Battery pack sealing cover and power battery

Abstract

The utility model discloses a battery pack sealing cover and a power battery, and belongs to the technical field of new energy. The battery pack sealing cover comprises a first continuous fiber reinforced composite material plate, a heat insulation layer, a buffer layer and a second continuous fiber reinforced composite material plate which are sequentially laminated, the first continuous fiber reinforced composite material plate comprises n1 layers of first continuous fiber reinforced resin sheets which are sequentially laminated in the thickness direction of the first continuous fiber reinforced composite material plate; the second continuous fiber reinforced composite material plate comprises n2 layers of second continuous fiber reinforced resin sheets which are sequentially laminated in the thickness direction of the second continuous fiber reinforced composite material plate. The battery pack sealing cover provided by the utility model not only is light in weight, high in strength and good in insulativity, but also can realize more excellent fire resistance and heat insulation performance by arranging the heat insulation layer; the buffer layer is arranged between the heat insulation layer and the second continuous fiber reinforced composite material plate, so that impact energy can be effectively absorbed, and the impact resistance of the sealing cover is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of new energy, and in particular to a battery pack sealing cover and a power battery. Background Art

[0002] New energy vehicles are developing rapidly, and the technology has advanced by leaps and bounds in recent years. Among them, the structure of power batteries (Pack) is also constantly evolving. The existing technology usually uses metal sealing covers or plastic sealing covers to seal the power batteries. Metal sealing covers, such as steel sealing covers and aluminum sealing covers, are heavy, costly, and not insulated; plastic sealing covers have the advantages of insulation and light weight, and have received more and more attention. However, most of the existing plastic sealing covers are single-layer PP structures or single-layer short glass fiber reinforced thermoplastic materials (such as LFT-D) board structures. The sealing covers of this type of structure have the defects of low impact resistance and poor thermal barrier properties, and cannot effectively deal with the problem of battery pack combustion caused by thermal runaway, or even the spread of fire.

[0003] Therefore, it is very necessary to design a battery pack sealing cover with good thermal barrier performance and good impact resistance. Utility Model Content

[0004] The purpose of the utility model is to overcome the shortcomings of the prior art and provide a battery pack sealing cover and a power battery. The battery pack sealing cover has the advantages of light weight and high strength insulation, and also has excellent thermal barrier performance and impact resistance.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0006] In a first aspect, the utility model provides a battery pack sealing cover, comprising a first continuous fiber reinforced composite plate, a heat insulating layer, a buffer layer and a second continuous fiber reinforced composite plate stacked in sequence; the thickness ratio of the heat insulating layer to the buffer layer is 1:(1-60); the first continuous fiber reinforced composite plate comprises n1 layers of first continuous fiber reinforced resin sheets stacked in sequence along its thickness direction, n1 is an integer greater than or equal to 1; the second continuous fiber reinforced composite plate comprises n2 layers of second continuous fiber reinforced resin sheets stacked in sequence along its thickness direction, n2 is an integer greater than or equal to 1.

[0007] As a preferred embodiment of the present invention, the angle between the continuous fibers in any two adjacent first continuous fiber reinforced resin sheets and the angle between the continuous fibers in any two adjacent second continuous fiber reinforced resin sheets are independently 0-90°.

[0008] As a preferred embodiment of the present invention, the thickness ratio of the thermal insulation layer to the buffer layer is 1:(6-12).

[0009] As a preferred embodiment of the present invention, the thickness of the first continuous fiber reinforced resin sheet and the thickness of the second continuous fiber reinforced resin sheet are independently 0.1-0.5 mm.

[0010] As a preferred embodiment of the present invention, the thickness of the first continuous fiber reinforced composite material plate and the thickness of the second continuous fiber reinforced composite material plate are independently 0.5-3 mm.

[0011] As a preferred implementation mode of the present utility model, n1 is 3-10, and n2 is 3-10.

[0012] As a preferred embodiment of the present utility model, the heat insulation layer is glass fiber cloth or asbestos cloth.

[0013] As a preferred embodiment of the present utility model, the thickness of the thermal insulation layer is 0.1-1 mm.

[0014] As a preferred embodiment of the present invention, the buffer layer is a honeycomb core or a glass fiber mat reinforced thermoplastic composite material plate.

[0015] As a preferred embodiment of the present invention, the thickness of the buffer layer is 1-6 mm.

[0016] As a preferred embodiment of the present invention, a first adhesive layer is provided between the thermal insulation layer and the buffer layer, and a second adhesive layer is provided between the thermal insulation layer and the first continuous fiber reinforced composite material plate.

[0017] As a preferred embodiment of the present invention, the battery pack sealing cover is a plate-like structure or a structure with one end open and a hollow interior.

[0018] In a second aspect, the utility model provides a power battery, comprising a tray, a battery pack and a battery pack sealing cover as described in the first aspect, wherein the tray and the battery pack sealing cover are combined to form a battery pack having a battery accommodating space, and the battery pack is disposed in the accommodating space of the battery pack.

[0019] Compared with the prior art, the beneficial effects of the utility model are:

[0020] (1) The battery pack sealing cover provided by the utility model is not only light in weight, high in strength, and good in insulation, but also can achieve more excellent fire resistance and heat barrier performance by providing a heat insulation layer;

[0021] (2) The utility model provides a buffer layer between the heat insulation layer and the second continuous fiber reinforced composite material plate, which can effectively absorb impact energy and improve the impact resistance of the sealing cover;

[0022] (3) The battery pack sealing cover provided by the utility model is suitable for new energy power batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of the layered structure of a battery pack sealing cover provided in one embodiment of the utility model;

[0024] Figure 2 An overall structural diagram of a battery pack sealing cover provided in one embodiment of the utility model;

[0025] Figure 3 This is a schematic diagram of the plywork provided by the utility model.

[0026] In the figure, 1-insulation layer, 2-buffer layer, 3-first continuous fiber reinforced composite material plate, 4-second continuous fiber reinforced composite material plate, 5-first adhesive layer, 6-second adhesive layer. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the embodiments of the utility model clearer, the technical solution in the embodiments of the utility model will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0028] See also Figure 1-2 The utility model provides a battery pack sealing cover, comprising a first continuous fiber reinforced composite material plate 3, a heat insulation layer 1, a buffer layer 2 and a second continuous fiber reinforced composite material plate 4 which are sequentially stacked; the first continuous fiber reinforced composite material plate 3 comprises n1 layers of first continuous fiber reinforced resin sheets which are sequentially stacked along its thickness direction, and n1 is an integer greater than or equal to 1; the second continuous fiber reinforced composite material plate 4 comprises n2 layers of second continuous fiber reinforced resin sheets which are sequentially stacked along its thickness direction, and n2 is an integer greater than or equal to 1.

[0029] Based on the above technical scheme, the battery pack sealing cover provided by the utility model is not only light in weight, high in strength, and good in insulation, but also can achieve more excellent fire resistance and heat barrier performance by setting the thermal insulation layer 1; the utility model sets a buffer layer 2 between the thermal insulation layer 1 and the second continuous fiber reinforced composite material plate 4, which can effectively absorb impact energy, thereby improving the impact resistance of the sealing cover.

[0030] The thickness ratio of the thermal insulation layer 1 and the buffer layer 2 is 1:(1-60), and is further preferably 1:(6-12). The utility model controls the thickness ratio of the thermal insulation layer 1 and the buffer layer 2 within the above range, which can ensure excellent fire resistance and ensure that the material has a relatively low thickness and weight. On the one hand, the buffer layer 2 can effectively play a role in impact resistance. The thicker the buffer layer 2, the better the impact resistance, but it will cause the battery pack sealing cover to be thicker and heavier as a whole, which is not conducive to the requirement of lightweight automobiles; on the other hand, the thermal insulation layer 1 can avoid or delay thermal runaway or burn-through problems caused by heat convergence; the thicker the thermal insulation layer 1, the better the fire resistance, but when the overall thickness of the product remains unchanged, part of the impact resistance will be sacrificed. Therefore, controlling the thickness ratio of the thermal insulation layer 1 and the buffer layer 2 within the range of 1:(1-60) can effectively balance the impact resistance and fire resistance of the battery pack sealing cover. By controlling the thickness ratio of the heat-insulating layer 1 and the buffer layer 2 within the range of 1:(6-12), the comprehensive performance of the impact resistance and fire resistance of the battery pack sealing cover is better.

[0031] In one embodiment, the angle between the continuous fibers in any two adjacent layers of the first continuous fiber reinforced resin sheet and the angle between the continuous fibers in any two adjacent layers of the second continuous fiber reinforced resin sheet are independently 0-90°, for example, 0°, 30°, 45°, 60°, 90° or a range consisting of any two values ​​therein.

[0032] The continuous fibers in any two adjacent layers of continuous fiber reinforced resin sheets adopt different laying angles, which can make the laminated continuous fiber reinforced composite material plate absorb external energy more effectively, effectively improve the shear resistance between each layer, and further improve the impact resistance of the battery pack sealing cover.

[0033] In one embodiment, the thickness of the first continuous fiber reinforced resin sheet and the thickness of the second continuous fiber reinforced resin sheet are independently 0.1-0.5 mm, for example, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm or a range consisting of any two of these values.

[0034] In one embodiment, the thickness of the first continuous fiber reinforced composite plate 3 and the thickness of the second continuous fiber reinforced composite plate 4 are each independently 0.5-3 mm, for example, 0.5 mm, 0.6 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm, 2.5 mm, 3 mm or a range consisting of any two of these values.

[0035] In one embodiment, n1 is 3-10, and n2 is 3-10.

[0036] The utility model controls the thickness of the first continuous fiber reinforced composite material plate 3 and the thickness of the second continuous fiber reinforced composite material plate 4 to 0.5-3 mm, and sets n1 to 3-10 and n2 to 3-10, which can effectively improve the impact resistance of the sealing cover.

[0037] In one embodiment, the total thickness of the sealing cover is 2-10 mm.

[0038] In one embodiment, the heat insulation layer 1 is glass fiber cloth or asbestos cloth.

[0039] In one embodiment, the thickness of the heat insulating layer 1 is 0.1-1 mm, for example, 0.1 mm, 0.3 mm, 0.5 mm, 0.7 mm, 1 mm or a range consisting of any two values ​​therein.

[0040] The utility model adopts glass fiber cloth or asbestos cloth of appropriate thickness as the heat insulation layer, which not only has good heat insulation performance, but also has the advantages of corrosion resistance, high temperature resistance, and non-combustion, and can enable the sealing cover to achieve more excellent fire resistance and heat barrier performance.

[0041] In one embodiment, the thickness of the buffer layer 2 is 1-6 mm, for example, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm or a range consisting of any two values ​​therein.

[0042] In one embodiment, the buffer layer 2 is a honeycomb core or a glass fiber mat reinforced thermoplastic composite material plate.

[0043] Specifically, the thickness of the honeycomb core is 1-6 mm; the thickness of the glass fiber mat reinforced thermoplastic composite material plate is 3-6 mm.

[0044] In one embodiment, a first adhesive layer 5 is disposed between the heat insulating layer 1 and the buffer layer 2, and the thickness of the first adhesive layer 5 is 0.1-0.3 mm.

[0045] In one embodiment, a second adhesive layer 6 is disposed between the thermal insulation layer 1 and the first continuous fiber reinforced composite material plate 3, and the thickness of the second adhesive layer 6 is 0.1-0.3 mm.

[0046] In one embodiment, the battery pack sealing cover is a plate-shaped structure, or a structure with one end open and a hollow interior.

[0047] In the utility model, the first continuous fiber reinforced resin sheet and the second continuous fiber reinforced resin sheet are each independently composited by continuous fibers and resin through an existing melt impregnation process, and the mass fraction of the continuous fibers in the first continuous fiber reinforced resin sheet and the mass fraction of the continuous fibers in the second continuous fiber reinforced resin sheet are each independently 30-70%, for example, it can be 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, or a range consisting of any two of these values.

[0048] The utility model limits the contents of continuous fibers and resins in the continuous fiber reinforced resin sheet, so that the continuous fiber reinforced resin sheet has the advantages of light weight and high strength.

[0049] Specifically, the continuous fibers in the first continuous fiber reinforced resin sheet and the continuous fibers in the second continuous fiber reinforced resin sheet are independently continuous glass fibers, continuous unidirectional carbon fibers, continuous unidirectional aramid fibers, continuous unidirectional basalt fibers or continuous unidirectional silicon carbide fibers.

[0050] Specifically, the resin in the first continuous fiber reinforced resin sheet and the resin in the second continuous fiber reinforced resin sheet are independently flame retardant polypropylene resin, non-flame retardant polypropylene resin, polyethylene, polystyrene, polycarbonate or polyamide.

[0051] Specifically, the buffer layer is a honeycomb core, and the honeycomb core is made of any one of homopolymer polypropylene resin, copolymer polypropylene resin and maleic anhydride graft copolymer polypropylene resin.

[0052] Specifically, each layer of the battery pack sealing cover is formed by an existing hot pressing process.

[0053] The utility model also provides a power battery, comprising a tray, a battery pack and a battery pack sealing cover as described in the utility model, wherein the tray and the battery pack sealing cover are combined to form a battery pack having a battery accommodating space, and the battery pack is arranged in the accommodating space of the battery pack.

[0054] The following examples are provided to facilitate understanding of the present invention. These examples are not provided to limit the scope of the claims.

[0055] Example 1

[0056] See also Figure 1-2 This embodiment provides a battery pack sealing cover, comprising a first continuous fiber reinforced composite material plate 3, a heat insulation layer 1, a buffer layer 2, and a second continuous fiber reinforced composite material plate 4 which are sequentially stacked in the thickness direction thereof;

[0057] The first continuous fiber reinforced composite material plate 3 includes n1 layers of first continuous fiber reinforced resin sheets stacked in sequence along the thickness direction thereof, where n1=3, and the thickness of the first continuous fiber reinforced resin sheet is 0.3 mm. Figure 3 The 3-layer first continuous fiber reinforced resin sheet is laid in a 0° / 90° / 0° manner;

[0058] The second continuous fiber reinforced composite material plate 4 includes n2 layers of second continuous fiber reinforced resin sheets stacked in sequence along the thickness direction thereof, n2=3, the thickness of the second continuous fiber reinforced resin sheet is 0.3 mm, and the horizontal X axis is 0° (such as Figure 3 The 3 layers of the second continuous fiber reinforced resin sheets are laid in a 0° / 90° / 0° manner;

[0059] The heat insulation layer 1 is glass fiber cloth, and the thickness of the heat insulation layer 1 is 0.5 mm; the buffer layer 2 is glass fiber felt, and the thickness of the buffer layer 2 is 6 mm; a first adhesive layer 5 is provided between the heat insulation layer 1 and the buffer layer 2, and the thickness of the first adhesive layer 5 is 0.1 mm; a second adhesive layer 6 is provided between the heat insulation layer 1 and the first continuous fiber reinforced composite material plate 3, and the thickness of the second adhesive layer 6 is 0.1 mm;

[0060] The first continuous fiber reinforced resin sheet and the second continuous fiber reinforced resin sheet are both composited with continuous glass fibers and flame-retardant polypropylene resin through an existing melt impregnation process. The mass fraction of the continuous glass fibers in the first continuous fiber reinforced resin sheet is 60%, and the mass fraction of the continuous glass fibers in the second continuous fiber reinforced resin sheet is 60%.

[0061] Example 2

[0062] This embodiment provides a battery pack sealing cover. The difference between this embodiment and embodiment 1 is that:

[0063] In this embodiment, n1=10, the thickness of the first continuous fiber reinforced resin sheet is 0.15 mm, the horizontal X-axis is 0°, and the laying method is 0° / 90° / 45° / -45° / 0° / 0° / -45° / 45° / 90° / 0°;

[0064] n2=10, the thickness of the second continuous fiber reinforced resin sheet is 0.15 mm, and the plying method is 0° / 90° / 45° / -45° / 0° / 0° / -45° / 45° / 90° / 0°;

[0065] The heat insulation layer 1 is glass fiber cloth, and the thickness of the heat insulation layer 1 is 0.1 mm; the buffer layer 2 is a glass fiber felt reinforced thermoplastic composite material board, and the thickness of the buffer layer 2 is 6 mm; a first adhesive layer 5 is provided between the heat insulation layer 1 and the buffer layer 2, and the thickness of the first adhesive layer 5 is 0.1 mm; a second adhesive layer 6 is provided between the heat insulation layer 1 and the second continuous fiber reinforced composite material board 4, and the thickness of the second adhesive layer 6 is 0.1 mm;

[0066] The mass fraction of continuous glass fibers in the first continuous fiber reinforced resin sheet is 65%, and the mass fraction of continuous glass fibers in the second continuous fiber reinforced resin sheet is 65%.

[0067] Example 3

[0068] This embodiment provides a battery pack sealing cover. The difference between this embodiment and embodiment 1 is that:

[0069] In this embodiment, the thickness of the first continuous fiber reinforced resin sheet is 0.5 mm;

[0070] The thickness of the second continuous fiber reinforced resin sheet is 0.5 mm;

[0071] The heat insulation layer 1 is asbestos cloth, and the thickness of the heat insulation layer 1 is 0.5 mm; the buffer layer 2 is a honeycomb core, and the thickness of the buffer layer 2 is 3 mm.

[0072] Example 4

[0073] This embodiment provides a battery pack sealing cover. The difference between this embodiment and embodiment 1 is that:

[0074] In this embodiment, the first continuous fiber reinforced composite material plate 3 includes n1 layers of first continuous fiber reinforced resin sheets stacked in sequence along the thickness direction thereof, n1=5, the thickness of the first continuous fiber reinforced resin sheet is 0.1 mm, and the horizontal X axis is 0° (such as Figure 3 In the direction of the X-axis in the figure), the first continuous fiber reinforced resin sheet adopts a laying method of 0° / 90° / 45° / -45° / 0°;

[0075] The second continuous fiber reinforced composite material plate 4 includes n2 layers of second continuous fiber reinforced resin sheets stacked in sequence along the thickness direction thereof, n2=5, the thickness of the second continuous fiber reinforced resin sheet is 0.1 mm, and the horizontal X axis is 0° (such as Figure 3 The n2 second continuous fiber reinforced resin sheets are laid in a manner of 0° / 90° / 45° / -45° / 0°;

[0076] The thickness of the thermal insulation layer is 0.1 mm, and the thickness of the buffer layer is 1 mm.

[0077] Performance Testing

[0078] The sealing cover of the above embodiment is subjected to the following performance tests:

[0079] (1) Insulation test:

[0080] The volume resistivity of the material is tested according to the national standard GB / T 31838.2-2019, and the test condition is an electrification time of 60s.

[0081] (2) Impact resistance test:

[0082] Refer to the standard ASTM D7136 / D7136M-20 to test the maximum dent depth of the sample with or without breakdown under 300J energy impact. Test conditions: hammer head diameter 25mm, hammer head weight 30kg, height 1m.

[0083] (3) Fire resistance test:

[0084] Place the prepared sealing cover sample under a 1200°C flame for 5 minutes and observe whether the sample is burned through.

[0085] The test results are shown in Table 1 below.

[0086] Table 1

[0087] Test items Volume resistivity / Ω*cm Drop hammer impact / mm Refractory Example 1 <![CDATA[1.01*10 11 ]]> No penetration, 6.32 Not burned through Example 2 <![CDATA[5.66*10 12 ]]> Not penetrated, 4.66 Not burned through Example 3 <![CDATA[6.38*10 11 ]]> No penetration, 5.69 Not burned through Example 4 <![CDATA[8.26*10 11 ]]> No penetration, 6.69 Not burned through

[0088] As can be seen from Table 1, the utility model provides excellent insulation, impact resistance and thermal barrier properties, and is suitable for new energy power batteries.

[0089] In the present invention, when it comes to numerical ranges, unless otherwise specified, the above numerical ranges are deemed to be continuous and include the minimum and maximum values ​​of the range, as well as each value between the minimum and maximum values. Further, when a range refers to an integer, each integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be merged. In other words, unless otherwise specified, all ranges disclosed in the present invention should be understood to include any and all sub-ranges included therein.

[0090] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0091] In the description of the present invention, it should be understood that the terms "upper" and "lower" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0092] Unless otherwise specified, the materials used in the present invention are all commercially available materials.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit the protection scope of the utility model. Although the utility model is described in detail with reference to the preferred embodiments, ordinary technicians in this field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the utility model.

Claims

1. A battery pack sealing cover, characterized in that: It comprises a first continuous fiber reinforced composite material plate, a heat insulating layer, a buffer layer and a second continuous fiber reinforced composite material plate which are sequentially stacked; the thickness ratio of the heat insulating layer to the buffer layer is 1:(1-60); the first continuous fiber reinforced composite material plate comprises n1 layers of first continuous fiber reinforced resin sheets which are sequentially stacked along its thickness direction, and n1 is an integer greater than or equal to 1; the second continuous fiber reinforced composite material plate comprises n2 layers of second continuous fiber reinforced resin sheets which are sequentially stacked along its thickness direction, and n2 is an integer greater than or equal to 1.

2. The battery pack sealing cover according to claim 1, characterized in that: The included angle of the continuous fibers in any two adjacent layers of the first continuous fiber reinforced resin sheet and the included angle of the continuous fibers in any two adjacent layers of the second continuous fiber reinforced resin sheet are independently 0-90°.

3. The battery pack sealing cover according to claim 1, characterized in that: The thickness of the first continuous fiber reinforced resin sheet is 0.1-0.5 mm; the thickness of the first continuous fiber reinforced composite material plate is 0.5-3 mm.

4. The battery pack sealing cover according to claim 1, characterized in that: The thickness ratio of the heat insulation layer to the buffer layer is 1:(6-12).

5. The battery pack sealing cover according to claim 1, characterized in that: n1 is 3-10, n2 is 3-10.

6. The battery pack sealing cover according to claim 1, characterized in that: The heat insulation layer is glass fiber cloth or asbestos cloth, and the thickness of the heat insulation layer is 0.1-1 mm.

7. The battery pack sealing cover according to claim 1, characterized in that: The buffer layer is a honeycomb core or a glass fiber mat reinforced thermoplastic composite material plate; the thickness of the buffer layer is 1-6 mm.

8. The battery pack sealing cover according to claim 1, characterized in that: A first adhesive layer is arranged between the heat insulation layer and the buffer layer, and a second adhesive layer is arranged between the heat insulation layer and the first continuous fiber reinforced composite material plate.

9. The battery pack sealing cover according to claim 7, characterized in that: The battery pack sealing cover is a plate-like structure or a structure with one end open and a hollow interior.

10. A power battery, characterized in that: The invention comprises a tray, a battery pack and a battery pack sealing cover as described in any one of claims 1 to 9, wherein the tray and the battery pack sealing cover are combined to form a battery pack having a battery accommodating space, and the battery pack is arranged in the accommodating space of the battery pack.

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