Patent Application
20250030102
The present disclosure relates to the technical field of vehicle batteries, and particularly, to a battery protection bottom plate, a battery pack composite protection structure, and a vehicle.
With the rapid development of electric vehicles, requirements for safety of electric vehicles are getting increasingly high. As a power battery pack is used as a power source of electric vehicles, the importance of safety of the power battery pack is obvious. A battery pack is generally located on a lower portion of a chassis of the electric vehicle, and is connected to the chassis by a bolt. A lower surface of the battery pack is exposed outside. During daily driving of the vehicle, a bottom of the battery pack is susceptible to collision, which leads to case breakage and protection failure. Stones bounced back at the bottom of the vehicle may also impact the battery pack during driving. In order to cope with complex working conditions, a protection plate is usually arranged at the bottom of the battery pack to protect the bottom of the battery pack. The protection plate is usually a steel plate, and a PVC layer is sprayed on a bottom surface of the protection plate to resist impact and corrosion. However, overall impact resistance of an existing protection plate still needs to be improved. Under an impact of an external hard object, the PVC layer on the bottom surface of the protection plate is susceptible to chalking and therefore drops from a surface of the protection plate, and then the internal steel plate is exposed, which affects corrosion resistance of the protection plate.
Against the problem that a surface PVC layer of an existing battery pack bottom protection plate drops when subjected to an impact, which leads to insufficient corrosion resistance, the present disclosure provides a battery protection bottom plate, a battery pack composite protection structure, and a vehicle.
The technical solutions adopted by the present disclosure to solve the above technical problems are as follows.
In a first aspect, the present disclosure provides a battery protection bottom plate, including a protective layer, a metal plate, and a fiber-reinforced resin layer. The metal plate is located between the protective plate and the fiber-reinforced resin layer, and the metal plate and the fiber-reinforced resin layer satisfy the following condition:
In some implementations, the metal plate and the fiber-reinforced resin layer satisfy the following condition:
In some implementations, the thickness d1 of the fiber-reinforced resin layer ranges from 0.6 mm to 2.0 mm.
In some implementations, the thickness d2 of the metal plate ranges from 0.7 mm to 1.6 mm.
In some implementations, the elongation ε2 at break of the metal plate ranges from 5% to 20%.
In some implementations, the tensile strength σ2 of the metal plate ranges from 590 MPa to 1180 MPa.
In some implementations, the elongation ε0 at break of the fiber-reinforced resin layer ranges from 2.5% to 8%.
In some implementations, the tensile strength σ0 of the fiber-reinforced resin layer ranges from 240 MPa to 380 MPa.
In some implementations, the protective layer includes a material of a fiber-reinforced resin, a resin coating, or an electrophoretic coating.
In some implementations, a thickness of the protective layer ranges from 0.4 mm to 1.6 mm.
In some implementations, 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 protective layer and the fiber-reinforced resin layer, and the metal plate is located inside the fiber-reinforced resin frame. A top surface of the fiber-reinforced resin frame is in contact with the protective layer, and a bottom surface of the fiber-reinforced resin frame is in contact with the fiber-reinforced resin layer.
In some implementations, multiple mounting holes are spaced apart on an inner side of an edge of the battery protection bottom plate, and the mounting holes penetrate through the protective layer, the fiber-reinforced resin frame and the fiber-reinforced resin layer.
In some implementations, each of the protective layer, the fiber-reinforced resin frame and the fiber-reinforced resin layer includes 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.
In some implementations, each of the protective layer, the fiber-reinforced resin frame and the fiber-reinforced resin layer includes a glass fiber-reinforced resin member, the glass fiber-reinforced resin member contains a glass fiber with a content weight ranging from 60% to 70%, and the glass fiber has an alkali content weight less than 0.8%.
In some implementations, the protective layer includes multiple layers of first fiber-reinforced prepregs stacked with each other.
In some implementations, the fiber-reinforced resin frame includes multiple layers of second fiber-reinforced prepregs stacked with each other.
In some implementations, the fiber-reinforced resin layer includes multiple layers of third fiber-reinforced prepregs stacked with each other.
In some implementations, the metal plate includes a steel plate, and a galvanized layer, a galvanized iron alloy layer or an electrophoretic paint protective layer is disposed at an outer surface of the steel plate.
In another aspect, the present disclosure provides a battery pack composite, including a battery pack and the battery protection bottom plate as described above. The battery protection bottom plate is disposed below the battery pack, and a buffer zone is formed between the battery pack and the battery protection bottom plate.
In some implementations, the buffer zone is filled with or includes a buffer layer, and the buffer layer is selected from a honeycomb-structured material or a rigid foam material.
In another aspect, the present disclosure provides a vehicle, including the battery protection bottom plate or the battery pack composite protection structure as described above.
In the battery protection bottom plate according to the present disclosure, a fiber-reinforced resin layer is compounded on a surface of a metal plate, and the fiber-reinforced resin layer is used as a bottom surface coating structure of the metal plate, so that the metal plate can be prevented from being in direct contact with air and external moisture, and the metal plate can be protected against corrosion. In addition, a fiber-reinforced resin has good mechanical strength, so that stiffness and strength of the metal plate are effectively improved, and therefore the metal plate has higher impact resistance.
Further, when fiber-reinforced resin layers are matched with metal plates, a battery protection bottom plate with excellent impact resistance can be obtained in some matching groups, while the surface of a fiber-reinforced resin layer is damaged in some matching groups. It is found that the tensile strength and the elongation at break of a selected fiber-reinforced resin layer need to have a certain corresponding relationship with the tensile strength and the elongation at break of the metal plate, so that adhesion between the fiber-reinforced resin layer and the metal plate can be ensured without being damaged when the battery protection bottom plate is impacted by external energy. With reference to the thicknesses of the fiber-reinforced resin layer and the metal plate, the following relationship is summarized:
When the thickness d1 of the fiber-reinforced resin layer, the thickness d2 of the metal plate, the elongation ε2 at break of the metal plate, the elongation ε0 at break of the fiber-reinforced resin layer, the tensile strength σ2 of the metal plate and the tensile strength σ0 of the fiber-reinforced resin layer satisfy the above condition, a battery protection bottom plate with excellent impact resistance and corrosion resistance is obtained.
In the drawings:
1: Battery protection bottom plate; 11: Protective layer; 111: First fiber-reinforced prepreg unidirectional tape; 112: First fiber woven fabric reinforced prepreg; 12: Metal plate; 13: Fiber-reinforced resin frame; 14: Fiber-reinforced resin layer; 15: Mounting hole; 2: Buffer layer; 3: Battery pack; 31: Tray; and 4: Buffer zone.
To make the to-be-solved technical problems, technical solutions and beneficial effects of the present disclosure clearer, the present disclosure is further described in detail below with reference to accompanying drawings and embodiments. It should be understood that the embodiments described herein are merely used to explain the present disclosure but are not to limit the present disclosure.
In the description of the present disclosure, it should be understood that orientation or position relationships indicated by the terms such as “upper”, “lower”, “top”, “bottom”, “inner” and “outer” are based on orientation or position relationships shown in the accompanying drawings, and are merely for ease of description of the present disclosure and simplification of the description, rather than indicating or implying that the apparatus or element referred to needs to have an orientation or be constructed and operated in an orientation, and therefore cannot be construed as limiting the present disclosure. In the description of the present disclosure, unless otherwise stated, “a plurality of/multiple” means two or more.
As shown in
The fiber-reinforced resin layer 14 as a bottom surface coating structure of the metal plate 12 can prevent the metal plate 12 from being in direct contact with air and external moisture, to protect the metal plate 12 against corrosion. In addition, a fiber-reinforced resin has good mechanical strength, so that stiffness and strength of the metal plate 12 are effectively improved, and therefore the metal plate has higher impact resistance.
Further, When fiber-reinforced resin layers 14 are matched with metal plates 12, a battery protection bottom plate 1 with excellent impact resistance can be obtained in some matching groups, while the surface of a fiber-reinforced resin layer 14 is damaged in some matching groups. It is found that the tensile strength and the elongation at break of a selected fiber-reinforced resin layer 14 need to have a certain corresponding relationship with the tensile strength and the elongation at break of the metal plate 12, so that adhesion between the fiber-reinforced resin layer 14 and the metal plate 12 can be ensured without being damaged when the battery protection bottom plate 1 is impacted by external energy. With reference to the thicknesses of the fiber-reinforced resin layer 14 and the metal plate 12, the following relationship is summarized:
When the thickness d1 of the fiber-reinforced resin layer 14, the thickness d2 of the metal plate 12, the elongation ε2 at break of the metal plate 12, the elongation ε0 at break of the fiber-reinforced resin layer 14, the tensile strength σ2 of the metal plate 12 and the tensile strength σ0 of the fiber-reinforced resin layer 14 satisfy the above condition, a battery protection bottom plate 1 with excellent impact resistance and corrosion resistance is obtained.
In some embodiments, the metal plate 12 and the fiber-reinforced resin layer 14 satisfy the following condition:
Through the definition of the above relationship, influences of material selection of the metal plate 12 and the fiber-reinforced resin layer 14 on impact resistance of the battery pack 3 can be synthesized, which is beneficial to preventing the fiber-reinforced resin layer 14 on the surface from dropping when the fiber-reinforced resin layer is subjected to an external impact, ensuring corrosion resistance of the battery protection bottom plate 1 and prolonging the service life.
In some embodiments, the thickness d1 of the fiber-reinforced resin layer 14 ranges from 0.6 mm to 2.0 mm.
In an embodiment, the thickness d1 of the 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.
The thickness d1 of the fiber-reinforced resin layer 14 is related to corrosion resistance of the metal plate 12 to external air and water vapor, and affects a bonding strength with the metal plate 12 and an overall strength after the compounding with the metal plate 12. When the thickness d1 of the fiber-reinforced resin layer 14 is in the above range, the dropping from the surface of the metal plate 12 can be prevented under a high-energy impact, and anti-corrosion and strength enhancement effects on the metal plate 12 can be effectively maintained.
In some embodiments, the thickness d2 of the metal plate 12 ranges from 0.7 mm to 1.6 mm.
In an embodiment, the thickness d2 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.
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, the protection strength thereof gradually increases as the thickness of the metal plate 12 increases, but a material cost thereof also gradually increases, and a ground clearance of a bottom of a vehicle 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 ensured, the cost can be effectively controlled, a distance from a ground can be ensured, and lightweight control of the vehicle can be facilitated.
In some embodiments, the elongation ε2 at break of the metal plate 12 ranges from 5% to 20%.
In an embodiment, the elongation ε2 at break of the metal plate 12 may be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 31%, 14%, 15%, 16%, 71%, 18%, 19% or 20%.
In some embodiments, the tensile strength σ2 of the metal plate 12 ranges from 590 MPa to 1180 MPa.
In an embodiment, 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.
The tensile strength σ2 and the elongation ε2 at break of the metal plate 12 may be tested by GB/T 228.1—2010 Metallic materials—Tensile testing—Part 1: Method of test at room temperature. The metal plate 12 as a component playing a major protective role in the battery protection bottom plate 1 is faced with complicated impact conditions, and the tensile strength σ2 thereof as a strength index of the metal plate 12 affects deformation resistance of the metal plate 12 within an elastic deformation range of the metal plate. When the tensile strength σ2 is higher, the metal plate 12 can resist a higher impact without irreversible deformation. The elongation ε2 at break affects fracture resistance of the metal plate 12 after deformation. When the elongation ε2 at break is higher, the metal plate 12 can resist a higher impact without cracking. However, generally, a higher tensile strength σ2 of the metal plate 12 indicates a lower elongation ε2 at break thereof. When the tensile strength σ2 and the elongation ε2 at break are within the above ranges, influences of different parameters on protective performance of the metal plate 12 can be effectively considered, and the impact resistance strength and cracking resistance of the metal plate 12 can be ensured.
In some embodiments, the elongation ε0 at break of the fiber-reinforced resin layer 14 ranges from 2.5% to 8%.
In an embodiment, the elongation ε0 at break of the fiber-reinforced resin layer 14 may be 2.5%, 2.6%, 2.8%, 2.9%, 3.0%, 3.1%, 3.2%, 3.3%, 3.4%, 3.5%, 3.6%, 3.8%, 3.9%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5% or 8%.
In some embodiments, the tensile strength σ0 of the fiber-reinforced resin layer 14 ranges from 240 MPa to 380 MPa.
In an embodiment, the tensile strength σ0 of the fiber-reinforced resin layer 14 may be 240 MPa, 260 MPa, 280 MPa, 290 MPa, 300 MPa, 310 MPa, 320 MPa, 330 MPa, 340 MPa, 350 MPa, 360 MPa, 370 MPa or 380 MPa.
The elongation ε0 at break of the fiber-reinforced resin layer 14 and the tensile strength σ0 of the fiber-reinforced resin layer 14 may be tested by GB/T 1447-2005 Fiber-reinforced plastics composites—Determination of tensile properties. Type I samples are suitable for fiber-reinforced thermoplastic plates, and samples are manufactured according to type I samples specified in the national standard for testing. When impacted, the fiber-reinforced resin layer 14 is a surface layer of the battery protection bottom plate 1 that is in direct contact with an impacting object, and the improvement of the tensile strength σ0 is beneficial to improving the deformation resistance of the fiber-reinforced resin layer 14. The increase of the tensile strength σ0 may lead to the decrease of the elongation ε0 at break, and affect adhesion of the fiber-reinforced resin layer 14 to the metal plate 12, resulting in delamination under the impact. When the tensile strength σ0 and the elongation ε0 at break of the fiber-reinforced resin layer 14 are within the above ranges, the fiber-reinforced resin layer 14 can effectively resist an external impact without delamination or dropping.
In practical applications, the above six parameters are interrelated and inseparable in terms of improving the impact resistance of the battery pack 3 and avoiding chalking and dropping of the fiber-reinforced resin layer. For example, when the tensile strength σ2 of the metal plate 12 cannot be well matched with the tensile strength σ0 of the fiber-reinforced resin layer 14, unsynchronized vibration is easily caused, which is more likely to cause delamination. When the elongation ε2 at break of the metal plate 12 cannot be well matched with the elongation Co at break of the fiber-reinforced resin layer 14, the fiber-reinforced resin layer 14 is susceptible to chalking due to an impact. The tensile strength σ2 of the metal plate 12 is related to the elongation ε2 at break of the metal plate 12, and the tensile strength σ0 of the fiber-reinforced resin layer 14 is related to the elongation ε0 at break of the fiber-reinforced resin layer 14. When the thickness d2 of the metal plate 12 and the thickness d1 of the fiber-reinforced resin layer 14 increase, requirements for the tensile strength σ2 of the metal plate 12 and the tensile strength σ0 of the fiber-reinforced resin layer 14 can be reduced, but correspondingly, the total mass and thickness of the battery protection bottom plate 1 are increased. This is not conducive to satisfying requirements for lightweight and cost control of the vehicle, and also leads to the reduction of the distance between the vehicle and the ground. This is not beneficial to satisfying lightweight requirements for the vehicle and controlling costs, and leads to the reduction of the ground clearance of the vehicle. Therefore, through the relationship
an influence of each of factors on protective performance of battery pack 3 is synthesized, which is beneficial to improving impact resistance of the battery protection bottom plate 1 and avoids delamination and surface chalking under an impact.
In some embodiments, a material of the protective layer 11 is selected from a fiber-reinforced resin material, a resin coating, or an electrophoretic coating. The protective layer 11 is configured to improve corrosion resistance and composite strength of the metal plate 12.
In some embodiments, the thickness of the protective layer 11 ranges from 0.4 mm to 1.6 mm. In an embodiment, the thickness of the protective 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 of the protective layer 11 mainly affects water vapor penetration resistance and the bonding strength of the protective layer 11 with the metal plate 12. When the thickness of the protective layer 11 is in the above range, the protective performance for the metal plate 12 can be effectively improved, and the bonding strength of the protective layer 11 with the metal plate 12 can be improved.
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 protective layer 11 and the fiber-reinforced resin layer 14, and the metal plate 12 is located inside the fiber-reinforced resin frame 13. Atop surface of the fiber-reinforced resin frame 13 is integrally connected to or in contact with the protective layer 11, and a bottom surface of the fiber-reinforced resin frame 13 is integrally connected to or in contact with the fiber-reinforced resin layer 14.
The fiber-reinforced resin frame 13 is arranged on a periphery of the metal plate 12 as a frame connection transition member for the protective layer 11 and the fiber-reinforced resin layer 14. This can effectively offset an influence of the thickness of the metal plate 12 on frame connection for the protective layer 11 and the fiber-reinforced resin layer 14, ensure the strength of a frame of the battery protection bottom plate 1, further facilitate use of the frame of the battery protection bottom plate 1 as a mounting structure of the battery protection bottom plate on a battery, and improve impact resistance of the battery protection bottom plate.
As shown in
The mounting holes 15 are configured to mount and fasten the battery protection bottom plate 1 to a bottom of the battery pack 3. The mounting holes 15 are provided in the inner side of the edge of the battery protection bottom plate 1, and sequentially run/penetrate through the protective layer 11, the fiber-reinforced resin frame 13, and the fiber-reinforced resin layer 14, so that the mounting holes 15 can be prevented from running through the metal plate 12, and the corrosion problem caused by the exposure of the metal plate 12 at the mounting holes 15 can be avoided. In addition, the fiber-reinforced resin frame 13 is beneficial to improving the overall thickness and tensile shear strength of a mounting position, and has sufficient mounting stability.
The multiple mounting holes 15 are provided around the periphery of the metal plate 12, so as to uniformly disperse a top gravity and a bottom impact force on the metal plate 12.
In an embodiment, during mounting, a connection member is provided to pass through the mounting hole 15 to secure the battery protection bottom plate 1 to the bottom of the battery pack 3. The connection member is a rivet, a screw or a bolt.
In different embodiments, resins of each of the protective layer 11, the fiber-reinforced resin frame 13 and the fiber-reinforced resin layer 14 are independently selected from thermosetting and/or thermoplastic materials. Examples may include, but are not limited to, an epoxy resin, phenolic plastic, phenols, cyanate esters, imides (such as polyimide, bismaleimide (BMI) and polyetherimide), polypropylenes, polyesters, benzoxazines, polybenzimidazoles, polybenzothiazoles, polyamides, polyamideimides, polysulfones, polyethersulfones, polycarbonates, polyethylene terephthalates and polyether ketones (such as polyether ketone (PEK), polyetheretherketone (PEEK) and polyether ketone ketone (PEKK)), or a combination thereof.
In different embodiments, fibers of each of the protective layer 11, the fiber-reinforced resin frame 13, and the fiber-reinforced resin layer 14 are independently selected from a glass fiber, an aramid fiber, a carbon fiber, a graphite fiber, a boron fiber, an aromatic polyamide fiber, or a mixture thereof.
The fibers of the protective layer 11, the fiber-reinforced resin frame 13, and the fiber-reinforced resin layer 14 may be embedded in resins in the form of chopped fibers, long-cut fibers, non-woven fabrics, unidirectional reinforced fiber base materials, woven fabrics, or the like.
In some embodiments, each of the protective layer 11, the fiber-reinforced resin frame 13, and the fiber-reinforced resin layer 14 is 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.
In some embodiments, the protective layer 11, the fiber-reinforced resin frame 13 and the fiber-reinforced resin layer 14 are made of a same resin material, and the same resin material can ensure affinity of materials between different layers, thereby ensuring an integration degree of combination between different layers and improving the overall strength.
In some embodiments, each of the protective layer 11, the fiber-reinforced resin frame 13 and the fiber-reinforced resin layer 14 is a glass fiber-reinforced resin member, and the glass fiber-reinforced resin member contains a glass fiber with a content weight ranging from 60% to 70%, which is beneficial to improving the material strength of the protective layer 11, the fiber-reinforced resin frame 13 and the fiber-reinforced resin layer 14.
In some embodiments, the alkali content weight of the glass fiber is less than 0.8%.
When the alkali content weight of the glass fiber is less than 0.8%, aging resistance of the protective layer 11, the fiber-reinforced resin frame 13, and the fiber-reinforced resin layer 14 are improved, and performance attenuation of the material after long-term use is slowed down.
In some embodiments, the glass fiber is selected from an E-glass fiber or an S-glass fiber.
In some embodiments, the protective layer 11 includes multiple layers of first fiber-reinforced prepregs stacked with each other.
In some embodiments, the fiber-reinforced resin frame 13 includes multiple layers of second fiber-reinforced prepregs stacked with each other.
In some embodiments, the fiber-reinforced resin layer 14 includes multiple layers of third fiber-reinforced prepregs stacked with each other.
As shown in
Fibers of each first fiber-reinforced prepreg unidirectional tape 111 are provided unidirectionally, and when subjected to a tensile force along a fiber extension direction, the fibers of the first fiber-reinforced prepreg unidirectional tape 111 can effectively bear the tensile force. Stress uniformity of the protective layer 11 in each direction is improved by staggering fiber arrangement directions of adjacent first fiber-reinforced prepreg unidirectional tapes 111 at approximately 90°.
The fiber-reinforced resin frame 13 includes multiple layers of second fiber-reinforced prepreg unidirectional tapes stacked with each other. Fibers of each second fiber-reinforced prepreg unidirectional tape are unidirectionally arranged. Fiber arrangement directions of two adjacent layers of second fiber-reinforced prepreg unidirectional tapes are staggered at approximately 90°, and an allowable ply angle deviation range of two adjacent layers of second fiber-reinforced prepreg unidirectional tapes is ±20°.
The fiber-reinforced resin layer 14 includes multiple layers of third fiber-reinforced prepreg unidirectional tapes stacked with each other. Fibers of each third fiber-reinforced prepreg unidirectional tape are unidirectionally arranged/disposed. Fiber arrangement directions of two adjacent layers of third fiber-reinforced prepreg unidirectional tapes are staggered at approximately 90°, and an allowable ply angle deviation range of two adjacent layers of third fiber-reinforced prepreg unidirectional tapes is +20°.
Fiber arrangements of the fiber-reinforced resin frame 13 and the fiber-reinforced resin layer 14 are similar to those of the protective layer 11, and details are not repeated.
As shown in
The fiber-reinforced resin frame 13 includes multiple layers of second fiber woven fabric reinforced prepregs stacked with each other, and fibers of each second fiber woven fabric reinforced prepreg form a woven fabric in a staggered form.
The fiber-reinforced resin layer 14 includes multiple layers of third fiber woven fabric reinforced prepregs stacked with each other, and fibers of each third fiber woven fabric reinforced prepreg form a woven fabric in a staggered form.
In some embodiments, the metal plate 12 is selected from iron and an alloy thereof, aluminum and an alloy thereof, magnesium and an alloy thereof, copper and an alloy thereof, titanium and an alloy thereof or nickel and an alloy thereof.
In an embodiment, the metal plate 12 is a steel plate, and a galvanized layer, a galvanized iron alloy layer or an electrophoretic paint protective layer is arranged at an outer surface of the steel plate.
Compared with other metal materials, the steel plate used as the metal plate 12 has a better tensile strength and elongation, can satisfy requirements for impact resistance, and is beneficial to improving a protective effect on the battery pack 3.
The galvanized layer, the galvanized iron alloy layer or the electrophoretic paint protective layer is arranged at the outer surface of the steel plate, to improve corrosion resistance of the steel plate. When the protective layer 11 or the fiber-reinforced resin layer 14 is damaged, a galvanic 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 prior to that the steel plate corrodes, thereby achieving a protective effect on the steel plate. The electrophoretic paint protective layer has good adhesion and can effectively isolate the steel plate from an external environment.
As shown in
Due to the adoption of the above battery protection bottom plate 1, the battery pack composite protection structure effectively ensures the protection strength and good corrosion resistance of the battery protection bottom plate 1 while a lower overall thickness is ensured.
In some embodiments, the battery pack 3 includes a tray 31 and a battery arranged on the tray 31.
In different embodiments, the buffer zone 4 may be provided between the battery pack 3 and the battery protection bottom plate 1 in different ways.
As shown in
As shown in
As shown in
In some embodiments, the buffer zone 4 is filled with a buffer layer 2, and the buffer layer 2 is selected from a honeycomb-structured material or a rigid foam material.
The honeycomb-structured material or the rigid foam material can absorb a collapse deformation space of the battery protection bottom plate under an external strong impact, buffer and absorb part of energy of the external strong impact, and prevent compression deformation of the battery protection bottom plate 1 from impacting on internal battery cores of the battery pack 3, thereby further protecting the battery pack 3.
In some embodiments, the honeycomb-structured material is selected from a polypropylene (PP) honeycomb material or an aluminum honeycomb material, and the rigid foam material is selected from a polyurethane (PU) rigid foam material, a polyethylene terephthalate (PET) rigid foam material, a polymethacrylimide (PMI) rigid foam material, a polyvinyl chloride (PVC) rigid foam material, a polyethylene terephthalate (PET) rigid foam material, a modified polypropylene (MPP) rigid foam material, a polylactic acid (PLA) rigid foam material, a polyimide (PI) rigid foam material, or an enhanced thermoplastic polyurethane (EPTU) rigid foam material.
Another embodiment of the present disclosure provides a vehicle, including the battery protection bottom plate or the battery pack composite protection structure as described above.
The present disclosure is further described below by embodiments.
This embodiment is used to illustrate a battery pack composite protection structure according to the present disclosure, which includes a battery pack, a buffer layer and a battery protection bottom plate. The battery protection bottom plate includes a metal plate, a protective layer, a fiber-reinforced resin frame, and a fiber-reinforced resin layer. The metal plate is a galvanized steel plate. The protective layer is made of a fiber-reinforced resin material. The metal plate is located between the protective layer and the fiber-reinforced resin layer. The fiber-reinforced resin layer is located below the metal plate, and the metal plate is located inside the fiber-reinforced resin frame. A top surface of the fiber-reinforced resin frame is integrally connected to or in contact with the protective layer, and a bottom surface of the fiber-reinforced resin frame is integrally connected to or in contact with the fiber-reinforced resin layer. 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. The buffer zone is filled with the buffer layer, and a frame of the battery protection bottom plate is mounted to a bottom frame of the battery pack by a rivet.
The thickness d1 of the fiber-reinforced resin layer is 1.6 mm. The thickness of the protective layer is 1.5 mm. The thickness d2 of the metal plate is 1.2 mm. The elongation ε2 at break of the metal plate is 18%, and the elongation ε0 at break of the fiber-reinforced resin layer is 3%. The tensile strength σ2 of the metal plate is 780 MPa, and the tensile strength σ0 of the fiber-reinforced resin layer is 380 MPa.
Embodiments 2 to 20 are used to illustrate a battery pack composite protection structure according to the present disclosure, which includes most of the structures in Embodiment 1, but differs in that:
the metal plate and the fiber-reinforced resin layer provided in each of Embodiments 2 to 20 in Table 1 are used.
Comparative Examples 1 to 5 are used to comparatively illustrate a battery pack composite protection structure according to the present disclosure, which includes most of the structures in Embodiment 1, but differs in that:
the metal plate and the fiber-reinforced resin layer provided in each of Comparative Examples 1 to 5 in Table 1 are used.
Performance of the battery pack composite protection structures according to the above embodiments and comparative examples was tested as follows.
1. A ball was used as an impact head to impact on a battery protection bottom plate of each battery pack composite protection structure, so as to simulate a working condition that a bottom of a whole vehicle is impacted by a foreign object. The ball had a diameter of 25 mm, a weight of 10 kg, impact energy of 300 J, and an impact speed of 8.5 m/s. A center point of the battery protection bottom plate and four points on the periphery were selected as impact points to impact for five times.
A dent deformation amount of a battery pack tray at each impact point was measured, and the impact point with the maximum dent deformation amount was selected and denoted as a dent deformation amount of a battery pack tray. Generally, it is required that the dent deformation amount is not greater than 3 mm with the energy impact of 300 J.
A vernier caliper was used to measure the diameter of a chalked area of the battery protection bottom plate after the battery protection bottom plate was impacted. Each single impact point was repeatedly measured for three times to determine an average value. An impact point with the largest diameter of the chalked area was selected and denoted as the chalking diameter of the fiber-reinforced resin layer being a surface layer. The chalking degree grading standard is as follows.
2. The battery pack composite protection structure was mounted on a vibration table to perform 300,000 kilometer mileage simulation vibration so as to check whether a joint was damaged after vibration and whether the battery protection bottom plate was delaminated.
300,000 kilometer mileage simulation vibration test: According to requirements of GB/T 2423.43, a test object was mounted on the vibration table, and a torque at each mounting point was tested and recorded. The vibration test was performed in three directions. For the test process, refer to GB/T 2423.56, with certain test conditions as follows.
First, random vibration was performed in a Z direction for 21 h (with random vibration conditions shown in Table 2), and then vibration was performed at a fixed frequency in the Z direction for 1 h (fixed frequency vibration conditions: fixed frequency of 24 Hz, and fixed frequency amplitude of 1 g).
Second, random vibration was performed in a Y direction for 21 h (with random vibration conditions shown in Table 2), and then vibration was performed at a fixed frequency in the Y direction for 1 h (fixed frequency vibration conditions: fixed frequency of 24 Hz, and fixed frequency amplitude of 1 g).
Furthermore, random vibration was performed in an X direction for 21 h (with random vibration conditions shown in Table 2), and then vibration was performed at a fixed frequency in the X direction for 1 h (fixed frequency vibration conditions: fixed frequency of 24 Hz, and fixed frequency amplitude of 1 g).
PSD stands for power spectral density, representing a power spectral density of vibration at a frequency. An r.m.s. value represents a comprehensive acceleration of vibration, and feeds back vibration intensity.
Obtained test results were filled in Table 3.
As can be seen from test results in Table 3, when the thickness d1 of the fiber-reinforced resin layer, the thickness d2 of the metal plate, the elongation ε2 at break of the metal plate, the tensile strength σ2 of the metal plate, the elongation ε0 at break of the fiber-reinforced resin layer, and the tensile strength σ0 of the fiber-reinforced resin layer satisfy the condition
a battery protection bottom plate with excellent impact resistance is obtained, which can prevent the fiber-reinforced resin layer on the surface of the metal plate from dropping under a long-term impact and improve corrosion resistance thereof.
The foregoing descriptions are merely some embodiments of the present disclosure, and are not to limit the present disclosure. Any modification, equivalent replacement, improvement, and the like made within the spirit and principle of the present disclosure shall fall within the protection scope of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202210612280.6 | May 2022 | CN | national |
This application is a continuation application of International Patent Application No. PCT/CN2023/096818, filed on May 29, 2023, which is based on and claims priority to and benefits of Chinese Patent Application No. 202210612280.6 filed on May 31, 2022. The entire content of all of the above-referenced applications is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/CN2023/096818 | May 2023 | WO |
| Child | 18896850 | US |
