Electricity using device, battery device, guard plate, and production method thereof

Abstract

The application provides a kind of electric device, battery device, protective plate and its production method, the production method of protective plate includes: providing the blank of nickel austenitic stainless steel material, the mass content of carbon in blank is 0.07%~0.12%; the blank is carried out hot rolling process;The blank after hot rolling is carried out cold rolling process, and the steel plate with target thickness is obtained;The steel plate is carried out cold stamping process.The production method of protective plate provided in the embodiment of the application is beneficial to reduce the risk of cracking or deformation of protective plate under the action of external load, and is beneficial to improve the reliability of protective plate.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to an electrical device, a battery device, a protective plate, and a method for manufacturing the same. Background Technology

[0002] Battery devices are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools, etc.

[0003] Protective plates can provide a certain degree of protection for battery cells and other structural components of battery devices. During use, these plates are inevitably subjected to loads such as vibration and impact. Improving the reliability of protective plates is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] This application provides an electrical device, a battery device, a protective plate, and a method for manufacturing the same, which helps to improve the reliability of the protective plate.

[0005] This application is achieved through the following technical solution:

[0006] In a first aspect, the production method of the protective plate provided in the embodiments of this application is used for a battery device. The production method of the protective plate includes: providing a billet of nickel-saving austenitic stainless steel, wherein the carbon content in the billet is 0.07% to 0.12% by mass; performing a hot rolling process on the billet; performing a cold rolling process on the hot-rolled billet to obtain a steel plate with a target thickness; and performing a cold stamping process on the steel plate.

[0007] The protective plate production method provided in this application uses nickel-saving austenitic stainless steel billets, and the carbon content in the billets is 0.07% to 0.12%. This results in protective plates with high tensile strength and yield strength, as well as high elongation after fracture. This helps reduce the risk of cracking or deformation of the protective plates under external loads and improves the reliability of the protective plates.

[0008] According to some embodiments of this application, during the cold rolling process of hot-rolled billets, rolls are used to cold roll the billets, and the surface roughness Ra of the rolls satisfies: 0.05μm≤Ra≤0.5μm.

[0009] In the above scheme, by setting the surface roughness Ra of the roll to satisfy: 0.05μm≤Ra≤0.5μm, it is easy to form a steel plate with the corresponding surface roughness, which is beneficial to improving the structural strength of the steel plate itself, as well as the bonding strength between the steel plate and the fiber resin layer.

[0010] According to some embodiments of this application, the surface roughness Ra of the roll satisfies: 0.1μm≤Ra≤0.4μm.

[0011] In the above scheme, by setting the surface roughness Ra of the roll to satisfy: 0.05μm≤Ra≤0.5μm, it is easy to form a steel plate with the corresponding surface roughness. This is beneficial to further improve the structural strength of the steel plate itself, and also to further improve the bonding strength between the steel plate and the fiber resin layer.

[0012] According to some embodiments of this application, before the steel plate is subjected to a cold stamping process, the method for manufacturing the protective plate further includes: annealing the cold-rolled steel plate.

[0013] In the above scheme, after the steel plate undergoes annealing, its hardness and residual stress are reduced, deformation and cracking tendency are decreased, and its machinability is improved, facilitating subsequent cold stamping processes. Furthermore, annealing increases the elongation after fracture of the steel plate, which helps to further reduce the risk of fracture of the protective plate under external loads.

[0014] According to some embodiments of this application, annealing of cold-rolled steel sheets includes: heating the steel sheet at a temperature of 850°C to 1050°C and holding it for 5 min to 15 min.

[0015] In the above scheme, by setting the heating temperature to 850℃~1050℃ and the holding time to 5min~15min, it is beneficial to further improve the elongation after fracture of the steel plate, thereby increasing the risk of the protective plate breaking under external load.

[0016] According to some embodiments of this application, the heating temperature is 900°C to 950°C.

[0017] In the above scheme, setting the heating temperature to 900℃~950℃ is beneficial to further improve the elongation after fracture of the steel plate, thereby increasing the risk of the protective plate breaking under external load.

[0018] According to some embodiments of this application, after heating the steel plate, the process further includes cooling the heated steel plate in air or water.

[0019] In the above solutions, water cooling or air cooling is simple to operate, low in cost, and the cooled steel plate has better hardness and strength. This not only improves the post-fracture productivity of the protective plate and reduces the risk of the protective plate breaking, but also helps to reduce the risk of deformation of the protective plate under external loads.

[0020] According to some embodiments of this application, annealing of cold-rolled steel sheets includes: annealing the steel sheets in an annealing furnace, wherein the protective gas in the annealing furnace is nitrogen or argon, and the dew point temperature of the protective gas is -50°C to -20°C.

[0021] The above scheme helps to reduce the risk of steel plates being damaged or corroded during the annealing process and enables the steel plates to maintain a relatively stable surface roughness.

[0022] According to some embodiments of this application, a cold rolling process is performed on the hot-rolled billet, including: cold rolling the billet when the work hardening rate n satisfies 15% ≤ n ≤ 25%, wherein n = (h1 - h2) / h1, where h1 is the thickness of the billet before cold rolling, and h2 is the target thickness.

[0023] In the above scheme, by controlling the work hardening rate during the cold rolling process to 15%≤n≤25%, it is beneficial to improve the tensile strength and yield strength of the produced protective plate, and further beneficial to reduce the risk of deformation of the protective plate under external impact, vibration and other loads.

[0024] According to some embodiments of this application, before the hot-rolled billet is subjected to a cold rolling process, the production method of the protective plate further includes: if the work hardening rate n cannot meet 15%≤n≤25%, the hot-rolled billet is subjected to a cold rolling process until the thickness h3 of the billet meets: 15%≤(h3-h2) / h3≤25%; and the cold-rolled billet is subjected to annealing treatment.

[0025] In the above scheme, when n cannot satisfy 15% ≤ n ≤ 25%, the hot-rolled billet needs to be cold-rolled first until the billet thickness meets the work hardening rate requirement of 15% ≤ n ≤ 25%. Then, the cold-rolled billet that meets the work hardening rate requirement is annealed to put the material in an annealed state. Then, the annealed billet is cold-rolled again, thus achieving the goal of ensuring n satisfies 15% ≤ n ≤ 25% during the cold rolling process, thereby improving the tensile strength and yield strength of the protective plate.

[0026] According to some embodiments of this application, when the work hardening rate n satisfies 15% ≤ n ≤ 25%, a cold rolling process is performed on the billet, including: performing a first cold rolling process on the billet to obtain a billet with a thickness greater than the target thickness; and performing at least one cold rolling process on the billet to obtain a steel plate with the target thickness.

[0027] In the above scheme, the billet undergoes at least two cold rolling processes during cold rolling. This allows for more precise control of the thickness of the cold-rolled steel plate and further reduces residual stress in the steel plate, thereby improving the performance stability of the steel plate.

[0028] According to some embodiments of this application, the first cold rolling process of the steel plate includes: performing a first cold rolling process on the billet until the thickness of the billet is 1.8 mm to 2.2 mm greater than the target thickness.

[0029] In the above scheme, the thickness of the billet after the first cold rolling process is 1.8mm to 2.2mm greater than the target thickness, so as to reserve processing allowance for at least one subsequent cold rolling process. This is beneficial to more accurately control the thickness of the cold-rolled steel plate and further improve the performance stability of the steel plate.

[0030] According to some embodiments of this application, before the steel plate is cold stamped, the production method of the protective plate further includes: sequentially performing pickling and finishing processes on the steel plate.

[0031] In the above scheme, before cold stamping the steel plate, impurities on the surface of the steel plate are removed and the steel plate is preliminarily shaped, which helps to improve the controllability of the shape of the produced protective plate and helps to reduce the risk of corrosion of the protective plate.

[0032] According to some embodiments of this application, after the steel plate is cold stamped, the production method of the protective plate further includes: sequentially performing laser processing and electrophoretic processing on the steel plate; and spraying a protective layer on the surface of the electrophoretically processed steel plate.

[0033] In the above scheme, laser processing can create structures such as mounting holes, while electrophoresis can provide a certain surface protection for the protective plate. After electrophoresis, a protective layer is sprayed onto the surface of the steel plate, which further reduces the risk of the protective plate being corroded by contact with water and oxygen in the air.

[0034] According to some embodiments of this application, after cold stamping the steel plate, the production method of the protective plate further includes: laying a fiber resin layer on at least one side of the steel plate along the thickness direction; performing a hot pressing process on the steel plate and the fiber resin layer, so that the steel plate and the fiber resin layer are connected to form a protective plate.

[0035] In the above scheme, by laying a fiber resin layer on at least one side of the steel plate along the thickness direction, the fiber resin layer can provide a certain protective effect on the steel plate and reduce the risk of corrosion of the steel plate. The bonding strength between the fiber resin layer and the steel plate is improved by hot pressing process.

[0036] According to some embodiments of this application, before providing the billet of nickel-saving austenitic stainless steel, the production method of the protective plate further includes: melting steel raw materials to obtain liquid steel; refining the molten steel in a converter; and casting the refined molten steel to obtain the billet of nickel-saving austenitic stainless steel. The mass percentages of each component in the billet are as follows: silicon: 0.3% to 1%, manganese: 8% to 12%, nickel: 0 to 2%, chromium: 12.5% ​​to 16%, and copper: 0 to 1.5%.

[0037] In the above scheme, refining austenitic stainless steel billets helps to reduce the production cost of protective plates and the transportation cost of raw materials during the production process, resulting in higher economic benefits.

[0038] According to some embodiments of this application, before the molten steel is refined in a converter, the method for producing the protective plate further includes adding silicon, manganese, nickel, chromium or copper to the molten steel so that the mass percentages of each component in the molten steel are as follows: silicon: 0.3% to 1%, manganese: 8% to 12%, nickel: 0 to 2%, chromium: 12.5% ​​to 16%, and copper: 0 to 1.5%.

[0039] In the above scheme, silicon, manganese, nickel, chromium or copper are added to molten steel to adjust the composition of each element in the molten steel, thereby improving the smelting efficiency of nickel-saving austenitic stainless steel billets.

[0040] Secondly, the protective plate provided in this application embodiment is manufactured using the production method of the protective plate provided in any of the above embodiments.

[0041] The protective plate provided in this application is manufactured using the production method of the protective plate provided in any of the above embodiments, and therefore has the same technical effect, which will not be repeated here.

[0042] Thirdly, the battery device provided in the embodiments of this application includes a housing, a battery cell, and a protective plate provided in the above embodiments, with the protective plate connected to the housing.

[0043] The battery device provided in this application embodiment has the same technical effect as the protective plate provided in the above embodiment, and will not be described again here.

[0044] Fourthly, the electrical device provided in the embodiments of this application includes the battery device provided in the above embodiments, and the battery device is used to provide electrical energy.

[0045] The power supply device provided in this application embodiment has the same technical effect as the battery device provided in the above embodiment, and will not be described again here.

[0046] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0047] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 This is a schematic diagram of the vehicle structure provided in an embodiment of this application;

[0049] Figure 2 This is a schematic diagram of the structure of the battery device provided in the embodiments of this application;

[0050] Figure 3 A cross-sectional view of the protective plate provided in an embodiment of this application;

[0051] Figure 4 A flowchart illustrating a method for producing a protective plate, as provided in this application embodiment;

[0052] Figure 5 A flowchart illustrating another method for producing a protective plate provided in this application embodiment;

[0053] Figure 6 A flowchart illustrating another method for producing a protective plate, as provided in this application embodiment.

[0054] The accompanying drawings are not necessarily drawn to scale.

[0055] Explanation of reference numerals in the attached figures:

[0056] 1-Vehicle; 1a-Motor; 1b-Controller;

[0057] 10 - Battery assembly; 11 - Housing; 111 - First sub-housing; 112 - Second sub-housing;

[0058] 20 - Protective plate; 21 - Steel plate; 22 - Fiber resin layer;

[0059] 30-cell battery. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0061] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0062] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0063] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0064] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0065] In this application, "multiple" refers to two or more (including two), and similarly, "multiple groups" refers to two or more (including two), and "multiple pieces" refers to two or more (including two).

[0066] The battery apparatus mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells connected in series, parallel, or mixed connections via a busbar.

[0067] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form a single module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0068] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cells housed within the housing.

[0069] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0070] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0071] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0072] In some embodiments, the battery device may be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0073] Battery devices typically include a housing and a protective plate. The housing houses the individual battery cells and related components such as the battery management system, while the protective plate is connected to the bottom of the housing to protect the individual battery cells and related components inside the housing. This reduces the risk of external impurities entering the housing and corroding the individual battery cells and related components, and also reduces the risk of external impacts or vibrations being transmitted to the individual battery cells and causing damage.

[0074] In related technologies, protective plates are prone to cracking or deformation under external impacts, vibrations, and other loads during use, which seriously affects their reliability.

[0075] In view of this, the production method of the protective plate provided in the embodiments of this application includes: providing a billet of nickel-saving austenitic stainless steel, wherein the carbon content in the billet is 0.07% to 0.12% by mass; performing a hot rolling process on the billet; performing a cold rolling process on the hot-rolled billet to obtain a steel plate with a target thickness; and performing a cold stamping process on the steel plate.

[0076] The production method of the protective plate provided in this application uses a nickel-saving austenitic stainless steel billet with a carbon content of 0.7% to 0.12% by mass. This results in a protective plate with high tensile strength and yield strength, as well as high elongation after fracture. This helps reduce the risk of cracking or deformation of the protective plate under external loads and improves the reliability of the protective plate.

[0077] The technical solutions described in the embodiments of this application are applicable to protective plates and their production methods, battery packs, and electrical devices using battery devices.

[0078] The battery device disclosed in this application can be used, but is not limited to, in electrical devices such as vehicles, ships, or aircraft. A power system for such an electrical device can be constructed using the battery device disclosed in this application.

[0079] This application provides an electrical device that uses a battery as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric bicycles, electric motorcycles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0080] For ease of explanation, the following embodiments will be described using a vehicle 1 as an example of an electrical device according to an embodiment of this application.

[0081] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1 provided in an embodiment of this application. Vehicle 1 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 10 is installed inside vehicle 1, and the battery device 10 can be located at the bottom, front, or rear of vehicle 1. The battery device 10 can be used to power vehicle 1; for example, the battery device 10 can serve as the operating power source for vehicle 1's electrical system, such as meeting the power requirements for starting, navigation, and operation of vehicle 1.

[0082] The vehicle 1 may also include a controller 1b and a motor 1a. The controller 1b is used to control the battery device 10 to supply power to the motor 1a, for example, for the power needs of the vehicle 1 during starting, navigation and driving.

[0083] In some embodiments of this application, the battery device 10 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0084] Please refer to Figure 2 , Figure 2 This is a schematic diagram of the structure of a battery device 10 provided in an embodiment of this application. The battery device 10 includes a housing 11 and a battery cell 30, with the battery cell 30 housed within the housing 11. The housing 11 provides a space for accommodating the battery cell 30, and the housing 11 can adopt various structures. In some embodiments, the housing 11 may include a first sub-housing 111 and a second sub-housing 112, which overlap each other, and together define a space for accommodating the battery cell 30. The second sub-box 112 can be a hollow structure with one end open, and the first sub-box 111 can be a plate-like structure. The first sub-box 111 covers the opening side of the second sub-box 112 so that the first sub-box 111 and the second sub-box 112 together define the accommodating space. Alternatively, the first sub-box 111 and the second sub-box 112 can both be hollow structures with one side open, and the opening side of the first sub-box 111 covers the opening side of the second sub-box 112.

[0085] In the battery device 10, there can be multiple battery cells 30, which can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 30 are connected in both series and parallel connections. Multiple battery cells 30 can be directly connected in series, parallel, or in a mixed configuration, and then the entire assembly of the multiple battery cells 30 is housed within the housing 11. Alternatively, the battery device 10 can also consist of multiple battery cells 30 first connected in series, parallel, or in a mixed configuration to form a battery cell assembly, and then these battery cell assemblies are connected in series, parallel, or in a mixed configuration to form a whole, which is then housed within the housing 11. The battery device 10 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 30.

[0086] Among them, the battery cell 30 can be a secondary battery or a primary battery; the battery cell 30 can also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited to these.

[0087] Firstly, such as Figure 2 , Figure 3 and Figure 4As shown, in the method for producing the protective plate provided in this application embodiment, the protective plate 20 is used in the battery device 10, and the method for producing the protective plate includes:

[0088] S10. Provides nickel-saving austenitic stainless steel billets, with a carbon content of 0.07% to 0.12% by mass.

[0089] S20. Hot rolling process is performed on the billet.

[0090] S30. The hot-rolled billet is subjected to a cold rolling process to obtain a steel plate 21 with the target thickness.

[0091] S40. The steel plate 21 is subjected to cold stamping process.

[0092] In step S10, a billet of nickel-saving austenitic stainless steel is provided. The billet can be produced in the process preceding step S10, or it can be obtained through procurement. Nickel-saving austenitic stainless steel reduces the amount of precious metals such as nickel while increasing the content of elements such as manganese and nitrogen. It also possesses excellent mechanical properties, certain corrosion resistance, and high heat resistance. Using nickel-saving austenitic stainless steel as raw material for the protective plate 20 helps to reduce the production cost of the protective plate 20 while ensuring it possesses excellent mechanical properties.

[0093] Specifically, the carbon content in the nickel-saving austenitic stainless steel is 0.07% to 0.12% by mass. Optionally, the billet may also contain elements such as silicon, manganese, nickel, chromium and copper, with the following mass contents: silicon: 0.3% to 1%, manganese: 8% to 12%, nickel: 0 to 2%, chromium: 12.5% ​​to 16%, copper: 0 to 1.5%, and other elements may be iron.

[0094] Optionally, the carbon content in the billet can be 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, or 0.12%, etc.

[0095] In step S20, the billet undergoes hot rolling, which includes heating, rough rolling, and finish rolling. Hot rolling reduces energy consumption during billet deformation and breaks down larger grains that were present during casting, allowing cracks to heal and reducing or eliminating casting defects. It also transforms the as-cast structure into a deformed structure, improving the billet's machinability and preparing it for subsequent protective component production.

[0096] In step S30, during the cold rolling process of the hot-rolled billet, the billet can undergo one or more cold rolling passes to roll the hot-rolled billet into a steel plate 21 with the target thickness. During the cold rolling process, the grains in the billet are elongated or flattened, and the grains are crushed, allowing the cracks in the billet to heal further. The rolling force can be controlled to ensure that the final steel plate 21 has the target thickness.

[0097] After step S30, the steel plate 21 with the target thickness has good tensile strength and yield strength, and good elongation, so as to facilitate the subsequent cold stamping process of the steel plate 21.

[0098] In step S40, the steel plate 21 is cold-stamped to achieve the required deformation, ultimately forming the structural shape of the protective plate 20. The cold-stamping process is simple and easy to control the final product morphology of the protective plate 20.

[0099] The carbon content in nickel-saving austenitic stainless steel has a significant impact on the mechanical properties of the final protective plate 20. Specifically, the lower the carbon content in the billet, the better the toughness of the protective plate 20 and the less likely it is to crack. Conversely, the higher the carbon content in the billet, the higher the strength of the protective plate 20 and the easier it is for the protective plate 20 to absorb more external impacts, vibrations, and other loads.

[0100] To this end, the inventors used nickel-saving austenitic stainless steel with different carbon content as raw materials and used the same processing technology to process protective plates 20. The effect of carbon content in the billet on the mechanical properties of the produced protective plates 20 is shown in Table 1 below. It should be noted that for different billets, only the carbon content of T is changed, while the carbon content of other trace elements or heavy metal elements remains unchanged.

[0101] Table 1. Effect of carbon content in nickel austenitic stainless steel billets on protective plate 20

[0102]

[0103]

[0104] As shown in Table 4 above, in the comparative examples where the carbon content in the billet is less than 0.07%, the protective plate 20 has lower tensile strength and yield strength, making it prone to deformation during use. In the comparative examples where the carbon content in the billet is greater than 0.12%, the protective plate 20 has lower elongation after fracture, increasing the risk of deformation during use.

[0105] Only in embodiments where the carbon content in the billet is between 0.07% and 0.12% by mass, the protective plate 20 has suitable tensile strength, yield strength, and elongation after fracture, and is not prone to breakage or deformation under external loads.

[0106] The production method of the protective plate provided in this application uses a nickel-saving austenitic stainless steel billet with a carbon content of 0.07% to 0.12%, which makes the produced protective plate 20 have high tensile strength and yield strength, as well as high elongation after fracture. This helps to reduce the risk of cracking or deformation of the protective plate 20 under external load, and improves the reliability of the protective plate 20.

[0107] In some embodiments, during the cold rolling process of the hot-rolled billet in S30, the billet is cold-rolled using rolls, and the surface roughness Ra of the rolls satisfies: 0.05μm≤Ra≤0.5μm.

[0108] Optionally, Ra can be 0.05μm, 0.1μm, 0.15μm, 0.2μm, 0.25μm, 0.3μm, 0.35μm, 0.4μm, 0.45μm or 0.5μm, etc.

[0109] It is understandable that during the cold rolling process of the billet using rolls, the rolls exert extrusion force on the surface of the billet, and the surface roughness of the rolls will be reflected on the formed steel plate 21.

[0110] In related technologies, it is usually necessary to combine steel billets with fiber resin composites in order to provide a certain degree of corrosion protection to steel plate 21 through the fiber resin composites.

[0111] After systematic analysis and long-term practice, the inventors discovered that when the surface roughness of the steel plate 21 is between 0.05μm and 0.5μm, the steel plate 21 and the fiber resin layer 22 have good bonding strength and good rigidity.

[0112] Therefore, by setting the surface roughness Ra of the roll to satisfy: 0.05μm≤Ra≤0.5μm, it is convenient to form a steel plate 21 with the corresponding surface roughness. This is beneficial to improving the structural strength of the steel plate 21 itself, as well as the bonding strength between the steel plate 21 and the fiber resin layer 22.

[0113] In some embodiments, the surface roughness Ra of the roll satisfies: 0.1 μm ≤ Ra ≤ 0.4 μm.

[0114] Optionally, Ra can be 0.1μm, 0.15μm, 0.2μm, 0.25μm, 0.3μm, 0.35μm, or 0.4μm, etc.

[0115] After further systematic analysis and long-term practice, the inventors discovered that by setting the surface roughness Ra of the roll to satisfy: 0.05μm≤Ra≤0.5μm, it is convenient to form a steel plate 21 with the corresponding surface roughness. This is beneficial to further improve the structural strength of the steel plate 21 itself, and also to further improve the bonding strength between the steel plate 21 and the fiber resin layer 22.

[0116] In some embodiments, such as Figure 5 As shown, before the cold stamping process of the steel plate 21 in step S40, the manufacturing method of the protective plate 20 also includes step S50, annealing the cold-rolled steel plate 21.

[0117] In other words, after the cold rolling process in step S30, and before cold stamping the steel plate 21, the steel plate 21 is annealed. Annealing can increase the elongation after fracture and the strain hardening index of the steel plate 21. In this application, for the nickel-saving austenitic stainless steel billet, after annealing, its elongation after fracture can reach more than 40%, and its strain hardening index can reach more than 0.27.

[0118] Therefore, after annealing, the hardness and residual stress of steel plate 21 are reduced, the tendency to deform and crack is decreased, and the machinability is improved, facilitating the subsequent cold stamping process. Furthermore, annealing increases the elongation after fracture and strain hardening index of steel plate 21, which further reduces the risk of fracture of protective plate 20 under external loads.

[0119] In some embodiments, S50, annealing the cold-rolled steel plate 21 includes: heating the steel plate 21 at a temperature of 850°C to 1050°C and holding it for 5 min to 15 min.

[0120] Optionally, during the annealing process, the heating temperature can be 850℃, 900℃, 950℃, 1000℃, or 1050℃, etc. The holding time can be 5 min, 8 min, 10 min, 12 min, or 15 min, etc.

[0121] After systematic analysis and long-term practice, the inventors discovered that by setting the heating temperature to 850℃~1050℃ and the holding time to 5min~15min, it is beneficial to further improve the elongation after fracture of the steel plate 21, thereby reducing the risk of the protective plate 20 breaking under external load.

[0122] In some embodiments, the heating temperature is 900°C to 950°C.

[0123] Optionally, the heating temperature can be 900℃, 910℃, 920℃, 930℃, 940℃ or 950℃, etc.

[0124] After further systematic analysis and long-term practice, the inventors discovered that setting the heating temperature to 900℃~950℃ is beneficial to further improve the elongation after fracture of the steel plate 21, thereby increasing the risk of the protective plate 20 breaking under external load.

[0125] In some embodiments, after heating the steel plate 21, the method further includes cooling the heated steel plate 21 in air or water.

[0126] In other words, during the annealing process of steel plate 21, after the heating and heat preservation processes are completed, steel plate 21 is cooled by air cooling or water cooling.

[0127] Water cooling or air cooling is simple to operate and low in cost. The cooled steel plate 21 has better hardness and strength, which improves the post-fracture productivity of the protective plate 20 and reduces the risk of the protective plate 20 breaking. At the same time, it also helps to reduce the risk of the protective plate 20 deforming under external load.

[0128] In some embodiments, the cold-rolled steel plate 21 is annealed, including annealing the steel plate 21 in an annealing furnace, wherein the protective gas in the annealing furnace is nitrogen or argon, and the dew point temperature of the protective gas is -50°C to -20°C.

[0129] Since the steel plate 21 needs to be heated during the annealing process, nitrogen or argon is used as the protective gas, and the dew point temperature of the protective gas is -50℃ to -20℃. Both nitrogen and argon are inert gases and do not easily react chemically with the surface of the steel plate 21. This helps to reduce the risk of the steel plate 21 being damaged or corroded during the annealing process and allows the steel plate 21 to maintain a relatively stable surface roughness.

[0130] In some embodiments, S30, performing a cold rolling process on the hot-rolled billet includes: performing a cold rolling process on the billet when the work hardening rate n satisfies 15% ≤ n ≤ 25%, wherein n = (h1 - h2) / h1, where h1 is the thickness of the billet before cold rolling, and h2 is the target thickness.

[0131] After systematic analysis and long-term practice, the inventors discovered that when the work hardening rate n satisfies 15% ≤ n ≤ 25%, the produced protective plate 20 exhibits high tensile strength and yield strength, along with suitable elongation after fracture and strain hardening index. Related experiments revealed that, when the work hardening rate n satisfies 15% ≤ n ≤ 25%, the tensile strength of the processed protective plate 20 exceeds 1200 MPa, while the yield strength exceeds 420 MPa.

[0132] The work hardening rate n can be calculated based on the target thickness and the thickness of the billet before cold rolling.

[0133] Therefore, by controlling the work hardening rate during the cold rolling process to 15% ≤ n ≤ 25%, it is beneficial to improve the tensile strength and yield strength of the produced protective plate 20, and further reduce the risk of deformation of the protective plate 20 under external impact, vibration and other loads.

[0134] In some embodiments, such as Figure 6 As shown, before the hot-rolled billet is subjected to cold rolling, the production method of the protective plate also includes: S60, when the work hardening rate n cannot meet 15%≤n≤25%, the hot-rolled billet is subjected to cold rolling until the thickness h3 of the billet meets: 15%≤(h3-h2) / h3≤25%.

[0135] The cold-rolled billet is then annealed.

[0136] In other words, based on the thickness of the hot-rolled billet and the target thickness, the required work hardening rate n can be calculated. If n cannot satisfy 15% ≤ n ≤ 25%, the hot-rolled billet needs to be cold-rolled first until the billet thickness meets the work hardening rate requirement of 15% ≤ n ≤ 25%. Then, the cold-rolled billet that meets the work hardening rate requirement is annealed to put the material in an annealed state. Finally, the annealed billet is cold-rolled again, thus achieving the goal of n satisfying 15% ≤ n ≤ 25% during the cold rolling process, thereby improving the tensile strength and yield strength of the protective plate 20.

[0137] In some embodiments, when the work hardening rate n satisfies 15% ≤ n ≤ 25%, the billet is subjected to a cold rolling process, including:

[0138] The billet is subjected to a first cold rolling process to obtain a billet with a thickness greater than the target thickness.

[0139] The billet is subjected to at least one cold rolling process to obtain a steel plate 21 with the target thickness.

[0140] In other words, during the cold rolling process of the billet, at least two cold rolling processes are carried out. This helps to more accurately control the thickness of the cold-rolled steel plate 21 and further reduce the residual stress in the steel plate 21, thereby improving the performance stability of the steel plate 21.

[0141] In some embodiments, the steel plate 21 is subjected to a first cold rolling process, which includes: performing a first cold rolling process on the billet until the thickness of the billet is 1.8 mm to 2.2 mm greater than the target thickness.

[0142] During the first cold rolling process of the billet, the thickness of the billet after cold rolling is slightly larger than the target thickness. The thickness of the billet after the first cold rolling process is 1.8mm to 2.2mm larger than the target thickness, so as to reserve processing allowance for at least one subsequent cold rolling process. This is beneficial to more accurately control the thickness of the cold-rolled steel plate 21, and further improve the performance stability of the steel plate 21.

[0143] In some embodiments, before cold stamping the steel plate 21 in step S40, the method for producing the protective plate further includes:

[0144] The steel plate 21 is subjected to pickling and finishing processes in sequence.

[0145] Pickling can remove impurities from the surface of steel plate 21, while finishing can perform preliminary treatment on the surface of steel plate 21 to initially control the size and surface morphology of steel plate 21.

[0146] Therefore, removing impurities from the surface of the steel plate 21 and performing preliminary shaping before cold stamping the steel plate 21 is beneficial to improving the controllability of the morphology of the produced protective plate 20 and reducing the risk of corrosion of the protective plate 20.

[0147] In some embodiments, after cold stamping the steel plate 21 in step S40, the method for producing the protective plate further includes:

[0148] The steel plate 21 is then subjected to laser processing and electrophoretic processing in sequence.

[0149] A protective layer is sprayed onto the surface of the steel plate 21 after electrophoresis.

[0150] Laser processing can create structures such as mounting holes, while electrophoresis can provide a certain level of surface protection for the protective plate 20. After electrophoresis, a protective layer is sprayed onto the surface of the steel plate 21, further reducing the risk of corrosion of the protective plate 20 due to contact with water and oxygen in the air.

[0151] In some embodiments, after cold stamping the steel plate 21, the method for producing the protective plate further includes:

[0152] A fiber resin layer 22 is laid on at least one side of the steel plate 21 along the thickness direction;

[0153] The steel plate 21 and the fiber resin layer 22 are hot-pressed together to form a protective plate 20.

[0154] Optionally, a fiber resin layer 22 may be laid on at least one side of the steel plate 21 along the thickness direction, or a fiber resin layer 22 may be laid on both sides of the steel plate 21 along the thickness direction.

[0155] In the hot pressing process, the resin material in the fiber resin layer 22 melts and comes into contact with the steel plate 21, and is fused together with the steel plate 21 during the cooling process. This helps to improve the bonding strength between the fiber resin layer 22 and the steel plate 21.

[0156] Therefore, by laying a fiber resin layer 22 on at least one side of the steel plate 21 along the thickness direction, the fiber resin layer 22 can provide a certain degree of protection for the steel plate 21, reduce the risk of corrosion of the steel plate 21, and improve the bonding strength between the fiber resin layer 22 and the steel plate 21 through the hot pressing process.

[0157] In some embodiments, before providing a nickel-saving austenitic stainless steel billet in step S10, the method for producing the protective plate further includes:

[0158] The steel raw material is smelted to obtain liquid steel;

[0159] The molten steel is refined in a converter and then cast to obtain a billet of nickel-saving austenitic stainless steel. The mass percentages of each component in the billet are as follows: silicon: 0.3%–1%, manganese: 8%–12%, nickel: 0–2%, chromium: 12.5%–16%, and copper: 0–1.5%.

[0160] In other words, the nickel-saving austenitic stainless steel billet is first formed through smelting, converter refining, and then casting. The mass percentages of each trace component in the nickel-saving austenitic stainless steel are as follows: silicon: 0.3%–1%, manganese: 8%–12%, nickel: 0–2%, chromium: 12.5%–16%, and copper: 0–1.5%.

[0161] By refining austenitic stainless steel billets, it is beneficial to reduce the production cost of protective plate 20 and the transportation cost of raw materials during the production process, resulting in higher economic benefits.

[0162] In some embodiments, before the molten steel is refined in a converter, the method for producing the protective plate further includes adding silicon, manganese, nickel, chromium or copper to the molten steel so that the mass percentages of each component in the molten steel are as follows: silicon: 0.3% to 1%, manganese: 8% to 12%, nickel: 0 to 2%, chromium: 12.5% ​​to 16%, and copper: 0 to 1.5%.

[0163] Understandably, to improve the mechanical properties of nickel-saving austenitic stainless steel, the composition of each element has corresponding requirements. However, the mass content of each element in the raw steel may not meet the requirements of nickel-saving austenitic stainless steel. By adding silicon, manganese, nickel, chromium, or copper to molten steel to adjust the composition of each element, the smelting yield of nickel-saving austenitic stainless steel billets can be improved.

[0164] Secondly, the protective plate 20 provided in this application embodiment is manufactured using the production method of the protective plate provided in any of the above embodiments.

[0165] The protective plate 20 provided in this application is manufactured using the production method of the protective plate provided in any of the above embodiments, and therefore has the same technical effect, which will not be repeated here.

[0166] Thirdly, the battery device 10 provided in the embodiments of this application includes a housing 11, a battery cell 30, and a protective plate 20 provided in the above embodiments, with the protective plate 20 connected to the housing 11.

[0167] The battery device 10 provided in this application embodiment has the same technical effect as the protective plate 20 provided in the above embodiment, and will not be described again here.

[0168] Fourthly, the electrical device provided in the embodiments of this application includes the battery device 10 provided in the above embodiments, and the battery device 10 is used to provide electrical energy.

[0169] The power supply device provided in this application embodiment has the same technical effect as the battery device 10 provided in the above embodiment, and will not be described again here.

[0170] In some embodiments, the production method of the protective plate provided in this application includes: S10, providing a billet of nickel-saving austenitic stainless steel, wherein the carbon content of the billet is 0.07% to 0.12% by mass. S20, performing a hot rolling process on the billet. S30, performing a cold rolling process on the hot-rolled billet to obtain a steel plate 21 with a target thickness. The billet is cold-rolled using rolls, and the surface roughness Ra of the rolls satisfies: 0.05μm≤Ra≤0.5μm, to obtain a steel plate 21 with a target thickness. The steel plate 21 is then subjected to pickling and finishing processes in sequence. S40, the steel plate 21 is subjected to cold stamping. The steel plate 21 is then subjected to laser processing and electrophoretic processing in sequence. A protective layer is sprayed onto the surface of the electrophoretically coated steel plate 21. A fiber resin layer 22 is laid on at least one side of the steel plate 21 along the thickness direction; the steel plate 21 and the fiber resin layer 22 are then hot-pressed together to form a protective plate 20.

[0171] The production method of the protective plate provided in this application uses a nickel-saving austenitic stainless steel billet with a carbon content of 0.07% to 0.12%, which makes the produced protective plate 20 have high tensile strength and yield strength, as well as high elongation after fracture. This helps to reduce the risk of cracking or deformation of the protective plate 20 under external load, and improves the reliability of the protective plate 20.

[0172] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for producing a protective plate, characterized in that, The protective plate is used in a battery device, and the method for producing the protective plate includes: A billet of nickel-saving austenitic stainless steel is provided, wherein the carbon content of the billet is 0.07% to 0.12% by mass; The billet is subjected to a hot rolling process; The hot-rolled billet is subjected to a cold rolling process to obtain a steel plate with the target thickness; The steel plate is subjected to a cold stamping process.

2. The method for producing the protective plate according to claim 1, characterized in that, During the cold rolling process of the hot-rolled billet, the billet is cold-rolled using rolls, and the surface roughness Ra of the rolls satisfies: 0.05μm≤Ra≤0.5μm.

3. The method for producing the protective plate according to claim 2, characterized in that, The surface roughness Ra of the roll satisfies: 0.1μm≤Ra≤0.4μm.

4. The method for producing the protective plate according to claim 1, characterized in that, Before the cold stamping process is performed on the steel plate, the manufacturing method of the protective plate further includes: The cold-rolled steel sheet is then annealed.

5. The method for producing the protective plate according to claim 4, characterized in that, The annealing treatment of the cold-rolled steel plate includes: heating the steel plate at a temperature of 850℃ to 1050℃ and holding it at that temperature for 5 minutes to 15 minutes.

6. The method for producing the protective plate according to claim 5, characterized in that, The heating temperature is 900℃~950℃.

7. The method for producing the protective plate according to claim 5, characterized in that, After heating the steel plate, the process further includes: The heated steel plate is cooled in air or water.

8. The method for producing the protective plate according to claim 4, characterized in that, The annealing treatment of the cold-rolled steel sheet includes: The steel plate is annealed in an annealing furnace, and the protective gas in the annealing furnace is nitrogen or argon, with a dew point temperature of -50℃ to -20℃.

9. The method for producing the protective plate according to claim 1, characterized in that, The cold rolling process of the hot-rolled billet includes: performing a cold rolling process on the billet when the work hardening rate n satisfies 15% ≤ n ≤ 25%, wherein n = (h1 - h2) / h1, where h1 is the thickness of the billet before cold rolling, and h2 is the target thickness.

10. The method for producing the protective plate according to claim 9, characterized in that, Before performing the cold rolling process on the hot-rolled billet, the method for producing the protective plate further includes: If the work hardening rate n cannot meet the requirement of 15% ≤ n ≤ 25%, the hot-rolled billet is subjected to a cold rolling process until the thickness h3 of the billet meets the requirement of 15% ≤ (h3-h2) / h3 ≤ 25%. The cold-rolled billet is then annealed.

11. The method for producing the protective plate according to claim 9, characterized in that, The process of cold rolling the billet when the work hardening rate n satisfies 15% ≤ n ≤ 25% includes: The billet is subjected to a first cold rolling process to obtain a billet with a thickness greater than the target thickness; The billet is subjected to at least one cold rolling process to obtain the steel plate having the target thickness.

12. The method for producing the protective plate according to claim 11, characterized in that, The first cold rolling process of the steel plate includes: performing a first cold rolling process on the billet until the thickness of the billet is 1.8 mm to 2.2 mm greater than the target thickness.

13. The method for producing the protective plate according to any one of claims 1 to 12, characterized in that, Before the cold stamping of the steel plate, the production method of the protective plate further includes: The steel plate is subjected to pickling and finishing processes in sequence.

14. The method for producing a protective plate according to any one of claims 1 to 12, characterized in that, The method for producing the protective plate after cold stamping the steel plate further includes: The steel plate is then subjected to laser processing and electrophoretic processing in sequence; A protective layer is sprayed onto the surface of the steel plate after electrophoresis.

15. The method for producing a protective plate according to any one of claims 1 to 12, characterized in that, The method for producing the protective plate after cold stamping the steel plate further includes: A fiber resin layer is laid on at least one side of the steel plate along its thickness direction; The steel plate and the fiber resin layer are subjected to a hot-pressing process to connect the steel plate and the fiber resin layer, forming a protective plate.

16. The method for producing a protective plate according to any one of claims 1 to 11, characterized in that, Before providing the nickel-saving austenitic stainless steel billet, the method for producing the protective plate further includes: The steel raw materials are smelted sequentially to obtain liquid steel; The molten steel is refined in a converter and then cast to obtain a billet of nickel-saving austenitic stainless steel. The mass percentages of the components in the billet are as follows: silicon: 0.3% to 1%, manganese: 8% to 12%, nickel: 0% to 2%, chromium: 12.5% ​​to 16%, and copper: 0% to 1.5%.

17. The method for producing the protective plate according to claim 16, characterized in that, Before the steel is refined in a converter, the production method of the protective plate further includes adding silicon, manganese, nickel, chromium or copper to the steel so that the mass percentages of each component in the steel are as follows: silicon: 0.3% to 1%, manganese: 8% to 12%, nickel: 0 to 2%, chromium: 12.5% ​​to 16%, copper: 0 to 1.5%.

18. A protective plate, characterized in that, It is manufactured using the production method of the protective plate provided in any one of claims 1 to 17.

19. A battery device, characterized in that, include: Box; The battery cell is housed within the casing; The protective plate as described in claim 18 is connected to the housing.

20. An electrical device, characterized in that, Includes the battery device as described in claim 19, the battery device being used to provide electrical energy.

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