Battery module

Abstract

A battery module according to one embodiment of the present invention comprises: a lower case in which a plurality of battery cells are accommodated; an upper case covering the lower case and having openings formed to discharge gas generated when the internal pressure of the battery cells is a predetermined value or higher; and an insulating unit coupled to one inner surface of the upper case to cover the openings, wherein the insulating unit is formed by having an insulating paper including: 55 parts by weight to 70 parts by weight of kaolin; 13 parts by weight to 22 parts by weight of 1,4-benzenedicarbonyl dichloride (C8H4Cl2O2); and 6 parts by weight to 11 parts by weight of aluminum hydroxide (Al(OH)3).

Description

battery module

[0001] Embodiments of the present invention relate to a battery module used for charging or supplying electricity in an electric vehicle, a power storage device, or a portable electronic product.

[0002]

[0003] Recently, technological development and demand for electric and hybrid vehicles, power storage devices, and uninterruptible power supplies (UPS) have increased, leading to a rapid increase in demand for secondary batteries as an energy source. In particular, battery packs used in electric and hybrid vehicles require high-power, large-capacity secondary batteries, and extensive research is being conducted on these batteries.

[0004] In particular, lithium secondary batteries are being actively used more frequently because they have a higher energy density per unit weight and can be rapidly charged compared to other secondary batteries such as conventional lead-acid batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and nickel-zinc batteries.

[0005] Lithium secondary batteries are used as power sources for portable electronic devices with an operating voltage of 3.6 V or higher, or by connecting multiple batteries in series or parallel to power high-power electric vehicles, hybrid vehicles, power tools, electric bicycles, power storage devices, uninterruptible power supplies, etc.

[0006] Meanwhile, when power is generated from a battery pack, heat is generated due to an electrochemical reaction, and if this heat remains in the cells inside the battery pack, the temperature of the cells increases, which worsens the operating conditions of the cells and causes poor power generation efficiency. In addition, the pressure inside the sealed battery pack increases due to the generated heat, which poses a risk of explosion, so ensuring safety is one of the important tasks.

[0007] In the past, a method of preventing explosion by forcibly cutting off the power supply was used to prevent explosion due to temperature rise caused by use of a battery pack.

[0008] Although this method immediately cuts off power and prevents further temperature rise in the battery pack, the problem is that the remaining temperature inside the battery pack can cause the battery pack to explode.

[0009]

[0010] The present invention has been devised to solve the problems of the prior art, and provides a battery module that can prevent an explosion of the battery module due to high temperature in advance by inducing an immediate temperature drop by discharging internal gas when the temperature of the battery module rises above a set pressure.

[0011]

[0012] In order to achieve the above-described object of the present invention, a battery module according to one embodiment of the present invention comprises: a lower case in which a plurality of battery cells are accommodated; an upper case formed to cover the lower case and have openings formed to discharge gas generated when the internal pressure of the battery cells is above a certain level; and an insulating part coupled to one surface of the upper case to cover the openings, wherein the insulating part is formed with an insulating paper formed to include 55 to 70 parts by weight of kaolin; 13 to 22 parts by weight of 1,4-benzenedicarbonyl dichloride (C8H4Cl2O2); and 6 to 11 parts by weight of aluminum hydroxide (Al(OH)3).

[0013] According to an example related to the present invention, a first region in which an adhesive layer is formed on one surface of the insulating paper to be attached to the upper case and a second region covering the openings are formed, and an open pattern is formed in the insulating paper corresponding to the second region to be ruptured when the gas is discharged.

[0014] According to an example related to the present invention, the thickness of the insulating paper is 0.10 to 0.15 mm, the open pattern includes lines formed with a notching depth of 50 to 90 μm, and the open pattern includes at least two intersections formed by the lines intersecting each other per opening.

[0015] According to an example related to the present invention, the insulating paper is 160 to 220 g / m 2 It is formed to have a basis weight of 1.3 to 1.6 g / cc, a density of 1.3 to 1.6 g / cc, a tensile strength of 30 to 50 N / cm, and a burst strength of 150 to 210 KPa.

[0016]

[0017] A battery module according to at least one embodiment of the present invention configured as described above can prevent explosion of the battery module due to high temperature by immediately lowering the temperature by discharging the internal gas when the temperature of the battery module rises above a set pressure. As a result, the stability of the battery module can be effectively increased, and the internal gas generated due to a rapid increase in pressure of the battery cell can be discharged in a preset direction to maintain a constant pressure within the battery.

[0018] In addition, by maintaining the battery voltage drop time constant, sufficient time can be secured for passengers on board the electric vehicle to escape in an emergency situation.

[0019]

[0020] Figure 1 is an exploded perspective view of a battery module according to one embodiment of the present invention.

[0021] Figure 2 is a conceptual diagram of the insulating sheet used in Figure 1.

[0022] Fig. 3 is a drawing showing one side of the insulating sheet shown in Fig. 1.

[0023]

[0024] Hereinafter, specific embodiments for carrying out the present invention will be described with reference to the drawings. The embodiments of the present invention are intended to explain one invention, and the scope of rights is not limited to the illustrated embodiments. Since the illustrated drawings have been enlarged to illustrate only the core contents and omitted the auxiliary contents for the clarity of the invention, they should not be interpreted as limited to the drawings. The suffixes "module" and "part" for components used in the following description are assigned or used interchangeably only for the convenience of writing the specification, and do not in themselves have a distinct meaning or role. In this specification, even in different embodiments, the same or similar components are assigned the same or similar reference numbers, and the description thereof is replaced with the first description. The singular expression used in this specification includes plural expressions unless the context clearly indicates otherwise.

[0025]

[0026] FIG. 1 is an exploded perspective view of a battery module according to one embodiment of the present invention, FIG. 2 is a conceptual diagram of an insulating sheet used in FIG. 1, and FIG. 3 is a drawing illustrating one side of the insulating sheet illustrated in FIG. 1.

[0027] Referring to FIGS. 1 to 3, a battery module according to one embodiment of the present invention includes a lower case (103), an upper case (102), and an insulating sheet (101).

[0028] The lower case (103) is formed to accommodate battery cells (104). The lower case (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 lower case (103) may be formed entirely of a metal material, and at least a portion thereof may be formed of a synthetic resin material. The battery cells may each be formed to include an electrode assembly and a cover. The electrode assembly may be formed with a separator interposed between a positive electrode plate and a negative electrode plate. The cover is formed to accommodate the electrode assembly. Electrode terminals may be formed on one side of the battery cell and the other side, and the battery cells may be electrically connected by a bus bar made of a metal material. When the internal pressure of the battery cell exceeds a certain level, a portion of the cover is broken, allowing gas to escape to the outside. At this time, the internal pressure may be 150 to 210 KPa.

[0029] An upper case (102) is coupled to the lower case (103) to cover the lower case (103). The upper case (102) has openings (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.

[0030] An insulating sheet (101) is formed on one surface of the upper case (102) to cover the openings (102a) formed in the upper case (102).

[0031] Referring to FIGS. 2 and 3, two areas are formed on one side of an insulating sheet (101). FIG. 2 illustrates the back side of the insulating sheet, and FIG. 3 illustrates the front side of the insulating sheet. An adhesive layer (120) is formed in a first area of ​​the insulating sheet. The first area includes most of the area that does not cover the openings in the insulating sheet. The adhesive layer (120) may be formed by bonding a double-sided tape to the insulating sheet (110). The second area is an area that covers the openings formed in the upper case (102), and an open pattern (111) is formed on the insulating sheet (110) corresponding to the second area. The part 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 first bonded by the adhesive layer (120), and the worker separates the release paper from the insulating sheet (101) and then bonds the insulating sheet (101) to the upper case (102). The insulating sheet (101) can be bonded to one inner surface or one outer surface of the upper case (102).

[0032] The thickness (d2) of the insulating paper (110) is preferably 0.10 to 0.15 mm, and the open pattern (111) formed on the insulating paper (110) is formed of lines formed with a notching depth of 50 to 90 μm. The notching depth may be changed according to the set internal pressure. When the internal pressure is 150 to 210 KPa, the notching depth (d1) of the open pattern (111) may be 50 to 90 μm. If the thickness of the insulating paper (110) is less than 0.1 mm, it may rupture at a lower pressure or may not induce rupture to the open pattern (111). On the other hand, if the thickness of the insulating paper (110) exceeds 0.15 mm, rupture may not occur easily, and thermal deformation may occur in the insulating paper (110).

[0033] Here, notching refers to forming a groove (111) of a certain shape in the insulating paper (110), and the groove (111) can be formed in the insulating paper (110) using a laser notching device or a press notching device (e.g., a punching device). The groove can be in the shape of a "U" or a "V". The open pattern can be manufactured in various shapes according to the designer's intention. For example, the open pattern can be "--" or include a "Y" as a part of the pattern.

[0034] According to a preferred embodiment, the open pattern (111) is formed by including at least two intersection points (111a, 111b) formed by lines intersecting each other per opening. This allows the open pattern (111) to rupture when the internal pressure exceeds a certain level, thereby forming multiple open holes, allowing gas to be discharged more smoothly and quickly.

[0035] Insulating paper (110) according to one embodiment of the present invention has a density of 160 to 220 g / m 2 It has a basis weight of 1.3 to 1.6 g / cc, a density of 1.3 to 1.6 g / cc, a tensile strength of 30 to 50 N / cm, and a burst strength of 150 to 210 KPa. In addition, it is preferable that the insulating paper (110) according to one embodiment of the present invention has a dielectric strength (Dielectrci Breakdown Voltage) of 1.4 KV / mm or more.

[0036] For the physical properties of the insulating paper described above, the insulating paper (110) is formed by a process of sheeting fibers, including 55 to 70 parts by weight of kaolin, 13 to 22 parts by weight of 1,4-benzenedicarbonyl dichloride (C8H4Cl2O2), and 6 to 11 parts by weight of aluminum hydroxide (Al(OH)3). That is, the insulating paper (110) according to one embodiment of the present invention can be manufactured by a method of sheeting aramid fibers.

[0037] Specifically, a wet papermaking method may be used, in which aramid fibers are dry mixed and then an air current is used to form an insulating paper, or aramid fibers are dispersed and mixed in a liquid medium, then discharged onto a liquid-permeable net or other support to form a sheet, the liquid is removed, and then dried. In the wet papermaking method, an aqueous slurry containing aramid fibers is supplied to a papermaking machine, dispersed, and then wound into a sheet by dehydration, slurrying, and drying. As the papermaking machine, a long-rolled papermaking machine, a round-rolled papermaking machine, or an inclined papermaking machine may be used. A method for manufacturing an insulating paper (110) using aramid fibers is generally known, and is disclosed, for example, in Patent Publication No. 10-2017-0099968.

[0038] The insulating paper (110) obtained in this way is pressurized at high temperature and high pressure between a pair of rollers to improve the density, heat resistance, mechanical strength, etc. When using a metal roller, it is preferable to work under conditions of a temperature of 220 to 260°C and a pressure of 280 to 320 kg / cm.

[0039] Here, aramid is classified into para-aramid, meta-aramid, and copolymers thereof depending on the substitution position of the amide group on the benzene ring. Examples of para-aramid include polyparaphenylene terephthalamide and its copolymers, poly(paraphenylene)-copoly(3,4'-diphenylether)terephthalamide (poly(paraphenylene)-copoly(3,4'-diphenylether)terephthalamide). Examples of meta-aramid include polymetaphenylene isophthalamide and its copolymers. These aramids are industrially produced, for example, by conventionally known interfacial polymerization methods, solution polymerization methods, etc., and can be obtained as commercial products, but are not limited thereto. However, in the present invention, 1,4-benzenedicarbonyl dichloride (C8H4Cl2O2) was used as the aramid fiber.

[0040] The insulating paper (110) may further comprise at least one binder. A resin may be used as the binder, which may be in the form of a water-soluble or dispersible polymer that is directly added to the papermaking dispersion, or may be in the form of thermoplastic binder fibers of a resin material mixed with aramid fibers so as to be activated as a binder by heat applied during drying or subsequent additional compression and / or heat treatment. Examples of the water-soluble or dispersible polymer include water-soluble or water-dispersible thermosetting resins such as polyamide resins, epoxy resins, phenol resins, urea resins, urethane resins, melamine formaldehyde resins, thermosetting polyester resins, and alkyd resins. Water-soluble polyamide resins are particularly useful. Aqueous solutions or dispersions of thermoplastic resins such as poly(vinyl alcohol), polypropylene, polyester, and poly(vinyl acetate) may also be used in the same manner. However, in the present invention, aluminum hydroxide (Al(OH)3) was used as a binder.

[0041] In addition, the insulating paper (110) may additionally include at least one type of filler. The type of filler is not particularly limited, but an inorganic filler is preferred, and examples thereof include clay such as mica, graphite, kaolin, and bentonite, carbon nanotubes, aluminum nitride, aluminum oxide, boron nitride, magnesium oxide, and zinc oxide, and thermally conductive fillers. In the present invention, kaolin was used.

[0042]

[0043] The battery module described above is not limited to the configuration and method of the embodiments described above, and the embodiments may be configured by selectively combining all or part of each embodiment so that various modifications can be made.

[0044]

[0045] A battery module according to an embodiment of the present invention can be used in automobiles, electronic products, etc. to which secondary batteries are applied.

Claims

1. A lower case that accommodates multiple battery cells; An upper case formed by covering the lower case and having openings formed to discharge gas generated when the internal pressure of the battery cell is above a certain level; and Including an insulating member bonded to one surface of the upper case to cover the above openings, The above insulating part, 55 to 70 parts by weight of kaolin; 13 to 22 parts by weight of 1,4-benzenedicarbonyl dichloride (C8H4Cl2O2); and A battery module characterized in that it is formed by including an insulating paper formed by including 6 to 11 parts by weight of aluminum hydroxide (Al(OH)3).

2. In paragraph 1, A first region in which an adhesive layer is formed on one side of the insulating paper to be attached to the upper case and a second region covering the openings are formed, A battery module characterized in that an open pattern is formed in the insulating paper corresponding to the second region so as to burst when the gas is discharged.

3. In paragraph 2, The thickness of the above insulating paper is 0.10 to 0.15 mm, The above open pattern includes lines formed with a notching depth of 50 to 90 μm, A battery module characterized in that the above open pattern includes at least two intersections formed by the lines intersecting each other per opening.

4. In paragraph 3, The above insulating paper is 160 to 220 g / m 2 A battery module characterized in that it is formed to have a basis weight of 1.3 to 1.6 g / cc, a density of 1.3 to 1.6 g / cc, a tensile strength of 30 to 50 N / cm, and a burst strength of 150 to 210 KPa.

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