Battery Housing lower Panel

Abstract

The present invention relates to a battery housing lower panel. The present invention comprises a flame-retardant sheet layer; and a composite layer formed on the flame-retardant sheet layer; wherein the composite layer may include a battery housing lower panel in which a resin is impregnated into a fabric.

Description

Technology Field

[0001] The present invention relates to a battery housing lower panel according to embodiments of the invention. Background Technology

[0002] Batteries and / or battery packs can pose various risks, such as electrical fires, due to external impact. Therefore, it may be required to ensure flame retardancy as a housing to protect batteries and / or battery packs. In particular, with the development and widespread adoption of electric vehicles, it is necessary to protect batteries and / or battery packs from external heat or impact to guarantee their safety.

[0003] To solve the aforementioned problems, the present invention aims to provide a battery pack housing panel with improved heat resistance and impact resistance. The problem to be solved

[0004] The present invention provides a battery housing lower panel with improved heat resistance and impact resistance by introducing a composite layer.

[0005] However, the problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned problems will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0006] According to one embodiment, the lower panel of the battery housing may comprise a flame-retardant sheet layer; and a composite layer formed on the flame-retardant sheet layer.

[0007] According to one embodiment, the flame-retardant sheet layer may comprise 30% to 70% by weight of polypropylene, 5% to 10% by weight of glass fiber, 10% to 20% by weight of phosphorus-nitrogen-based flame retardant, 10% to 20% by weight of expanded graphite, 0.1% to 10% by weight of antioxidant, and 0.1% to 10% by weight of lubricant.

[0008] According to one embodiment, the composite layer may comprise a fabric comprising at least one selected from the group consisting of polypropylene, glass fiber-based fabrics, and phosphorus-nitrogen-based flame retardants.

[0009] According to one embodiment, the fabric comprises glass fibers, and the glass fibers may comprise 300 to 2400 tex counts.

[0010] According to one embodiment, the fabric is formed by arranging in the warp direction and the weft direction, and the fabric density in the warp direction and the fabric density in the weft direction may each be 10 pieces / inch to 2000 pieces / inch.

[0011] According to one embodiment, the fabric may be manufactured in a plain weave or a twill weave.

[0012] According to one embodiment, the resin is a thermoplastic resin, and the thermoplastic resin may comprise at least one selected from the group consisting of polypropylene, polyamide, and polyethylene.

[0013] According to one embodiment, the weight ratio of fabric to resin in the composite layer may be 50 to 70: 50 to 30.

[0014] According to one embodiment, the composite layer may be a single layer or two or more layers.

[0015] According to one embodiment, the thickness of the lower panel of the battery housing may be 1.0 mm to 2.4 mm.

[0016] According to one embodiment, the flame retardant rating of the lower panel of the battery housing may satisfy the MS300-08 standard with a combustion speed of 12 mm / min or less.

[0017] According to one embodiment, the flame resistance performance of the flame-retardant sheet layer may be such that perforation occurs after 5 minutes under conditions of a flame temperature of 1100 ℃ to 1300 ℃.

[0018] According to one embodiment, the specific gravity of the lower panel of the battery housing may be 1.2 to 1.5. Effects of the invention

[0019] The present invention can provide a battery housing panel with improved heat resistance and impact resistance. Specific details for implementing the invention

[0020] Embodiments of the present invention will be described in detail below with reference to the examples. In describing the present invention, specific descriptions of related known functions or configurations will be omitted if it is determined that such detailed descriptions may unnecessarily obscure the essence of the present invention. Furthermore, the terms used in this specification are used to appropriately express preferred embodiments of the present invention, and these may vary depending on the intentions of the user or operator, or the conventions of the field to which the present invention belongs. Accordingly, the definitions of these terms should be based on the content throughout this specification.

[0021] Throughout the specification, when it is stated that a component is located "on" another component, this includes not only cases where a component is in contact with another component, but also cases where another component exists between the two components.

[0022] Throughout the specification, when a part is described as "including" a certain component, this means that it does not exclude other components but may include additional components.

[0023] In this document, phrases such as “A or B,” “at least one of A and B,” “at least one of A or B,” “A, B or C,” “at least one of A, B and C,” and “at least one of A, B, or C” may each include any one of the items listed together with the corresponding phrase, or all possible combinations thereof. Terms such as “first,” “second,” or “first” or “second” may be used simply to distinguish a component from another component and do not limit the components in any other aspect (e.g., importance or order). For example, appropriate results may be achieved even if the described techniques are performed in a different order than described, and / or the described components are combined or combined in a form different from described, or are substituted or replaced by other components or equivalents. Therefore, other implementations, other embodiments, and equivalents to the claims set forth below are also within the scope of the claims.

[0024] Hereinafter, the battery housing panel of the present invention will be described in detail with reference to the embodiments. However, the present invention is not limited to these embodiments.

[0025] According to one embodiment, the lower panel of the battery housing of the present invention may include a flame-retardant sheet layer; and a composite layer formed on the flame-retardant sheet layer.

[0026] According to one embodiment, the flame-retardant sheet layer may comprise 30% to 70% by weight of polypropylene, 5% to 10% by weight of glass fiber, 10% to 20% by weight of phosphorus-nitrogen-based flame retardant, 10% to 20% by weight of expanded graphite, 0.1% to 10% by weight of antioxidant, and 0.1% to 10% by weight of lubricant. According to one embodiment, the flame-retardant sheet layer may improve heat resistance, flame retardancy, and impact resistance by applying the aforementioned content ranges.

[0027] According to one embodiment, the heat distortion temperature (HDT) (based on 455 kPa) of the polypropylene may be 60 ℃ to 210 ℃. According to one embodiment, the polypropylene resin may have a heat distortion temperature at 455 kPa of 60 ℃ to 210 ℃; 70 ℃ to 200 ℃; 80 ℃ to 200 ℃; 100 ℃ to 200 ℃; 120 ℃ to 200 ℃; or 170 ℃ to 200 ℃.

[0028] According to one embodiment, the glass fiber may have a fiber length of 50 μm to 400 μm and a diameter (or thickness) of 10 μm to 50 μm.

[0029] According to one embodiment, the phosphorus-nitrogen-based flame retardant may comprise polyphosphate ammonium or pyrophosphate ammonium.

[0030] According to one embodiment, the expandable graphite may be a material with excellent fire resistance that protects combustible materials by expanding at a high rate due to flames during a fire and providing a thermal insulation effect. For example, the expandable graphite may have an expansion rate of 20 ml / g to 500 ml / g and a size (particle diameter) of 20 mesh to 300 mesh.

[0031] According to one embodiment, the antioxidant may be selected from bisphenol-based, polymeric phenol-based, aromatic-based, and phosphorus-based antioxidants, but is not limited thereto.

[0032] According to one embodiment, the lubricant may be, but is not limited to, paraffin, polyethylene wax, stearic acid, alkaline earth metal stearate (e.g., zinc stearate, calcium stearate, etc.), vinylidene fluoride-hexafluoropropylene polymer, polyester polyol, erucamide, oleic amide, etc.

[0033] According to one embodiment, the composite layer is a fabric impregnated with resin, and the fabric may be a fabric comprising one or more types selected from the group consisting of polypropylene, glass fiber-based fabrics, and phosphorus-nitrogen-based flame retardants. The fabric may have a tex count of 300 to 2400. Preferably, the fabric may include glass fibers, and the glass fibers may have a tex count of 600 to 1200.

[0034] According to one embodiment, the fabric may be a fabric formed by arranging in the warp direction and the weft direction, for example, the fabric density in the warp direction and the fabric density in the weft direction may each be 10 to 2000 fibers / inch. According to one embodiment, the fabric may be manufactured in a plain weave or a twill weave.

[0035] According to one embodiment, the resin is a thermoplastic resin, and the thermoplastic resin may comprise one or more selected from the group consisting of polypropylene, polyamide 6, polyamide 66, polyetheretherketone, polycarbonate, polyphenylenesulfone, polyphenylene ether, and polyurethane. Preferably, it may comprise polypropylene, polyamide, or polyethylene resin.

[0036] According to one embodiment, the thermoplastic resin may have a heat distortion temperature (HDT) (based on 455 kPa) of 60 ℃ to 210 ℃. According to one embodiment, the thermoplastic resin may have a heat distortion temperature at 455 kPa of 60 ℃ to 210 ℃; 70 ℃ to 200 ℃; 80 ℃ to 200 ℃; 100 ℃ to 200 ℃; 120 ℃ to 200 ℃; or 170 ℃ to 200 ℃.

[0037] According to one embodiment, the weight ratio of the fabric to the resin in the composite layer may be 50 to 70: 50 to 30. By applying the mentioned weight ratio, heat resistance and impact resistance can be improved.

[0038] According to one embodiment, the flame resistance performance of the flame-retardant sheet layer can provide flame resistance performance in which perforation occurs after 30 minutes under conditions of a flame temperature of 1100 ℃ to 1300 ℃.

[0039] According to one embodiment, the thickness of the battery housing panel may be 1.0 mm to 2.4 mm; 1.2 mm to 2.4 mm; 1.5 mm to 2.4 mm; or 1.8 mm to 2.0 mm.

[0040] According to one embodiment, the flame retardant rating of the lower panel of the battery housing may satisfy the MS300-08 standard with a combustion speed of 12 mm / min or less.

[0041] According to one embodiment, the specific gravity of the lower panel of the battery housing may be 1.2 to 1.5; 1.3 to 1.5 or 1.4 to 1.5.

[0042] Example 1 (Battery housing lower panel)

[0043] A composite sheet was produced by impregnating a glass fiber fabric (600 tex count) with polyethylene resin and drying it at room temperature. In the composite sheet, the mass ratio of fabric to resin is 50:60, and the thickness of the composite sheet is 1.0 T.

[0044] A flame-retardant sheet having a thickness of 0.6 T was produced by mixing polypropylene resin (50 wt%), glass fiber (10 wt%), phosphorus-nitrogen-based flame retardant (20 wt%), expanded graphite (15 wt%), antioxidant (2 wt%), and lubricant (3 wt%), and then extruding the mixture into a sheet shape. A release film is attached to one side of the flame-retardant sheet.

[0045] A battery housing lower panel was manufactured by placing the flame-retardant sheet on the composite sheet and compressing it.

[0046] Examples 2 to 5 were carried out in the same manner as Example 1, except that composite sheets and flame-retardant sheets were produced according to Table 1 below.

[0047]

[0048] * Glass fiber: Average length approx. 400 µm and average diameter approx. 40 µm

[0049] Polypropylene resin: Heat distortion temperature approx. 170 ℃ to approx. 200 ℃

[0050] Phosphorus-nitrogen based flame retardant: Ammonium polyphosphate

[0051] Expanded Graphite: Average expansion rate 300 ml / g, 150 mesh

[0052] Lubricant: Calcium stearate and paraffin (1:1 (w / w))

[0053] The physical properties of the panels produced in Examples 1 and 5 were measured by the following method. The measurement results confirmed that the heat resistance and impact resistance were excellent.

[0054] (1) Specific gravity

[0055] It was measured according to ASTM D 792 (Standard Test Methods for Density and Specific Gravity (Relative Density) of Plastics).

[0056] (2) Heat distortion temperature

[0057] The heat distortion temperature was measured according to ISO 75.

[0058] (3) Surface impact energy

[0059] The surface impact energy was measured according to ISO 6603.

[0060] (4) Flame retardancy rating and flame resistance evaluation

[0061] The flame retardancy rating was determined using the "MS300-08" standard measurement method, and the flame resistance evaluation was performed by measuring the time to perforation at a flame temperature of 1100 ℃ to 1300 ℃.

[0062] Although the embodiments have been described above by a limited number of examples, those skilled in the art can make various modifications and variations from the description above. For example, suitable results may be achieved even if the described techniques are performed in a different order than described, and / or the described components are combined or assembled in a form different from described, or are replaced or substituted by other components or equivalents. Therefore, other implementations, other embodiments, and equivalents to the claims below are also within the scope of the claims.

Claims

Claim 1 A battery housing lower panel comprising: a flame-retardant sheet layer; and a composite layer formed on the flame-retardant sheet layer; wherein the composite layer is a fabric impregnated with resin, and the flame-retardant sheet layer comprises 30% to 70% by weight of polypropylene, 5% to 10% by weight of glass fiber, 10% to 20% by weight of phosphorus-nitrogen-based flame retardant, 10% to 20% by weight of expanded graphite, 0.1% to 10% by weight of antioxidant, and 0.1% to 10% by weight of lubricant, wherein the glass fiber has a fiber length of 50 μm to 400 μm and a diameter of 10 μm to 50 μm, and the thickness of the battery housing lower panel is 1.0 mm to 2.4 mm. Claim 2 delete Claim 3 A battery housing lower panel according to claim 1, wherein the composite layer comprises polypropylene, a glass fiber-based fabric, and a fabric comprising a phosphorus-nitrogen-based flame retardant. Claim 4 A battery housing lower panel according to claim 1, wherein the fabric comprises glass fibers, and the glass fibers of the fabric comprise 300 to 2400 tex counts. Claim 5 A battery housing lower panel according to claim 4, wherein the fabric is formed by arranging in the warp direction and the weft direction, and the fabric density in the warp direction and the fabric density in the weft direction are each 10 pieces / inch to 2000 pieces / inch. Claim 6 In claim 1, the battery housing lower panel, wherein the fabric is manufactured in plain weave or twill weave. Claim 7 A battery housing lower panel according to claim 1, wherein the resin is a thermoplastic resin, and the thermoplastic resin comprises at least one selected from the group consisting of polypropylene, polyamide, and polyethylene. Claim 8 A battery housing lower panel according to claim 1, wherein the weight ratio of fabric to resin in the composite layer is 50 to 70: 50 to 30. Claim 9 A battery housing lower panel according to claim 1, wherein the composite layer is a single layer or two or more layers. Claim 10 delete Claim 11 A battery housing lower panel according to claim 1, wherein the flame retardant grade of the battery housing lower panel satisfies the MS300-08 standard with a combustion speed of 12 mm / min or less. Claim 12 A battery housing lower panel according to claim 1, wherein the flame resistance performance of the flame-retardant sheet layer is such that perforation occurs after 5 minutes under flame temperature conditions of 1100 ℃ to 1300 ℃. Claim 13 A battery housing lower panel according to claim 1, wherein the specific gravity of the battery housing lower panel is 1.2 to 1.5.

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