Battery protection plate

Abstract

This invention discloses a battery protection plate, belonging to the field of polymer material technology, comprising a polyester layer, wherein the polyester layer includes polyester and continuous fibers, the polyester including polyester containing terephthalic acid units and cyclohexanediethanol units; the mass percentage of polyester in the polyester layer is 17-60%; the number of single filaments of the continuous fibers is 600-800. By controlling the mass percentage of polyester in the polyester layer and the number of single filaments of the continuous fibers within the scope of this application, the bonding between polyester and continuous fibers can be improved, and stronger structural support can be synergistically enhanced, the processing temperature can be reduced, and the process window for impregnation with continuous fibers can be expanded, making the structure of the polyester layer more uniform and dense. When the polyester layer is subjected to external force, the stress transmission and dispersion effect is improved, effectively improving the rigidity and stability of the battery protection plate.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a battery protection plate. Background Technology

[0002] With the rapid development of new energy vehicles, their safety and performance optimization have become the focus of research. The battery packs of new energy electric vehicles are usually located in a low position on the chassis, making them susceptible to impacts, collisions, or even punctures from sharp objects on the road during driving. This can lead to serious safety problems such as battery damage, short circuits, spontaneous combustion, or even explosions.

[0003] Traditional battery pack protection panels are mostly made of metal materials, such as iron or aluminum. While these materials have a certain strength, their high density results in heavy panels, increasing vehicle energy consumption and hindering the lightweight development of new energy vehicles. Furthermore, metal panels are prone to deformation or breakage under significant impact, failing to effectively protect the battery pack. Some fiberglass panels are manufactured using environmentally unfriendly processes and are difficult to recycle after molding. Therefore, developing high-performance battery pack protection panels is crucial for ensuring the safe operation of new energy vehicles. In recent years, composite materials have gradually become ideal materials for new energy vehicle protection panels due to their advantages such as lightweight, high strength, recyclability, and high design flexibility.

[0004] Patent CN215451600U discloses a battery pack bottom protection plate and a vehicle. The protection plate includes two fiberglass layers and a metal layer sandwiched between the two fiberglass layers. One of the fiberglass layers is attached to the bottom of the battery pack. The fiberglass layer is made of one of polypropylene-based continuous fiberglass, polyamide-based continuous fiberglass, or polyurethane-based continuous fiberglass. The metal layer is made of steel or aluminum. The thickness of the fiberglass layer is 1mm to 3mm, and the thickness of the metal layer is 0.5mm to 2.5mm. The outermost layer of the glass fiber layer of the battery pack is also covered with a foam layer, which is made of one of polyvinyl chloride foam, polyurethane foam and polyethylene terephthalate foam, with a thickness of 3mm to 10mm. The thermoplastic composite material eliminates the need for metal surface treatment, which improves the corrosion resistance of the protective plate and saves the cost of surface treatment. However, due to the poor structural rigidity of resins such as polypropylene, it cannot effectively suppress the sagging of the protective plate and cannot reduce the deformation of the metal material after impact, resulting in the impact resistance not meeting the requirements.

[0005] Therefore, this application is submitted. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a battery protection plate. The battery protection plate of this invention has excellent rigidity and stability and can effectively prevent battery leakage or short circuit caused by structural deformation or damage.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A battery protection plate includes a polyester layer comprising polyester and continuous fibers, the polyester comprising polyester containing terephthalic acid units and cyclohexanediol units; The polyester content in the polyester layer is 17-60% by mass. The continuous fiber has 600 to 800 filaments.

[0008] As an embodiment of this application, the battery protection plate satisfies: A / B=150~460, where A is the tensile modulus value of the dipped yarn of the continuous fiber in GPa, and B is the mass percentage content of polyester in the polyester layer.

[0009] As an embodiment of this application, the polyester includes at least one of polyethylene terephthalate-1,4-cyclohexanediethanol ester and polyethylene terephthalate-1,4-cyclohexanediethanol ester.

[0010] As an embodiment of this application, the continuous fiber includes at least one of continuous glass fiber, continuous carbon fiber, continuous aramid fiber, continuous basalt fiber, and continuous silicon carbide fiber; As an embodiment of this application, the tensile modulus of the dipped yarn of the continuous fiber is 80~93GPa; the mass percentage of polyester in the polyester layer is 20~60%.

[0011] As an embodiment of this application, the diameter of the continuous fiber is 8~22μm, preferably 12~15μm.

[0012] As an embodiment of this application, the polyester layer comprises the following components by weight percentage: 17-60% polyester, 37-80% continuous fiber, 0-2% dispersant, and 0-1% antioxidant.

[0013] As an embodiment of this application, the polyester layer comprises the following components by weight percentage: 30-50% polyester, 50-65% continuous fiber, 0.5-1.5% dispersant, and 0.5-0.8% antioxidant.

[0014] As an embodiment of this application, the polyester layer comprises n layers of polyester sheets stacked sequentially along its thickness direction, where n is an integer from 1 to 20, and the included angle between the continuous fibers in adjacent polyester sheets is 30 to 100°.

[0015] As an implementation scheme of this application, at least one of the following (1) to (3) is satisfied: (1) The antioxidants include at least one of the following: thioester antioxidants, hindered phenolic antioxidants, hydroxylamine antioxidants, phosphite antioxidants, and phosphate antioxidants; (2) The dispersant includes at least one of montan wax, zinc stearate, calcium stearate, magnesium stearate, polyethylene wax, oxidized polyethylene wax, ethylene bis-stearamide, and erucamide; (3) The mass ratio of the polyester to the continuous fiber is 1:(0.8~3.4), preferably 1:(1~2).

[0016] As an embodiment of this application, it also includes an intermediate layer, the polyester layer being located on two surfaces of the intermediate layer, the intermediate layer comprising a foam layer and / or a metal layer.

[0017] As an embodiment of this application, the thickness of the polyester layer is 0.5~2mm; The thickness of the intermediate layer is 0.5~5mm.

[0018] The beneficial effects of this invention are as follows: The polyester layer of this application includes polyester and continuous fibers. The polyester includes polyester containing terephthalic acid units and cyclohexanediethanol units. By controlling the mass percentage of polyester in the polyester layer and the number of continuous fiber monofilaments within the scope of this application, the bonding between polyester and continuous fibers can be improved, and stronger structural support can be synergistically enhanced. The processing temperature can be reduced, and the process window for impregnation with continuous fibers can be expanded, making the structure of the polyester layer more uniform and dense. When the polyester layer is subjected to external force, the stress transmission and dispersion effect can be improved, effectively improving the rigidity of the battery protection plate and the stability of the battery protection plate. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the polyester layer in this application.

[0020] Figure 2 This is a schematic diagram of the structure of a battery protection plate according to an embodiment of this application.

[0021] Figure 3 This is a schematic diagram of the structure of a battery protection plate according to another embodiment of this application.

[0022] Figure 4 This is a schematic diagram of the structure of a metal layer according to an embodiment of this application.

[0023] Figure 5 This is a schematic diagram of the structure of the metal layer according to another embodiment of this application.

[0024] The markings in the diagram are: 1. Polyester layer; 2. Foam layer; 3. Metal layer; 31. Base layer; 32. Coating. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] In this application, numerical ranges are referred to as continuous unless otherwise specified, and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0027] The raw materials used in the examples and comparative examples are as follows: Polyethylene terephthalate-1,4-cyclohexanediethanol ester-1 (referred to as resin-1 in the table): melt index is 18 g / 10 min, sourced from Eastman Chemical Company, USA, grade DN114.

[0028] Polyethylene terephthalate-1,4-cyclohexanediethanol ester-2 (referred to as resin-2 in the table): melt index is 15 g / 10 min, sourced from Liaoyang Petrochemical, China, grade MRB-412-D1.

[0029] Polyethylene terephthalate-1,4-cyclohexanediethanol ester (referred to as resin-3 in the table): melt index is 22 g / 10 min, sourced from SK Korea, grade JN-200.

[0030] Polybutylene terephthalate (referred to as resin-4 in the table): melt index is 20 g / 10 min, sourced from DuPont, USA, grade PT X209.

[0031] Polypropylene (referred to as resin-5 in the table): The melt flow rate was measured to be 20 g / 10 min at 230 °C / 2.16 kg, Basel, EP548R.

[0032] Continuous Glass Fiber-1: Source: Taishan Glass Fiber, Grade: E-glass fiber, 550 monofilaments, tensile modulus of impregnated yarn: 73 GPa.

[0033] Continuous Glass Fiber-2: Source: Taishan Glass Fiber, Brand: TCR-Glass Fiber, Number of Monofilaments: 635, Tensile Modulus of Impregnated Yarn: 80GPa.

[0034] Continuous Glass Fiber-3: Source: Taishan Glass Fiber, Brand: HMG-Glass Fiber, Number of Monofilaments: 640, Tensile Modulus of Impregnated Yarn: 88GPa.

[0035] Continuous Glass Fiber-4: Source: Taishan Glass Fiber, Brand: TS-Glass Fiber, Number of Monofilaments: 710, Tensile Modulus of Impregnated Yarn: 90GPa.

[0036] Continuous Glass Fiber-5: Source: Taishan Glass Fiber, Brand: THM-1-Glass Fiber, Number of Monofilaments: 718, Tensile Modulus of Impregnated Yarn: 93GPa.

[0037] Continuous Glass Fiber-6: Source: medium alkali glass fiber, grade: SMC2400-1000, number of monofilaments: 1000, tensile modulus of impregnated yarn: 75GPa.

[0038] Dispersant-1: Mondan wax, grade TR044W, Shanghai Zhuangjing Chemical.

[0039] Dispersant-2: Oxidized polyethylene wax, grade 4202E, Mitsui Group.

[0040] Antioxidant-1: Antioxidant SONOX 225G, commercially available.

[0041] Antioxidant-2: Antioxidant 1010, commercially available.

[0042] Unless otherwise specified, all components and raw materials used in the embodiments and comparative examples of this invention are commercially available, and the same type of components and raw materials are used in each parallel experiment.

[0043] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0044] Please see Figure 1 This application provides a battery protection plate, including a polyester layer 1, which includes polyester and continuous fibers, wherein the polyester comprises a polyester having terephthalic acid units and cyclohexanediethanol units. The mass percentage of the polyester in the polyester layer 1 is 17-60%, for example, it can be 17%, 18%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60% or any two of these values. The number of monofilaments in the continuous fiber is 600, 610, 620, 630, 635, 650, 660, 680, 700, 710, 800, or any two of these values.

[0045] The number of single filaments in the continuous fiber in the polyester layer can be tested as follows: the polyester layer is separated from the battery protective plate, calcined at 700°C for 30 minutes in an air atmosphere, the remaining ash is dispersed in ethanol and separated by ultrasonic sedimentation to obtain continuous fibers, the continuous fibers are immersed in ethanol and broken, samples are prepared, the cross-section is observed under a scanning electron microscope, and the number of filaments in a single fiber is identified and counted using software. The average value of 10 samples is calculated to obtain the number of filaments.

[0046] The polyester layer 1 of this application includes polyester and continuous fibers. The polyester includes polyester containing terephthalic acid units and cyclohexanediethanol units. By controlling the mass percentage content of the polyester in the polyester layer 1 and the number of continuous fiber monofilaments within the scope of this application, the bonding between the polyester and the continuous fibers can be improved, and stronger structural support can be synergistically enhanced. The processing temperature can be reduced, and the process window for impregnation with the continuous fibers can be expanded, making the structure of the polyester layer more uniform and dense. When the polyester layer is subjected to external force, the stress transmission and dispersion effect can be improved, effectively improving the rigidity of the battery protection plate and the stability of the battery protection plate.

[0047] In one embodiment, the battery protective plate satisfies: A / B = 150~460, where A is the tensile modulus of the dipped yarn of the continuous fiber in GPa, and B is the mass percentage of polyester in the polyester layer.

[0048] The inventors discovered that the tensile modulus of the dipped yarn of continuous fibers directly affects the product's resistance to external forces and its ability to withstand internal interaction forces. When the percentage of polyester in the polyester layer is further optimized and controlled according to the selection of glass fibers with different tensile moduli of dipped yarns, so that the ratio of the two is within the above range, the interaction effect between continuous fibers and polyester is better, which makes the product have better resistance to external forces and less deformation after being subjected to force.

[0049] In some embodiments, the battery protection plate satisfies: A / B = 150, 180, 200, 210, 250, 280, 300, 400, 410, 420, 450, 460, or any two of these values. In one embodiment, the polyester comprises at least one of polyethylene terephthalate-1,4-cyclohexanediethanol ester and polyethylene terephthalate-1,4-cyclohexanediethanol ester.

[0050] In one embodiment, the polyester comprises at least one of polyethylene terephthalate-1,4-cyclohexanediethanol ester and polyethylene terephthalate-1,4-cyclohexanediethanol ester. In particular, when polyethylene terephthalate-1,4-cyclohexanediethanol ester is used, the molecular structure contains 1,4-cyclohexanediethanol and ethylene glycol structural units. The introduction of 1,4-cyclohexanediethanol and ethylene glycol structural units can improve the interaction force between polyester chain ends, making the molecular chain more ordered and compact, improving the interfacial strength with continuous fibers, and further improving the rigidity and stability of the battery protection plate.

[0051] In one embodiment, the 1,4-cyclohexanediethanol content in the polyester is 10-40% by mass, for example, it can be 10%, 15%, 20%, 25%, 30%, 35%, 40% or any two of these values.

[0052] In one embodiment, the polyester contains 20-30% by mass of 1,4-cyclohexanediethanol.

[0053] In one embodiment, the continuous fiber includes at least one of continuous glass fiber, continuous carbon fiber, continuous aramid fiber, continuous basalt fiber, and continuous silicon carbide fiber. In one embodiment, the tensile modulus of the dipped yarn of the continuous fiber is 80~93 GPa, and the tensile modulus of the dipped yarn of the continuous fiber is measured according to ASTM D 2343-2017.

[0054] The mass percentage of the polyester in the polyester layer 1 is 20-60%, for example, it can be 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60% or any two of these values.

[0055] In one embodiment, the diameter of the continuous fiber is 8 to 22 μm, for example, it can be 8 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, 22 μm or any two of these values.

[0056] In one embodiment, the diameter of the continuous fiber is 12-15 μm.

[0057] In one embodiment, the polyester layer 1 comprises n layers of polyester sheets (with the same formulation as polyester layer 1) stacked sequentially along its thickness direction, where n is an integer from 1 to 20. By stacking the polyester sheets as polyester layer 1, external energy can be effectively absorbed, the shear resistance between the sheets can be effectively improved, and the impact resistance of the protective plate can be further improved.

[0058] In one embodiment, the included angle between the continuous fibers in adjacent polyester sheets is 30° to 100°, for example, it can be 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85°, 90°, 95°, 100°, or any two of these values. Using different layup angles for adjacent resin sheets can effectively improve the shear resistance between the layers, thereby further improving the impact resistance of the battery protective plate.

[0059] In one embodiment, the thickness of the single layer of the polyester sheet is 0.2~0.5 mm.

[0060] In one embodiment, the polyester layer 1 comprises the following components by mass percentage: 17-60% polyester, 37-80% continuous fiber, 0-2% dispersant, and 0-1% antioxidant. By using the polyester layer 1 composed of the above-mentioned specific proportions of polyester, continuous fiber, dispersant, and antioxidant, the stability of the polyester layer 1 can be further improved, the compatibility between polyester and continuous fiber can be improved, and the impact resistance of the battery protection plate can be further improved.

[0061] In one embodiment, the polyester layer 1 comprises the following components by weight percentage: 30-50% polyester, 50-65% continuous fiber, 0.5-1.5% dispersant, and 0.5-0.8% antioxidant.

[0062] In one embodiment, the antioxidant includes at least one of thioester antioxidants, hindered phenolic antioxidants, hydroxylamine antioxidants, phosphite antioxidants, and phosphate antioxidants.

[0063] In one embodiment, the thioester antioxidant includes at least one of dialkyl thiodipropionate or pentaerythritol tetra(3-lauryl thiopropionate).

[0064] In one embodiment, the hindered phenolic antioxidant comprises at least one of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, vinyl bis(oxyvinyl)bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate], or 3,9-bis[1,1-dimethyl-2-[(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane.

[0065] In one embodiment, the hydroxylamine antioxidant includes bis(octadecyl)hydroxylamine.

[0066] In one embodiment, the phosphite antioxidant includes at least one of tris(2,4-di-tert-butylphenyl) phosphite and pentaerythritol dibis(2,4-tert-butylphenyl) phosphite.

[0067] In one embodiment, the phosphate antioxidant includes bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphate.

[0068] In one embodiment, the dispersant includes at least one of montan wax, zinc fatty acid, calcium stearate, magnesium stearate, polyethylene wax, oxidized polyethylene wax, ethylene bis-stearamide, and erucamide.

[0069] In one embodiment, the mass ratio of the polyester to the continuous fiber is 1:(0.8~3.4).

[0070] In one embodiment, the mass ratio of the polyester to the continuous fiber is 1:(1~2).

[0071] In one embodiment, the thickness of the polyester layer 1 is 0.5 to 2 mm, for example, it can be 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm or any two of these values.

[0072] In one embodiment, the polyester layer 1 is prepared by: According to the formula, the components except the continuous fiber are mixed evenly to obtain a mixture. The mixture is put into an extruder for melt mixing. At the same time, the continuous glass fiber is fully spread by the spreading roller and fully impregnated with resin at the die head. After cooling and shaping, a polyester unidirectional tape is obtained. The polyester unidirectional tape is laid at different angles and heated and cooled by a roller press to obtain a polyester layer.

[0073] In one embodiment, the battery protective plate further includes a foam layer 2.

[0074] In one implementation, such as Figure 2 As shown, the polyester layer 1 is located on both surfaces of the foam layer 2. By adopting such a battery protection plate, with the polyester layer 1 located on both surfaces of the foam layer 2, stress can be better dispersed, effectively preventing the foam layer 2 from absorbing water and increasing the weight of the battery protection plate. It can also further improve the impact resistance of the protection plate assembly and provide the safety of the whole vehicle.

[0075] In one embodiment, the thickness of the foam layer 2 is 0.5~5mm, for example, it can be 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm or any two of these values.

[0076] In one embodiment, the foam layer 2 comprises at least one of polyethylene, polypropylene, polystyrene, polycarbonate, polyamide, polyimide, polyphenylene sulfide, and polyetheretherketone.

[0077] In one embodiment, the foam layer 2 comprises polypropylene (PP), which, as the matrix material, imparts properties such as lightweight, high strength, and resistance to chemical corrosion to the material.

[0078] In one embodiment, the foamed layer 2 uses supercritical carbon dioxide or nitrogen as a foaming agent. Supercritical carbon dioxide or nitrogen, as a foaming agent, forms a uniform single-phase solution under high temperature and pressure, causing the material to foam through physical methods, forming a micron-scale closed-cell structure. The thickness of the foamed layer is 0.5~5mm. In one embodiment, the battery protection plate further includes a metal layer 3.

[0079] In one implementation, such as Figure 3 As shown, the polyester layer 1 is located on both surfaces of the metal layer 3. By adopting the battery protection plate with the polyester layer 1 located on both surfaces of the metal layer 3, stress can be better dispersed, the metal layer 3 can be effectively prevented from rusting, and the impact resistance of the protection plate assembly can be further improved, thus providing the safety of the entire vehicle.

[0080] In one embodiment, the thickness of the metal layer 3 is 0.2 to 5 mm, for example, it can be 0.2 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 2 mm, 3 mm, 4 mm, 5 mm or any two of these values.

[0081] In one implementation, please refer to Figures 4-5As shown, the metal layer 3 includes a base layer 31 and a plating layer 32 located on at least one surface of the base layer 31; the base layer 31 is selected from iron and its alloys, aluminum and its alloys, magnesium and its alloys, copper and its alloys, titanium and its alloys or nickel and its alloys, and the plating layer 32 is a zinc plating layer 32, a zinc-iron alloy plating layer 32 or a zinc-magnesium alloy plating layer 32.

[0082] The metal layer 3 and the polyester layer 1 are bonded together by adhesive or hot pressing.

[0083] The foamed layer 2 and the polyester layer 1 are bonded together by adhesive or hot pressing.

[0084] It should be noted that the base layer 31 includes two opposing first and second surfaces in the thickness direction. The coating 32 is disposed on at least one surface of the base layer 31. Those skilled in the art should understand that the coating 32 can be disposed on the first surface, the second surface, or both the first and second surfaces simultaneously. Those skilled in the art can choose according to actual needs. It should be noted that the aforementioned "surface" can be the entire area of ​​the first and / or second surface, or a portion of the first and / or second surface. This application has no particular limitations, as long as the purpose of this application is achieved.

[0085] In one embodiment, the base layer 31 is a steel plate, steel strip, or aluminum plate.

[0086] In one embodiment, the zinc content in the coating 32 is 10% to 100% by mass, for example, it can be 10%, 20%, 50%, 80%, 100% or any two of these values.

[0087] In one embodiment, the thickness of the base layer 31 is 0.5~5mm, for example, it can be 0.5mm, 0.6mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 2mm, 3mm, 4mm, 5mm or any two of these values.

[0088] In one embodiment, the thickness of the coating 32 is 0.1 to 2 mm, for example, it can be 0.1 mm, 0.2 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 2 mm or any two of these values.

[0089] The following embodiments are provided to facilitate understanding of the invention. These embodiments are not intended to limit the scope of the claims.

[0090] Examples and Comparative Examples The structure and thickness of the battery protection plates in the embodiments and comparative examples are shown in Table 1.

[0091] Examples 1-21 and Comparative Examples 1-5 all include an upper polyester layer, a foaming layer and a lower polyester layer arranged sequentially, with thicknesses as shown in Table 1. Each layer is laminated by hot pressing.

[0092] The foam layer is made of MPP material and has a thickness of 3mm.

[0093] Example 22 includes an upper polyester layer, a metal layer and a lower polyester layer arranged sequentially, with thicknesses as shown in Table 1. The metal layer includes a steel plate and a zinc layer, with the zinc layer close to the upper polyester layer. Each layer is composited by hot pressing.

[0094] The preparation methods of the polyester layers (upper polyester layer and lower polyester layer) in Examples 1-21 and Comparative Examples 1-5 all include the following steps: according to the formula, the components except the continuous fiber are mixed evenly to obtain a mixture; the mixture is put into an extruder for melt mixing, while the continuous glass fiber is fully spread through the spreading roller and fully impregnated with resin at the die head; after cooling and shaping, a polyester unidirectional tape is obtained; the polyester unidirectional tape is laid at different angles and heated and cooled by a roller press to obtain a polyester layer.

[0095] The preparation method of the polypropylene layer (upper polypropylene layer and lower polypropylene layer) of Comparative Example 6 includes the following steps: According to the formula, the components except the continuous fiber are mixed evenly to obtain a mixture. The mixture is put into an extruder for melt mixing. At the same time, the continuous glass fiber is fully spread through the spreading roller and fully impregnated with resin at the die head. After cooling and shaping, a polypropylene unidirectional tape is obtained. The polypropylene unidirectional tape is stacked at different angles and heated and cooled by a roller press to obtain a polypropylene layer.

[0096] Table 1 The formulations of the polyester layers (with the same formulation for the upper and lower polyester layers) in the examples and comparative examples are shown in Tables 2 and 3 (Tables 2 and 3 are all mass percentages).

[0097] Table 2 Table 3 Test case Drop hammer impact force: Tested according to ASTM D7136, hammer head diameter d=25mm; Deformation: First, a layer of space sand is laid on the non-impact surface of the bottom guard plate. Then, a drop hammer is used to impact the impact surface of the bottom guard plate. After the impact is completed, the bottom guard plate is removed, and the deformation of the bottom guard plate after the drop hammer impact is tested by measuring the indentation of the space sand.

[0098] Table 4 As can be seen from Table 4, the battery protection plate described in this application has excellent rigidity, with a drop hammer impact force ≥460J and a deformation ≤6mm.

[0099] As can be seen from the comparison of the embodiments and comparative examples 1-2, this application significantly improves the impact force of the drop hammer on the protective plate and reduces the amount of deformation by controlling the number of monofilaments of the continuous fiber.

[0100] As can be seen from Comparative Example 3, not any polyester can achieve the expected protective effect. In the product described in this invention, the polyester containing terephthalic acid units and cyclohexanediethanol units has better bonding with continuous fibers, stronger resistance to external factors, and is more conducive to withstanding external stress.

[0101] As can be seen from the comparison of the embodiments and comparative examples 4-5, this application significantly improves the impact force of the protective plate and reduces the deformation by controlling the mass percentage of the polyester in the polyester layer to be 17-60%.

[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A battery protection plate, characterized in that, Includes a polyester layer, the polyester layer comprising polyester and continuous fibers, the polyester comprising polyester containing terephthalic acid units and cyclohexanediethanol units; The polyester content in the polyester layer is 17-60% by mass; The continuous fiber has 600 to 800 filaments.

2. The battery protection plate according to claim 1, characterized in that, The battery protection plate satisfies the following condition: A / B = 150~460, where A is the tensile modulus of the dipped yarn of the continuous fiber in GPa, and B is the mass percentage of polyester in the polyester layer.

3. The battery protection plate according to claim 2, characterized in that, The polyester includes at least one of polyethylene terephthalate-1,4-cyclohexanediethanol ester and polyethylene terephthalate-1,4-cyclohexanediethanol ester; the continuous fiber includes at least one of continuous glass fiber, continuous carbon fiber, continuous aramid fiber, continuous basalt fiber, and continuous silicon carbide fiber.

4. The battery protection plate according to claim 2, characterized in that, The tensile modulus of the dipped yarn of the continuous fiber is 80~93 GPa; the mass percentage of polyester in the polyester layer is 20~60%.

5. The battery protection plate according to claim 1, characterized in that, The diameter of the continuous fiber is 8~22μm.

6. The battery protection plate according to claim 1, characterized in that, The polyester layer comprises the following components by weight percentage: 17-60% polyester, 37-80% continuous fiber, 0-2% dispersant, and 0-1% antioxidant; preferably, the polyester layer comprises the following components by weight percentage: 30-50% polyester, 50-65% continuous fiber, 0.5-1.5% dispersant, and 0.5-0.8% antioxidant.

7. The battery protection plate according to claim 1, characterized in that, The polyester layer comprises n layers of polyester sheets stacked sequentially along its thickness direction, where n is an integer from 1 to 20, and the included angle between the continuous fibers in adjacent polyester sheets is 30 to 100°.

8. The battery protection plate according to claim 6, characterized in that, Satisfy at least one of the following (1) to (3): (1) The antioxidants include at least one of the following: thioester antioxidants, hindered phenolic antioxidants, hydroxylamine antioxidants, phosphite antioxidants, and phosphate antioxidants; (2) The dispersant includes at least one of montan wax, zinc stearate, calcium stearate, magnesium stearate, polyethylene wax, oxidized polyethylene wax, ethylene bis-stearamide, and erucamide.

9. (3) The mass ratio of the polyester to the continuous fiber is 1:(0.8~3.4), preferably 1:(1~2); The battery protection plate according to claim 6 is characterized in that, It also includes an intermediate layer, the polyester layer being located on both surfaces of the intermediate layer, the intermediate layer comprising a foam layer and / or a metal layer.

10. The battery protection plate according to claim 9, characterized in that, The thickness of the polyester layer is 0.5~2mm; the thickness of the intermediate layer is 0.5~5mm.

Images