Water-cooled plate, preparation method thereof and electric vehicle

Abstract

This invention relates to the field of water-cooled plate technology, specifically to a water-cooled plate, its manufacturing method, and an electric vehicle. The water-cooled plate includes an upper plate and a lower plate that are arranged opposite to and fixedly connected. Along the thickness direction of the water-cooled plate, the upper plate includes an upper high-strength layer and an upper fast-conducting heat layer stacked sequentially from top to bottom, and the lower plate includes a brazing layer, a lower high-strength layer, and a lower fast-conducting heat layer stacked sequentially from top to bottom. The upper and lower high-strength layers are each made of 7-series or 6-series aluminum alloy. The upper and lower fast-conducting heat layers are both made of 3-series aluminum alloy. The upper plate has a flat plate structure, and the lower plate is recessed in a direction away from the upper plate to form a groove area, which is covered and sealed by the upper plate. This water-cooled plate has high overall strength, good impact resistance, and is not easily cracked after impact, thus improving battery safety.

Description

Technical Field

[0001] This invention relates to the field of water-cooled plate technology, and more specifically, to a water-cooled plate, its preparation method, and an electric vehicle. Background Technology

[0002] Currently, water-cooled plates for new energy vehicles are generally made by welding two aluminum plates. The upper plate is a single 3-series aluminum-manganese alloy plate (such as 3003), and the lower plate is a double-layer composite aluminum plate, with the two layers made of 3-series aluminum-manganese alloy and 4-series aluminum-silicon alloy respectively (such as 3003+4343). Cooling channels are stamped into the lower plate, and then the upper and lower plates are welded together to form a water-cooled plate assembly.

[0003] The new national standard for batteries, GB 38031-2025, will be implemented on July 1, 2026. The new standard requires that after a single cell experiences thermal runaway, the battery system must remain free of fire and explosion for at least two hours, with all monitoring points maintaining a temperature below 60°C. This standard sets higher requirements for battery safety. Currently, the most common cause of battery fires in new energy vehicles is scraping or dragging the battery under the vehicle, such as when the vehicle hits a roadside green belt or collides with a stone step. However, current water-cooled plates have low strength; when the battery is impacted, the water-cooled plate is prone to deformation or even cracking, reducing its cooling effect, causing the cell temperature to overheat, leading to thermal runaway and battery fires. To assess battery safety, the national standard specifies a bottom impact test, requiring an impact energy of 150J. The C-NCAP 2024 version has added a bottom impact test for electric vehicles. Both of these tests place higher demands on the impact energy absorption performance of the battery assembly (including the water-cooled plate).

[0004] Existing technology protects the battery water-cooling plate by installing a bottom protective plate underneath it. Commonly used bottom protective plates include high-strength steel bottom protective plates and non-metallic composite bottom protective plates. However, when the bottom of the battery is hit, the bottom protective plate will still impact the water-cooling plate after it deforms. Since the water-cooling plate material has low strength, the deformation and cracking of the water-cooling plate can easily lead to thermal runaway and fire in the battery.

[0005] In view of this, the present invention is hereby proposed. Summary of the Invention

[0006] The primary objective of this invention is to provide a water-cooled plate with high overall strength, good impact resistance, and resistance to cracking after impact, thereby improving battery safety.

[0007] The second objective of this invention is to provide a method for preparing a water-cooled plate.

[0008] A third objective of this invention is to provide an electric vehicle.

[0009] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: This invention first provides a water-cooled plate, which includes an upper plate and a lower plate that are disposed opposite to and fixedly connected. Along the thickness direction of the water-cooled plate, the upper plate includes an upper high-strength layer and an upper rapid heat conduction layer stacked sequentially from top to bottom, and the lower plate includes a brazing layer, a lower high-strength layer, and a lower rapid heat conduction layer stacked sequentially from top to bottom. The upper high-strength layer and the lower high-strength layer are each made of 7-series aluminum alloy or 6-series aluminum alloy. The upper rapid heat conduction layer and the lower rapid heat conduction layer are both made of 3-series aluminum alloy. The upper plate has a flat plate structure, and the lower plate is recessed in a direction away from the upper plate to form a groove area. The upper plate covers and seals the groove area.

[0010] Furthermore, the upper plate also includes an upper anti-corrosion layer located above the upper high-strength layer.

[0011] Furthermore, the lower plate also includes a lower anti-corrosion layer located below the lower rapid heat conduction layer.

[0012] Furthermore, the thickness of the upper plate is 0.8mm to 1.5mm.

[0013] Furthermore, the thickness ratio of the upper anti-corrosion layer, the upper high-strength layer, and the upper rapid heat-conducting layer is 8~15:60~80:10~30.

[0014] Furthermore, the thickness of the lower plate is 0.8mm to 1.5mm.

[0015] Furthermore, the thickness ratio of the brazing layer, the lower high-strength layer, the lower rapid heat-conducting layer, and the lower anti-corrosion layer is 8~15:60~80:10~30:8~15.

[0016] Furthermore, the upper anti-corrosion layer and / or the lower anti-corrosion layer are made of 1-series aluminum alloy.

[0017] Furthermore, the material of the brazing layer is 4-series aluminum alloy.

[0018] The present invention also provides a method for preparing the above-mentioned water-cooled plate, comprising the following steps: stamping the composite layer to obtain a lower plate, brazing the lower plate and the upper plate together, and performing artificial aging treatment after cooling.

[0019] Furthermore, the stamping depth is 1 to 2 times the thickness of the composite layer.

[0020] Furthermore, the deformation rate of the stamping is 5% to 10%.

[0021] Furthermore, before stamping, a dry film lubricant is sprayed onto the surface of the composite layer or the surface of the stamping die in contact with the composite layer to form a lubricating film with a thickness of 30~80μm.

[0022] Furthermore, the brazing temperature is 605℃~620℃, and the brazing time is 10~20min.

[0023] Furthermore, the temperature of the artificial aging treatment is 160℃~200℃, and the time of the artificial aging treatment is 1~4h.

[0024] The present invention also provides an electric vehicle, which includes the above-described water-cooled plate, or a water-cooled plate prepared according to the above-described method for preparing the water-cooled plate.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention significantly improves the overall strength of the water-cooled plate and enhances its impact resistance, thereby avoiding cracking of the water-cooled plate and improving the safety performance of the battery. Attached Figure Description

[0026] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the structure of the water-cooled plate provided by the present invention; Figure 2 A partial structural schematic diagram of the water-cooled plate provided by the present invention; Figure 3 A schematic diagram of the layer structure of the upper plate provided by the present invention; Figure 4 This is a schematic diagram of the layer structure of the lower plate provided by the present invention. Detailed Implementation

[0028] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0029] Unless otherwise specified, in this invention, terms such as "first aspect," "second aspect," "third aspect," and "fourth aspect" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, terms such as "first," "second," "third," and "fourth" serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.

[0030] Unless otherwise specified, the terms "comprising" and "including" as used in this invention can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0031] Unless otherwise specified, in this invention, "one or more" or "at least one" refers to any one, any two, or any two or more of the listed items. "Several" refers to any two or more.

[0032] In a first aspect, the present invention provides a high-strength water-cooled plate, see [link to previous article]. Figure 1 and Figure 2 As shown, it includes an upper plate and a lower plate that are positioned opposite each other and fixedly connected. For example, the upper plate and the lower plate are connected by brazing.

[0033] See Figure 3 and Figure 4 As shown, both the upper and lower plates are multi-layered composite structures. Along the thickness direction of the water-cooled plate, the upper plate includes an upper high-strength layer and an upper rapid heat-conducting layer stacked sequentially from top to bottom, and the lower plate includes a brazing layer, a lower high-strength layer, and a lower rapid heat-conducting layer stacked sequentially from top to bottom. That is, the upper rapid heat-conducting layer of the upper plate is at least partially connected to the brazing layer of the lower plate.

[0034] It is understandable that the above "from top to bottom" refers to the direction from the upper plate to the lower plate.

[0035] The material of the upper high-strength layer is 7-series aluminum alloy (i.e., 7××× series aluminum alloy) or 6-series aluminum alloy (i.e., 6××× series aluminum alloy).

[0036] The material of the lower high-strength layer is 7-series aluminum alloy (i.e., 7××× series aluminum alloy) or 6-series aluminum alloy (i.e., 6××× series aluminum alloy).

[0037] Both the upper and lower rapid heat conduction layers are made of 3-series aluminum alloy (i.e., 3××× series aluminum alloy).

[0038] See Figure 2The upper plate has a flat plate structure, and the lower plate is recessed in a direction away from the upper plate to form a groove area. The upper plate covers and seals the groove area. It can be understood that the groove area is a closed flow channel.

[0039] This invention features a novel composite structure of upper and lower plates. Since the lower square plate undergoes greater deformation during stamping (the stamping process that forms the grooves), this invention sets the lower rapid heat conduction layer to use a 3-series aluminum alloy with better plasticity. This layer is designed below the lower high-strength layer made of 7-series or 6-series aluminum alloy, which ensures overall deformation coordination of the water-cooled plate and avoids problems such as interlayer cracks.

[0040] This invention improves the overall strength of the water-cooled plate and enhances its impact resistance. In the event of accidents such as vehicle bottoming out, stone impact, or collision, it can prevent the water-cooled plate from cracking and prevent coolant leakage. It ensures that the water-cooled plate can work normally after the accident, and the battery cooling is not affected. It avoids safety problems such as thermal runaway, fire, and explosion caused by high battery temperature, improves battery safety, meets regulatory requirements, and protects passenger safety.

[0041] For some specific implementation methods, see Figure 3 The upper plate also includes an upper anti-corrosion layer located above the upper high-strength layer. That is, the upper plate includes an upper anti-corrosion layer, an upper high-strength layer, and an upper rapid heat conduction layer stacked sequentially from top to bottom.

[0042] For some specific implementation methods, see Figure 4 The lower plate also includes a lower anti-corrosion layer located below the lower rapid heat conduction layer. That is, the lower plate includes a brazing layer, a lower high-strength layer, a lower rapid heat conduction layer, and a lower anti-corrosion layer stacked sequentially from top to bottom.

[0043] It is understandable that when there are no anti-corrosion requirements for the water-cooled plate, the upper and lower plates do not need to be equipped with upper and lower anti-corrosion layers.

[0044] In some specific embodiments, the thickness of the upper plate is 0.8mm to 1.5mm, for example 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm or 1.5mm.

[0045] In some specific embodiments, the thickness ratio of the upper anti-corrosion layer, the upper high-strength layer, and the upper rapid heat-conducting layer is 8~15 (e.g., 8, 9, 10, 11, 12, 13, 14, or 15): 60~80 (e.g., 60, 65, 70, 75, or 80): 10~30 (e.g., 10, 15, 20, 25, or 30). This helps to further improve the overall strength of the water-cooled plate.

[0046] In some specific embodiments, the thickness of the lower plate is 0.8mm to 1.5mm, for example 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm or 1.5mm.

[0047] In some specific embodiments, the thickness ratio of the brazing layer, the lower high-strength layer, the lower rapid heat-conducting layer, and the lower anti-corrosion layer is 8~15 (e.g., 8, 9, 10, 11, 12, 13, 14, or 15): 60~80 (e.g., 60, 65, 70, 75, or 80): 10~30 (e.g., 10, 15, 20, 25, or 30): 8~15 (e.g., 8, 9, 10, 11, 12, 13, 14, or 15). This helps to further improve the overall strength of the water-cooled plate.

[0048] In some specific embodiments, the upper anti-corrosion layer and / or the lower anti-corrosion layer are made of 1-series aluminum alloy (i.e., 1××× series aluminum alloy).

[0049] In some specific embodiments, the material of the brazing layer is 4-series aluminum alloy (i.e., 4××× series aluminum alloy).

[0050] Secondly, the present invention provides a method for preparing a water-cooled plate, comprising the following steps: stamping a composite layer to obtain a lower plate, brazing the lower plate and an upper plate together, and then performing artificial aging treatment after cooling.

[0051] It is understood that the aforementioned composite layer includes a brazing layer, a lower high-strength layer, and a lower rapid heat conduction layer stacked sequentially, or a brazing layer, a lower high-strength layer, a lower rapid heat conduction layer, and a lower anti-corrosion layer stacked sequentially.

[0052] The upper plate includes an upper high-strength layer and an upper rapid heat conduction layer stacked in sequence, or an upper anti-corrosion layer, an upper high-strength layer and an upper rapid heat conduction layer stacked in sequence.

[0053] The preparation method is simple to operate, has a short process, and produces a water-cooled plate with high overall strength.

[0054] In some specific embodiments, the stamping depth is 1 to 2 times the thickness of the composite layer. Here, the stamping depth refers to the depth of the recess formed in the composite layer or lower plate after stamping, i.e., the depth of the groove region.

[0055] In some specific embodiments, the deformation rate of the composite layer during stamping is 5% to 10%, for example, 5%, 6%, 7%, 8%, 9% or 10%.

[0056] By controlling the stamping parameters, it is possible to avoid concentrated local deformation, excessive thinning, and insufficient local strength.

[0057] In some specific embodiments, the stamping is carried out using a cold stamping process, and the composite layer is in the O state (annealed state), with an elongation after fracture of ≥20%, which has good stamping performance.

[0058] In some specific embodiments, before stamping, a dry film lubricant is sprayed onto the surface of the composite layer or the surface of the stamping die in contact with the composite layer to form a lubricating film with a thickness of 30~80μm (e.g., 30μm, 40μm, 50μm, 60μm, 70μm or 80μm).

[0059] Preferably, a dry film lubricant is sprayed onto the surface of the lower anti-corrosion layer in the composite layer or onto the surface of the stamping die in contact with it to achieve low friction (friction coefficient of about 0.05) between the surface of the stamping die and the surface of the lower anti-corrosion layer, thereby further reducing the thinning of the lower anti-corrosion layer and friction damage.

[0060] In some specific embodiments, the brazing temperature is 605℃~620℃, for example 605℃, 610℃, 615℃ or 620℃; the brazing time is 10~20min, for example 10min, 12min, 15min, 18min or 20min.

[0061] In some specific implementations, the cooling method includes air cooling or water cooling.

[0062] In some specific implementations, the temperature of the artificial aging treatment is 160℃~200℃, for example 160℃, 170℃, 180℃, 190℃ or 200℃; the time of the artificial aging treatment is 1~4h, for example 1h, 2h, 3h or 4h.

[0063] By controlling the manufacturing parameters of the water-cooled plate, it is beneficial to further improve its strength.

[0064] Thirdly, the present invention provides an electric vehicle comprising the above-described water-cooled plate, or a water-cooled plate prepared according to the above-described method for preparing the water-cooled plate.

[0065] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0066] Example 1 The water-cooled plate provided in this embodiment includes an upper plate and a lower plate that are arranged opposite to each other and fixedly connected.

[0067] Along the thickness direction of the water-cooled plate, the upper plate includes an upper anti-corrosion layer, an upper high-strength layer and an upper rapid heat conduction layer stacked from top to bottom, and the lower plate includes a brazing layer, a lower high-strength layer, a lower rapid heat conduction layer and a lower anti-corrosion layer stacked from top to bottom.

[0068] Both the upper and lower high-strength layers are made of 7-series aluminum alloy (grade 7003).

[0069] Both the upper and lower rapid heat conduction layers are made of 3-series aluminum alloy (grade 3003).

[0070] Both the upper and lower anti-corrosion layers are made of 1-series aluminum alloy (grade 1060).

[0071] The material of the brazing layer is 4-series aluminum alloy (grade 4343).

[0072] The total thickness of the upper plate is 1.2mm, of which the thicknesses of the upper anti-corrosion layer, the upper high-strength layer and the upper rapid heat conduction layer are 0.1mm, 0.8mm and 0.3mm respectively (that is, the thickness ratio of the upper anti-corrosion layer, the upper high-strength layer and the upper rapid heat conduction layer is 10:80:30).

[0073] The total thickness of the lower plate is 1.2mm, of which the thicknesses of the brazing layer, the lower high-strength layer, the lower rapid heat conduction layer and the lower anti-corrosion layer are 0.1mm, 0.7mm, 0.3mm and 0.1mm respectively (that is, the thickness ratio of the brazing layer, the lower high-strength layer, the lower rapid heat conduction layer and the lower anti-corrosion layer is 10:70:30:10).

[0074] The upper plate is a flat structure, and the lower plate is recessed in the direction away from the upper plate to form a groove area. The upper plate covers and seals the groove area.

[0075] The method for preparing the water-cooled plate provided in this embodiment includes the following steps: the lower plate is formed into a coolant flow channel by a stamping process, wherein the stamping depth is 1.5 times the thickness of the composite layer used, the stamping deformation rate is 8%, and a dry film lubricant is sprayed on the surface of the stamping die before stamping to form a lubricating film with a thickness of 50μm; after cleaning, both the lower plate and the upper plate are brazed at a brazing temperature of 610℃ for 15 minutes, and after brazing, they are rapidly cooled with compressed air and then subjected to artificial aging treatment at 180℃ for 4 hours.

[0076] Example 2 The water-cooled plate and its preparation method provided in this embodiment are basically the same as those in Embodiment 1, except that: (1) the material of the upper high-strength layer and the lower high-strength layer is 6-series aluminum alloy (6061 grade), and (2) after cooling, artificial aging treatment is performed at 200°C for 2 hours.

[0077] Example 3 The water-cooled plate and its preparation method provided in this embodiment are basically the same as those in Embodiment 1, except that: the material of the upper high-strength layer is 6-series aluminum alloy (the same grade as in Embodiment 2), and the material of the lower high-strength layer is 7-series aluminum alloy (the same grade as in Embodiment 1).

[0078] Example 4 The water-cooled plate and its preparation method provided in this embodiment are basically the same as those in Embodiment 1, except that: the total thickness of the upper plate is 0.85 mm, and the thicknesses of the upper anti-corrosion layer, the upper high-strength layer and the upper rapid heat conduction layer are 0.15 mm, 0.6 mm and 0.1 mm respectively (that is, the ratio of the thicknesses of the upper anti-corrosion layer, the upper high-strength layer and the upper rapid heat conduction layer is 15:60:10).

[0079] Example 5 The water-cooled plate and its preparation method provided in this embodiment are basically the same as those in Embodiment 1, except that: the total thickness of the lower plate is 1.2 mm, and the thicknesses of the brazing layer, the lower high-strength layer, the lower rapid heat conduction layer and the lower anti-corrosion layer are 0.15 mm, 0.8 mm, 0.1 mm and 0.15 mm respectively (that is, the ratio of the thicknesses of the brazing layer, the lower high-strength layer, the lower rapid heat conduction layer and the lower anti-corrosion layer is 15:80:10:15).

[0080] Example 6 The water-cooled plate and its preparation method provided in this embodiment are basically the same as those in Embodiment 1, except that: there is no upper anti-corrosion layer in the upper plate and no lower anti-corrosion layer in the lower plate.

[0081] Comparative Example 1 The water-cooled plate provided in this comparative example includes an upper plate and a lower plate that are arranged opposite to each other and fixedly connected.

[0082] The upper plate is made of 3-series aluminum alloy (grade 3003) with a thickness of 1.2 mm. Along the thickness direction of the water-cooling plate, the lower plate consists of 3-series aluminum alloy plate (grade 3003) and 4-series aluminum alloy plate (grade 4343) stacked sequentially from top to bottom. The total thickness of the lower plate is 1.2 mm, of which the 4-series aluminum alloy plate is a brazing layer with a thickness of 0.1 mm.

[0083] The upper plate is a flat structure, and the lower plate is recessed in the direction away from the upper plate to form a groove area. The upper plate covers and seals the groove area.

[0084] The preparation method of the water-cooled plate provided in this comparative example includes the following steps: the lower plate is formed into a coolant flow channel by stamping process, wherein the stamping depth is 1.5 times the thickness of the composite layer used, the stamping deformation rate is 8%, and a dry film lubricant is sprayed on the surface of the stamping die before stamping to form a lubricating film with a thickness of 50μm; after cleaning, both the lower plate and the upper plate are brazed at a brazing temperature of 610℃ for 15 minutes, and after brazing, they are rapidly cooled with compressed air and then subjected to artificial aging treatment at 180℃ for 4 hours.

[0085] Comparative Example 2 The water-cooled plate and its preparation method provided in this comparative example are basically the same as those in Example 1, except that: the upper high-strength layer and the lower high-strength layer are both made of 3-series aluminum alloy (the same grade as in Example 1), and the upper rapid heat conduction layer and the lower rapid heat conduction layer are both made of 7-series aluminum alloy (the same grade as in Example 1).

[0086] Comparative Example 3 The water-cooled plate and its preparation method provided in this comparative example are basically the same as those in Example 1, except that the total thickness of the upper plate is 1.2 mm, and the thicknesses of the upper anti-corrosion layer, the upper high-strength layer and the upper rapid heat conduction layer are 0.1 mm, 0.3 mm and 0.8 mm respectively (that is, the ratio of the thicknesses of the upper anti-corrosion layer, the upper high-strength layer and the upper rapid heat conduction layer is 10:30:80).

[0087] Comparative Example 4 The water-cooled plate and its preparation method provided in this comparative example are basically the same as those in Example 1, except that: the total thickness of the lower plate is 1.2 mm, and the thicknesses of the brazing layer, the lower high-strength layer, the lower rapid heat conduction layer and the lower anti-corrosion layer are 0.1 mm, 0.3 mm, 0.7 mm and 0.1 mm respectively (that is, the ratio of the thicknesses of the brazing layer, the lower high-strength layer, the lower rapid heat conduction layer and the lower anti-corrosion layer is 10:30:70:10).

[0088] Experimental Example Samples were taken and tensile strength tests were conducted on the brazed portions of the upper and lower plates of the water-cooled plates prepared in each embodiment and comparative example. The test results are shown in Table 1.

[0089] Table 1. Tensile strength test results of each water-cooled plate

[0090] As can be seen from Table 1, the water-cooled plates prepared in each embodiment have high strength. In contrast, Comparative Example 1 uses a water-cooled plate commonly used in the industry, and its strength is significantly lower than that of the embodiments.

[0091] Meanwhile, in Comparative Example 2, the strength decreased due to unsuitable materials in the corresponding layers. In Comparative Examples 3 and 4, the strength also decreased due to unsuitable thickness ratios of the layers in the upper and lower plates.

[0092] As can be seen, the present invention significantly improves the overall strength of the water-cooled plate, thereby improving the safety performance of the battery.

[0093] Although the present invention has been illustrated and described with specific embodiments, it should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; those skilled in the art should understand that modifications can be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein, without departing from the spirit and scope of the present invention; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention; therefore, this means that all such substitutions and modifications that fall within the scope of the present invention are included in the appended claims.

Claims

1. A water-cooled plate, characterized in that, This includes an upper plate and a lower plate that are positioned relative to each other and fixedly connected; Along the thickness direction of the water-cooled plate, the upper plate includes an upper high-strength layer and an upper fast-conducting heat layer stacked sequentially from top to bottom, and the lower plate includes a brazing layer, a lower high-strength layer and a lower fast-conducting heat layer stacked sequentially from top to bottom; The upper high-strength layer and the lower high-strength layer are each made of 7-series aluminum alloy or 6-series aluminum alloy. Both the upper rapid heat conduction layer and the lower rapid heat conduction layer are made of 3-series aluminum alloy. The upper plate has a flat plate structure, and the lower plate is recessed in a direction away from the upper plate to form a groove area. The upper plate covers and seals the groove area.

2. The water-cooled plate according to claim 1, characterized in that, The upper plate also includes an upper anti-corrosion layer located above the upper high-strength layer; And / or, the lower plate may further include a lower anti-corrosion layer located below the lower rapid heat conduction layer.

3. The water-cooled plate according to claim 2, characterized in that, The thickness of the upper plate is 0.8mm~1.5mm; And / or, the thickness ratio of the upper anti-corrosion layer, the upper high-strength layer and the upper rapid heat conduction layer is 8~15:60~80:10~30.

4. The water-cooled plate according to claim 2, characterized in that, The thickness of the lower plate is 0.8mm~1.5mm; And / or, the thickness ratio of the brazing layer, the lower high-strength layer, the lower rapid heat-conducting layer and the lower anti-corrosion layer is 8~15:60~80:10~30:8~15.

5. The water-cooled plate according to claim 2, characterized in that, The upper anti-corrosion layer and / or the lower anti-corrosion layer are made of 1-series aluminum alloy.

6. The water-cooled plate according to any one of claims 1 to 5, characterized in that, The material of the brazing layer is 4-series aluminum alloy.

7. The method for preparing the water-cooled plate according to any one of claims 1 to 6, characterized in that, Includes the following steps: The composite layer is stamped to obtain the lower plate, which is then brazed to the upper plate and cooled before undergoing artificial aging treatment.

8. The method for preparing the water-cooled plate according to claim 7, characterized in that, The stamping depth is 1 to 2 times the thickness of the composite layer, and the stamping deformation rate is 5% to 10%. And / or, before the stamping, a dry film lubricant is sprayed onto the surface of the composite layer or the surface of the stamping die in contact with the composite layer to form a lubricating film with a thickness of 30~80μm.

9. The method for preparing the water-cooled plate according to claim 7, characterized in that, The brazing temperature is 605℃~620℃, and the brazing time is 10~20min; And / or, the temperature of the artificial aging treatment is 160℃~200℃, and the time of the artificial aging treatment is 1~4h.

10. An electric vehicle, characterized in that, This includes the water-cooled plate as described in any one of claims 1 to 6, or the water-cooled plate prepared by the method described in any one of claims 7 to 9.

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