Battery module

Abstract

A battery module according to one embodiment of the present invention comprises: a lower case for accommodating a plurality of battery cells; an upper case covering the lower case and provided with an opening formed so as to discharge gas generated when the internal pressure of the battery cells is equal to or greater than a certain value; and an insulating part coupled to one surface of the inner side of the upper case so as to cover the opening, the insulating part being provided with insulating paper, the insulating paper containing: 55-70 parts by weight of kaolin (Kaolin); 13 parts by weight to 22 parts by weight of 1, 4-phthaloyl dichloride (C8H4Cl2O2); and 6 to 11 parts by weight of aluminum hydroxide (Al (OH) 3).

Description

Technical Field

[0001] An embodiment of the present invention relates to a battery module, which is used for charging or supplying power in an electric vehicle, a power storage device or a portable electronic product. Background Art

[0002] Recently, the technical development and demand for electric vehicles, hybrid vehicles, power storage devices, uninterruptible power supply devices, etc. have increased, and as a result, the demand for secondary batteries as energy sources has increased dramatically. In particular, the battery packs used in electric vehicles or hybrid vehicles are high-power, large-capacity secondary batteries, and a lot of research is being conducted on this.

[0003] In particular, lithium secondary batteries have a higher energy density per unit weight than other secondary batteries such as existing lead storage batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and nickel-zinc batteries, and can be charged quickly, so their use is actively increasing.

[0004] For lithium secondary batteries, their operating voltage is above 3.6V, and they are used as power sources for portable electronic devices, or multiple batteries are connected in series or in parallel for high-power electric vehicles, hybrid vehicles, power tools, electric bicycles, power storage devices, uninterruptible power supply devices, etc.

[0005] On the other hand, when the battery pack generates electricity, heat is generated due to electrochemical reactions. When this heat still remains in the cells inside the battery pack, the temperature of the cells increases, causing the working conditions of the cells to deteriorate, thereby posing a hidden danger of poor power generation efficiency. Moreover, due to the heat generated, the pressure inside the sealed battery pack increases, thereby posing a risk of explosion. Therefore, ensuring safety is one of the most important goals.

[0006] Conventionally, in order to prevent explosions caused by temperature rise due to use of battery packs, a method of forcibly cutting off the power supply has been adopted to prevent explosions.

[0007] This method immediately cuts off the power supply to prevent the temperature of the battery pack from rising, but there is a problem that the temperature remaining inside the battery pack may cause the battery pack to explode. Summary of the invention

[0008] Problems to be solved by the invention

[0009] The present invention is proposed to solve the above-mentioned existing technical problems, and its purpose is to provide a battery module, wherein when the temperature of the battery module rises above a set pressure, the internal gas is discharged to induce immediate cooling, thereby preventing the explosion of the battery module caused by high temperature in advance.

[0010] Solutions for solving problems

[0011] In order to achieve the purpose of the present invention as described above, a battery module according to an embodiment of the present invention includes: a lower shell, which accommodates a plurality of battery cells; an upper shell, which covers the lower shell and is provided with an opening, wherein the opening is formed to discharge gas generated when the internal pressure of the battery cells is above a certain level; and an insulating portion, which is combined with one side of the upper shell in a manner covering the opening, and the insulating portion has insulating paper, wherein the insulating paper includes: 55 to 70 parts by weight of kaolin; 13 to 22 parts by weight of 1,4-phthaloyl dichloride (C 8 H 4 Cl 2 O 2 ); and 6 to 11 parts by weight of aluminum hydroxide (Al(OH) 3 ).

[0012] According to an example of the present invention, a first area and a second area are formed on one side of the insulating paper, an adhesive layer is formed on the first area so as to be attached to the upper shell, the second area covers the opening, and an open pattern is formed on the insulating paper corresponding to the second area, and the open pattern is formed in a manner of being broken when the gas is discharged.

[0013] According to one example of the present invention, the thickness of the insulating paper is 0.10 mm to 0.15 mm, the open pattern includes lines formed with a notching depth of 50 μm to 90 μm, and the open pattern includes at least two intersections formed by the lines intersecting each other in each of the openings.

[0014] According to one example of the present invention, the insulating paper is formed to have a thickness of 160 g / m 2 Up to 220g / m 2 The weight ratio is 1.3 g / cc to 1.6 g / cc, the density is 30 N / cm to 50 N / cm, and the burst strength is 150 KPa to 210 KPa.

[0015] Effects of the Invention

[0016] In the battery module of at least one embodiment of the present invention constructed as described above, when the temperature of the battery module rises to above the set pressure, the internal gas is discharged to induce immediate cooling, thereby preventing the battery module from exploding due to high temperature in advance. As a result, the stability of the battery module can be effectively improved, and the internal gas generated by the rapid increase in the pressure of the battery cell is discharged along the preset direction, so that the pressure inside the battery can be kept constant.

[0017] Furthermore, by keeping the battery voltage drop time constant, sufficient evacuation time for passengers in electric vehicles in an emergency can be ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 FIG. 4 is an exploded perspective view of a battery module according to an embodiment of the present invention.

[0019] Figure 2 for Figure 1 Schematic diagram of the insulating sheet used in.

[0020] Figure 3 To show Figure 1 FIG. 1 is a diagram of one side of an insulating sheet shown in FIG. DETAILED DESCRIPTION

[0021] Hereinafter, the specific implementation mode of the present invention will be described with reference to the accompanying drawings. The embodiments of the present invention are used to illustrate an invention, and the scope of rights is not limited to the illustrated embodiments. In the illustrated drawings, for the clarity of the invention, only the core content is magnified and the additional content is omitted. Therefore, it cannot be limited to the drawings for interpretation. The suffixes "module" and "unit" of the constituent elements used in the following description are only given or mixed for the ease of writing the description, and they themselves do not have mutually distinguishable meanings or functions. In this specification, even in different embodiments, the same or similar structures are given the same or similar figure marks, and the description thereof is replaced by the first description. Unless the context clearly states otherwise, the singular expressions used in this specification include the plural expressions.

[0022] Figure 1 is an exploded perspective view of a battery module according to an embodiment of the present invention. Figure 2 for Figure 1 Schematic diagram of the insulating sheet used in, Figure 3 To show Figure 1 FIG. 1 is a diagram of one side of an insulating sheet shown in FIG.

[0023] Reference Figures 1 to 3 A battery module according to an embodiment of the present invention includes a lower shell 103 , an upper shell 102 and an insulating sheet 101 .

[0024] The lower shell 103 is formed to accommodate the battery cell 104. The lower shell 103 may be formed of a metal or synthetic resin material, or at least a portion thereof may be formed of different materials. For example, the entirety may be formed of a metal material, and at least a portion thereof may be formed of a synthetic resin material. The battery cells may be formed to include an electrode assembly and a cover portion, respectively. The electrode assembly may be formed in a state where a separator is provided between the anode plate and the cathode plate. The cover portion is formed to accommodate the electrode assembly. Electrode terminals may be formed on one side and the other side of the battery cell, and the battery cell may be electrically connected via a busbar of a metal material. If the internal pressure of the battery cell becomes above a certain level, a portion of the cover portion is damaged and the gas is discharged to the outside. At this time, the internal pressure may be 150KPa to 210KPa.

[0025] The upper case 102 is combined with the lower case 103 in a manner of covering the lower case 103. The upper case 102 is provided with an opening 102a formed to discharge gas generated when the internal pressure of the battery cell is above a certain level. The upper case 102 may be formed of a metal or synthetic resin material, or at least a portion thereof may be formed of different materials.

[0026] The insulating sheet 101 is formed on one surface of the upper case 102 so as to cover an opening 102 a formed in the upper case 102 .

[0027] Reference Figure 2 and Figure 3 , two regions are formed on one side of the insulating sheet 101. Figure 2 The back side of the insulating paper is shown in Figure 3 The front side of the insulating paper is shown in FIG. An adhesive layer 120 is formed in a first area of ​​the insulating paper. The first area includes most of the area of ​​the insulating paper that does not cover the opening. The adhesive layer 120 can be formed by bonding a double-sided tape to the insulating paper 110. The second area is an area covering the opening formed in the upper shell 102, and an open pattern 111 is formed on the insulating paper 110 corresponding to the second area. The portion where the open pattern 111 is not formed becomes the first area, and the insulating sheet 101 is provided to the assembler in a state where the release paper and the insulating paper 110 are combined at one time through the adhesive layer 120. After the operator separates the release paper from the insulating sheet 101, the insulating sheet 101 is combined with the upper shell 102. The insulating sheet 101 can be combined with one inner side or one outer side of the upper shell 102.

[0028] The thickness d of the insulating paper 110 2The opening pattern 111 formed on the insulating paper 110 is preferably 0.10 mm to 0.15 mm. The opening pattern 111 formed on the insulating paper 110 is composed of lines formed with a notching depth of 50 μm to 90 μm. The notching depth may vary according to the set internal pressure. When the internal pressure is 150 KPa to 210 KPa, the notching depth d of the open pattern 111 is 1 It may be 50 μm to 90 μm. If the thickness of the insulating paper 110 is less than 0.1 mm, it may be broken at a lower pressure, or the breaking may not be induced by the open pattern 111. On the contrary, if the thickness of the insulating paper 110 is greater than 0.15 mm, it may not be broken well, and thermal deformation may occur in the insulating paper 110.

[0029] The slotting refers to forming a slot 111 of a certain shape on the insulating paper 110, and the slot 111 can be formed on the insulating paper 110 by a laser slotting device or a punching slotting device (for example, a punching device). The slot can be in a "U" shape or a "V" shape, etc. The open pattern can be made into various shapes according to the designer's intention. For example, the open pattern can include "-" or "Y" as part of the pattern.

[0030] According to a preferred embodiment, the open pattern 111 is formed to include at least two intersections 111a and 111b formed by intersecting lines in each opening portion. Thus, when the internal pressure is above a certain level, the open pattern 111 is broken to form a plurality of openings, so that the gas can be discharged more smoothly and quickly.

[0031] The insulating paper 110 according to an embodiment of the present invention has a thickness of 160 g / m 2 Up to 220g / m 2 The insulating paper 110 has a basis weight of 1.3 g / cc to 1.6 g / cc, a density of 30 N / cm to 50 N / cm, and a burst strength of 150 KPa to 210 KPa. In addition, the insulating paper 110 according to an embodiment of the present invention preferably has a dielectric breakdown voltage of 1.4 KV / mm or more.

[0032] In order to achieve the physical properties of the insulation paper described above, the insulation paper 110 includes 55 to 70 parts by weight of kaolin, 13 to 22 parts by weight of 1,4-phthaloyl dichloride, and 1,4-phthaloyl dichloride. 8 H 4 Cl 2 O 2 ) and 6 to 11 parts by weight of aluminum hydroxide (Al(OH) 3), and is formed by a process of laminating the fibers. That is, the insulating paper 110 according to an embodiment of the present invention may be manufactured by a method of laminating aramid fibers.

[0033] Specifically, after the aramid fibers are dry-mixed, an air flow is used to form insulating paper, or the following wet papermaking method can be used: after the aramid fibers are dispersed and mixed in a liquid medium, they are discharged onto a support such as a liquid permeable net and sheeted, and the liquid is removed and then dried. In the wet papermaking method, an aqueous slurry containing aramid fibers is supplied to a papermaking machine and dispersed, and then dehydrated, squeezed and dried to be wound into a sheet. As a papermaking machine, a long-net papermaking machine, a cylinder papermaking machine, an inclined papermaking machine, etc. can be used. The method of manufacturing insulating paper 110 using aramid fibers is known, and as an example, the method has been disclosed in Korean Publication Patent 10-2017-0099968, etc.

[0034] The insulating paper 110 obtained in the above manner is hot-pressed between a pair of rollers at high temperature and high pressure to improve density, heat resistance, mechanical strength, etc. When a metal roller is used, it is preferably operated at a temperature of 220°C to 260°C and a line pressure of 280kg / cm to 320kg / cm.

[0035] Among them, according to the substitution position of the amide group on the benzene ring, aramid is divided into para-aramid, meta-aramid and their copolymers. As para-aramid, poly(p-phenylene terephthalamide) and its copolymer, poly(p-phenylene)-copoly(3,4'-diphenyl ether) terephthalamide (poly(p-phenylene)-copoly(3,4'-diphenyl ether) terephthalamide), etc. are shown. As meta-aramid, poly(m-phenylene isophthalamide) and its copolymer, etc. are shown. For example, these aramids are industrially manufactured by the existing well-known interfacial polymerization method, solution polymerization method, etc., and can be purchased as commercial products, but are not limited to this. However, in the present invention, 1,4-phthaloyl dichloride (C 8 H 4 Cl 2 O 2 ) as aramid fiber.

[0036] The insulating paper 110 may further include at least one adhesive. A resin may be used as an adhesive. The resin used as an adhesive may be in the form of a water-soluble or dispersible polymer directly added to a dispersion for papermaking, or may be in the form of a thermoplastic adhesive fiber of a resin material mixed with aramid fibers to activate it as an adhesive by heat applied during drying or subsequent additional compression and / or heating treatment. As water-soluble or dispersible polymers, water-soluble or water-dispersible thermosetting resins such as polyamide resins, epoxy resins, phenolic resins, urea-formaldehyde resins, polyurethane resins, melamine formaldehyde resins, thermosetting polyester resins, alkyd resins, etc. may be shown. Particularly useful are water-soluble polyamide resins. Aqueous solutions or aqueous dispersions of thermoplastic resins such as polyvinyl alcohol, polypropylene, polyester, polyvinyl acetate, etc. may also be used. However, in the present invention, aluminum hydroxide (Al(OH) 3 ) as an adhesive.

[0037] In addition, the insulating paper 110 may further include at least one filler. The type of filler is not particularly limited, but is preferably an inorganic filler, for example, clay such as mica, graphite, kaolin, bentonite, etc.; thermal conductive fillers such as carbon nanotubes, aluminum nitride, aluminum oxide, boron nitride, magnesium oxide, zinc oxide, etc. Kaolin is used in the present invention.

[0038] The battery module as described above is not limited to the structures and methods of the above embodiments, and the above embodiments may be configured by selectively combining all or part of the embodiments so that various modifications can be made.

[0039] Industrial Applicability

[0040] The battery module according to the embodiment of the present invention can be used in automobiles, electronic products, etc. that use secondary batteries.

Claims

1. A battery module, characterized in that: include: A lower housing that accommodates a plurality of battery cells; an upper case covering the lower case and having an opening formed to discharge gas generated when the internal pressure of the battery cell is above a certain level; and an insulating portion connected to one surface of the upper housing in a manner covering the opening, The insulating portion includes insulating paper, wherein the insulating paper includes: 55 to 70 parts by weight of kaolin; 13 to 22 parts by weight of 1,4-phthaloyl dichloride (C8H4Cl2O2); and 6 to 11 parts by weight of aluminum hydroxide (Al(OH)3).

2. The battery module according to claim 1, characterized in that: A first region and a second region are formed on one side of the insulating paper, wherein an adhesive layer is formed on the first region so as to be attached to the upper shell, and the second region covers the opening. An open pattern is formed in the insulating paper corresponding to the second region, and the open pattern is formed so as to be broken when the gas is discharged.

3. The battery module according to claim 2, characterized in that: The thickness of the insulating paper is 0.10 mm to 0.15 mm. The open pattern includes lines formed with a groove depth of 50 μm to 90 μm, The open pattern includes at least two intersections formed by the lines crossing each other in each of the openings.

4. The battery module according to claim 3, characterized in that: The insulating paper is formed to have a thickness of 160 g / m 2 Up to 220g / m 2 The weight, density of 1.3g / cc to 1.6g / cc, tensile strength of 30N / cm to 50N / cm and burst strength of 150KPa to 210KPa are provided.

Images