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

Abstract

Battery protection bottom plate, composite protection structure for battery pack, and vehicle. The battery protection bottom plate includes an upper fiber-reinforced resin layer, a metal plate, and a lower fiber-reinforced resin layer, and the metal plate is located between the upper fiber-reinforced resin layer and the lower fiber-reinforced resin layer. The upper fiber-reinforced resin layer and the lower fiber-reinforced resin layer satisfy the condition of 0.4 ≦ d2 / d1 ≦ 2, where d1 is the thickness of the lower fiber-reinforced resin layer measured in mm, and d2 is the thickness of the upper fiber-reinforced resin layer measured in mm.

Description

Technical Field

[0001] Cross - reference to Related Applications This disclosure claims the priority and benefits of Chinese Patent Application No. 202221380910.3, filed on May 31, 2022. The entire content of the above - referenced application is incorporated herein by reference.

[0002] This disclosure relates to the field of vehicle battery technology, and more particularly, to a battery protection bottom plate, a composite protection structure for a battery pack, and a vehicle.

Background Art

[0003] With the rapid development of electric vehicles, people's requirements for the safety of electric vehicles are increasing. Since the power battery pack is used as the power source of an electric vehicle, the safety of the power battery pack is very important. In an electric vehicle, the battery pack is generally located under the chassis of the vehicle and is connected to the chassis through bolts. The lower surface of the battery pack is exposed. Therefore, during the daily driving of the vehicle, the bottom of the battery pack is easily hit, causing damage to the housing and poor protection. Also, during driving, the bouncing of small stones at the bottom causes an impact on the battery pack. To cope with complex operating conditions, a protection plate is usually arranged at the bottom of the battery pack, and by using this protection plate, the bottom of the battery pack is protected. Due to the exposure of the existing protection plate and the long - term impact on the protection plate, the protective coating of the protection plate is prone to delamination and cavitation, and the protective coating is easily damaged by the cavities, resulting in corrosion of the protective coating and affecting the mechanical strength and impact resistance of the protection plate.

Summary of the Invention

Problems to be Solved by the Invention

[0004] In view of the problems of the existing battery protection bottom plate, such as the protective coating being cavitated under impact and insufficient corrosion resistance performance, this disclosure provides a battery protection bottom plate and a composite protection structure for a battery pack.

Means for Solving the Problems

[0005] To solve the foregoing technical problems, the technical solutions used in the present disclosure are as follows.

[0006] According to one aspect, the present disclosure provides a battery protection bottom plate. The battery protection bottom plate includes an upper fiber-reinforced resin layer, a metal plate, and a lower fiber-reinforced resin layer. The metal plate is located between the upper fiber-reinforced resin layer and the lower fiber-reinforced resin layer. The upper fiber-reinforced resin layer and the lower fiber-reinforced resin layer satisfy the condition of 0.4 ≦ d2 / d1 ≦ 2.

[0007] d1 is the thickness of the lower fiber-reinforced resin layer measured in mm. d2 is the thickness of the upper fiber-reinforced resin layer measured in mm.

[0008] In some embodiments, the upper fiber-reinforced resin layer and the lower fiber-reinforced resin layer satisfy the condition of 0.5 ≦ d2 / d1 ≦ 1.7.

[0009] In some embodiments, the thickness d1 of the lower fiber-reinforced resin layer is 0.6 mm to 2.0 mm.

[0010] In some embodiments, the thickness d2 of the upper fiber-reinforced resin layer is 0.4 mm to 1.6 mm.

[0011] In some embodiments, the battery protection bottom plate further 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 upper surface of the fiber-reinforced resin frame is integrally connected to the upper fiber-reinforced resin layer. The bottom surface of the fiber-reinforced resin frame is integrally connected to the lower fiber-reinforced resin layer.

[0012] In some embodiments, a plurality of mounting holes are spaced apart at positions where the upper fiber-reinforced resin layer, the fiber-reinforced resin frame, and the lower fiber-reinforced resin layer overlap.

[0013] In some embodiments, 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 member, a glass fiber-reinforced polypropylene resin member, a glass fiber-reinforced polyethylene resin member, a glass fiber-reinforced polycarbonate resin member, or a glass fiber-reinforced polystyrene resin member.

[0014] In some embodiments, the upper fiber-reinforced resin layer includes a plurality of layers of a first fiber-reinforced prepreg laminated to each other. The fiber-reinforced resin frame includes a plurality of layers of a second fiber-reinforced prepreg laminated to each other. The lower fiber-reinforced resin layer includes a plurality of layers of a third fiber-reinforced prepreg laminated to each other.

[0015] In some embodiments, the thickness of the metal plate is 0.7 mm to 1.5 mm.

[0016] In some embodiments, the metal plate is a steel plate. A zinc layer, a zinc-iron alloy layer, or an electrophoretic coating protection layer is provided on the outer surface of the steel plate.

[0017] According to another aspect, the present disclosure provides a composite protection structure for a battery pack. The composite protection structure for a battery pack includes a battery pack and the aforementioned battery protection bottom plate. The battery protection bottom plate is disposed below the battery pack. A buffer region is formed between the battery pack and the battery protection bottom plate.

[0018] In some embodiments, the buffer region is filled with a buffer layer. The buffer layer is selected from a honeycomb material or a rigid foam material.

[0019] According to another aspect, the present disclosure provides a vehicle. The vehicle includes the aforementioned battery protection bottom plate or the aforementioned composite protection structure for a battery pack.

[0020] According to the battery protection bottom plate provided by the present disclosure, the upper fiber-reinforced resin layer and the lower fiber-reinforced resin layer are laminated on the front and back surfaces of the metal plate. In this way, the upper fiber-reinforced resin layer and the lower fiber-reinforced resin layer can improve the corrosion resistance of the metal plate, and the lower fiber-reinforced resin layer can withstand the impact of small stones or the like on the bottom of the battery protection bottom plate, and avoid the corrosion of the impact part. Further, after the upper fiber-reinforced resin layer and the lower fiber-reinforced resin layer are laminated on the metal plate, the rigidity and strength of the metal plate are effectively increased, so the metal plate has a high impact resistance.

[0021] Furthermore, through a number of experiments, the inventor has found that the relationship between the thickness d1 of the lower fiber-reinforced resin layer and the thickness d2 of the upper fiber-reinforced resin layer affects the uniformity of the upper and lower temperatures of the battery protection bottom plate during hot pressing, and thus affects the bonding consistency between the lower fiber-reinforced resin layer, the upper fiber-reinforced resin layer and the metal plate. When the thickness d1 of the lower fiber-reinforced resin layer and the thickness d2 of the upper fiber-reinforced resin layer satisfy the condition of 0.4 ≦ d2 / d1 ≦ 2, the bonding performance between the lower fiber-reinforced resin layer, the upper fiber-reinforced resin layer and the metal plate can be better ensured. As a result, delamination and cavitation of the battery protection bottom plate under long-term impact can be avoided, and the protection of the corrosion resistance of the metal plate can be ensured. When the thickness d1 of the lower fiber-reinforced resin layer and the thickness d2 of the upper fiber-reinforced resin layer satisfy the above conditions, it is speculated that the temperature uniformity of the lower fiber-reinforced resin layer and the upper fiber-reinforced resin layer during hot pressing can be improved. Therefore, the consistency of the bonding performance between the lower fiber-reinforced resin layer, the upper fiber-reinforced resin layer and the metal plate is effectively enhanced, and the overall bonding effect and impact resistance effect are improved.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Mode for Carrying Out the Invention

[0023] In order to make the technical problems, technical solutions, and beneficial effects solved by the present disclosure more understandable, the present disclosure will be described in more detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present disclosure and do not limit the present disclosure.

[0024] In the description of the present disclosure, the orientation or positional relationship indicated by terms such as "upper side", "lower side", "upper part", "bottom", "inner side" and "outer side" is based on the orientation or positional relationship shown in the drawings, and it is not indicated or suggested that the devices or components mentioned need to have a specific orientation or need to be constructed and operated in a specific orientation. It should be understood that this is only for the convenience and conciseness of the exemplification and description of the present disclosure. Therefore, such terms should not be construed as limitations of the present disclosure. In the description of the present disclosure, unless otherwise specified, "a plurality of" means two or more.

[0025] Referring to FIG. 1, an embodiment of the present disclosure provides a battery protection bottom plate 1. The battery protection bottom plate 1 includes an upper fiber-reinforced resin layer 11, a metal plate 12, and a lower fiber-reinforced resin layer 14. The metal plate 12 is located between the upper fiber-reinforced resin layer 11 and the lower fiber-reinforced resin layer 14. The upper fiber-reinforced resin layer 11 and the lower fiber-reinforced resin layer 14 satisfy the condition of 0.4 ≦ d2 / d1 ≦ 2.

[0026] d1 is the thickness of the lower fiber-reinforced resin layer 14 measured in mm. d2 is the thickness of the upper fiber-reinforced resin layer 11 measured in mm. For example, d2 / d1 may be 0.4, 0.6, 0.9, 1, 1.4, 1.7, 2, etc.

[0027] The upper fiber-reinforced resin layer 11 and the lower fiber-reinforced resin layer 14 are laminated on the front and back surfaces of the metal plate 12. In this way, 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, and the lower fiber-reinforced resin layer 14 can withstand the impact of small stones or the like on the bottom of the battery protection bottom plate 1, and avoid corrosion of the impact part. Further, after the upper fiber-reinforced resin layer 11 and the lower fiber-reinforced resin layer 14 are laminated on the metal plate 12, the rigidity and strength of the metal plate 12 are effectively increased, whereby the metal plate 12 has a higher impact resistance.

[0028] Furthermore, through numerous experiments, the inventor of the present invention has found that the relationship between the thickness d1 of the lower fiber-reinforced resin layer 14 and the thickness d2 of the upper fiber-reinforced resin layer 11 affects the uniformity of the upper and lower temperatures of the battery protection bottom plate 1 during hot pressing, and thus affects the bonding consistency between the lower fiber-reinforced resin layer 14 and the upper fiber-reinforced resin layer 11 and the metal plate 12. When the thickness d1 of the lower fiber-reinforced resin layer 14 and the thickness d2 of the upper fiber-reinforced resin layer 11 satisfy the condition of 0.4 ≦ d2 / d1 ≦ 2, the bonding performance between the lower fiber-reinforced resin layer 14 and the upper fiber-reinforced resin layer 11 and the metal plate 12 can be ensured to be better. Thereby, delamination and cavitation of the battery protection bottom plate 1 under long-term impact can be avoided, and protection of the corrosion resistance of the metal plate can be ensured. When the thickness d1 of the lower fiber-reinforced resin layer 14 and the thickness d2 of the upper fiber-reinforced resin layer 11 satisfy the aforementioned conditions, it is presumed that the temperature uniformity of the lower fiber-reinforced resin layer 14 and the upper fiber-reinforced resin layer 11 during hot pressing can be improved. Therefore, the consistency of the bonding performance between the lower fiber-reinforced resin layer 14 and the upper fiber-reinforced resin layer 11 and the metal plate 12 is effectively enhanced, and the overall bonding effect and impact resistance effect are improved.

[0029] In some embodiments, the upper fiber-reinforced resin layer 11 and the lower fiber-reinforced resin layer 14 satisfy the condition of 0.5 ≦ d2 / d1 ≦ 1.7. For example, d2 / d1 may be 0.5, 0.8, 1.1, 1.3, 1.5, 1.7, etc.

[0030] Through the limitation of the foregoing relational expression, the influence of the thickness of the upper fiber-reinforced resin layer 11 and the thickness of the lower fiber-reinforced resin layer 14 on the impact resistance performance of the battery pack 3 can be grasped, and the service life of the battery protection bottom plate 1 can be easily extended.

[0031] In some embodiments, the thickness d1 of the lower fiber-reinforced resin layer 14 is 0.6 mm to 2.0 mm.

[0032] Specifically, the thickness d1 of the lower fiber-reinforced resin layer 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, 2.0 mm, etc.

[0033] The lower fiber-reinforced resin layer 14 is the surface layer of the battery protection bottom plate 1 that directly contacts an impact object from the outside. The thickness d1 of the lower fiber-reinforced resin layer 14 is related to the effect of the metal plate 12 resisting corrosion by outside air and moisture, and also affects the bonding strength between the lower fiber-reinforced resin layer 14 and the metal plate 12 and the overall strength after the lower fiber-reinforced resin layer 14 is laminated on the metal plate 12. When the thickness d1 of the lower fiber-reinforced resin layer 14 is within the aforementioned range, it is possible to avoid peeling off from the surface of the metal plate 12 under high-energy impact, and the effect of enhancing the corrosion resistance and strength of the metal plate 12 can be effectively maintained.

[0034] In some embodiments, the thickness d2 of the upper fiber-reinforced resin layer 11 is 0.4 mm to 1.6 mm.

[0035] Specifically, the thickness d2 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, 1.6 mm, etc.

[0036] The thickness of the upper fiber-reinforced resin layer 11 mainly affects the moisture penetration resistance performance of the upper fiber-reinforced resin layer 11 and the bonding strength between the upper fiber-reinforced resin layer 11 and the metal plate 12. When the thickness d2 of the upper fiber-reinforced resin layer 11 is within the aforementioned range, the performance of protecting the metal plate 12 can be effectively enhanced, and the bonding strength between the upper fiber-reinforced resin layer 11 and the metal plate 12 can be improved.

[0037] In some embodiments, the thickness of the metal plate 12 is 0.7 mm to 1.5 mm.

[0038] Specifically, the thickness 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, etc.

[0039] The thickness of the metal plate 12 affects the overall mechanical strength of the battery protection bottom plate 1. When the thickness of the metal plate 12 is within the aforementioned range, it becomes possible to ensure the overall mechanical strength of the battery protection bottom plate 1, the cost can be effectively suppressed, the distance from the ground can be ensured, and the weight reduction of the vehicle can also be easily achieved.

[0040] As shown in FIG. 1, in some embodiments, the battery protection bottom plate 1 further 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 upper surface of the fiber-reinforced resin frame 13 is integrally connected to the upper fiber-reinforced resin layer 11. The bottom surface of the fiber-reinforced resin frame 13 is integrally connected to the lower fiber-reinforced resin layer 14.

[0041] The fiber-reinforced resin frame 13 is disposed on the outer peripheral portion of the metal plate 12 and is used as a transition member for connecting the frame positions of the upper fiber-reinforced resin layer 11 and the lower fiber-reinforced resin layer 14. In this way, the influence of the thickness of the metal plate 12 on the connection between the frames of the upper fiber-reinforced resin layer 11 and the lower fiber-reinforced resin layer 14 can be effectively eliminated, the strength of the frame position of the battery protection bottom plate 1 can be ensured, and thereby, the frame position of the battery protection bottom plate 1 can be used as an attachment structure of the battery protection bottom plate 1 to the battery, and the impact resistance ability of the battery protection bottom plate 1 can be improved.

[0042] As shown in FIG. 5, in some embodiments, a plurality of mounting holes 15 are arranged at intervals at positions where the upper fiber-reinforced resin layer 11, the fiber-reinforced resin frame 13, and the lower fiber-reinforced resin layer 14 overlap.

[0043] Specifically, the overlapping positions of the upper fiber-reinforced resin layer 11, the fiber-reinforced resin frame 13, and the fiber-reinforced resin layer 14 are the frame positions of the battery protection bottom plate 1. The plurality of mounting holes 15 are arranged at intervals along the frame positions of the battery protection bottom plate 1. The mounting holes 15 penetrate through the upper fiber-reinforced resin layer 11, the fiber-reinforced resin frame 13, and the fiber-reinforced resin layer 14 in sequence.

[0044] The mounting holes 15 are used for mounting and clamping and fixing the battery protection bottom plate 1 to the bottom of the battery pack 3, and the mounting holes 15 are arranged at the overlapping positions of the upper fiber-reinforced resin layer 11, the fiber-reinforced resin frame 13, and the lower fiber-reinforced resin layer 14. In this way, it can be prevented that the mounting holes 15 penetrate through the metal plate 12, and it can be prevented that the metal plate 12 is exposed at the mounting holes 15, thereby avoiding corrosion. Also, the fiber-reinforced resin frame 13 can have sufficient mounting stability in order to improve the overall thickness and tensile shear strength of the mounting position.

[0045] The plurality of mounting holes 15 are arranged along the outer peripheral portion of the metal plate 12 to uniformly disperse the upper gravity and bottom impact force applied to the metal plate 12.

[0046] Specifically, during installation, a connecting member for fixing the battery protection bottom plate 1 to the bottom of the battery pack 3 through the mounting holes 15 is arranged. The connecting member is a rivet, a screw, or a bolt.

[0047] 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 each independently selected from thermosetting materials and / or thermoplastic materials. Examples include, but are not limited to, epoxy resins, phenolic resins, phenols, cyanates, imides (e.g., polyimides, bismaleimides (BMI), and polyetherimides), polypropylene, polyester, benzoxazine, polybenzimidazole, polybenzothiazole, polyamide, polyamideimide, polysulfone, polyethersulfone, polycarbonate, polyethylene terephthalate, polyether ketones (e.g., polyether ketone (PEK), polyether ether ketone (PEEK), and polyether ketone ketone (PEKK)), and combinations thereof.

[0048] 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 each independently selected from glass fibers, aramid fibers, carbon fibers, graphite fibers, boron fibers, aromatic polyamide fibers, or mixtures thereof.

[0049] 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 short-cut fibers, long-cut fibers, non-woven fabrics, unidirectional reinforced fiber substrates, woven fabrics, etc.

[0050] 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 members, glass fiber-reinforced polypropylene resin members, glass fiber-reinforced polyethylene resin members, glass fiber-reinforced polycarbonate resin members, or glass fiber-reinforced polystyrene resin members.

[0051] In some embodiments, the same resin material is selected for the upper fiber-reinforced resin layer 11, the fiber-reinforced resin frame 13, and the lower fiber-reinforced resin layer 14. By ensuring the affinity between the materials of different layers, the same resin material can ensure a certain degree of bonding between different layers and improve the overall strength.

[0052] In some embodiments, the upper fiber-reinforced resin layer 11 includes a plurality of layers of the first fiber-reinforced prepreg 110 laminated to each other. The fiber-reinforced resin frame 13 includes a plurality of layers of the second fiber-reinforced prepreg laminated to each other. The lower fiber-reinforced resin layer 14 includes a plurality of layers of the third fiber-reinforced prepreg laminated to each other.

[0053] As shown in FIG. 2, the upper fiber-reinforced resin layer 11 includes a plurality of layers of the first fiber-reinforced prepreg tape 111 laminated to each other. The fiber arrangement directions of two adjacent layers of the first fiber-reinforced prepreg tape 111 are laid in a manner that intersects at approximately 90°. The allowable deviation range of the laying angles of two adjacent layers of the first fiber-reinforced prepreg tape 111 is ±20°.

[0054] The fibers in the first fiber-reinforced prepreg tape 111 are arranged in one direction. When the fibers in the first fiber-reinforced prepreg tape 111 are subjected to a tensile force along the extending direction of the fibers, they can effectively bear the tensile force. By laying the fiber arrangement directions of adjacent first fiber-reinforced prepreg tapes 111 in a manner that intersects at approximately 90°, the uniformity of the force applied to the upper fiber-reinforced resin layer 11 in all directions can be improved.

[0055] The fiber-reinforced resin frame 13 includes a plurality of layers of the second fiber-reinforced prepreg tape laminated to each other. The fibers in the second fiber-reinforced prepreg tape are arranged in one direction. The fiber arrangement directions of two adjacent layers of the second fiber-reinforced prepreg tape are laid in a manner that intersects at approximately 90°. The allowable deviation range of the laying angles of two adjacent layers of the second fiber-reinforced prepreg tape is ±20°.

[0056] The lower fiber-reinforced resin layer 14 includes a plurality of layers of a third fiber-reinforced prepreg tape laminated to each other. The fibers in the third fiber-reinforced prepreg tape are arranged in one direction. The fiber arrangement directions of two adjacent layers of the third fiber-reinforced prepreg tape are laid in such a manner as to intersect at approximately 90°. The allowable deviation range of the laying angles of two adjacent layers of the third fiber-reinforced prepreg tape is ±20°.

[0057] The fiber arrangement of the fiber-reinforced resin frame and the fiber arrangement of the lower fiber-reinforced resin layer are the same as those of the upper fiber-reinforced resin layer. Details will not be described again.

[0058] As shown in FIG. 3, in another embodiment, the upper fiber-reinforced resin layer 11 includes a plurality of layers of a first fiber fabric-reinforced prepreg 112 laminated to each other. The fibers in the first fiber fabric-reinforced prepreg 112 form a fabric in such a crossed manner.

[0059] The fiber-reinforced resin frame 13 includes a plurality of layers of a second fiber fabric-reinforced prepreg laminated to each other. The fibers in the second fiber fabric-reinforced prepreg form a fabric in such a crossed manner.

[0060] The lower fiber-reinforced resin layer 14 includes a plurality of layers of a third fiber fabric-reinforced prepreg laminated to each other. The fibers in the third fiber fabric-reinforced prepreg form a fabric in such a crossed manner.

[0061] 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.

[0062] In some embodiments, the metal plate 12 is a steel plate. A zinc layer, a zinc-iron alloy layer, or an electrophoretic coating protection layer is provided on the outer surface of the steel plate.

[0063] When compared with other metal materials, using a steel plate as the metal plate 12 has good tensile strength and elongation, so the requirement of impact resistance can be satisfied, and the protection for the battery pack 3 can be improved.

[0064] On the outer surface of the steel plate, a zinc layer, a zinc-iron alloy layer, or an electrophoretic coating protection layer is provided to enhance the corrosion resistance performance of the steel plate. When damage occurs to the upper fiber-reinforced resin layer 11 or the lower fiber-reinforced resin layer 14, due to the galvanic effect formed between the zinc layer or the zinc-iron alloy layer and the steel plate, the zinc layer or the zinc-iron alloy layer is corroded prior to the steel plate, thereby protecting the steel plate. And because the electrophoretic coating protection layer has good adhesion, the steel plate is effectively isolated from the external environment.

[0065] As shown in FIG. 4, another embodiment of the present disclosure provides a composite protection structure 10 for a battery pack. The composite protection structure 10 for a battery pack includes the battery pack 3 and the aforementioned battery protection bottom plate 1. The battery protection bottom plate 1 is disposed below the battery pack 3. A buffer region 4 is formed between the battery pack 3 and the battery protection bottom plate 1.

[0066] Since the composite protection structure 10 for a battery pack uses the aforementioned battery protection bottom plate 1, the protection strength of the battery protection bottom plate 1 and the stable connection between the battery protection bottom plate 1 and the battery pack 3 are effectively ensured, and the overall thinness is ensured.

[0067] In some embodiments, the battery pack 3 includes a tray 31 and a battery disposed on the tray 31.

[0068] In different embodiments, the buffer region 4 may be arranged in different forms between the battery pack 3 and the battery protection bottom plate 1.

[0069] As shown in FIG. 6, in one embodiment, a groove is disposed inwardly on the bottom surface of the tray 31 to form the buffer region 4. The battery protection bottom plate 1 is in a flat plate shape. The battery protection bottom plate 1 covers the buffer region 4.

[0070] As shown in FIG. 7, in one embodiment, the frame position of the battery protection bottom plate 1 is connected to the bottom surface of the tray 31. The groove portion is disposed inwardly on the bottom surface of the tray 31. The battery protection bottom plate 1 protrudes along the direction facing away from the tray 31, and a buffer region 4 is formed between the tray 31 and the battery protection bottom plate 1.

[0071] As shown in FIG. 8, in one embodiment, the frame position of the battery protection bottom plate 1 is connected to the bottom surface of the tray 31. The bottom surface of the tray 31 is a flat surface. The battery protection bottom plate 1 protrudes along the direction facing away from the tray 31, and a buffer region 4 is formed between the tray 31 and the battery protection bottom plate 1.

[0072] In some embodiments, the buffer region 4 is filled with a buffer layer 2. The buffer layer 2 is selected from a honeycomb material or a rigid foam material.

[0073] The honeycomb material or the rigid foam material can absorb the crushing deformation space of the battery protection bottom plate 1 under a strong external impact, buffer and absorb part of the energy of the strong external impact, and prevent the compression and deformation of the battery protection bottom plate 1 from impacting the internal core of the battery pack 3, thereby further protecting the battery pack 3.

[0074] In some embodiments, the honeycomb material is selected from a PP honeycomb material or an aluminum honeycomb material. The rigid foam material is selected from a PU rigid foam material, a PET rigid foam material, a PMI rigid foam material, a PVC rigid foam material, a PET rigid foam material, an MPP rigid foam material, a PLA rigid foam material, a PI rigid foam material or an EPTU rigid foam material.

[0075] Another embodiment of the present disclosure provides a vehicle 100. As shown in FIG. 9, the vehicle 100 includes the aforementioned battery protection bottom plate 1 or the aforementioned composite protection structure 10 for a battery pack.

[0076] The present disclosure will be further described below through embodiments.

Table 1

[0077] Embodiment 1 This embodiment is used to explain that the composite protection structure for a battery pack disclosed in the present disclosure includes a battery pack, a buffer layer, and a battery protection bottom plate. The battery protection bottom plate includes 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 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 upper surface of the fiber-reinforced resin frame is integrally connected to the upper fiber-reinforced resin layer. 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 disposed below the battery pack. A buffer region is formed between the battery pack and the battery protection bottom plate. The buffer region is filled with a buffer layer. The frame of the battery protection bottom plate is attached to the bottom frame position of the battery pack through rivets.

[0078] The thickness d1 of the lower fiber-reinforced resin layer is 1.0 mm. The thickness of the metal plate is 0.8 mm. The thickness d2 of the upper fiber-reinforced resin layer is 1.6 mm.

[0079] Embodiments 2 - 10 Embodiments 2 - 10 are used to explain that the composite protection structure for a battery pack disclosed in the present disclosure includes most of the structures in Embodiment 1. The difference is that the upper fiber-reinforced resin layer and the lower fiber-reinforced resin layer provided in Embodiments 2 - 10 of Table 1 are used.

[0080] Comparative Examples 1 and 2 Comparative Examples 1 and 2 are used to comparatively explain that the composite protection structure for a battery pack disclosed in the present disclosure includes most of the structures in Embodiment 1. The difference is that the upper fiber-reinforced resin layer and the lower fiber-reinforced resin layer provided in Comparative Examples 1 and 2 of Table 1 are used.

[0081] Performance Test Performance tests are conducted on the composite protection structure for the battery pack provided in the foregoing embodiments and comparative examples.

[0082] A sphere is used as an impact body to apply an impact to the battery protection bottom plate of the composite protection structure for the battery pack, and the operating situation where the bottom of the entire vehicle collides with a foreign object is simulated. The diameter of the sphere was 25 mm, the weight of the sphere was 10 kg, the impact energy was 300 J, and the impact speed was 8.5 m / s. As the impact points, the center point of the battery protection bottom plate and four points around the center point were selected, and five impacts were applied.

[0083] The diameter of the pulverized area after the battery protection bottom plate was impacted was measured using calipers. A single impact point was measured three times, and the average value was obtained. The impact point having the pulverized area with the maximum diameter was selected and recorded as the diameter of the pulverized area of the battery protection bottom plate. Generally, it is required that the diameter of the pulverized area be 10 mm or less.

[0084] The diameter of the delaminated cavity after the battery protection bottom plate was impacted was measured using calipers. A single impact point was measured three times, and the average value was obtained. The impact point having the cavity with the maximum diameter was selected and recorded as the size of the cavity of the battery protection bottom plate. The degree of cavitation was determined according to the following evaluation criteria.

[0085] R1: No delamination.

[0086] R2: Slight delamination where the size of the cavity is less than 4 mm in diameter.

[0087] R3: Slight delamination where the size of the cavity is less than 8 mm in diameter.

[0088] R4: Delamination where the size of the cavity exceeds 8 mm in diameter.

[0089] The obtained test results are listed in Table 2.

Table 2

[0090] From the test results in Table 2, it can be seen that the relationship between the thickness of the upper fiber-reinforced resin layer and the thickness of the lower fiber-reinforced resin layer is limited, so that the bonding strength between the upper fiber-reinforced resin layer, the lower fiber-reinforced resin layer and the metal plate is effectively increased, and thereby the delamination caused by impact can be avoided.

[0091] The foregoing description is only a preferred embodiment of the present disclosure and is not intended to limit the present disclosure. Any modification, equivalent substitution, or improvement made within the spirit and principle of the present disclosure shall fall within the protection scope of the present disclosure.

Description of Reference Numerals

[0092] 100 Vehicle 10 Composite protection structure for battery pack 1 Battery protection bottom plate 11 Upper fiber-reinforced resin layer 110 First fiber-reinforced prepreg 111 First fiber-reinforced prepreg tape 112 First fiber fabric-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 region

Claims

1. 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 upper fiber-reinforced resin layer (11) and the lower fiber-reinforced resin layer (14) satisfy the condition of 0.4 ≦ d ２ / d １ ≦ 2, where d １ is the thickness of the lower fiber-reinforced resin layer (14) measured in mm, and d ２ is the thickness of the upper fiber-reinforced resin layer (11) measured in mm, the battery protection bottom plate (1).

2. The upper fiber-reinforced resin layer (11) and the lower fiber-reinforced resin layer (14) satisfy the condition of 0.5 ≦ d ２ / d １ ≦ 1.7, the battery protection bottom plate (1) according to Claim 1.

3. The thickness d １ of the lower fiber-reinforced resin layer (14) is 0.6 mm to 2.0 mm, the battery protection bottom plate (1) according to Claim 1 or 2.

4. The thickness d ２ of the upper fiber-reinforced resin layer (11) is 0.4 mm to 1.6 mm, the battery protection bottom plate (1) according to any one of Claims 1 to 3.

5. The battery protection bottom plate (1) further comprises 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 upper 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), the battery protection bottom plate (1) according to any one of Claims 1 to 4.

6. The battery protection bottom plate (1) according to claim 5, wherein a plurality of mounting holes (15) are arranged at intervals at positions where the upper fiber-reinforced resin layer (11), the fiber-reinforced resin frame (13), and the lower fiber-reinforced resin layer (14) overlap.

7. The battery protection bottom plate (1) according to claim 5 or 6, wherein 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 a glass fiber-reinforced polyamide resin member, a glass fiber-reinforced polypropylene resin member, a glass fiber-reinforced polyethylene resin member, a glass fiber-reinforced polycarbonate resin member, or a glass fiber-reinforced polystyrene resin member.

8. The upper fiber-reinforced resin layer (11) includes a plurality of layers of a first fiber-reinforced prepreg (110) laminated to each other. The fiber-reinforced resin frame (13) includes a plurality of layers of a second fiber-reinforced prepreg laminated to each other. The battery protection bottom plate (1) according to any one of claims 5 to 7, wherein the lower fiber-reinforced resin layer (14) includes a plurality of layers of a third fiber-reinforced prepreg laminated to each other.

9. The battery protection bottom plate (1) according to any one of claims 1 to 8, wherein the thickness of the metal plate (12) is 0.7 mm to 1.5 mm.

10. The battery protection bottom plate (1) according to any one of claims 1 to 9, wherein the metal plate (12) is a steel plate, and a zinc layer, a zinc-iron alloy layer, or an electrophoretic coating protection layer is provided on the outer surface of the steel plate.

11. A composite protection structure (10) for a battery pack, comprising a battery pack (3) and the battery protection bottom plate (1) according to any one of claims 1 to 10, wherein the battery protection bottom plate (1) is disposed below the battery pack (3), and a buffer region (4) is formed between the battery pack (3) and the battery protection bottom plate (1).

12. The buffer region (4) is filled with a buffer layer (2), and the buffer layer (2) is selected from a honeycomb material or a rigid foam material. The composite protection structure (10) for a battery pack according to claim 11.

13. A vehicle (100) comprising the battery protection bottom plate (1) according to any one of claims 1 to 10, or comprising the composite protection structure (10) for a battery pack according to claim 11 or 12.

Images