Composite laminate

Abstract

A composite laminate according to an embodiment of the present invention comprises: a one-way tape layer containing a thermoplastic resin and continuous fibers; and the first metal layer is formed on the one-way adhesive tape layer. Based on the total weight of the one-way adhesive tape layer, the content of the continuous fibers is more than 40wt%. The flame retardancy and lightness of the composite laminate can be improved.

Description

Technical Field

[0001] Embodiments of the present invention relate to a composite laminate, and more particularly, to a composite laminate including a metal layer. Background Art

[0002] Metal and plastic composites are used in the automotive industry. Metal materials such as steel and aluminum, while thermally stable, are highly corrosive. Furthermore, steel is heavy, requiring lightweighting to improve fuel efficiency.

[0003] Composite materials are being researched as metal replacements. Known composite materials include unidirectional tape (UD tape), carbon fiber-reinforced plastics (CFRP), and glass fiber-reinforced plastics (GFRP). Composite materials (such as UD tape and CFRP) offer low weight and corrosion resistance, but their low elongation may limit their formability.

[0004] Recently, extensive research has been conducted on environmentally friendly vehicles, such as electric vehicles, and these issues also exist in electric vehicles. In the case of electric vehicles, the battery pack, which includes a large number of secondary batteries, accounts for a large proportion of the vehicle's weight, necessitating a lightweight battery pack. Furthermore, the inclusion of a large number of secondary batteries increases the risk of explosion due to chain reactions such as electrolyte leakage and gas generation, leading to heat generation. Therefore, a material that is both stable and lightweight is required. Summary of the Invention

[0005] (1) Technical issues to be resolved

[0006] A technical problem of the present invention is to provide a composite laminate with improved stability.

[0007] One object of the present invention is to provide a battery housing with increased stability.

[0008] A technical problem of the present invention is to provide a battery assembly with improved stability.

[0009] (2) Technical solution

[0010] A composite laminate according to an embodiment of the present invention includes: a unidirectional tape layer comprising a thermoplastic resin and continuous fibers; and a first metal layer formed on the unidirectional tape layer. The continuous fibers comprise at least 40% by weight, based on the total weight of the unidirectional tape layer.

[0011] According to an exemplary embodiment, the composite laminate may further include a second metal layer formed on a bottom surface of the unidirectional tape layer.

[0012] According to an exemplary embodiment, the content of the continuous fibers may be 60 wt % or more, based on the total weight of the unidirectional tape layer.

[0013] According to an exemplary embodiment, the thermoplastic resin may further include a flame retardant.

[0014] According to an exemplary embodiment, the continuous fiber may include one or more selected from the group consisting of carbon fiber, glass fiber, and polypropylene fiber.

[0015] According to an exemplary embodiment, the unidirectional tape layer may include a plurality of continuous fiber layers, each of which includes continuous fibers impregnated in the thermoplastic resin. Furthermore, the unidirectional tape layer may include two or more continuous fiber layers.

[0016] According to an exemplary embodiment, the unidirectional tape layer may include 7 or less continuous fiber layers.

[0017] According to an exemplary embodiment, the thickness of the unidirectional tape layer may be 0.4 mm or more and 3.5 mm or less.

[0018] According to an exemplary embodiment, the first metal layer may be formed of one or more selected from aluminum, steel, or alloys thereof.

[0019] According to exemplary embodiments, the second metal layer may be formed of the same metal as the first metal layer.

[0020] According to an exemplary embodiment, the thickness of the second metal layer may be 0.05 mm to 1.2 mm.

[0021] A battery case according to an embodiment of the present invention may include the composite laminate of the above-described embodiment.

[0022] A battery assembly according to an embodiment of the present invention may include a plurality of battery cells stacked on one another and the battery case of the above embodiment formed in a manner of wrapping at least a portion of the stacked plurality of battery cells.

[0023] (3) Beneficial effects

[0024] The corrosion resistance and flame retardancy of the composite laminate according to the above embodiment can improve the stability of the battery and prevent the spread of flames due to battery damage.

[0025] According to an exemplary embodiment, the composite laminate may include the continuous fibers within a specified content range. When the content of the continuous fibers is within the specified range, the flame retardancy of the composite laminate may be improved.

[0026] According to the exemplary embodiment, the thickness of each layer included in the composite laminate may be adjusted, and thus, both lightness and flame retardancy of the composite laminate may be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figures 1 to 5 is a schematic cross-sectional view illustrating a composite laminate according to an exemplary embodiment.

[0028] Figure 6a and Figure 6b is a schematic diagram illustrating a unidirectional tape layer of a composite laminate according to an exemplary embodiment.

[0029] Figure 7 is a schematic oblique view illustrating a battery assembly including a composite laminate according to an exemplary embodiment.

[0030] Figures 8a to 8c 2 is a schematic cross-sectional view for explaining a stacking order of a composite stack according to an exemplary embodiment.

[0031] Figure 9 Schematic diagrams are shown for explaining a method of manufacturing a composite laminate according to an exemplary embodiment.

[0032] Description of reference numerals:

[0033] 105: Continuous fiber layer 110: Unidirectional tape layer

[0034] 115: Primary unidirectional tape layer 120: Metal layer

[0035] 125: Primary metal layer 150: Adhesive layer

[0036] 210: Mold 215: Molding part DETAILED DESCRIPTION

[0037] The embodiments disclosed herein provide a composite laminate comprising a unidirectional tape layer and a metal layer, and also provide a battery case and a battery assembly comprising the composite laminate.

[0038] The exemplary embodiments are described in more detail with reference to the accompanying drawings. However, the drawings and embodiments of this specification serve to better understand the technical concept of the present invention, and therefore the present invention should not be interpreted as being limited to the contents described in these drawings and embodiments.

[0039] The terms "upper," "upper layer," "lower," and "lower layer" used in the present invention do not specify absolute positions but are used in a relative sense. For example, the terms are used to specify other areas relative to a specific reference plane.

[0040] Figures 1 to 5 is a schematic cross-sectional view illustrating a composite laminate according to an exemplary embodiment.

[0041] Reference Figure 1 and Figure 2 The composite laminate 100 may include a unidirectional tape layer 110 and a metal layer 120 formed on the unidirectional tape layer 110. Figure 2 As shown, the composite laminate 100 may further include an adhesive layer 150 , and the adhesive layer 150 may be formed between the unidirectional tape layer 110 and the metal layer 120 .

[0042] Reference Figure 3 and Figure 4 The composite laminate 100 may include: a unidirectional tape layer 110; a first metal layer 121, the first metal layer 121 being formed on the unidirectional tape layer; and a second metal layer 122, the second metal layer 122 being formed on the bottom surface of the unidirectional tape layer. Figure 4 As shown, the composite laminate 100 may further include an adhesive layer 150 , which may include a first adhesive layer 151 between the unidirectional tape layer 110 and the first metal layer 121 and a second adhesive layer 152 between the unidirectional tape layer 110 and the second metal layer 122 .

[0043] Reference Figure 5 The composite laminate 100 may include two or more unidirectional tape layers 110 and two or more metal layers 120. For example, a first adhesive layer 151 and a first metal layer 121 may be formed on the top of the first unidirectional tape layer 111, and a second adhesive layer 152 and a second metal layer 122 may be formed on the bottom of the first unidirectional tape layer 111. A third adhesive layer 153 and the second unidirectional tape layer 112 may be formed on the bottom of the second metal layer. For example, the unidirectional tape layers 110 and the metal layers 120 may be alternately stacked in sequence, with an adhesive layer 150 included between the unidirectional tape layers 110 and the metal layers 120.

[0044] For example, the composite laminate 100 includes two or more unidirectional tape layers 110 and two or more metal layers 120, and the thickness of each layer can be adjusted. Thus, even if formed into a multi-layer structure, the thickness or weight of the composite laminate 100 can be within a specified range.

[0045] Figure 6a and Figure 6bis a schematic diagram illustrating a unidirectional tape layer of a composite laminate according to an exemplary embodiment.

[0046] Reference Figure 6a and Figure 6b The unidirectional tape layer 110 may include two or more continuous fiber layers 105 .

[0047] According to an exemplary embodiment, the unidirectional tape layer 110 may include a thermoplastic resin and continuous fibers oriented in one direction. For example, the continuous fibers may be oriented and impregnated with the thermoplastic resin to produce the continuous fiber layer 105, and the continuous fiber layer 105 may be oriented and sequentially stacked to produce the unidirectional tape layer 110.

[0048] According to an exemplary embodiment, the unidirectional tape layer 110 may include a thermoplastic resin. The unidirectional tape layer 110 including the thermoplastic resin can be bonded to the metal layer 120 under relatively low temperature and pressure conditions. In addition, the physical properties of the unidirectional tape layer 110 can be adjusted according to the content of the thermoplastic resin included in the unidirectional tape layer 110.

[0049] For example, the thermoplastic resin may include polypropylene (PP), high-density polyethylene (HDPE), polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), thermoplastic polyurethane (TPU), acrylonitrile butadiene styrene (ABS), polycarbonate (PC), polyphenylene sulfide (PPS), polyamide (PA), polyetherimide (PEI), polyoxymethylene (POM), polyetheretherketone (PEEK), polyaryletherketone (PAEK), etc.

[0050] In one embodiment, the thermoplastic resin may comprise polypropylene.

[0051] According to an exemplary embodiment, the thermoplastic resin may include polypropylene, and the content of the polypropylene may be 60 wt % or less based on the total weight of the unidirectional tape layer 110 .

[0052] In one embodiment, based on the total weight of the unidirectional tape layer 110 , the content of the polypropylene may be 60 wt % or less, 50 wt % or less and 10 wt % or more, 50 wt % or less and 20 wt % or more, or 40 wt % or less and 20 wt % or more.

[0053] Within the above range, a lightweight composite laminate can be achieved.

[0054] According to an exemplary embodiment, the thermoplastic resin may further include a flame retardant. For example, the thermoplastic resin may include polypropylene and a flame retardant.

[0055] For example, the flame retardant may include phosphorus-based flame retardants, boron-based flame retardants, magnesium-based flame retardants, aluminum-based flame retardants, nitrogen-based flame retardants, antimony-based flame retardants, halogen-based flame retardants, non-halogen-based flame retardants, etc. In some embodiments, the flame retardant may include a phosphorus-based flame retardant.

[0056] According to an exemplary embodiment, the flame retardant may be present in an amount of 15 to 45 wt % based on the total weight of the thermoplastic resin. In one embodiment, the flame retardant may be present in an amount of 20 to 40 wt % or 25 to 35 wt % based on the total weight of the thermoplastic resin. Within these ranges, the flame retardancy of the thermoplastic resin can be improved. Therefore, the flame retardancy of the composite laminate can be improved.

[0057] According to an exemplary embodiment, the unidirectional tape layer 110 may include continuous fibers oriented in one direction and may include two or more stacked continuous fiber layers 105. The physical properties of the unidirectional tape layer 110 may be partially adjusted depending on the orientation of the continuous fiber layers 105.

[0058] According to an exemplary embodiment, the content of the continuous fibers oriented in one direction included in the unidirectional tape layer 110 may be 40 wt % or more, 50 wt % or more, 60 wt % or more, or 60 wt % or more and 90 wt % or less, based on the total weight of the unidirectional tape layer 110.

[0059] Within the above weight range, the flame retardancy of the composite laminate can be improved, as well as its elongation and flexural properties. For example, if the continuous fiber content is below the above range, the flame retardancy of the composite laminate may be reduced, and the structure may collapse or be perforated due to flames, thus failing to suppress thermal runaway of the secondary battery.

[0060] The content of the continuous fibers may be the total weight of the continuous fibers contained in the continuous fiber layer 105 .

[0061] The content of the continuous fibers can be adjusted based on the design process of the unidirectional tape layer. For example, in an impregnation mold, the continuous fibers are spread unidirectionally or multidirectionally, and thermoplastic resin can be supplied from the top or bottom to impregnate the continuous fibers, thereby forming the unidirectional tape layer 110. Alternatively, the continuous fibers can be supplied unidirectionally or multidirectionally to the thermoplastic resin to impregnate the continuous fibers, thereby forming the unidirectional tape layer 110. The content of the continuous fibers can be adjusted to the above range by adjusting the supply speed of the continuous fibers or the thermoplastic resin, the impregnation speed, the impregnation temperature, and other factors.

[0062] According to an exemplary embodiment, the continuous fibers of the continuous fiber layer 105 may include one or more of carbon fibers, glass fibers, and polypropylene fibers.

[0063] According to an exemplary embodiment, the cross-sectional diameter of the monofilament of the continuous fiber may be 10 μm to 30 μm. For example, the cross-sectional diameter of the monofilament of the continuous fiber may be 12 μm to 18 μm, 14 μm to 17 μm, or 15 μm to 17 μm.

[0064] The content of the continuous fibers of the unidirectional tape layer 110 may be increased within the above range.

[0065] For example, Figure 6a As shown, the unidirectional tape layer 110 may include a continuous fiber layer arranged parallel to the continuous fibers of the first continuous fiber layer 105a. For example, a second continuous fiber layer 105b arranged parallel to the continuous fibers of the first continuous fiber layer 105a may be laminated on the first continuous fiber layer 105a. A third continuous fiber layer 105c arranged parallel to the continuous fibers of the first continuous fiber layer 105a may be laminated on the second continuous fiber layer 105b. A fourth continuous fiber layer 105d arranged parallel to the continuous fibers of the first continuous fiber layer 105a may be laminated on the third continuous fiber layer 105c.

[0066] For example, Figure 6b As shown in , the unidirectional tape layer 110 may include a continuous fiber layer that is aligned perpendicularly to the continuous fibers of the first continuous fiber layer 105a. For example, a second continuous fiber layer 105b that is aligned perpendicularly to the continuous fibers of the first continuous fiber layer 105a may be laminated on the first continuous fiber layer 105a. A third continuous fiber layer 105c that is aligned parallel to the continuous fibers of the first continuous fiber layer 105a may be laminated on the second continuous fiber layer 105b. A fourth continuous fiber layer 105d that is aligned perpendicularly to the continuous fibers of the first continuous fiber layer 105a may be laminated on the third continuous fiber layer 105c.

[0067] The arrangement and stacking structure of the continuous fiber layer are not limited to the above description. The continuous fiber layer can be stacked to form a specified angle with the arrangement of the continuous fibers contained in the first continuous fiber layer 105a, for example, 0°, 45°, 90°, 135°, 180°, etc.

[0068] According to an exemplary embodiment, the unidirectional tape layer 110 may include 10 or fewer continuous fiber layers 105. In some embodiments, the unidirectional tape layer 110 may include 7 or fewer continuous fiber layers 105.

[0069] For example, the unidirectional tape layer 110 may include 3 to 7 continuous fiber layers 105. However, the number of continuous fiber layers 105 is provided for illustrative purposes only and may be adjusted based on desired properties. For example, the unidirectional tape layer 110 may include 8 or more continuous fiber layers by adjusting the thickness of the continuous fiber layers.

[0070] According to an exemplary embodiment, the thickness of the unidirectional tape layer 110 may be 0.4 mm to 3.5 mm.

[0071] According to exemplary embodiments, the thickness of the unidirectional tape layer 110 may be 0.4 mm to 3.3 mm, 0.5 mm to 3.2 mm, 0.5 mm to 3.0 mm, 0.55 mm to 2.8 mm, or 0.55 mm to 2.4 mm.

[0072] Within the above range, the flame retardancy of the composite laminate 100 can be ensured while reducing the weight. For example, if the thickness of the unidirectional tape layer 110 exceeds the above range, the weight increases and the composite laminate 100 cannot be lightweighted. If the thickness of the unidirectional tape layer 110 is less than the above range, the flame retardancy cannot be ensured.

[0073] The metal layer 120 may include aluminum, steel, magnesium, titanium, etc.

[0074] According to an exemplary embodiment, the metal layer 120 may include one or more of aluminum, steel, and alloys thereof.

[0075] According to an exemplary embodiment, the thickness of the metal layer 120 may be 0.05 mm to 1.2 mm.

[0076] According to exemplary embodiments, the thickness of metal layer 120 may be 0.08 mm to 1.1 mm, 0.1 mm to 1.1 mm, 0.1 mm to 1.05 mm, or 0.1 mm to 1.0 mm. In some embodiments, the thickness of metal layer 120 may be 0.15 mm to 1.0 mm, 0.15 mm to 1.0 mm, or 0.2 mm to 1.0 mm.

[0077] Within the above-mentioned thickness range, the weight of the composite laminate can be reduced. For example, if the thickness of the metal layer 120 exceeds the above-mentioned range, the weight increases, and lightweighting of the composite laminate 100 may not be achieved. For example, if the thickness of the metal layer 120 is less than the above-mentioned range, flame retardancy may not be achieved even if the metal layer 120 and the unidirectional tape layer 110 are repeatedly laminated.

[0078] The thickness of the unidirectional tape layer 110 and the thickness of the metal layer 120 can be partially adjusted according to the structure of the composite laminate. Figure 5As shown, when the composite laminate includes two or more unidirectional tape layers 110 or three or more metal layers 120, the thickness of each unidirectional tape layer 110 and metal layer 120 can be adjusted within a range that can reduce the weight of the composite laminate. However, the thickness of each unidirectional tape layer 110 and metal layer 120 can be adjusted within the thickness range of each layer described above.

[0079] According to an exemplary embodiment, the composite laminate 100 may include: a unidirectional tape layer 110; a first metal layer 121, which is formed on the unidirectional tape layer 110; and a second metal layer 122, which is formed on the bottom surface of the unidirectional tape layer 110.

[0080] According to exemplary embodiments, the first metal layer 121 and the second metal layer 122 may be the same metal.

[0081] For example, when the first metal layer 121 includes steel, the second metal layer 122 may include steel, and when the first metal layer 121 includes aluminum, the second metal layer 122 may include aluminum.

[0082] According to an exemplary embodiment, the composite laminate 100 may include: a unidirectional tape layer 110; a first aluminum metal layer formed on the top of the unidirectional tape layer 110; and a second aluminum metal layer formed on the bottom of the unidirectional tape layer 110.

[0083] For example, when the composite laminate 100 includes the first aluminum metal layer and the second aluminum metal layer, the thickness of the first aluminum metal layer and the second aluminum metal layer can be 0.2 mm to 0.4 mm. In this case, the thickness of the unidirectional tape layer 110 can also be 0.8 mm to 1.6 mm.

[0084] According to an exemplary embodiment, when the metal layer 120 includes steel, the second metal layer 122 may not be included. For example, when the composite laminate 100 includes the first steel metal layer, the thickness of the first steel metal layer may be 0.2 mm to 0.4 mm. In this case, the thickness of the unidirectional tape layer 110 may also be 0.8 mm to 1.6 mm.

[0085] For example, the value of the composite laminate 100 according to the following Formula 1 may be 5% or more.

[0086] Formula 1: BA / B×100

[0087] (In the above formula 1, B is the weight of steel with a thickness of 0.6 mm, and A is the weight of the composite laminate.)

[0088] In the above-mentioned formula 1, the weights of the steel and the composite laminate may be values measured based on the same width and the same length.

[0089] For example, the value according to Formula 1 of the composite laminate 100 may be 10 wt % or more. In accordance with lightweighting of the composite laminate 100 , the value according to Formula 1 may be within the above range.

[0090] According to an exemplary embodiment, the composite laminate 100 may further include an adhesive layer 150 formed between the unidirectional tape layer 110 and the metal layer 120 .

[0091] For example, the adhesive layer 150 may include an epoxy-based adhesive, an acrylic-based adhesive, a silicon-based adhesive, a polyurethane-based adhesive, a rubber adhesive, a polyolefin-based adhesive, a silica-based adhesive, or the like.

[0092] According to an exemplary embodiment, the adhesive layer 150 may include a polyolefin-based adhesive. For example, the adhesive layer 150 may include maleic anhydride-graft polypropylene (MAPP).

[0093] For example, when the adhesive layer 150 includes a polypropylene-based adhesive, it may be bonded to the metal layer 120 while minimizing changes in physical properties of the unidirectional tape layer 110 .

[0094] For example, the thickness of the adhesive layer 150 may be 0.05 mm to 0.2 mm.

[0095] Figure 7 is a schematic oblique view illustrating a battery assembly including a composite laminate according to an exemplary embodiment.

[0096] Reference Figure 7 The battery assembly may include a plurality of battery cells (not shown) stacked on each other and a battery case formed in a manner of wrapping at least a portion of the stacked plurality of battery cells.

[0097] The battery case may include a top cover 310, a front cover 320a, a rear cover 320b, a side cover 330, and a bottom cover (not shown). The six sides of the battery cells are protected from foreign matter and external impacts by the covers (310, 320, 330).

[0098] The covering portion may include the composite laminate 100 described above.

[0099] Figures 8a to 8cis a schematic diagram for explaining a stacked structure of a composite stack included in a cover portion of a battery case according to an exemplary embodiment.

[0100] Reference Figures 8a to 8b When the composite laminate 100 includes an odd number of metal layers 120 , the arrangement of the unidirectional tape layers 110 and the metal layers 120 may be different.

[0101] For example, when an odd number of metal layers 120 are included, the composite laminate 100 may form directionality of flame retardancy. For example, the arrangement of the composite laminate 100 may be different depending on the metal type of the metal layer 120.

[0102] For example, when the metal layer 120 including steel is included in the composite laminate 100 in an odd number of layers, the unidirectional tape layer 110 may face the plurality of battery cells and the metal layer 120 may face the outside direction of the battery assembly.

[0103] For example, when the metal layer 120 including aluminum is included in the composite laminate 100 in an odd number of layers, the unidirectional tape layer 110 may face the outer direction of the battery assembly, and the metal layer 120 may face the battery cell side.

[0104] For example, when the metal layer 120 includes aluminum, in the direction toward the unidirectional tape layer 110 ( Figure 8a When a high temperature flame is applied in the direction of the arrow (in the direction of the arrow), a portion of the composite laminate 100 may be burned or only a thickness change may occur. Figure 8b When a high-temperature flame is applied in the direction of the arrow (in the direction of the arrow), perforation may occur in the composite laminate 100.

[0105] For example, when the metal layer 120 comprises steel, in the direction toward the unidirectional tape layer 110 ( Figure 8a When a high-temperature flame is applied in the direction of the arrow (in the direction of the arrow), the unidirectional tape layer 110 may melt and the structure of the composite laminate 100 may collapse. Figure 8b When a high-temperature flame is applied in the direction of the arrow (in the direction of the arrow), a portion of the composite laminate 100 may burn or only a thickness change may occur.

[0106] Therefore, thermal stability of the battery assembly can be ensured, and thermal runaway can be suppressed.

[0107] Reference Figure 8c When the composite laminate 100 includes an even number of metal layers 120 , the first metal layer 121 on the upper surface of the unidirectional tape layer 110 and the second metal layer 122 on the lower surface can be arranged in any direction on the covering portion.

[0108] For example, the unidirectional tape layers 110 are located between the metal layers 120 , and a high-temperature flame may be applied to the metal layers 120 from the outside, but the composite laminate is not perforated, thereby protecting the plurality of battery cells from external and internal heat.

[0109] For example, the plurality of battery cells may include: a positive electrode; a negative electrode, the negative electrode being disposed opposite to the positive electrode; and a separator.

[0110] The positive electrode may include a positive electrode current collector and a positive electrode mixture layer disposed on at least one side of the positive electrode current collector.

[0111] The positive electrode current collector may comprise stainless steel, nickel, aluminum, titanium, or alloys thereof, or aluminum or stainless steel surface-treated with carbon, nickel, titanium, or silver.

[0112] The positive electrode mixture layer may include a positive electrode active material. The positive electrode active material may include a compound that can reversibly intercalate and deintercalate lithium ions.

[0113] According to an exemplary embodiment, the positive active material may include lithium-nickel metal oxide. The lithium-nickel metal oxide may further include at least one of cobalt (Co), manganese (Mn), and aluminum (Al).

[0114] The positive electrode active material may further include a coating element or a doping element. For example, an element substantially identical to or similar to the auxiliary element may be used as the coating element or the doping element. For example, the above elements may be used alone or in combination of two or more.

[0115] The negative electrode may include a negative electrode current collector and a negative electrode mixture layer disposed on at least one side of the negative electrode current collector.

[0116] Non-limiting examples of the negative electrode current collector include copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, and a polymer substrate coated with a conductive metal.

[0117] The negative electrode mixture layer may contain a negative electrode active material. The negative electrode active material may be a material that can intercalate and deintercalate lithium ions. For example, the negative electrode active material may include carbon-based materials such as crystalline carbon, amorphous carbon, carbon composites, and carbon fibers; lithium metal; lithium alloys; silicon (Si)-containing materials; or tin (Sn)-containing materials.

[0118] Examples of the amorphous carbon include hard carbon, soft carbon, coke, mesocarbon microbeads (MCMB), and mesophase pitch-based carbon fibers (MPCF).

[0119] Examples of the crystalline carbon include graphite-based carbon such as natural graphite, artificial graphite, graphitized coke, graphitized MCMB, and graphitized MPCF.

[0120] A separator may be provided between the positive electrode and the negative electrode to prevent a short circuit between the positive electrode and the negative electrode and to maintain the flow of ions.

[0121] The separator may comprise a porous polymer film or a porous nonwoven fabric. The porous polymer film may comprise a polyolefin-based polymer such as an ethylene polymer, a propylene polymer, an ethylene / butene copolymer, an ethylene / hexene copolymer, and an ethylene / methacrylate copolymer. The porous nonwoven fabric may comprise a high-melting-point glass fiber, a polyethylene terephthalate fiber, or the like.

[0122] The separator may also include a ceramic-based material. For example, inorganic particles may be coated on or dispersed in the polymer film to improve heat resistance.

[0123] The separator may have a single-layer or multi-layer structure including the above-mentioned polymer film and / or non-woven fabric.

[0124] Figure 9 Schematic diagrams are shown for explaining a method of manufacturing a composite laminate according to an exemplary embodiment.

[0125] Reference Figure 9 A primary composite laminate may be prepared, the primary composite laminate including a primary unidirectional tape layer 115 and a primary metal layer 125 formed on the primary unidirectional tape layer 115. The primary composite laminate may be placed in a mold (e.g., S10 process). Heat and pressure may be applied to the primary composite laminate by a molding unit (215, 215') (e.g., S20 process). The molded primary composite laminate may be cooled (e.g., S30 process).

[0126] According to an exemplary embodiment, a primary composite laminate may be formed by forming a primary first metal layer on an upper surface of the primary unidirectional tape layer 115 and forming a primary second metal layer on a lower surface of the primary unidirectional tape layer 115 .

[0127] The primary unidirectional tape layer 115 and the primary metal layer 125 may be identical to the aforementioned unidirectional tape layer 110 and the metal layer 120 except for thickness. For example, the primary unidirectional tape layer 115 may include a thermoplastic resin and continuous fibers oriented in one direction.

[0128] The thickness of the primary unidirectional tape layer 115 can be adjusted to about 10% of the thickness range of the unidirectional tape layer 110 . In addition, the thickness of the primary metal layer 125 can be adjusted to about 10% of the thickness range of the metal layer 120 .

[0129] According to an exemplary embodiment, a primary adhesive layer may be further included between the primary unidirectional tape layer 115 and the primary metal layer 125. The primary adhesive layer may be the same as the adhesive layer described above.

[0130] According to an exemplary embodiment, the primary composite laminate may be molded at a temperature of 130° C. to 170° C. in the molding part ( 215 , 215 ′).

[0131] According to an exemplary embodiment, the primary composite laminate may be molded at a molding part ( 215 , 215 ′) at a pressure of 10 kPa to 300 kPa.

[0132] For example, the primary unidirectional tape layer 115 may comprise a thermoplastic resin so that the composite laminate can be manufactured under relatively mild conditions within the temperature and pressure ranges described above.

[0133] The forming section (215, 215') may use a device for applying heat and pressure. For example, a hand press, a roller press, etc. may be used as the forming section. For example, the primary composite laminate may be formed by a calendaring process.

[0134] The molding unit may laminate the primary unidirectional tape layer 115 and the primary metal layer 125 to form a whole.

[0135] According to an exemplary embodiment, the formed primary composite laminate may be cooled at a temperature in the range of 0° C. to 30° C. The formed primary composite laminate may be rapidly cooled at a temperature in the above range to maintain the continuous fiber alignment of the unidirectional tape layer.

[0136] Below, specific embodiments are proposed to help understand the present invention, but these embodiments are only used to illustrate the present invention and are not used to limit the claims. Various changes and modifications can be made to the embodiments within the scope and technical ideas included in the present invention. This is obvious to those skilled in the art, and it is natural that such variations and modifications fall within the scope of the claims.

[0137] Examples and Comparative Examples

[0138] Manufacturing Example: Production of Unidirectional Tape Layers (UD Tapes)

[0139] Manufacturing Example 1-1. Manufacturing of a Flame-Retardant Unidirectional Tape Layer

[0140] A flame retardant polypropylene resin (ADEKA, FR-2500S) was added to a polypropylene resin to a content of 25 to 35 wt %. Glass fibers were impregnated into the flame retardant polypropylene resin to a content of 60 wt %. Four layers of the glass fiber-impregnated polypropylene resin were stacked to produce a unidirectional tape layer with a thickness of 1.1 mm.

[0141] Manufacturing Example 1-2. Manufacturing of a Flame-Retardant Unidirectional Tape Layer

[0142] A unidirectional tape layer was produced by the same method as in Production Example 1-1, except that six layers (ply) of the polypropylene resin impregnated with the glass fiber were laminated to change the thickness to 1.6 mm.

[0143] Manufacturing Example 1-3. Manufacturing of a Flame-Retardant Unidirectional Tape Layer

[0144] A unidirectional tape layer was produced by the same method as in Production Example 1-1, except that 8 layers (ply) of the polypropylene resin impregnated with the glass fiber were laminated to change the thickness to 2.2 mm.

[0145] Manufacturing Example 2. Manufacturing of a flame-retardant unidirectional tape layer

[0146] A unidirectional tape layer was manufactured by the same method as in Manufacturing Example 1-1, except that the content of the glass fiber was changed to 50 wt %.

[0147] Manufacturing Example 3. Manufacturing of a flame-retardant unidirectional tape layer

[0148] A unidirectional adhesive tape layer was manufactured by the same method as in Manufacturing Example 1-1, except that the content of the glass fiber was changed to 70 wt %.

[0149] Manufacturing Example 4. Manufacturing of a non-flame retardant unidirectional tape layer

[0150] A unidirectional adhesive tape layer was manufactured by the same method as in Manufacturing Example 1-1, except that a polypropylene resin not containing the flame retardant was used.

[0151] Manufacturing Example 5. Manufacturing of a Flame-Retardant Unidirectional Tape Layer

[0152] A unidirectional tape layer was manufactured by the same method as in Manufacturing Example 1-1, except that the content of the glass fiber was changed to 30 wt %.

[0153] Example 1. Production of a composite laminate (1)

[0154] A 0.05 mm thick maleic anhydride grafted polypropylene (MAPP) film was laminated onto a first metal layer comprising aluminum or steel, and a unidirectional adhesive tape layer according to any one of Manufacturing Examples 1-1, 1-2, 1-3, 2, 3, or 4 was laminated onto the MAPP film to form a first primary laminate. The first primary laminate was then placed in a mold and passed through a heating zone at 130°C to 170°C to bond the layers, depending on the type of unidirectional adhesive tape, and then passed through a cooling zone at 30°C to rapidly cool the layers, thereby producing a first composite laminate.

[0155] The types and thicknesses of the layers included in the first composite laminate are shown in Table 1 below.

[0156] [Table 1]

[0157]

[0158] Example 2. Production of a composite laminate (2)

[0159] A first primary laminate was formed using the same method as in Example 1. A 0.05 mm thick MAPP film and a second metal layer were sequentially laminated on the unidirectional tape layer of the first primary laminate to form a second primary laminate. This second primary laminate was then placed in a mold and passed through a heating zone at 130°C to 170°C to bond the layers, depending on the type of unidirectional tape, and then through a cooling zone at 30°C to rapidly cool the layers, thereby producing a second composite laminate.

[0160] The types and thicknesses of the layers included in the second composite laminate are shown in Table 2 below.

[0161] [Table 2]

[0162]

[0163] Comparative Example 1. Single Metal Layer

[0164] Aluminum single-layer metal layers with thicknesses of 0.3 mm, 1.0 mm, 2.0 mm, 2.5 mm, and 3.0 mm were manufactured.

[0165] Comparative Example 2. Single-layer unidirectional tape

[0166] A single-layer unidirectional tape layer having a thickness of 1.1 mm was produced according to the above-mentioned Production Examples 1-1, 2, 3, and 4.

[0167] Comparative Example 3. Preparation of a composite laminate

[0168] A composite laminate is manufactured by the same method as in Example 1, except that polytetrafluoroethylene (PTFE) is used instead of the first metal layer comprising aluminum or steel.

[0169] Comparative Example 4. Preparation of a composite laminate

[0170] A composite laminate is manufactured by the same method as in Example 1, except that a unidirectional tape layer according to Manufacturing Example 5 is used instead of any one of the unidirectional tape layers in Manufacturing Example 1-1, Manufacturing Example 1-2, Manufacturing Example 1-3, Manufacturing Example 2, Manufacturing Example 3 and Manufacturing Example 4.

[0171] The types and thicknesses of the layers included in the single metal layer, single unidirectional tape layer, or composite laminate according to Comparative Examples 1 to 4 are shown in Table 3 below.

[0172] [Table 3]

[0173]

[0174] Experimental example

[0175] (1) Evaluation of flame resistance

[0176] The flame retardancy of the single-layer or composite laminates according to the above-described Examples and Comparative Examples was evaluated.

[0177] A welding torch was placed 10 cm away from the single layer or composite laminate in the thickness direction, and the distance was adjusted again so that the temperature of the welding torch spark on the surface of the single layer or composite laminate reached 1100°C. Heat was then applied to the single layer or composite laminate to evaluate whether a hole occurred and when the hole occurred.

[0178] In the case of the first composite laminate of Example 1, the composite laminate of Comparative Example 3, and the composite laminate of Comparative Example 4, the flame retardancy of the metal layer facing the welding lamp and the flame retardancy of the unidirectional tape layer facing the welding lamp were evaluated respectively.

[0179] As experimental results, the flame retardancy evaluation results according to the following examples are shown in Table 4, and the flame retardancy evaluation results according to the following comparative examples are shown in Table 5.

[0180] [Table 4]

[0181]

[0182]

[0183] As shown in Table 4, in the composite laminate according to Example 1, the flame retardancy test results were different when heat was applied at the metal layer and when heat was applied at the unidirectional (UD) tape layer.

[0184] In the case of Example 1-1 including a steel metal layer and a flame-retardant treated unidirectional tape layer, no perforation occurred regardless of the type of surface to which heat was applied.

[0185] In Examples 1-4, which included an aluminum metal layer and a flame-retardant unidirectional tape layer, perforation was observed within 5 minutes when heat was applied directly to the metal layer. However, when heat was applied directly to the flame-retardant unidirectional tape layer, no perforation occurred even after 10 minutes or more.

[0186] In the case of Examples 1-20 including a steel metal layer and a non-flame retardant treated unidirectional tape layer, perforation occurred when heat was applied directly to the non-flame retardant treated unidirectional tape layer, but no perforation occurred when heat was applied directly to the metal layer.

[0187] In the case of Example 1-21 including an aluminum metal layer and a non-flame retardant treated unidirectional tape layer, perforation occurred regardless of the type of surface to which heat was applied.

[0188] In the case of the composite laminate including the first metal layer, the unidirectional tape layer, and the second metal layer, it was confirmed that no perforation occurred regardless of the flame retardant treatment of the unidirectional tape layer, and the flame retardant properties were significantly improved.

[0189] [Table 5]

[0190]

[0191]

[0192] As shown in Table 5, in the cases of Comparative Examples 1-1 to 1-5 corresponding to the single metal layer, the time of occurrence of perforation is delayed as the thickness of the metal layer increases, but perforation occurs even when the thickness of the metal layer is equivalent to or greater than 3.0 mm.

[0193] In the case of Comparative Examples 2-1 and 2-4 corresponding to a single unidirectional tape layer, the occurrence of perforation was delayed as the flame retardant treatment was performed, but perforation occurred within a short period of time even after the flame retardant treatment.

[0194] In the case of Comparative Examples 3-1 to 3-3 in which polytetrafluoroethylene (PTFE) was used instead of the metal layer, the time for the occurrence of perforation was delayed as the thickness of the PTFE increased, but perforation occurred within 5 minutes in all cases.

[0195] In the case of Comparative Examples 4-1 and 4-2 using unidirectional tape layers with a low glass fiber content, it was confirmed that the occurrence of perforation could not be delayed even when the same metal and thickness as those in the examples were used.

[0196] (2) Evaluation of lightweighting rate

[0197] The lightweighting ratio of the composite laminates of the above examples was evaluated. The lightweighting ratio was evaluated using the weight of a 100 mm × 100 mm × 0.6 mm steel sheet with the same length and width. The lightweighting ratio was calculated using the following equation 1. The evaluation results are shown in Tables 6 and 7.

[0198] - Formula 1: BA / B×100

[0199] In the above formula, B is the weight of the above-mentioned reference steel, and A is the weight of the above-mentioned composite laminate.

[0200] [Table 6]

[0201]

[0202]

[0203] As shown in Table 6, it was confirmed that the weight increased as the thickness of the metal layer or the unidirectional tape layer increased, and the weight reduction rate decreased compared to the reference steel.

[0204] In the case of the composite laminates of Examples 1-16 to 1-19, which were manufactured using unidirectional tape layers having different glass fiber contents, there was no significant difference in thickness or weight of the composite laminates. Furthermore, in the case of the composite laminates of Examples 1-20 and 1-21, which were manufactured using unidirectional tape layers without a flame retardant, there was no significant difference in thickness or weight of the composite laminates.

[0205] [Table 7]

[0206]

[0207] As shown in Table 7, when steel is used as the metal layer, weight reduction cannot be achieved.

Claims

1. A composite laminate comprising: a unidirectional tape layer comprising a thermoplastic resin and continuous fibers; as well as a first metal layer, the first metal layer being formed on the unidirectional tape layer, Wherein, based on the total weight of the unidirectional tape layer, the content of the continuous fibers is greater than 40 wt %.

2. The composite laminate according to claim 1, wherein The composite laminate further includes a second metal layer formed on a bottom surface of the unidirectional tape layer.

3. The composite laminate according to claim 1, wherein Based on the total weight of the unidirectional tape layer, the content of the continuous fibers is greater than 60 weight %. The composite laminate according to claim 1 , wherein: The thermoplastic resin further comprises a flame retardant. The composite laminate according to claim 1 , wherein: The continuous fibers include at least one selected from carbon fibers, glass fibers, and polypropylene fibers. The composite laminate according to claim 1 , wherein: The unidirectional tape layer includes a plurality of continuous fiber layers, each of which contains continuous fibers impregnated in the thermoplastic resin. The unidirectional tape layer includes two or more continuous fiber layers.

7. The composite laminate according to claim 6, wherein: The unidirectional tape layer includes no more than 7 layers of the continuous fiber layer. The composite laminate according to claim 1 , wherein: The thickness of the unidirectional tape layer is greater than or equal to 0.4 mm and less than or equal to 3.5 mm.

9. The composite laminate according to claim 1, wherein The first metal layer is formed of at least one selected from aluminum, steel, or alloys thereof.

10. The composite laminate according to claim 2, wherein The second metal layer is formed of the same metal as the first metal layer. The composite laminate according to claim 2 , wherein: The thickness of the second metal layer is 0.05 mm to 1.2 mm. 12 . A battery case comprising the composite laminate according to claim 1 .

13. A battery assembly comprising: A plurality of battery cells stacked on each other; and a battery case according to claim 12 formed so as to wrap at least a portion of the stacked plurality of battery cells.

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