Battery protection bottom plate, battery pack composite protection structure and vehicle

Abstract

The present invention provides a battery protection base plate, comprising an upper fiber reinforced resin layer, a metal plate and a lower fiber reinforced resin layer, wherein the metal plate is located between the upper fiber reinforced resin layer and the lower fiber reinforced resin layer; and the following conditions are met:. At the same time, the present invention also discloses a battery pack composite protection structure comprising the above-mentioned battery protection base plate. The battery protection base plate provided by the present invention has good impact resistance and reduces the risk of connection failure of the battery protection base plate under long-term vibration conditions.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicle batteries, and in particular relates to a battery protection bottom plate, a battery pack composite protection structure and a vehicle. Background Art

[0002] The battery pack of new energy electric vehicles is usually installed at the bottom of the vehicle. Faced with more complex working conditions, it is easy to be impacted by external hard objects such as stones during driving. It is usually necessary to set certain protective measures at the bottom of the battery pack to avoid the battery pack being affected by the impact, resulting in surface damage and electrolyte leakage. The existing battery pack bottom protection scheme mainly protects the bottom of the battery pack by setting a steel plate. In order to prevent the steel plate from being corroded by factors such as water vapor, an electrophoresis process is used for anti-corrosion treatment. In addition, since the bottom of the steel plate is directly exposed to the bottom of the vehicle body, it is necessary to spray a 0.5-1.2mm PVC layer on the side of the steel plate facing the ground to play a role in resisting stone impact, while preventing the electrophoresis layer from being scratched, so as to avoid affecting the anti-corrosion effect.

[0003] Since the overall rigidity of the flat steel plate is relatively poor, the steel plate needs to be stamped. However, the high-strength steel plate used in the existing battery pack bottom protection structure is difficult to stamp, which affects the production efficiency. At the same time, the overall impact resistance of the existing steel plate is relatively poor. When impacted, the steel plate generates large vibrations, which can easily cause damage or falling off of connectors such as rivets at the steel plate installation position. The PVC layer on the surface of the steel plate is easily affected by the impact and falls off, affecting its corrosion resistance. Summary of the invention

[0004] In view of the problems that the existing battery pack bottom protection structure has insufficient impact resistance and connection failure under vibration conditions, the present invention provides a battery protection bottom plate, a battery pack composite protection structure and a vehicle.

[0005] The technical solution adopted by the present invention to solve the above technical problems is as follows:

[0006] In one aspect, the present invention provides a battery protection bottom plate, comprising an upper fiber reinforced resin layer, a metal plate and a lower fiber reinforced resin layer, wherein the metal plate is located between the upper fiber reinforced resin layer and the lower fiber reinforced resin layer; and the metal plate, the upper fiber reinforced resin layer and the lower fiber reinforced resin layer meet the following conditions:

[0007]

[0008] Wherein, d1 is the thickness of the lower fiber reinforced resin layer, in mm;

[0009] d2 is the thickness of the metal plate, in mm;

[0010] d3 is the thickness of the upper fiber reinforced resin layer, in mm;

[0011] ρ1 is the density of the lower fiber reinforced resin layer, in g / cm 3 ;

[0012] ρ2 is the density of the metal plate, in g / cm 3 ;

[0013] ρ3 is the density of the upper fiber reinforced resin layer, in g / cm 3 ;

[0014] σ1 is the tensile strength of the lower fiber-reinforced resin layer, in MPa;

[0015] σ2 is the tensile strength of the metal plate, in MPa;

[0016] σ3 is the tensile strength of the upper fiber reinforced resin layer, in MPa.

[0017] Optionally, the metal plate, the upper fiber reinforced resin layer and the lower fiber reinforced resin layer meet the following conditions:

[0018] Optionally, the thickness d3 of the upper fiber reinforced resin layer is 0.4-1.6 mm; the thickness d1 of the lower fiber reinforced resin layer is 0.6-2 mm.

[0019] Optionally, the thickness d2 of the metal plate is 0.7-1.6 mm.

[0020] Optionally, the density ρ2 of the metal plate is 2.7-8.5 g / cm 3 .

[0021] Optionally, the density ρ3 of the upper fiber reinforced resin layer is 1.3-1.9 g / cm 3 The density ρ1 of the lower fiber reinforced resin layer is 1.3-1.9 g / cm 3 .

[0022] Optionally, the tensile strength σ2 of the metal plate is 590 to 1180 MPa.

[0023] Optionally, the tensile strength σ3 of the upper fiber reinforced resin layer is 240 to 380 MPa, and the tensile strength σ1 of the lower fiber reinforced resin layer is 240 to 380 MPa.

[0024] Optionally, the battery protection base plate also includes a fiber reinforced resin frame, the metal plate and the fiber reinforced resin frame are located between the upper fiber reinforced resin layer and the lower fiber reinforced resin layer, the metal plate is located inside the fiber reinforced resin frame, the top surface of the fiber reinforced resin frame is integrally connected to the upper fiber reinforced resin layer, and the bottom surface of the fiber reinforced resin frame is integrally connected to the lower fiber reinforced resin layer.

[0025] Optionally, a plurality of mounting holes are spaced apart on the inner side of the edge of the battery protection bottom plate, and the mounting holes sequentially pass through the upper fiber reinforced resin layer, the fiber reinforced resin frame and the lower fiber reinforced resin layer.

[0026] Optionally, the upper fiber reinforced resin layer, the fiber reinforced resin frame and the lower fiber reinforced resin layer are each independently selected from a glass fiber reinforced polyamide resin part, a glass fiber reinforced polypropylene resin part, a glass fiber reinforced polyethylene resin part, a glass fiber reinforced polycarbonate resin part or a glass fiber reinforced polystyrene resin part.

[0027] Optionally, the upper fiber-reinforced resin layer, the fiber-reinforced resin frame and the lower fiber-reinforced resin layer are all glass fiber-reinforced resin parts, the glass fiber-reinforced resin parts contain 50% to 70% of glass fibers, and the alkali content of the glass fibers is less than 0.8%.

[0028] Optionally, the upper fiber-reinforced resin layer comprises a plurality of first fiber-reinforced prepregs laminated on each other;

[0029] The fiber-reinforced resin frame includes multiple layers of second fiber-reinforced prepreg laminated on each other;

[0030] The lower fiber-reinforced resin layer includes a plurality of third fiber-reinforced prepregs stacked one on the other.

[0031] Optionally, the metal plate is a steel plate, and a galvanized layer, a galvanized iron alloy layer or an electrophoretic paint protective layer is provided on the outer surface of the steel plate.

[0032] On the other hand, the present invention also provides a battery pack composite protection structure, including a battery pack and the battery protection bottom plate as described above, wherein the battery protection bottom plate is arranged below the battery pack, and a buffer zone is formed between the battery pack and the battery protection bottom plate.

[0033] Optionally, the buffer zone is filled with a buffer layer, and the buffer layer is selected from a honeycomb material or a hard foam material.

[0034] On the other hand, the present invention provides a vehicle comprising the battery protection bottom plate or the battery pack composite protection structure as described above.

[0035] According to the battery protection base plate provided by the present invention, the upper fiber reinforced resin layer and the lower fiber reinforced resin layer are compounded on the front and back surfaces of the metal plate. On the one hand, the upper fiber reinforced resin layer and the lower fiber reinforced resin layer can improve the corrosion resistance of the metal plate. At the same time, the lower fiber reinforced resin layer can resist the impact of stones and the like on the bottom of the battery protection base plate, thereby avoiding corrosion problems at the impact site. On the other hand, after the upper fiber reinforced resin layer and the lower fiber reinforced resin layer are compounded with the metal plate, the stiffness and strength of the metal plate are effectively improved, and the metal plate has higher impact resistance. There is no need for additional stamping treatment of the metal plate, thereby improving production efficiency.

[0036] Furthermore, in terms of improving the impact resistance of the battery protection bottom plate, there is an obvious correlation between the thickness d3 of the upper fiber reinforced resin layer, the thickness d1 of the lower fiber reinforced resin layer, the thickness d2 of the metal plate, the density ρ2 of the metal plate, the density ρ3 of the upper fiber reinforced resin layer, the density ρ1 of the lower fiber reinforced resin layer, the tensile strength σ2 of the metal plate, the tensile strength σ3 of the upper fiber reinforced resin layer and the tensile strength σ1 of the lower fiber reinforced resin layer. Specifically, when the thickness d3 of the upper fiber reinforced resin layer, the thickness d1 of the lower fiber reinforced resin layer, the thickness d2 of the metal plate, the density ρ2 of the metal plate, the density ρ3 of the upper fiber reinforced resin layer, the density ρ1 of the lower fiber reinforced resin layer, the tensile strength σ2 of the metal plate, the tensile strength σ3 of the upper fiber reinforced resin layer and the tensile strength σ1 of the lower fiber reinforced resin layer satisfy the relationship: This is beneficial to ensure that when the battery protection base plate is subjected to energy impact at a certain speed, its upper fiber reinforced resin layer and its lower fiber reinforced resin layer are not damaged, and can adapt to the application conditions of long-term impact conditions. At the same time, it reduces the risk of connection failure of the battery protection base plate under long-term vibration conditions, thereby improving the connection stability of the installation position of the battery protection base plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a structural schematic diagram of the battery protection bottom plate provided by the present invention;

[0038] Figure 2 It is a schematic diagram of the structure of different first fiber-reinforced prepreg unidirectional tapes in the upper fiber-reinforced resin layer provided by the present invention;

[0039] Figure 3 It is a schematic diagram of the structure of different first fiber woven cloth reinforced prepregs in the upper fiber reinforced resin layer provided by the present invention;

[0040] Figure 4 It is a structural schematic diagram of the battery pack composite protection structure provided by the present invention;

[0041] Figure 5 yes Figure 4 The enlarged schematic diagram of point A in the middle;

[0042] Figure 6 is a bottom cross-sectional schematic diagram of a battery pack composite protection structure provided by an embodiment of the present invention;

[0043] Figure 7 is a bottom cross-sectional schematic diagram of a battery pack composite protection structure provided by another embodiment of the present invention;

[0044] Figure 8 It is a schematic bottom cross-sectional view of a battery pack composite protective structure provided by another embodiment of the present invention.

[0045] The reference numerals in the drawings of the specification are as follows:

[0046] 1. Battery protection base plate; 11. Upper fiber reinforced resin layer; 111. First fiber reinforced prepreg unidirectional tape; 112. First fiber woven cloth reinforced prepreg; 12. Metal plate; 13. Fiber reinforced resin frame; 14. Lower fiber reinforced resin layer; 15. Mounting hole; 2. Buffer layer; 3. Battery pack; 31. Tray; 4. Buffer zone. DETAILED DESCRIPTION

[0047] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0048] In the description of the present invention, it should be understood that the terms "upper", "lower", "top", "bottom", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the 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 cannot be understood as limiting the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0049] See also Figure 1 As shown, an embodiment of the present invention provides a battery protection bottom plate 1, comprising an upper fiber reinforced resin layer 11, a metal plate 12 and a lower fiber reinforced resin layer 14, wherein the metal plate 12 is located between the upper fiber reinforced resin layer 11 and the lower fiber reinforced resin layer 14; and the metal plate 12, the upper fiber reinforced resin layer 11 and the lower fiber reinforced resin layer 14 meet the following conditions:

[0050]

[0051] Wherein, d1 is the thickness of the lower fiber reinforced resin layer 14, in mm;

[0052] d2 is the thickness of the metal plate 12, in mm;

[0053] d3 is the thickness of the upper fiber reinforced resin layer 11, in mm;

[0054] ρ1 is the density of the lower fiber reinforced resin layer 14, in g / cm 3 ;

[0055] ρ2 is the density of the metal plate 12, in g / cm 3 ;

[0056] ρ3 is the density of the upper fiber reinforced resin layer 11, in g / cm 3 ;

[0057] σ1 is the tensile strength of the lower fiber reinforced resin layer 14, in MPa;

[0058] σ2 is the tensile strength of the metal plate 12, in MPa;

[0059] σ3 is the tensile strength of the upper fiber reinforced resin layer 11, and the unit is MPa.

[0060] The upper fiber reinforced resin layer 11 and the lower fiber reinforced resin layer 14 are compounded on the front and back surfaces of the metal plate 12. On the one hand, the upper fiber reinforced resin layer 11 and the lower fiber reinforced resin layer 14 can improve the corrosion resistance of the metal plate 12. At the same time, the lower fiber reinforced resin layer 14 can resist the impact of stones and the like on the bottom of the battery protection bottom plate 1, thereby avoiding corrosion problems at the impact site. On the other hand, after the upper fiber reinforced resin layer 11 and the lower fiber reinforced resin layer 14 are compounded with the metal plate 12, the stiffness and strength of the metal plate 12 are effectively improved, and the metal plate 12 has higher impact resistance. There is no need for additional stamping treatment of the metal plate 12, thereby improving production efficiency.

[0061] Furthermore, in terms of improving the impact resistance of the battery protection bottom plate 1, there is an obvious correlation between the thickness d3 of the upper fiber reinforced resin layer 11, the thickness d1 of the lower fiber reinforced resin layer 14, the thickness d2 of the metal plate 12, the density ρ2 of the metal plate 12, the density ρ3 of the upper fiber reinforced resin layer 11, the density ρ1 of the lower fiber reinforced resin layer 14, the tensile strength σ2 of the metal plate 12, the tensile strength σ3 of the upper fiber reinforced resin layer 11 and the tensile strength σ1 of the lower fiber reinforced resin layer 14. Specifically, when the thickness d3 of the upper fiber reinforced resin layer 11, the thickness d1 of the lower fiber reinforced resin layer 14, the thickness d2 of the metal plate 12, the density ρ2 of the metal plate 12, the density ρ3 of the upper fiber reinforced resin layer 11, the density ρ1 of the lower fiber reinforced resin layer 14, the tensile strength σ2 of the metal plate 12, the tensile strength σ3 of the upper fiber reinforced resin layer 11 and the tensile strength σ1 of the lower fiber reinforced resin layer 14 satisfy the relationship: This is beneficial to ensure that when the battery protection base plate 1 is subjected to energy impact at a certain speed, the upper fiber reinforced resin layer 11 and the lower fiber reinforced resin layer 14 are not damaged, and can adapt to the application conditions of long-term impact conditions. At the same time, it reduces the risk of connection failure of the battery protection base plate 1 under long-term vibration conditions, thereby improving the connection stability of the installation position of the battery protection base plate 1.

[0062] In some embodiments, the metal plate 12, the upper fiber reinforced resin layer 11 and the lower fiber reinforced resin layer 14 meet the following conditions:

[0063] By defining the above relationship, the influence of the material selection of the metal plate 12 , the upper fiber reinforced resin layer 11 and the lower fiber reinforced resin layer 14 on the impact resistance of the battery pack 3 can be comprehensively considered, which is beneficial to improving the service life of the battery pack 3 .

[0064] In some embodiments, the thickness d3 of the upper fiber reinforced resin layer 11 is 0.4-1.6 mm; the thickness d1 of the lower fiber reinforced resin layer 14 is 0.6-2 mm.

[0065] Specifically, the thickness d3 of the upper fiber reinforced resin layer 11 may be 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm or 1.6 mm. The thickness d1 of the lower fiber reinforced resin layer 14 may be 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.8 mm or 2.0 mm.

[0066] The thickness d3 of the upper fiber reinforced resin layer 11 and the thickness d1 of the lower fiber reinforced resin layer 14 affect the protective effect on the metal plate 12 and the enhancement effect on the mechanical properties of the metal plate 12. When the thickness d3 of the upper fiber reinforced resin layer 11 and the thickness d1 of the lower fiber reinforced resin layer 14 are within the above range, they can avoid falling off the surface of the metal plate 12 under high-energy impact, and can effectively maintain the anti-corrosion and strength enhancement effects on the metal plate 12.

[0067] In some embodiments, the thickness d2 of the metal plate 12 is 0.7-1.6 mm.

[0068] Specifically, the thickness d of the metal plate 12 may be 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm or 1.6 mm.

[0069] The thickness d2 of the metal plate 12 affects the overall mechanical strength of the battery protection bottom plate 1. When the tensile strength of the metal plate 12 is constant, as the thickness of the metal plate 12 increases, its protection strength gradually increases, but its material cost also gradually increases, and the distance from the bottom of the vehicle to the ground is reduced. When the thickness d2 of the metal plate 12 is within the above range, the overall mechanical strength of the battery protection bottom plate 1 can be guaranteed, the cost can be effectively controlled, the distance from the ground can be guaranteed, and the lightweight control of the vehicle is also facilitated.

[0070] In some embodiments, the density ρ2 of the metal plate 12 is 2.7-8.5 g / cm 3 .

[0071] Specifically, the density ρ2 of the metal plate 12 may be 2.7 g / cm 3 、3.1g / cm 3 , 3.5g / cm 3 、 4.2g / cm 3 , 4.8g / cm 3 , 5.3g / cm 3, 5.7g / cm 3 、6.0g / cm 3 、6.7g / cm 3 , 7.5g / cm 3 、7.6g / cm 3 、 7.8g / cm 3 , 8.0g / cm 3 , 8.1g / cm 3 、8.2g / cm 3 、8.3g / cm 3 、8.4g / cm 3 or 8.5g / cm 3 .

[0072] The density ρ2 of the metal plate 12 can be adjusted by selecting the material and specific model of the metal plate 12, and is related to the weight and mechanical strength of the metal plate 12. When the density ρ2 of the metal plate 12 is within the above range, it has better mechanical strength and is beneficial to the lightweight control of the vehicle.

[0073] In some embodiments, the density ρ3 of the upper fiber reinforced resin layer 11 is 1.3-1.9 g / cm 3 The density ρ1 of the lower fiber reinforced resin layer 14 is 1.3-1.9 g / cm 3 .

[0074] Specifically, the density ρ3 of the upper fiber reinforced resin layer 11 and the density ρ1 of the lower fiber reinforced resin layer 14 can be independently selected from 1.3 g / cm 3 , 1.4g / cm 3 , 1.5g / cm 3 , 1.6g / cm 3 , 1.7g / cm 3 、 1.8g / cm 3 or 1.9 g / cm 3 .

[0075] The density ρ3 of the upper fiber reinforced resin layer 11 and the density ρ1 of the lower fiber reinforced resin layer 14 are related to the materials of the selected resin and reinforcing fibers, and are also affected by the content of reinforcing fibers. When the density ρ3 of the upper fiber reinforced resin layer 11 and the density ρ1 of the lower fiber reinforced resin layer 14 are within the above range, they contain sufficient reinforcing fibers, which is beneficial to improving the tensile strength of the upper fiber reinforced resin layer 11 and the lower fiber reinforced resin layer 14.

[0076] In some embodiments, the tensile strength σ2 of the metal plate 12 is 590-1180 MPa.

[0077] Specifically, the tensile strength σ2 of the metal plate 12 may be 590 MPa, 600 MPa, 650 MPa, 700 MPa, 750 MPa, 800 MPa, 850 MPa, 900 MPa, 950 MPa, 1000 MPa or 1180 MPa.

[0078] The tensile strength σ2 of the metal plate 12 can be tested according to GB / T 228.1-2010 Tensile test for metallic materials Part 1: Room temperature test scheme. When the tensile strength σ2 is higher, the metal plate 12 can resist higher impacts without irreversible deformation. However, generally, the higher the tensile strength σ2 of the metal plate 12, the lower its elongation at break will be. When the tensile strength σ2 of the metal plate 12 is within the above range, the impact resistance and anti-cracking performance of the metal plate 12 can be effectively guaranteed.

[0079] In some embodiments, the tensile strength σ3 of the upper fiber reinforced resin layer 11 is 240-380 MPa, and the tensile strength σ1 of the lower fiber reinforced resin layer 14 is 240-380 MPa.

[0080] Specifically, the tensile strength σ3 of the upper fiber reinforced resin layer 11 and the tensile strength σ1 of the lower fiber reinforced resin layer 14 may be independently selected from 240 MPa, 280 MPa, 290 MPa, 300 MPa, 310 MPa, 320 MPa, 330 MPa, 340 MPa, 350 MPa, 360 MPa, 370 MPa or 380 MPa.

[0081] The tensile strength σ3 of the upper fiber reinforced resin layer 11 and the tensile strength σ1 of the lower fiber reinforced resin layer 14 can be tested according to the GB / T 1447-2005 fiber reinforced plastic tensile performance test method. The type I specimen is suitable for fiber reinforced thermoplastic sheets. The samples are made according to the type I specimen specified in the national standard for testing. The improvement of the tensile strength σ3 of the upper fiber reinforced resin layer 11 and the tensile strength σ1 of the lower fiber reinforced resin layer 14 is conducive to improving the tensile strength of the upper fiber reinforced resin layer 11 and the lower fiber reinforced resin layer 14. anti-deformation ability; however, as the tensile strength σ3 of the upper fiber reinforced resin layer 11 and the tensile strength σ1 of the lower fiber reinforced resin layer 14 increase, the adhesion of the upper fiber reinforced resin layer 11 and the lower fiber reinforced resin layer 14 to the metal plate 12 will be affected, resulting in delamination under impact; when the tensile strength σ3 of the upper fiber reinforced resin layer 11 and the tensile strength σ1 of the lower fiber reinforced resin layer 14 are within the above-mentioned range, the upper fiber reinforced resin layer 11 and the lower fiber reinforced resin layer 14 can effectively resist external impact without delamination or falling off.

[0082] With regard to improving the battery pack 3 from delamination and rivet fatigue damage, the above nine parameters are interrelated and inseparable. For example, when the thickness d3 of the upper fiber reinforced resin layer 11, the thickness d2 of the metal plate 12 or the thickness d1 of the lower fiber reinforced resin layer 14 increases, or the density ρ2 of the metal plate 12, the density ρ3 of the upper fiber reinforced resin layer 11 or the density ρ1 of the lower fiber reinforced resin layer 14 increases, the impact resistance of the battery protection floor 1 is improved, and at the same time, the requirements for the tensile strength σ2 of the metal plate 12, the tensile strength σ3 of the upper fiber reinforced resin layer 11 and the tensile strength σ1 of the lower fiber reinforced resin layer 14 can be reduced. However, this will correspondingly lead to an increase in the total mass and total thickness of the battery protection floor 1, which is not conducive to the lightweight requirements and cost control of the vehicle, and also leads to a reduction in the vehicle's ground clearance. When the tensile strength σ2 of the metal plate 12 increases, its ability to resist deformation is enhanced, but it is also more likely to break when deformed. When the tensile strength σ2 of the metal plate 12 is not well matched with the tensile strength σ3 of the upper fiber-reinforced resin layer 11 and the tensile strength σ1 of the lower fiber-reinforced resin layer 14, it is easy to cause vibration asynchrony, and thus it is more likely to cause delamination. Therefore, through the relationship Comprehensively considering the influence of various factors on the protection performance and anti-vibration performance of the battery pack 3 is conducive to achieving better impact resistance and longer service life.

[0083] like Figure 1 As shown, in some embodiments, the battery protection bottom plate 1 also includes a fiber reinforced resin frame 13, the metal plate 12 and the fiber reinforced resin frame 13 are located between the upper fiber reinforced resin layer 11 and the lower fiber reinforced resin layer 14, the metal plate 12 is located inside the fiber reinforced resin frame 13, the top surface of the fiber reinforced resin frame 13 is integrally connected to the upper fiber reinforced resin layer 11, and the bottom surface of the fiber reinforced resin frame 13 is integrally connected to the lower fiber reinforced resin layer 14.

[0084] A fiber reinforced resin frame 13 is arranged on the periphery of the metal plate 12 as a transition piece for connecting the frame position of the upper fiber reinforced resin layer 11 and the lower fiber reinforced resin layer 14, which can effectively offset the influence of the thickness of the metal plate 12 on the frame connection of the upper fiber reinforced resin layer 11 and the lower fiber reinforced resin layer 14, ensure the frame position strength of the battery protection base plate 1, and further facilitate to use the frame position of the battery protection base plate 1 as its installation structure on the battery, thereby improving its impact resistance.

[0085] like Figure 5 As shown, in some embodiments, a plurality of mounting holes 15 are spaced apart on the inner side of the edge of the battery protection base plate 1 , and the mounting holes 15 sequentially pass through the upper fiber reinforced resin layer 11 , the fiber reinforced resin frame 13 and the lower fiber reinforced resin layer 14 .

[0086] The mounting hole 15 is used for mounting and fastening the battery protection bottom plate 1 at the bottom of the battery pack 3. By arranging the mounting hole 15 on the inner side of the edge of the battery protection bottom plate 1 and sequentially passing through the upper fiber reinforced resin layer 11, the fiber reinforced resin frame 13 and the lower fiber reinforced resin layer 14, it is possible to avoid the mounting hole 15 passing through the metal plate 12, thereby avoiding corrosion problems caused by the metal plate 12 being exposed at the mounting hole 15. At the same time, the fiber reinforced resin frame 13 is conducive to improving the overall thickness and tensile shear strength of the mounting position, and has sufficient installation stability.

[0087] The plurality of mounting holes 15 are disposed around the outer circumference of the metal plate 12 to evenly disperse the top gravity and the bottom impact force on the metal plate 12 .

[0088] Specifically, during installation, a connecting piece is arranged to pass through the installation hole 15 to fix the battery protection bottom plate 1 to the bottom of the battery pack 3, and the connecting piece is a rivet, a screw or a bolt.

[0089] In different embodiments, the resins of the upper fiber reinforced resin layer 11, the fiber reinforced resin frame 13 and the lower fiber reinforced resin layer 14 are independently selected from thermosetting and / or thermoplastic materials. Examples may include, but are not limited to, epoxy resins, phenolic plastics, phenols, cyanates, imides (e.g., polyimide, bismaleimide (BMI), polyetherimide), polypropylenes, polyesters, benzoxazines, polybenzimidazoles, polybenzothiazoles, polyamides, polyamide-imides, polysulfones, polyethersulfones, polycarbonates, polyethylene terephthalate and polyetherketones (e.g., polyetherketone (PEK), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), etc.) and combinations thereof.

[0090] In different embodiments, the fibers of the upper fiber reinforced resin layer 11, the fiber reinforced resin frame 13 and the lower fiber reinforced resin layer 14 are independently selected from glass fibers, aramid fibers, carbon fibers, graphite fibers, boron fibers, aramid fibers and mixtures thereof.

[0091] The fibers of the upper fiber reinforced resin layer 11 , the fiber reinforced resin frame 13 and the lower fiber reinforced resin layer 14 may be embedded in the resin in the form of chopped fibers, chopped fibers, non-woven fabrics, unidirectional reinforced fiber substrates, woven fabrics, and the like.

[0092] In some embodiments, the upper fiber reinforced resin layer 11, the fiber reinforced resin frame 13 and the lower fiber reinforced resin layer 14 are each independently selected from glass fiber reinforced polyamide resin parts or glass fiber reinforced polypropylene resin parts, glass fiber reinforced polyethylene resin parts, glass fiber reinforced polycarbonate resin parts or glass fiber reinforced polystyrene resin parts.

[0093] In some embodiments, the fiber reinforced resin layer, the fiber reinforced resin frame 13 and the lower fiber reinforced resin layer 14 are made of the same resin material. The same resin material can ensure the affinity of the materials between different layers, thereby ensuring the degree of integration between different layers and improving the overall strength.

[0094] In some embodiments, the upper fiber reinforced resin layer 11, the fiber reinforced resin frame 13 and the lower fiber reinforced resin layer 14 are all glass fiber reinforced resin parts, and the glass fiber reinforced resin parts contain 50% to 70% glass fiber, which is beneficial to improving the material strength of the upper fiber reinforced resin layer 11, the fiber reinforced resin frame 13 and the lower fiber reinforced resin layer 14.

[0095] In some embodiments, the glass fibers have an alkali content of <0.8%.

[0096] When the alkali content of the glass fiber is lower than 0.8%, it is beneficial to improve the anti-aging performance of the upper fiber reinforced resin layer 11, the fiber reinforced resin frame 13 and the lower fiber reinforced resin layer 14, and slow down the performance degradation of the materials after long-term use.

[0097] In some embodiments, the glass fiber is selected from E glass fiber or S glass fiber.

[0098] In some embodiments, the upper fiber-reinforced resin layer 11 includes a plurality of first fiber-reinforced prepregs stacked on top of each other;

[0099] The fiber-reinforced resin frame 13 includes multiple layers of second fiber-reinforced prepreg laminated on each other;

[0100] The lower fiber-reinforced resin layer 14 includes a plurality of third fiber-reinforced prepregs stacked one on another.

[0101] like Figure 2 As shown, the upper fiber reinforced resin layer 11 includes multiple layers of first fiber reinforced prepreg unidirectional tapes 111 stacked on each other, the fiber arrangement direction of two adjacent layers of the first fiber reinforced prepreg unidirectional tapes 111 is approximately 90° staggered, and the allowable deviation range of the ply angle of two adjacent layers of the first fiber reinforced prepreg unidirectional tapes 111 is ±20°.

[0102] The fibers in the first fiber reinforced prepreg unidirectional tape 111 are arranged unidirectionally. When subjected to a tensile force along the fiber extension direction, the fibers in the first fiber reinforced prepreg unidirectional tape 111 can effectively bear the tensile force. By arranging the fibers of adjacent first fiber reinforced prepreg unidirectional tapes in an approximately 90° staggered manner, it is beneficial to improve the uniformity of force on the upper fiber reinforced resin layer 11 in all directions.

[0103] The fiber reinforced resin frame 13 includes multiple layers of second fiber reinforced prepreg unidirectional tapes stacked on each other, the fibers in the second fiber reinforced prepreg unidirectional tapes are arranged unidirectionally, the fiber arrangement directions of two adjacent layers of the second fiber reinforced prepreg unidirectional tapes are staggered at approximately 90°, and the allowable deviation range of the ply angle of two adjacent layers of the second fiber reinforced prepreg unidirectional tapes is ±20°.

[0104] The lower fiber reinforced resin layer 14 includes multiple layers of third fiber reinforced prepreg unidirectional tapes stacked on each other, the fibers in the third fiber reinforced prepreg unidirectional tapes are arranged unidirectionally, the fiber arrangement directions of two adjacent layers of the third fiber reinforced prepreg unidirectional tapes are staggered at approximately 90°, and the allowable deviation range of the ply angle of two adjacent layers of the third fiber reinforced prepreg unidirectional tapes is ±20°.

[0105] The fiber arrangement of the fiber reinforced resin frame 13 and the lower fiber reinforced resin layer 14 is similar to that of the upper fiber reinforced resin layer 11 , and will not be described in detail.

[0106] like Figure 3 As shown, in another embodiment, the upper fiber reinforced resin layer 11 includes multiple layers of first fiber woven cloth reinforced prepreg 112 stacked on each other, and the fibers in the first fiber woven cloth reinforced prepreg 112 form a woven cloth in a staggered form.

[0107] The fiber reinforced resin frame 13 includes a plurality of second fiber woven cloth reinforced prepregs stacked on each other, wherein the fibers in the second fiber woven cloth reinforced prepregs are woven in an interlaced manner.

[0108] The lower fiber-reinforced resin layer 14 includes a plurality of third fiber woven cloth reinforced prepregs stacked on each other, wherein the fibers in the third fiber woven cloth reinforced prepregs are woven in an interlaced manner.

[0109] In some embodiments, the metal plate 12 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.

[0110] In some embodiments, the metal plate 12 is a steel plate, and the outer surface of the steel plate is provided with a galvanized layer, a galvanized iron alloy layer or an electrophoretic paint protective layer.

[0111] Compared with other metal materials, the steel plate used as the metal plate 12 has better tensile strength and elongation, can meet the impact resistance requirements, and is beneficial to improving the protection of the battery pack 3.

[0112] A galvanized layer, a galvanized iron alloy layer or an electrophoretic paint protective layer is provided on the outer surface of the steel plate to improve the anti-corrosion performance of the steel plate. When the upper fiber reinforced resin layer 11 or the lower fiber reinforced resin layer 14 is damaged, the galvanic cell effect formed by the galvanized layer or the galvanized iron alloy layer and the steel plate causes the galvanized layer or the galvanized iron alloy layer to corrode before the steel plate, thereby protecting the steel plate. The electrophoretic paint protective layer has good adhesion and can effectively isolate the steel plate from the external environment.

[0113] like Figure 4 As shown, another embodiment of the present invention provides a battery pack composite protection structure, including a battery pack 3 and the battery protection bottom plate 1 as described above, wherein the battery protection bottom plate 1 is arranged below the battery pack 3, and a buffer zone 4 is formed between the battery pack 3 and the battery protection bottom plate 1.

[0114] Since the battery pack composite protection structure adopts the above-mentioned battery protection bottom plate 1, the protection strength of the battery protection bottom plate 1 and the stable connection of the battery protection bottom plate 1 on the battery pack 3 are effectively guaranteed while ensuring a relatively low overall thickness.

[0115] In some embodiments, the battery pack 3 includes a tray 31 and batteries disposed on the tray 31 .

[0116] In different embodiments, the buffer zone 4 may be disposed between the battery pack 3 and the battery protection base plate 1 in different ways.

[0117] like Figure 6 As shown, in one embodiment, a groove is provided inwardly on the bottom surface of the tray 31 to form the buffer zone 4 , and the battery protection bottom plate 1 is in the shape of a flat plate, and the battery protection bottom plate 1 covers the buffer zone 4 .

[0118] like Figure 7 As shown, in one embodiment, the frame position of the battery protection base plate 1 is connected to the bottom surface of the tray 31, and a groove is provided inwardly on the bottom surface of the tray 31. The battery protection base plate 1 protrudes away from the tray 31 to form the buffer zone 4 between the tray 31 and the battery protection base plate 1.

[0119] like Figure 8As shown, in one embodiment, the frame of the battery protection base plate 1 is connected to the bottom surface of the tray 31, the bottom surface of the tray 31 is a plane, and the battery protection base plate 1 protrudes away from the tray 31 to form the buffer zone 4 between the tray 31 and the battery protection base plate 1.

[0120] In some embodiments, the buffer zone 4 is filled with a buffer layer 2 , and the buffer layer 2 is selected from a honeycomb material or a hard foam material.

[0121] Honeycomb material or hard foam material can absorb the collapse deformation space of the battery protection plate under the action of strong external impact, buffer and absorb part of the energy of the strong external impact, prevent the compression deformation of the battery protection bottom plate 1 from impacting the internal battery cells of the battery pack 3, and further protect the battery pack 3.

[0122] In some embodiments, the honeycomb material is selected from PP honeycomb material or aluminum honeycomb material; the rigid foam material is selected from PU rigid foam material, PET rigid foam material, PMI rigid foam material, PVC rigid foam material, PET rigid foam material, MPP rigid foam material, PLA rigid foam material, PI rigid foam material or EPTU foam material.

[0123] Another embodiment of the present invention provides a vehicle, comprising the battery protection bottom plate or the battery pack composite protection structure as described above.

[0124] The present invention is further described below by way of examples.

[0125] Table 1

[0126]

[0127]

[0128] Example 1

[0129] This embodiment is used to illustrate the composite protective structure of a battery pack disclosed in the present invention, including a battery pack, a buffer layer and a battery protection bottom plate, the battery protection bottom plate including a metal plate, an upper fiber reinforced resin layer, a fiber reinforced resin frame and a lower fiber reinforced resin layer, the metal plate is a galvanized steel plate, the metal plate is located between the upper fiber reinforced resin layer and the lower fiber reinforced resin layer, the metal plate is located inside the fiber reinforced resin frame, the top surface of the fiber reinforced resin frame is integrally connected to the upper fiber reinforced resin layer, and the bottom surface of the fiber reinforced resin frame is integrally connected to the lower fiber reinforced resin layer; the battery protection bottom plate is arranged below the battery pack, a buffer zone is formed between the battery pack and the battery protection bottom plate, the buffer zone is filled with the buffer layer, and the frame of the battery protection bottom plate is installed at the bottom frame position of the battery pack by rivets.

[0130] The thickness d3 of the upper fiber reinforced resin layer is 1.6 mm, the thickness d1 of the lower fiber reinforced resin layer is 1.6 mm, the thickness d2 of the metal plate is 1.6 mm, and the density ρ2 of the metal plate is 7.9 g / cm 3 The density ρ3 of the upper fiber reinforced resin layer is 1.7 g / cm 3 The density ρ1 of the lower fiber reinforced resin layer is 1.7 g / cm 3 , the tensile strength σ2 of the metal plate is 780 MPa, the tensile strength σ3 of the upper fiber reinforced resin layer is 360 MPa, and the tensile strength σ1 of the lower fiber reinforced resin layer is 360 MPa.

[0131] Embodiments 2 to 27

[0132] Examples 2 to 27 are used to illustrate the composite protection structure of the battery pack disclosed in the present invention, including most of the structures in Example 1, and the differences are as follows:

[0133] The upper fiber reinforced resin layer, the metal plate and the lower fiber reinforced resin layer provided in Examples 2 to 27 in Table 1 were used.

[0134] Comparative Examples 1 to 7

[0135] Comparative Examples 1 to 7 are used to compare and illustrate the composite protection structure of the battery pack disclosed in the present invention, including most of the structures in Example 1, and the differences are:

[0136] The upper fiber-reinforced resin layer, the metal plate and the lower fiber-reinforced resin layer provided in Comparative Examples 1 to 7 in Table 1 were used.

[0137] Performance Testing

[0138] The following performance tests were performed on the composite protection structures of the battery packs provided in the above embodiments and comparative examples:

[0139] 1. Use a sphere as an impact head to impact the battery protection bottom plate of the battery pack composite protection structure to simulate the working condition where the bottom of the vehicle is hit by a foreign object. The diameter of the sphere is 25 mm, the weight is 10 kg, the impact energy is 300 J, and the impact speed is 8.5 m / s. The center point of the battery protection bottom plate and four points around the center point are selected as impact points, and five impacts are performed.

[0140] Measure the dent deformation of the battery pack tray at each impact point, select the impact point with the largest dent deformation, and record it as the dent deformation of the battery pack tray. Generally, the dent deformation requirement for a 300J energy impact is no more than 3mm.

[0141] 2. Install the battery pack composite protection structure on a vibration table and perform 30w mileage simulated vibration to check the installation status of rivets after vibration and whether the battery protection bottom plate is delaminated.

[0142] 30w mileage simulated vibration test: According to the requirements of GB / T 2423.43, the test object is installed on the vibration table, and the torque of each installation point is tested and recorded. The vibration test is carried out in three directions. The test process refers to GB / T 2423.56. The specific test conditions are as follows:

[0143] First, random vibration was applied in the Z direction for 21 h (random vibration conditions are shown in Table 2), and then fixed frequency vibration was applied in the Z direction for 1 h (fixed frequency vibration conditions: 24 Hz fixed frequency, 1 g fixed frequency amplitude);

[0144] Secondly, random vibration was applied in the Y direction for 21 h (the random vibration conditions are shown in Table 2), and then fixed frequency vibration was applied in the Y direction for 1 h (fixed frequency vibration conditions: 24 Hz fixed frequency, 1 g fixed frequency amplitude);

[0145] Furthermore, random vibration was applied in the X direction for 21 h (the random vibration conditions are shown in Table 2), and then fixed-frequency vibration was applied in the X direction for 1 h (the fixed-frequency vibration conditions were: 24 Hz fixed-frequency frequency, 1 g fixed-frequency amplitude).

[0146] Among them, PSD stands for power spectral density, which represents the power spectral density of vibration at a certain frequency; the rms value represents the comprehensive acceleration of vibration and feedbacks the vibration intensity.

[0147] Table 2 Random vibration test

[0148]

[0149]

[0150] The test results obtained are entered in Table 3.

[0151] Table 3

[0152]

[0153]

[0154] It can be seen from the test results in Table 3 that the thickness d3 of the upper fiber reinforced resin layer, the thickness d1 of the lower fiber reinforced resin layer, the thickness d2 of the metal plate, the density ρ2 of the metal plate, the density ρ3 of the upper fiber reinforced resin layer, the density ρ1 of the lower fiber reinforced resin layer, the tensile strength σ2 of the metal plate, the tensile strength σ3 of the upper fiber reinforced resin layer and the tensile strength σ1 of the lower fiber reinforced resin layer have interrelated effects in improving the impact resistance of the battery pack and the installation stability of the battery protection base plate. When these conditions are met, the obtained battery pack composite protection structure can adapt to the application conditions of long-term impact conditions.

[0155] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A battery protection base plate, characterized in that: It comprises an upper fiber reinforced resin layer, a metal plate and a lower fiber reinforced resin layer, wherein the metal plate is located between the upper fiber reinforced resin layer and the lower fiber reinforced resin layer; and the metal plate, the upper fiber reinforced resin layer and the lower fiber reinforced resin layer meet the following conditions: Wherein, d1 is the thickness of the lower fiber reinforced resin layer, in mm; d2 is the thickness of the metal plate, in mm; d3 is the thickness of the upper fiber reinforced resin layer, in mm; ρ1 is the density of the lower fiber reinforced resin layer, in g / cm 3 ; ρ2 is the density of the metal plate, in g / cm 3 ; ρ3 is the density of the upper fiber reinforced resin layer, in g / cm 3 ; σ1 is the tensile strength of the lower fiber-reinforced resin layer, in MPa; σ2 is the tensile strength of the metal plate, in MPa; σ3 is the tensile strength of the upper fiber-reinforced resin layer, in MPa; The thickness d3 of the upper fiber reinforced resin layer is 0.4-1.6 mm or 1.7 mm; the thickness d1 of the lower fiber reinforced resin layer is 0.6-2 mm or 0.4 mm, the thickness d2 of the metal plate is 0.7-1.6 mm, and the density ρ2 of the metal plate is 2.7-8.5 g / cm 3 The density of the upper fiber reinforced resin layer is ρ3 1.3-1.9 g / cm 3 The density ρ1 of the lower fiber reinforced resin layer is 1.3-1.9 g / cm 3 The tensile strength σ2 of the metal plate is 590~1180MPa or 370MPa, the tensile strength σ3 of the upper fiber reinforced resin layer is 240~380MPa, and the tensile strength σ1 of the lower fiber reinforced resin layer is 240~380MPa.

2. The battery protection bottom plate according to claim 1, characterized in that: The metal plate, the upper fiber-reinforced resin layer and the lower fiber-reinforced resin layer satisfy the following conditions:

3. The battery protection bottom plate according to claim 1, characterized in that: The battery protection bottom plate also includes a fiber reinforced resin frame, the metal plate and the fiber reinforced resin frame are located between the upper fiber reinforced resin layer and the lower fiber reinforced resin layer, the metal plate is located inside the fiber reinforced resin frame, the top surface of the fiber reinforced resin frame is integrally connected to the upper fiber reinforced resin layer, and the bottom surface of the fiber reinforced resin frame is integrally connected to the lower fiber reinforced resin layer.

4. The battery protection bottom plate according to claim 3, characterized in that: A plurality of mounting holes are spaced apart on the inner side of the edge of the battery protection bottom plate, and the mounting holes sequentially pass through the upper fiber reinforced resin layer, the fiber reinforced resin frame and the lower fiber reinforced resin layer.

5. The battery protection bottom plate according to claim 3, characterized in that: The upper fiber reinforced resin layer, the fiber reinforced resin frame and the lower fiber reinforced resin layer are each independently selected from glass fiber reinforced polyamide resin, glass fiber reinforced polypropylene resin, glass fiber reinforced polyethylene resin, glass fiber reinforced polycarbonate resin or glass fiber reinforced polystyrene resin.

6. The battery protection bottom plate according to claim 3, characterized in that: The upper fiber reinforced resin layer, the fiber reinforced resin frame and the lower fiber reinforced resin layer are all glass fiber reinforced resin parts. The glass fiber reinforced resin parts contain 50% to 70% of glass fibers, and the alkali content of the glass fibers is less than 0.8%.

7. The battery protection bottom plate according to claim 3, characterized in that: The upper fiber-reinforced resin layer comprises a plurality of first fiber-reinforced prepregs stacked on top of each other; The fiber-reinforced resin frame includes multiple layers of second fiber-reinforced prepreg laminated on each other; The lower fiber-reinforced resin layer includes a plurality of third fiber-reinforced prepregs stacked one on the other.

8. The battery protection bottom plate according to claim 1, characterized in that: The metal plate is a steel plate, and a zinc-plated layer, a galvanized iron alloy layer or an electrophoretic paint protective layer is arranged on the outer surface of the steel plate.

9. A battery pack composite protection structure, characterized in that: It comprises a battery pack and a battery protection bottom plate as claimed in any one of claims 1 to 8, wherein the battery protection bottom plate is arranged below the battery pack, and a buffer zone is formed between the battery pack and the battery protection bottom plate.

10. The battery pack composite protection structure according to claim 9, characterized in that: The buffer zone is filled with a buffer layer, and the buffer layer is selected from honeycomb material or hard foam material.

11. A vehicle, characterized in that: It includes the battery protection bottom plate as described in any one of claims 1 to 8, or includes the battery pack composite protection structure as described in claim 9 or 10.

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