Protective structure, battery device and electric equipment

Abstract

The invention discloses a protection structure, a battery device and electric equipment. The protection structure comprises a base body and a plurality of protection layers which are connected to the base body and arranged in the thickness direction of the base body in a stacked mode, and in the stacking direction of the protection layers, the strength of at least part of the protection layers is gradually increased. In this way, the protective layer with the strength gradually increased can improve the energy absorption and buffering capacity of the whole protective structure, so that the protective structure has higher impact resistance.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and more specifically, to a protective structure, a battery device and an electrical device. Background Art

[0002] The battery pack is one of the core components of electric vehicles. It provides the power for the vehicle to travel. However, in extreme environments, the performance and safety of the battery pack face great challenges. For example, in mountainous environments, higher requirements are placed on the impact resistance of the battery pack. The existing battery pack box has low impact resistance. External impact will directly damage the battery box and cause direct damage to the internal battery. Summary of the invention

[0003] Embodiments of the present application provide a protective structure, a battery device, and an electrical device.

[0004] The protective structure of the embodiment of the present application is used for a battery device, and the protective structure includes a substrate and a plurality of protective layers connected to the substrate and stacked along the thickness direction of the substrate. In the direction in which the protective layers are stacked, the strength of at least some of the plurality of protective layers gradually increases.

[0005] In the protective structure of the embodiment of the present application, the protective structure includes a substrate and a plurality of protective layers connected to the substrate and stacked along the thickness direction of the substrate, and in the direction of stacking the protective layers, the strength of at least some of the plurality of protective layers gradually increases. In this way, the protective layers with gradually increasing strength can improve the energy absorption and buffering capacity of the entire protective structure, so that the protective structure has a stronger impact resistance.

[0006] In certain embodiments, the strength of at least a portion of the protective layer increases linearly or nonlinearly or at intervals.

[0007] In this way, different strength increment methods can be freely selected to meet different needs and improve the application scope of the protective structure.

[0008] In certain embodiments, the total thickness of the plurality of protective layers is 2 mm to 15 mm.

[0009] In this way, the total thickness of the multiple protection layers is set within this range, and the thickness can be reduced as much as possible to make the protection structure thinner while ensuring the protection capability.

[0010] In certain embodiments, the protective layer is a polyurea coating.

[0011] In this way, polyurea coating has excellent protective effects in terms of explosion-proof, impact-resistant, anti-corrosion and waterproofing. At the same time, polyurea coating can realize the thermal insulation function as an ultra-efficient energy-saving thermal insulation material.

[0012] In certain embodiments, the protective layers have the same thickness, and the tensile strength of at least a portion of the protective layers gradually increases.

[0013] In this way, when preparing multiple protective layers on a substrate, it is only necessary to adjust the tensile strength of different protective layers. The thickness of each protective layer is consistent, making the protective layers easier to prepare.

[0014] In certain embodiments, the hardness of the at least partial protective layer gradually increases so that the strength of the at least partial protective layer gradually increases.

[0015] In this way, the hardness of at least part of the protective layer gradually increases, that is, the outermost protective layer has the strongest ability to resist the invasion of hard objects, so as to protect other internal protective layers and substrates and improve the protective capability of the protective structure.

[0016] In certain embodiments, the protective layer has a tensile strength of 2 MPa-50 MPa.

[0017] In this way, the tensile strength of the protective layer is set within this range, which can effectively improve the strength of the protective structure.

[0018] In certain embodiments, a plurality of the protective layers are sequentially formed on one side of the substrate by direct spraying.

[0019] In this way, preparing the protective layer by spraying makes the preparation process of the protective structure simpler.

[0020] In certain embodiments, the protective structure further includes an anti-corrosion layer, and the anti-corrosion layer is disposed between the substrate and the protective layer.

[0021] In this way, the anti-corrosion layer can prevent the substrate from being corroded and increase the service life of the substrate.

[0022] The battery device according to the embodiment of the present application includes a housing and the protective structure described in any one of the above embodiments, wherein the protective structure is connected to the housing or the base structure of the protective structure is a part of the housing.

[0023] In the protective structure and battery device of the embodiment of the present application, the protective structure includes a substrate and a plurality of protective layers connected to the substrate and stacked along the thickness direction of the substrate, and in the direction of stacking the protective layers, the strength of at least some of the plurality of protective layers gradually increases. In this way, the protective layers with gradually increasing strength can improve the energy absorption and buffering capacity of the entire protective structure, so that the protective structure has a stronger impact resistance.

[0024] In some embodiments, the shell includes a base plate and a frame, the base plate and the frame enclose a receiving cavity for placing a battery module, the base is constructed as the base plate, and the strength of at least part of the protective layer gradually increases in a direction away from the receiving cavity.

[0025] In this way, the bottom plate and the frame can protect the battery module inside the shell and prevent the internal battery module from being impacted and vibrated by the outside world.

[0026] In some embodiments, the protective structure is bonded to one side of the housing.

[0027] In this way, the protective structure can serve as an auxiliary means to protect the shell, thereby improving the safety performance of the battery module.

[0028] In some embodiments, the battery device further includes a protection plate, which is disposed on a side of the protection structure away from the housing.

[0029] In this way, the protective plate can be set on one side of the shell to provide protection on one side of the shell. The protective plate and the shell can clamp the protective structure therebetween from both sides, and the protective plate can resist the invasion and collision of external foreign objects.

[0030] In certain embodiments, the battery device further includes a bonding layer disposed between the protection plate and the protection structure.

[0031] In this way, the adhesive layer can make the connection between the protective structure and the shell and the protective plate more stable.

[0032] The electrical equipment of the embodiment of the present application includes the battery device described in any one of the above embodiments, or includes the protective structure described in any one of the above embodiments.

[0033] In the protective structure, battery device and electrical equipment of the embodiment of the present application, the protective structure includes a substrate and a plurality of protective layers connected to the substrate and stacked along the thickness direction of the substrate, and in the direction of stacking of the protective layers, the strength of at least some of the plurality of protective layers gradually increases. In this way, the protective layers with gradually increasing strength can improve the energy absorption and buffering capacity of the entire protective structure, so that the protective structure has a stronger impact resistance.

[0034] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0036] Figure 1 is a schematic structural diagram of a battery device according to an embodiment of the present application;

[0037] Figure 2 is another structural schematic diagram of a battery device according to an embodiment of the present application;

[0038] Figure 3 It is a module schematic diagram of the electrical equipment in the implementation mode of the present application.

[0039] Description of main component symbols:

[0040] Battery device 100;

[0041] Protective structure 10, protective layer 11, first protective layer 111, second protective layer 112, substrate 12, anti-corrosion layer 20, adhesive layer 30, shell 40, battery module 41, bottom plate 42, frame 43, accommodating cavity 44, protective plate 50, and electrical equipment 200. DETAILED DESCRIPTION

[0042] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0043] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0044] The disclosure below provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the various specific processes and examples of materials provided in the present application, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0045] See also Figure 1 and Figure 2 The protective structure 10 of the embodiment of the present application is used for a battery device 100. The protective structure 10 includes a substrate 12 and a plurality of protective layers 11 connected to the substrate 12 and stacked along the thickness direction of the substrate 12. In the direction in which the protective layers 11 are stacked, the strength of at least some of the plurality of protective layers 11 gradually increases.

[0046] In the protective structure 10 of the embodiment of the present application, the protective structure 10 includes a base 12 and a plurality of protective layers 11 connected to the base 12 and stacked along the thickness direction of the base 12. In the stacking direction of the protective layers 11, the strength of at least some of the protective layers 11 in the plurality of protective layers 11 gradually increases. In this way, the protective layers 11 with gradually increasing strength can improve the energy absorption and buffering capabilities of the entire protective structure 10, so that the protective structure 10 has a stronger impact resistance.

[0047] In the embodiment of the present application, the setting position and structural type of the substrate 12 are not limited to meet different needs. In one embodiment, the substrate 12 can be a part of the shell 40 of the battery device 100. For example, the substrate 12 can be the bottom plate 42 of the shell 40, and the protective structure 10 can be the bottom plate 42 of the shell 40 and a plurality of stacked protective layers 11 arranged on the outer surface of the bottom plate 42. In another embodiment, the substrate 12 can also be an independent structural plate or a structural layer that is the same as the protective layer 11. The protective structure 10 is connected to the shell 40 after the overall manufacturing is completed. In another embodiment, the substrate 12 can also be a part of the outer shell of the electrical device 200. For example, when the electrical device is a vehicle, the substrate 12 can be a part of the vehicle floor. In the following, the substrate 12 is a metal plate and is used as the bottom plate 42 of the shell 40 for example.

[0048] See also Figure 1 and Figure 2 In some embodiments, the strength of at least a portion of the protective layer 11 increases linearly or nonlinearly or at intervals.

[0049] In this way, different strength increasing methods can be freely selected to meet different requirements and improve the application scope of the protective structure 10.

[0050] See also Figure 1 and Figure 2 In some embodiments, the total thickness of the plurality of protective layers 11 is 2 mm to 15 mm. For example, the total thickness of the plurality of protective layers 11 may be 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, or 15 mm.

[0051] In this way, the total thickness of the plurality of protective layers 1 is set within this range, and the thickness can be reduced as much as possible to make the protective structure 10 thinner while ensuring the protective capability.

[0052] See also Figure 1 and Figure 2 In some embodiments, the protective layer 11 is a polyurea coating.

[0053] In this way, the polyurea coating has excellent protective effects in terms of explosion-proof, impact-resistant, anti-corrosion and waterproofing. At the same time, the polyurea coating can realize the thermal insulation function as an ultra-efficient energy-saving thermal insulation material.

[0054] See also Figure 1 and Figure 2 In some embodiments, the thickness of the protective layer 11 is the same, and the tensile strength of at least a portion of the protective layer 11 gradually increases.

[0055] In this way, when preparing multiple protective layers 11 on the substrate 12, it is only necessary to adjust the tensile strength of different protective layers 11. The thickness of each protective layer 11 is consistent, making the protective layers 11 easier to prepare.

[0056] See also Figure 1 and Figure 2 In some embodiments, the hardness of at least a portion of the protective layer 11 gradually increases so that the strength of at least a portion of the protective layer 11 gradually increases.

[0057] In this way, the hardness of at least part of the protective layer 11 gradually increases, that is, the outermost protective layer 11 has the strongest ability to resist the invasion of hard objects, so as to protect other internal protective layers 11 and the matrix 12 and improve the protective ability of the protective structure 10.

[0058] In addition, in the embodiments of the present application, the specific type of strength is not limited, and it is sufficient that at least part of the protective layer 11 has a gradually increasing trend to meet various requirements. For example, the gradually increasing strength of at least part of the protective layer 11 can also be one or more of compressive strength, yield strength, tensile strength, compressive strength, shear strength, bending strength and torsional strength.

[0059] See also Figure 1 and Figure 2 In some embodiments, the tensile strength of the protective layer 11 is 2 MPa-50 MPa. For example, the tensile strength of the protective layer 11 can be 2 MPa, 5 MPa, 10 MPa, 15 MPa, 20 MPa, 25 MPa, 30 MPa, 35 MPa, 40 MPa, 45 MPa, or 50 MPa.

[0060] Thus, the tensile strength of the protective layer 11 is set within this range, which can effectively improve the strength of the protective structure 10 .

[0061] See also Figure 1 and Figure 2 In some embodiments, a plurality of protective layers 11 are sequentially formed on one side of the substrate 12 by direct spraying.

[0062] Thus, preparing the protective layer 11 by spraying simplifies the preparation process of the protective structure 10. In the process of preparing the protective layer 11, it can be achieved by spraying layer by layer to facilitate the preparation of the protective structure 10.

[0063] See also Figure 1 and Figure 2 In some embodiments, the protective structure 10 further includes an anti-corrosion layer 20 , which is disposed between the substrate 12 and the protective layer 11 .

[0064] In this way, the anti-corrosion layer can prevent the substrate 12 from being corroded, thereby increasing the service life of the substrate 12 .

[0065] In the implementation manner of the present application, the specific material of the anti-corrosion layer 20 is not limited to meet different requirements. For example, the anti-corrosion layer 20 can be an epoxy primer layer.

[0066] In addition, in the embodiment of the present application, there is no limitation on the thickness and tensile strength of each protective layer 11. It is only necessary that the thickness and tensile strength of the multiple protective layers 11 have a gradually increasing trend to meet different needs.

[0067] Specifically, the tensile strength of the protective layer 11 may increase linearly or nonlinearly or at intervals. In one example, the tensile strength of the protective layer 11 may increase linearly, that is, from top to bottom in the thickness direction, the tensile strength of each protective layer 11 increases successively and in an arithmetic progression, and the bottom protective layer 11 has the highest tensile strength. In another example, the tensile strength of the protective layer 11 may increase nonlinearly, that is, from top to bottom in the thickness direction, the tensile strength of each protective layer 11 increases, but not linearly. In another example, the tensile strength of the protective layer 11 may increase at intervals, that is, from top to bottom in the thickness direction, the tensile strength may increase after one or more protective layers 11 are separated.

[0068] The protective structure 10 of the embodiment of the present application is a multifunctional gradient protective coating structure, which can spray polyurea coatings of different strengths on the bottom surface of the battery shell 40 or the surface of the protective plate 50 in sequence to form a continuous gradient protective coating. Among them, the farther away from the shell 40, the greater the strength of the protective layer 11. The polyurea coating with greater strength can absorb a large amount of energy at a high strain rate, and its inner soft polyurea coating has better deformation ability to form a buffer layer. Moreover, the gradient structure interface of different protective layers 11 can reflect a large amount of stress shock waves, thereby improving its impact protection capability. The multifunctional gradient protective structure 10 of the embodiment of the present application has multifunctional uses such as impact protection, corrosion protection, and heat preservation. Compared with the single type of polyurea coating in the prior art, the gradient protection design from hard to soft greatly improves its protective performance.

[0069] In addition, in the embodiments of the present application, there is no limitation on the number of protective layers 11 , and the number of protective layers 11 only needs to be greater than or equal to three to achieve different functions.

[0070] See also Figure 1 and Figure 2 The battery device 100 of the embodiment of the present application includes a shell 40 and a protective structure 10 of any one of the above embodiments, and the protective structure 10 is connected to the shell 40 or the base 12 of the protective structure 10 is constructed as a part of the shell 40.

[0071] In the protective structure 10 and the battery device 100 of the embodiment of the present application, the protective structure 10 includes a substrate 12 and a plurality of protective layers 11 connected to the substrate 12 and stacked along the thickness direction of the substrate 12. In the stacking direction of the protective layers 11, the strength of at least some of the protective layers 11 in the plurality of protective layers 11 gradually increases. In this way, the protective layers 11 with gradually increasing strength can improve the energy absorption and buffering capabilities of the entire protective structure 10, so that the protective structure 10 has a stronger impact resistance.

[0072] See also Figure 1 and Figure 2 In some embodiments, the shell 40 includes a bottom plate 42 and a frame 43, which enclose a receiving cavity 44 for placing the battery module 41. The substrate 12 is constructed as the bottom plate 42. In the direction away from the receiving cavity 44, the strength of at least part of the protective layer 11 gradually increases.

[0073] In this way, the bottom plate 42 and the frame 43 are arranged on the housing 40 of the battery device 100 to protect the battery module 41 inside the housing 40 and prevent the battery module 41 inside from being impacted and vibrated by the outside.

[0074] See also Figure 1 and Figure 2In some embodiments, the battery device 100 further includes a protective plate 50 , which is disposed on a side of the protective structure 10 away from the housing 40 .

[0075] In this way, the protective plate 50 can be set on one side of the shell 40 to provide protection on one side of the shell 40. The protective plate 50 and the shell 40 can clamp the protective structure 10 therebetween from both sides, and the protective plate 50 can resist the invasion and collision of external foreign objects.

[0076] See also Figure 1 and Figure 2 In some embodiments, the battery device 100 further includes a bonding layer 30 , which is disposed between the protective plate 50 and the protective structure 10 .

[0077] In this way, the adhesive layer 30 can make the connection between the protective structure 10 and the shell 40 and the protective plate 50 more stable.

[0078] See also Figure 1 and Figure 2 In some embodiments, the battery device 100 also includes an anti-corrosion layer 20 and an adhesive layer 30; the anti-corrosion layer 20 is arranged between the shell 40 and the protective structure 10, and the adhesive layer 30 is arranged between the protective plate 50 and the protective structure 10; the adhesive layer 30 is arranged between the shell 40 and the protective structure 10, and the anti-corrosion layer 20 is arranged between the protective plate 50 and the protective structure 10.

[0079] In this way, the anti-corrosion layer 20 and the bonding layer 30 can make the connection between the protective structure 10 and the shell 40 and the protective plate 50 more stable.

[0080] Please combine Figure 1 and Figure 2 ,exist Figure 1 The bottom plate 42 of the middle shell 40 may be a substrate 12, which may be used as a first metal plate. An anti-corrosion layer 20 is formed on one side of the bottom plate 42, and then a protective structure 10 is formed on the anti-corrosion layer 20. The protective plate 50 may be used as a second metal plate, and an adhesive layer 30 is formed on one side of the protective plate 50 close to the protective structure 10. Figure 2 The middle protective plate 50 can be used as the first metal plate, an anti-corrosion layer 20 is formed on one side of the protective plate 50, and then a protective structure 10 is formed on the anti-corrosion layer 20. The bottom plate 42 of the shell 40 can be used as the second metal plate, and an adhesive layer 30 is formed on the side of the bottom plate 42 of the shell 40 close to the protective structure 10.

[0081] In the embodiment of the present application, one of the first metal plate and the second metal plate can be used as the shell 40 of the battery device 100, and the other can be used as the protective plate 50, that is, the protective structure 10 is arranged between the shell 40 and the protective plate 50. In this way, forming the protective structure 10 on the first metal plate can be to sequentially form the protective layer 11 on the shell 40, or to sequentially form the protective layer 11 on the protective plate 50. Compared with the prior art in which the polyurea coating is directly sprayed on the surface of the battery shell 40, the gradient protective structure 10 in the embodiment of the present application can be formed from the protective plate 50 or from the shell 40, and the preparation means are more abundant.

[0082] Exemplarily, the battery device 100 can be a battery pack of a vehicle, and the battery pack is composed of a battery module 41 and a shell 40 from the inside to the outside, and the battery pack is composed of a shell 40, a protective structure 10 and a protective plate 50 from top to bottom to cope with the hazards on the ground. In this way, the protective structure 10 can act as a buffer layer to absorb external shocks and vibrations, and can also act as a thermal insulation layer to protect the temperature of the battery module 41 inside the shell 40. At the same time, the outermost protective plate 50 can form the first line of defense to resist the invasion and collision of external foreign objects.

[0083] It should be noted that one of the first metal plate and the second metal plate is the shell 40, and the other is the protective plate 50. Among the multiple polyurea coatings, the polyurea coating close to the protective plate 50 has a high hardness, and the polyurea coating close to the shell 40 has a low hardness, so as to form a gradient protective coating from hard to soft.

[0084] Optionally, the high-strength polyurea coating includes any one of polyurea elastomer monomers or carbon nanotubes, graphene, and nano-ceramic particle reinforced composite polyurea elastomers. In this way, the strength of the protective structure 10 can be improved, and the impact on the interior of the protective structure 10 can be avoided.

[0085] Optionally, the thickness of the gradient protective coating is between 2 mm and 12 mm, and the gradient structure is composed of at least three layers of polyurea coatings of different strength types, each layer has an equal thickness, and the thickness of a single layer is equal to the total thickness divided by the number of layers laid. In this way, the thickness of each layer of polyurea coating is uniform, which is conducive to the preparation of the polyurea coating.

[0086] Optionally, the strength distribution of each layer of polyurea coating can be linear, nonlinear, or incremental. The strength difference between each layer of polyurea coating is equal, or the strength difference between each layer of polyurea coating increases exponentially. In this way, the strength of adjacent layers of polyurea coating increases according to a certain setting, which can effectively improve the protection capability. At the same time, the strength difference can be set according to different standards to cope with different usage scenarios.

[0087] Optionally, the anti-corrosion layer 20 and the gradient protective coating may be sprayed on one of the surface of the shell 40 and the protective plate 50, and a thin layer of adhesive may be sprayed on the other surface of the surface of the shell 40 and the protective plate 50. The adhesive includes at least one of epoxy resin, polyurethane, polyvinyl acetal, and polyvinyl acetate. In this way, the preparation efficiency of the protective structure 10 can be improved.

[0088] Optionally, the thickness of the primer is between 0.1 mm and 0.5 mm. Thus, the primer is set at this thickness, which can make the protective structure 10 thinner and lighter while ensuring normal use.

[0089] Optionally, the protective plate 50 is made of any one of aluminum, steel, titanium, and magnesium, and the thickness of the protective plate 50 is between 0.5 mm and 2 mm. Thus, the thickness of the protective plate 50 is set within this range, which can have better protection capability and make the protective plate 50 thinner.

[0090] Specifically, the protective structure 10 of the present application integrates impact protection, corrosion protection, heat preservation and other multifunctional uses through the gradient protective coating, and no longer needs to add additional materials to achieve independent functions, making it more integrated. Under the premise of the same protection capability, compared with the polyurea coating of a single structure, the thickness required for the gradient protective coating is smaller, which increases the utilization space of the battery pack in the vehicle height direction, can accommodate more battery modules 41, increase the battery pack charge, and increase the cruising range of the new energy car wash.

[0091] Furthermore, multiple layers of protection are arranged outside the battery shell 40. First, the outermost metal plate has the characteristics of high hardness and anti-puncture. At the same time, there is a gradient protective coating from hard to soft between the shell 40 and the protective plate 50. In particular, the surface of the protective plate 50 has a higher strength polyurea coating, which enables it to absorb a large amount of energy under high strain rates. The inner layer of low-strength polyurea coating has better deformation ability and forms a buffer layer. At the same time, the gradient structure interface can reflect a large amount of stress shock waves, thereby improving its impact protection ability and explosion resistance, thereby protecting the battery module 41 from damage in extremely harsh environments.

[0092] The protective plate 50 used in the following examples is 1mm high-strength hot-formed steel, and the battery housing 40 is made of 1.5mm high-strength aluminum alloy. All implementation cases adopt the bottom impact condition, in which the mass of the extruded ball head is 5Kg and the impact energy is 300J. The test conditions refer to the 2022 version of the "Electric Vehicle Safety Guidelines" compiled by the China Association of Automobile Manufacturers, China Automotive Power Battery Battery Industry Innovation Alliance and China Electric Vehicle Charging Infrastructure Promotion Alliance.

[0093] Exemplarily, please refer to Table 1, take the shell 40 of the battery box as an example, and perform a deformation deflection test on the shell 40. In Example 1, three raw materials for preparing polyurea with tensile strengths of 5MPa, 15MPa and 25MPa, 1mm thick high-strength hot-formed steel, 1.5mm thick aluminum alloy battery shell 40 and battery module 41 assembly are selected respectively. Grind the surface of the steel plate clean before spraying, then spray 0.2mm epoxy primer, and continue to spray the polyurea coating with a tensile strength of 25MPa after drying. Stop spraying after spraying to 2mm, spray the polyurea coating with a tensile strength of 15MPa again after curing, stop spraying after spraying to 2mm, and continue to spray the polyurea coating with a tensile strength of 5MPa after curing. Similarly, stop spraying after 2mm. After curing, a gradient protective coating with strength from high to low can be obtained. The total thickness of the protective structure 10 is 6mm. Adhesive is brushed on the outer surface of the battery shell 40 and bonded to the above-sprayed gradient protective coating, ultimately obtaining a battery pack with a multifunctional gradient protective coating structure.

[0094] In Example 2, the gradient protective coating is still 3 layers, the strength of the polyurea coating is nonlinearly distributed, and three raw materials for preparing polyurea with tensile strengths of 5 MPa, 20 MPa and 25 MPa are selected. The remaining conditions and preparation methods are the same as those in Example 1.

[0095] In Comparative Example 1, no gradient protective coating was used, and only 1 mm thick high-strength hot-formed steel was retained, that is, a 6 mm hollow structure was formed between the steel plate and the battery housing 40 .

[0096] In Comparative Example 2, a single type of polyurea coating was used, and its tensile strength was 15 MPa.

[0097] In Example 3, four raw materials for preparing polyurea with tensile strengths of 5 MPa, 15 MPa, 25 MPa and 35 MPa were selected, and four types of polyurea coatings were used to form a gradient protective coating. Polyurea coatings from hard to soft were sprayed on the surface of the steel plate in sequence, and the thickness of each layer of polyurea coating was 1.5 mm, and the total thickness of the protective structure 10 was 6 mm. The remaining conditions and preparation methods were the same as those in Example 1.

[0098] In Example 4, four raw materials for preparing polyurea with tensile strengths of 5 MPa, 15 MPa, 25 MPa and 35 MPa were selected, and four types of polyurea coatings were used to form a gradient protective coating. Polyurea coatings from hard to soft were sprayed on the surface of the steel plate in sequence, and the thickness of each layer of polyurea coating increased by 2 mm, and the total thickness of the protective structure 10 was 8 mm. The remaining conditions and preparation methods were the same as those in Example 1.

[0099] Table 1

[0100] name Shell deformation deflection / mm Example 1 3.7 Example 2 3.5 Comparative Example 1 5 Comparative Example 2 4.2 Example 3 3.2 Example 4 2.8

[0101] It can be seen from Table 1 that compared with Comparative Example 1, when a single or gradient protective coating is added between the protective plate 50 and the battery shell 40, the deformation deflection of the battery shell 40 is significantly reduced, indicating that its impact resistance is significantly improved and the damage to the battery module 41 is lower.

[0102] Compared with the single protective coating in Comparative Example 2, the deflection of the battery shell 40 of the battery pack with gradient protective coating in Example 1 and Example 2 is reduced from 4.2mm to 3.7 and 3.5mm under 300J energy impact, indicating that the gradient protective coating can consume higher energy when facing impact. The energy consumption of the gradient protective coating in Example 2 reaches 80J, which is much higher than the energy consumption of 50J for single protection.

[0103] Comparing Example 1 with Example 3, it is found that under the condition of equal total thickness, as the number of polyurea layers or interfaces in the gradient protective coating increases, the deformation deflection of the battery casing 40 decreases from 3.7 mm to 3.2 mm, and its protective capability is significantly improved.

[0104] Comparing Example 3 with Example 4, it is found that as the thickness of the gradient protective coating increases, the deformation deflection of the battery casing 40 decreases from 3.2 mm to 2.8 mm, and its protective capability is also significantly improved.

[0105] The above examples and comparative examples show that when the battery pack with this multifunctional protective coating faces bumps or collisions with foreign objects, the deformation of the battery shell 40 is significantly reduced, and it has more excellent protection performance, reducing the risk of battery pack loss of control. In addition, in the embodiments of the present application, the specific material of the protective layer 11 is not limited to meet different needs. The design concept of the present application is a gradient protective coating structure, that is, a structural design with high to low strength or hardness. In addition to the polyurea coating used in the gradient protective coating in this application, if other superelastic polymer materials, such as rubber, are used, the effect achieved by this patent can also be achieved.

[0106] See also Figure 3 The electric device 200 of the embodiment of the present application includes the battery device 100 of any one of the above embodiments, or includes the protective structure 10 of any one of the above embodiments.

[0107] In the protective structure 10, the battery device 100 and the electrical equipment 200 of the embodiment of the present application, the protective structure 10 includes a substrate 12 and a plurality of protective layers 11 connected to the substrate 12 and stacked along the thickness direction of the substrate 12. In the stacking direction of the protective layers 11, the strength of at least some of the protective layers 11 in the plurality of protective layers 11 gradually increases. In this way, the protective layers 11 with gradually increasing strength can improve the energy absorption and buffering capacity of the entire protective structure 10, so that the protective structure 10 has a stronger impact resistance.

[0108] In the embodiments of the present application, the specific type of the electric device 200 is not limited to meet various requirements. For example, the electric device 200 may be a vehicle, and the battery device 100 may be a battery pack of the vehicle. In this case, the protective structure 10 and the protective plate 50 may be sequentially arranged on the lower side of the battery pack to cope with the impact of various debris on the ground.

[0109] The manufacturing method of the protective structure 10 of the embodiment of the present application is used to prepare the protective structure 10 of any one of the above embodiments. The manufacturing method of the protective structure 10 includes:

[0110] 01, providing a first metal plate;

[0111] 02, forming an anti-corrosion layer 20 on one side of the first metal plate;

[0112] 03, forming a first protective layer 111 on a side of the anti-corrosion layer 20 away from the first metal plate;

[0113] 04, forming a second protective layer 112 on a side of the first protective layer 111 away from the anti-corrosion layer 20;

[0114] 05, forming one or more protective layers 11 on a side of the second protective layer 112 away from the first protective layer 111;

[0115] 06. Providing a second metal plate;

[0116] 07, forming a bonding layer 30 on a side of the second metal plate close to the protective layer 11;

[0117] 08. Tightly bond the adhesive layer to the protective layer 11, wherein the adhesive layer is connected to a protective layer 11 farthest from the first metal plate.

[0118] In the manufacturing method of the protective structure 10 of the embodiment of the present application, the steps for applying the protective structure 10 to the battery pack are as follows: In step 01, a first metal plate is provided, and the first metal plate is polished clean to be free of impurities and the like. Then, step 02 is performed, and epoxy primer is sprayed on the polished side, and the epoxy primer is dried to form an epoxy primer layer. Spray the first layer of polyurea coating, and wait for the first layer of polyurea coating to dry. Then, a second layer of polyurea coating is formed on the side of the first layer of polyurea coating away from the anti-corrosion layer 20, and wait for the second layer of polyurea coating to dry. By analogy, a multi-layer polyurea coating can be formed, and only the number of polyurea coatings needs to be greater than or equal to three layers. Then, a second metal plate is provided, and an adhesive layer 30 is formed on the side of the second metal plate close to the protective layer 11, and the adhesive layer is tightly combined with the protective layer 11, wherein the adhesive layer is connected to a protective layer 11 farthest from the first metal plate.

[0119] In the description of the embodiments of the present application, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0120] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0121] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A protective structure, characterized in that: The protective structure is used for a battery device, and includes a substrate and a plurality of protective layers connected to the substrate and stacked along the thickness direction of the substrate. In the direction in which the protective layers are stacked, the strength of at least some of the plurality of protective layers gradually increases.

2. The protective structure according to claim 1, characterized in that: The strength of at least part of the protective layer increases linearly or nonlinearly or at intervals.

3. The protective structure according to claim 1, characterized in that: The total thickness of the plurality of protective layers is 2 mm to 15 mm.

4. The protective structure according to claim 1, characterized in that: The protective layer is a polyurea coating.

5. The protective structure according to claim 1, characterized in that: The thickness of the protective layer is the same, and the tensile strength of at least part of the protective layer gradually increases.

6. The protective structure according to claim 1, characterized in that: The hardness of at least part of the protective layer gradually increases so that the strength of at least part of the protective layer gradually increases.

7. The protective structure according to claim 5, characterized in that: The tensile strength of the protective layer is 2MPa-50MPa.

8. The protective structure according to claim 1, characterized in that: The plurality of protective layers are sequentially formed on one side of the substrate by direct spraying.

9. The protective structure according to claim 1, characterized in that: The protective structure further comprises an anti-corrosion layer, and the anti-corrosion layer is arranged between the substrate and the protective layer.

10. A battery device, characterized in that: It comprises a shell and the protective structure according to any one of claims 1 to 9, wherein the protective structure is connected to the shell or the base structure of the protective structure is a part of the shell.

11. The battery device according to claim 10, characterized in that: The shell includes a bottom plate and a frame, the bottom plate and the frame enclose a receiving cavity, the receiving cavity is used to place the battery module, the base is constructed as the bottom plate, and the strength of at least part of the protective layer gradually increases in a direction away from the receiving cavity.

12. The battery device according to claim 10, characterized in that: The protective structure is bonded to one side of the shell.

13. The battery device according to any one of claims 10 to 12, characterized in that: The battery device further includes a protection plate, which is arranged on a side of the protection structure away from the housing.

14. The battery device according to claim 13, characterized in that: The battery device further includes an adhesive layer disposed between the protection plate and the protection structure.

15. An electrical equipment, characterized in that: A battery device comprising any one of claims 10 to 14, or a protective structure comprising any one of claims 1 to 9.

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