled to the lower case 40 and the upper case 50 to complete the appearance of the battery module 100. At this time, the side cover 60 may be made of a rigid material, for example, an insulating material such as resin or a conductive material such as metal.

[0066] A circuit part 70 may be disposed between the case 30 including the upper case 50 , the lower case 40 , and the side cover 60 coupled to each other by the fastening part 1 and the plurality of secondary battery cells 10 .

[0067] The circuit part 70 may be connected to the electrode leads 15 of the plurality of secondary battery cells 10 through the bus bar 80 , and may have a connection terminal 72 for connection to the outside.

[0068] The connection terminal 72 of the circuit part 70 may be exposed to the outside through the terminal hole 52 formed in the upper case 50 , and the terminal hole 52 of the upper case 50 may be formed to correspond to the size and shape of the connection terminal 72 .

[0069] In addition, an insulating plate 90 may be provided between the housing 30 and the bus bar 80. The insulating plate 90 is provided to ensure insulation between the housing 30 and the bus bar 80. Therefore, the insulating plate 90 may be formed of an insulating material such as resin or rubber, and may be formed in a size to face the entire bus bar 80.

[0070] In a specific embodiment, the upper shell 50 included in the shell component can be made of a flame retardant composite material including an insulation layer, wherein the insulation layer contains an inorganic long fiber network and an organic binder, and the inorganic long fiber network is formed by weaving a plurality of first fibers (weft yarns) arranged along a first direction and second fibers (warp yarns) arranged along a second direction intersecting the first direction with each other.

[0071] That is, the flame retardant composite material including the heat insulation layer itself may be the upper case 50 .

[0072] As an example, the angle at which the first fiber (weft yarn) and the second fiber (warp yarn) cross can be 30° to 90°. By weaving within the above angle range to form an inorganic long fiber network, excellent thermal insulation and durability can be achieved. Specifically, the angle can be 45° to 90°, and more specifically, the angle can be 60° to 90°.

[0073] According to a specific embodiment, the thermal insulation layer may include a plurality of unit thermal insulation layers stacked together. In this case, the thermal insulation layer may be stacked in such a manner that the directions of the first fibers (weft yarns) contained in the unit thermal insulation layers are different from each other.

[0074] As an embodiment, 1-20, 1-10 or 4-8 unit thermal insulation layers may be stacked in the thermal insulation layer.

[0075] As an example, when the thermal insulation layer includes a first unit thermal insulation layer, a second unit thermal insulation layer, a third unit thermal insulation layer, a fourth unit thermal insulation layer, a fifth unit thermal insulation layer and a sixth unit thermal insulation layer, each unit thermal insulation layer may contain an inorganic long fiber network and an organic binder, wherein the inorganic long fiber network is formed by weaving a plurality of first fibers (weft yarns) arranged along a first direction and second fibers (warp yarns) arranged along a second direction intersecting the first direction with each other.

[0076] At this time, the first fibers (weft yarns) contained in each unit insulation layer may be stacked in a manner that the directions of the first fibers (weft yarns) contained in each unit insulation layer are different from each other, and the first fibers (weft yarns) contained in each adjacent unit insulation layer may be arranged at an angle that differs by more than 0° and less than 90°, specifically, an angle of 30° to 90°. At this time, the above angle range is only an example and can be freely adjusted within the above angle range as needed.

[0077] As an example, the thickness of each unit insulation layer may be independently 0.1-15 mm, specifically 0.3-10 mm.

[0078] In a specific embodiment, the inorganic long fibers contained in the unit insulation layer may include glass long fibers. By including glass long fibers, excellent insulation and durability can be achieved, and the large area and reproducibility of the glass long fiber network can be easily achieved.

[0079] Furthermore, the long glass fibers may include fabrics in which fibers (yarns) are arranged in only one direction. As an example, the long glass fibers may use unidirectional fabrics, non-crimp fabrics, woven fabrics, etc., but are not limited thereto.

[0080] In addition, the organic binder contained in the unit heat insulation layer may include a curable polymer. The curable polymer may include any one selected from unsaturated polyester resins, epoxy resins, urea-formaldehyde resins, melamine resins, phenolic resins, resorcinol resins and polyurethanes, or a mixture of two or more thereof. Specifically, the curable polymer may be an unsaturated polyester resin or an epoxy resin, and more specifically, may be an unsaturated polyester resin.

[0081] As a specific embodiment, the unit thermal insulation layer may further include an inorganic filler.

[0082] By further including an inorganic filler in the unit heat insulating layer, the propagation of heat or flame can be more effectively suppressed, and there is an advantage that the durability can be further improved.

[0083] Specifically, when a fire occurs in the battery module 100, the temperature may rise to about 1200°C, and an explosion may occur due to the increase in temperature and pressure inside the module. Therefore, by making the flame retardant composite material include a unit heat insulation layer composed of a woven inorganic long fiber network, an organic binder and an inorganic filler, excellent heat insulation and durability can be achieved, so the spread of heat or flame can be effectively suppressed.

[0084] The inorganic filler can be evenly distributed on the inorganic long fiber network. Therefore, it can have structural stability in all temperature ranges, and can ensure long-term stability by suppressing dust or debris generated by the inorganic filler.

[0085] At this time, uniformly distributed may mean highly dispersed and uniformly distributed.

[0086] The shape of the inorganic filler is not particularly limited, and may be, for example, granulated, fibrous, rod-shaped, spherical, plate-shaped, or flake-shaped. Specifically, the inorganic filler may be granulated.

[0087] When the inorganic filler is in a granular form, it can be more evenly distributed on the woven inorganic long fiber network and can effectively suppress the spread of heat or flame.

[0088] The inorganic filler can be used without restriction, as long as it can effectively prevent the spread of heat or flame and improve durability. For example, the inorganic filler can include any one or a mixture of two or more selected from metal hydroxides, mica, biotite, muscovite, sericite, metal oxides, metal carbonates, silicon dioxide, diatomaceous earth, dawsonite, barium sulfate, talc, clay, montmorillonite, bentonite, activated clay, sepiolite, imogolite, glass beads, silica-based hollow spheres, aluminum nitride, boron nitride, silicon nitride, carbon black, graphite, carbon fiber, carbon hollow spheres, charcoal powder, potassium titanate, magnesium sulfate, lead zirconate titanate, zinc stearate, calcium stearate, aluminum borate, molybdenum sulfide, silicon carbide, stainless steel fiber, zinc borate, various magnetic powders, slag fiber, fly ash, and dewatered sludge. This is just an example and is not necessarily limited to this.

[0089] Preferably, the inorganic filler may include any one or both selected from heat absorbing materials or heat expanding materials. The unit heat insulating layer may include heat absorbing materials or heat expanding materials as inorganic fillers, or may include heat absorbing materials and heat expanding materials as inorganic fillers at the same time. More preferably, when heat absorbing materials and heat expanding materials are included at the same time, the propagation of heat or flame can be effectively suppressed. At this time, the weight ratio of heat absorbing materials to heat expanding materials may be 1:0.8 to 1.4. More specifically, the weight ratio of heat absorbing materials to heat expanding materials may be 1:1.1 to 1.4.

[0090] The endothermic material may include any one or more selected from aluminum hydroxide, talc, calcium carbonate, diatomaceous earth, titanium oxide, zeolite or white carbon black, but is not necessarily limited thereto. The endothermic material may function as an endothermic material through a dehydration reaction, and may be used without restriction as long as it can quickly absorb high-temperature heat when a fire occurs in the module. Specifically, the endothermic material may start an endothermic reaction at a temperature above 110°C, and may exhibit an endothermic performance of more than 50% of the total endothermic performance within a temperature range of 110-150°C, for example, 50-80% of the endothermic performance. More specifically, the endothermic material may be aluminum hydroxide.

[0091] The thermal expansion material may include any one or more selected from mica, biotite, muscovite, vermiculite, kaolin, thermal expansion graphite, perlite, and bentonite, but is not necessarily limited thereto. The thermal expansion material may be used without restriction as long as the space for heat or flame movement can be closed or the propagation of heat or flame can be prevented. Specifically, the thermal expansion material may be mica.

[0092] Preferably, the inorganic filler can use aluminum hydroxide and mica at the same time. When a fire occurs in the module, aluminum hydroxide quickly absorbs heat to suppress the temperature rise inside the battery module, while mica prevents the spread of flames, thereby achieving optimal performance.

[0093] In a specific embodiment, when the unit thermal insulation layer is projected in a direction perpendicular to the surface, the inorganic filler on the woven inorganic long fiber network included may have an area fraction of 80% or more based on the total area of ​​the unit thermal insulation layer surface. Within the above range, the propagation of heat or flame can be effectively suppressed, and excellent durability can be achieved. Specifically, the area fraction may be 85% or more, more specifically 90% or more, and substantially 99% or less.

[0094] In a specific embodiment, the average diameter of the inorganic filler may be 1-50 μm. Within the above range, the inorganic filler is evenly distributed in the inorganic long fiber network, thereby achieving excellent thermal insulation and durability. Specifically, the average diameter of the inorganic filler may be 5-40 μm, more specifically 10-30 μm.

[0095] In addition, the unit thermal insulation layer may further include additives such as flame retardants known in the art.

[0096] In a specific embodiment, the unit thermal insulation layer may independently contain 40-80 weight % of inorganic long fibers, 10-30 weight % of organic binder, 1-15 weight % of inorganic filler and 5-20 weight % of additives relative to the total weight. Within the above range, the spread of heat or flame can be effectively suppressed. Specifically, the unit thermal insulation layer may independently contain 50-80 weight % of inorganic long fibers, 12-18 weight % of organic binder, 2-8 weight % of inorganic filler and 10-20 weight % of additives relative to the total weight. More specifically, the unit thermal insulation layer may independently contain 50-80 weight % of inorganic long fibers, 14-18 weight % of organic binder and 4-8 weight % of inorganic filler relative to the total weight.

[0097] As described above, the upper case 50 may be made of a flame retardant composite material including a heat insulating layer including the above-mentioned plurality of unit heat insulating layers.

[0098] As a specific embodiment, a plurality of unit heat insulation layers may contain inorganic short fibers and an organic binder independently of each other. More specifically, the unit heat insulation layer containing inorganic short fibers and an organic binder may be located at the outermost side of the flame retardant composite material.

[0099] At this time, the organic binder is the same as or similar to the organic binder contained in the above-mentioned unit heat insulating layer, and thus a detailed description thereof is omitted.

[0100] By making the first unit insulation layer and the second unit insulation layer located at the outermost side of the flame retardant composite material each contain inorganic short fibers and an organic binder, the formability of the flame retardant composite material can be improved, and it can be easily combined with the following metal parts, so that the flame retardant composite material itself can be used as the upper shell 50.

[0101] As a specific embodiment, the inorganic short fibers may include any one or more selected from glass fibers, silica fibers, alumina fibers, aluminum silicate fibers, zirconium oxide fibers or mineral fibers. Specifically, the inorganic short fibers may be chopped glass fibers.

[0102] In the case of chopped glass fibers, excellent formability can be achieved, and moisture or foreign matter can be effectively prevented from passing through the module. The average length of the chopped glass fibers can be 10-50 mm. Within the above range, excellent formability can be achieved, and moisture and foreign matter can be prevented from passing through. Specifically, the average length of the chopped glass fibers can be 20-30 mm.

[0103] In a specific embodiment, the outermost first unit insulation layer and the second unit insulation layer of the flame retardant composite material can further contain inorganic reinforcing materials independently of each other. Durability can be improved by including inorganic reinforcing materials, and the inorganic reinforcing materials can include, for example, any one selected from metal oxides, metal hydroxides, metal carbonates, silica, diatomaceous earth, carbon sodium aluminum stone, barium sulfate, talc, clay, mica, biotite, muscovite, sericite, montmorillonite, bentonite, activated clay, sepiolite, imogolite, glass beads, silica-based hollow spheres, aluminum nitride, boron nitride, silicon nitride, carbon black, graphite, carbon fiber, carbon hollow spheres, charcoal powder, potassium titanate, magnesium sulfate, lead zirconate titanate, zinc stearate, calcium stearate, aluminum borate, molybdenum sulfide, silicon carbide, stainless steel fiber, zinc borate, various magnetic powders, slag fiber, fly ash, dehydrated sludge, or a mixture of two or more thereof. The inorganic reinforcing material is not particularly limited, but can specifically be aluminum oxide.

[0104] As a specific embodiment, the first unit thermal insulation layer and the second unit thermal insulation layer may independently contain inorganic short fibers: organic binder in a weight ratio of 4:6 to 9:1, specifically 5:5 to 9:1, more specifically 6:4 to 8:2.

[0105] As a specific embodiment, the thickness of the first unit thermal insulation layer and the second unit thermal insulation layer can be independently 0.1-10 mm, specifically 0.3-5.1 mm, but the thickness of the unit thermal insulation layer is only an example and the present invention is not limited thereto.

[0106] By making the thickness of the first unit heat insulating layer and the second unit heat insulating layer satisfy the above range, the moldability of the flame retardant composite material can be improved, and thus the flame retardant composite material itself can be used as the upper case 50 .

[0107] At this time, the thicknesses of the first unit heat insulating layer and the second unit heat insulating layer may be different from or the same as each other.

[0108] In a specific embodiment, the thickness ratio of the first unit insulation layer located at the outermost side of the flame retardant composite material and comprising inorganic short fibers and organic adhesive to the second unit insulation layer can be 1:1 to 1:15, specifically 1:1 to 1:10, but the thickness ratio is only an example and the present invention is not limited to the thickness ratio.

[0109] In order to improve the moldability of the flame-retardant composite material while effectively suppressing the spread of heat or flame, it is advantageous for the thickness ratio of the first unit insulation layer: the second unit insulation layer to satisfy the above range.

[0110] In a specific embodiment, the upper shell 50 made of the flame-retardant composite material may further include a metal component.

[0111] As described above, the upper shell 50 made of the above-mentioned flame-retardant composite material itself maintains its structure even in a high-temperature flame, thereby effectively suppressing the spread of heat or flame, but has poor ductility characteristics, so there may be a risk of damage to the fastening portion 1 where stress is concentrated due to the swelling phenomenon of the secondary battery cell.

[0112] However, by further including a metal member in the upper case 50 , there is an advantage that the structural rigidity of the upper case 50 including the fastening portion 1 can be improved so as to withstand concentrated stress caused by the swelling phenomenon of the secondary battery cells.

[0113] As non-limiting examples, the metal parts may include metals such as iron, gold, silver, nickel, chromium, titanium, stainless steel, copper, molybdenum, etc., but are not limited thereto. As long as the metal has a high melting point and excellent ductility characteristics, it can be used without restriction.

[0114] At this time, the metal component may be located at the outermost side or the inner side of the upper housing 50 .

[0115] That is, in the upper shell 50 made of a flame-retardant composite material including an insulation layer comprising a plurality of unit insulation layers, when the metal component is located at the outermost side, the metal component may be located on a first unit insulation layer or a second unit insulation layer, which is located at the outermost side of the flame-retardant composite material and is exposed to the outside and contains inorganic short fibers and an organic binder, and when the metal component is located inside, the metal component may be located between layers of a plurality of unit insulation layers included in the insulation layer.

[0116] Figure 3 is an enlarged perspective view of an upper housing 50 further including a metal component 500 according to a specific embodiment.

[0117] Reference Figure 3 , the metal component 500 may be provided in such a manner that the fastening parts 1 located at both ends of the upper housing 50 are connected to each other.

[0118] A plurality of fastening parts 1 for combining with the side cover 60 and the lower case 40 are located at the two ends.

[0119] That is, the metal part 500 can be connected to the fastening parts 1 arranged opposite to each other at the two ends of the upper shell 50 and can be located in the length direction of the upper shell 50 or in a direction perpendicular to the length direction, and can be located both in the length direction of the upper shell 50 and in a direction perpendicular to the length direction.

[0120] Therefore, by connecting and including at least one or more metal parts 500 and the fastening parts 1 located at both ends to each other, the structural rigidity of the upper case 50 made of the flame-retardant composite material can be improved.

[0121] Figure 4 is an enlarged perspective view of an upper housing 50 further including a metal component 500 according to another specific embodiment.

[0122] Reference Figure 4 , two or more fastening parts 1 located at one end of the upper shell 50 can be arranged in a manner of being continuously connected to the metal component 500.

[0123] In addition, the metal member 500 may have the same shape as one end of the upper case 50 where the fastening part 1 is located and may be disposed in such a manner as to be in contact with all the fastening parts 1 located at the one end. Therefore, it is possible to effectively prevent the fastening part 1 from being damaged due to module deformation caused by the swelling phenomenon of the secondary battery cell.

[0124] Figure 5is an enlarged perspective view of an upper housing 50 further including a metal component 500 according to another specific embodiment.

[0125] Reference Figure 5 The upper shell 50 may include a first metal component 501 and a second metal component 502, wherein the first metal component 501 is arranged in a manner connected to the fastening parts 1 located at the two ends of the upper shell 50, and the second metal component 502 has the same shape as the shape of one end of the upper shell 50 and is arranged in a manner connected to all the fastening parts 1 located at the one end.

[0126] At this time, the fastening portion 1 is in doubly contact with the first metal component 501 and the second metal component 502 , thereby having an advantage of further improving the structural rigidity of the upper housing 50 .

[0127] Figure 6 is an enlarged perspective view of an upper housing 50 further including a metal component 500 according to another specific embodiment.

[0128] Reference Figure 6 , the metal component 500 may be located on at least one side of the upper shell 50 including the fastening portion 1 .

[0129] That is, the metal member 500 may have the same shape as one surface of the upper case 50 including the fastening portion 1 and be provided so as to correspond to the entire surface of the upper case 50 .

[0130] Therefore, there is an effect of effectively preventing damage to the fastening portion 1 while improving the elongation characteristics of the entire surface of the upper case 50 .

[0131] As a non-limiting specific example, according to the design of the battery module, various holes may be formed in the upper case 50. Therefore, the heat insulating layer included in the upper case 50 and the metal component 500 located on at least one side of the upper case 50 may also form holes.

[0132] Furthermore, a specific embodiment of the present invention may provide a battery pack including the battery module.

[0133] As described above, a battery module including a shell component made of a flame-retardant composite material has excellent structural rigidity and can suppress the spread of heat or flame when a secondary battery cell catches fire, and a battery pack including the battery module has the advantage of improving stability by effectively preventing a thermal runaway phenomenon caused by the ignition of a secondary battery cell.

[0134] Hereinafter, the present invention will be described in detail by way of examples. However, the following examples are only used to illustrate the present invention, and the content of the present invention is not limited by the following examples. At this time, unless otherwise defined, the technical terms and scientific terms used have the meanings commonly understood by those skilled in the art to which the present invention belongs. In addition, the repeated description of the technical features and functions identical to those of the prior art is omitted.

[0135] (Manufacturing Example) Manufacture of flame-retardant composite material

[0136] Each flame retardant composite material having a thickness of 1 mm was manufactured using the composition of Table 1 below.

[0137] (Table 1)

[0138]

[0139] At this time, in Manufacturing Examples 1 and 2 except Manufacturing Example 3, the short glass fibers contained in the first unit insulation layer and the second unit insulation layer located on the outermost side of the flame-retardant composite material use short glass fibers with a length of 25.4 mm, and the woven long glass fibers use woven long glass fibers in which the first fibers (weft yarns) and the second fibers (warp yarns) are crossed at 60°.

[0140] In addition, in Manufacturing Examples 1 and 2, a thermal insulation layer having 8 unit thermal insulation layers stacked in total was prepared, wherein in Manufacturing Example 1, in the thermal insulation layer having the third unit thermal insulation layer / the fourth unit thermal insulation layer / the fifth unit thermal insulation layer / the sixth unit thermal insulation layer / the seventh unit thermal insulation layer / the eighth unit thermal insulation layer stacked, the arrangement direction of the first fibers (weft yarns) contained in the third unit thermal insulation layer was used as a reference (0°), and the first fibers (weft yarns) contained in each unit thermal insulation layer were set to 90°, -45°, 45°, 90°, and 0°, respectively, and in Manufacturing Example 2, the first fibers (weft yarns) contained in each unit thermal insulation layer were set to be parallel to the arrangement direction of the first fibers (weft yarns) contained in the third unit thermal insulation layer.

[0141] (Example 1)

[0142] Among the housing components composed of the lower housing, the side cover and the upper housing, the flame-retardant composite material of Production Example 1 was molded to prepare the upper housing. At this time, the lower housing and the side cover made of aluminum were used.

[0143] Next, a plurality of secondary battery cells are housed in the case member, and then bolts and nuts are fastened to the respective fastening portions, thereby manufacturing a battery module.

[0144] (Example 2)

[0145] The upper casing was prepared by the same method as in Example 1 except that the flame-retardant composite material of Manufacturing Example 2 was molded.

[0146] (Example 3)

[0147] The battery module was manufactured by the same method as in Example 1 except that an iron metal bar and fastening parts at both ends of the prepared upper case were connected to each other and then bolts and nuts were fastened to the fastening parts.

[0148] (Example 4)

[0149] The battery module was manufactured by the same method as in Example 1, except that the iron metal strips were arranged in contact with the fastening parts at both ends in the length direction of the upper case, and then bolts and nuts were fastened to the fastening parts.

[0150] (Example 5)

[0151] The battery module was manufactured by the same method as in Example 1 except that the iron metal bars used in Examples 3 and 4 were provided at the same time, and then bolts and nuts were fastened to the fastening parts.

[0152] (Example 6)

[0153] The battery module was manufactured by the same method as in Example 1 except that an iron metal plate was provided to contact the entire upper surface of the upper case including the fastening portion, and then bolts and nuts were fastened to the fastening portion.

[0154] (Comparative Example 1)

[0155] The upper casing was prepared by the same method as in Example 1 except that the flame-retardant composite material of Manufacturing Example 3 was molded.

[0156] (Comparative Example 2)

[0157] A battery module was manufactured by the same method as in Example 1 except that an upper case made of aluminum was used instead of the upper case prepared by molding the flame-retardant composite material of Manufacturing Example 1.

[0158] (Evaluation example)

[0159] According to the GB / T-38031 safety test, one of the safety tests for battery modules, any battery cell contained in the battery module is ignited to above 1200°C to intentionally simulate thermal runaway. The thermal runaway phenomenon is allowed to continue for 30 minutes while confirming whether the battery module explodes.

[0160] As a result of the evaluation, in the case of Comparative Example 2 including the upper shell made of aluminum, it was confirmed that a hole was generated in the upper shell, and the flame spread rapidly within 5 minutes based on the time point of intentional ignition.

[0161] On the other hand, in the case of Examples 1 to 6, it was confirmed that no hole was formed in the upper casing, and therefore the propagation speed of the flame could be significantly delayed.

[0162] Among them, in the case of Examples 3 to 6 in which the upper shell further includes metal parts, the flame did not propagate even after 8 minutes, and a relatively excellent flame propagation delay effect was observed. In particular, in the case of Examples 5 and 6, the flame propagation delay effect was confirmed to be the best.

[0163] The embodiments of the present invention are described above, but the present invention is not limited to the above embodiments, but can be implemented in various forms different from each other, and those skilled in the art of the present invention can understand that it can be implemented by other specific schemes without changing the technical ideas or essential features of the present invention. Therefore, it should be understood that the embodiments described above are exemplary and not restrictive in all aspects.

Claims

1. A battery module, the battery module accommodating a plurality of secondary battery cells in a case member, the case member comprising an upper case, a lower case and a side cover coupled to each other by a fastening portion, The upper shell is made of a flame-retardant composite material including an insulation layer, wherein the insulation layer contains an inorganic long fiber network and an organic adhesive, and the inorganic long fiber network is formed by weaving a plurality of first fibers, i.e., weft yarns, arranged along a first direction and second fibers, i.e., warp yarns, arranged along a second direction intersecting the first direction with each other.

2. The battery module according to claim 1, wherein: The upper housing further includes a metal component.

3. The battery module according to claim 2, wherein: The metal component is located at the outermost side or the inner side of the upper shell.

4. The battery module according to claim 2, wherein: The metal component is provided in a manner of being connected to one or more fastening parts located at both ends of the upper housing.

5. The battery module according to claim 2, wherein: Two or more fastening parts located at one end of the upper shell are provided in a manner of being continuously connected to the metal component.

6. The battery module according to claim 2, wherein: The metal component is located on at least one side of the upper housing including the fastening portion.

7. The battery module according to claim 1, wherein: The thermal insulation layer includes a plurality of stacked unit thermal insulation layers.

8. The battery module according to claim 7, wherein: The directions of the first fibers, ie, weft yarns, of the adjacent unit insulation layers in the plurality of unit insulation layers are the same as or different from each other.

9. The battery module according to claim 7, wherein: The thermal insulation layer comprises 1 to 10 thermal insulation unit layers stacked therein.

10. The battery module according to claim 7, wherein: The unit thermal insulation layer further includes an inorganic filler.

11. The battery module according to claim 10, wherein: The inorganic filler comprises any one or both selected from heat absorbing materials and heat expanding materials.

12. The battery module according to claim 11, wherein: The heat absorbing material comprises one or more selected from aluminum hydroxide, talc, calcium carbonate, diatomaceous earth, titanium oxide, zeolite or white carbon black.

13. The battery module according to claim 11, wherein: The thermal expansion material comprises any one or more selected from mica, biotite, muscovite, vermiculite, kaolin, thermal expansion graphite, perlite, and bentonite.

14. The battery module according to claim 1, wherein: The inorganic long fibers include glass long fibers.

15. The battery module according to claim 1, wherein: The organic binder includes a curable polymer.

16. The battery module according to claim 15, wherein: The curable polymer includes an unsaturated polyester.

17. A battery pack comprising a battery module accommodating a plurality of secondary battery cells in a case member, the case member comprising an upper case, a lower case, and a side cover coupled to each other by a fastening portion, The upper shell is made of a flame-retardant composite material including an insulation layer, wherein the insulation layer contains an inorganic long fiber network and an organic adhesive, and the inorganic long fiber network is formed by weaving a plurality of first fibers, i.e., weft yarns, arranged along a first direction and second fibers, i.e., warp yarns, arranged along a second direction intersecting the first direction with each other.

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