Liquid cooling plate, power battery, energy storage battery and preparation method of liquid cooling plate

Abstract

The invention provides a liquid cooling plate, a power battery, an energy storage battery and a preparation method of the liquid cooling plate, and the liquid cooling plate comprises a cover plate which is provided with a first core material layer; the runner plate is provided with a second core material layer, and the cover plate is arranged on the runner plate; the first core material layer and the second core material layer are both made of 6XXX series aluminum alloy and comprise the following elements of 0.3%-0.7% of Si, 0.6%-0.9% of Mg, 0.1%-0.3% of Cu, 0.05%-0.3% of Zn, 0.01%-0.15% of Mn, 0.01%-0.08% of Zr, 0.001%-0.1% of Cr, 0.001%-0.04% of Ti and 0.05%-0.6% of Fe, and the content of Si is lower than that of Mg. Through the technical scheme provided by the invention, the problem of low structural strength of the liquid cooling plate in the prior art can be solved.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a liquid cooling plate, a power battery, an energy storage battery and a method for preparing the liquid cooling plate. Background Art

[0002] At present, battery systems such as power batteries or energy storage batteries require liquid cooling plates for heat dissipation. However, liquid cooling plates in the prior art are mostly prepared using traditional 3003 / 4045 and 3003 low-strength composite plates. The main function of such traditional composite plates is limited to cooling and dissipating the battery module. Its yield strength is only between 40MPa and 60MPa, and its strength performance is low. It cannot carry loads. During the installation process, a bracket is usually required to support the battery module. However, in order to ensure the structural strength of the bracket, the bracket is usually made of steel, which not only increases the weight of the battery system, which is contrary to the goal of lightweighting, but also increases the production cost of the battery system. At the same time, the preparation processes of steel materials such as stamping, welding, and painting are not only complicated and time-consuming, but also cause negative pollution to the air environment. Summary of the invention

[0003] The present invention provides a liquid cooling plate, a power battery, an energy storage battery and a method for preparing the liquid cooling plate, so as to solve the problem of low structural strength of the liquid cooling plate in the prior art.

[0004] According to one aspect of the present invention, a liquid cooling plate is provided, the liquid cooling plate comprising: a cover plate, the cover plate having a first upper protective layer, a first core material layer and a first lower protective layer, the first upper protective layer and the first lower protective layer are respectively located on both sides of the first core material layer; a flow channel plate, the flow channel plate having a first welding layer, a second upper protective layer, a second core material layer and a second lower protective layer arranged in sequence, the cover plate is arranged on the flow channel plate, the first welding layer is used to fix the first lower protective layer and the flow channel plate, and a flow channel is arranged on one side of the flow channel plate facing the cover plate, and the flow channel is used to circulate fluid; the first core material layer and the second core material layer are both 6XXX series aluminum alloy, and the 6XXX series aluminum alloy includes the following elements in terms of mass percentage: S The content of i element is 0.3~0.7%, the content of Mg element is 0.6~0.9%, the content of Cu element is 0.1~0.3%, the content of Zn element is 0.05~0.3%, the content of Mn element is 0.01~0.15%, the content of Zr element is 0.01~0.08%, the content of Cr element is 0.001~0.1%, the content of Ti element is 0.001~0.04%, the content of Fe element is 0.05~0.6%, and the content of Si element is lower than that of Mg element, the total content of inevitable impurities is ≤0.15wt%, the content of single impurity is lower than 0.05wt%, and the balance is Al element.

[0005] Furthermore, the liquid cooling plate also includes: a support plate, the support plate has a third core material layer, the flow channel plate is arranged on the support plate, the support plate is used to support the flow channel plate, and the third core material layer is a 6XXX series aluminum alloy; a plurality of reinforcing plates, the plurality of reinforcing plates are arranged at intervals along the length direction of the support plate, the length direction of the reinforcing plate extends along the width direction of the support plate, the plurality of reinforcing plates all have a fourth core material layer, the support plate is arranged on the plurality of reinforcing plates, and the fourth core material layer is a 6XXX series aluminum alloy.

[0006] Furthermore, the support plate also has a third upper protective layer, a third lower protective layer and a second welding layer, the third upper protective layer and the third lower protective layer are respectively located on both sides of the third core material layer, the second welding layer is located on the side of the third upper protective layer away from the third core material layer, and the second welding layer is used to fix the second lower protective layer and the support plate; the reinforcement plate also has a fourth upper protective layer, a fourth lower protective layer and a third welding layer, the fourth upper protective layer and the fourth lower protective layer are respectively located on both sides of the fourth core material layer, the third welding layer is located on the side of the fourth upper protective layer away from the fourth core material layer, and the third welding layer is used to fix the third lower protective layer and the reinforcement plate; the third upper protective layer, the third lower protective layer, the fourth upper protective layer and the fourth lower protective layer are 3XXX series aluminum alloy, and the second welding layer and the third welding layer are 4XXX series aluminum alloy.

[0007] Furthermore, a supporting protrusion is arranged on the supporting plate, and the supporting protrusion is symmetrically arranged with the structure of the circulation channel, and the top of the supporting protrusion abuts against the bottom of the circulation channel.

[0008] Furthermore, the width of the reinforcement plate is set between 200 mm and 400 mm, and the length of the reinforcement plate is set between 500 mm and 800 mm.

[0009] Further, the mass ratio of Si element to Mg element is (0.50~0.67):1; and / or, the mass ratio of Cu element to Zn element is (1~2):1; and / or, the mass ratio of Mn element, Zr element and Cr element is 1:(0.27~4):(0.5~0.7); and / or, the first upper protective layer, the first lower protective layer, the second upper protective layer and the second lower protective layer are 3XXX series aluminum alloy, and the 3XXX series aluminum alloy is selected from any one or more of 3003 alloy, 3004 alloy and 3105 alloy; and / or, the first welding layer is 4XXX series aluminum alloy, and the 4XXX series aluminum alloy is selected from any one or more of 4004 alloy, 4045 alloy, 4047 alloy, 4104 alloy, 4147 alloy and 4343 alloy.

[0010] Furthermore, the thickness of the cover plate and / or the flow channel plate is set between 0.5 mm and 3.0 mm.

[0011] Furthermore, the ratio of the thickness of the first upper protective layer and the first lower protective layer to the overall thickness of the cover plate is set between 10% and 15%, and / or the ratio of the thickness of the second upper protective layer and the second lower protective layer to the overall thickness of the flow channel plate is set between 10% and 15%, and / or the ratio of the first welding layer to the overall thickness of the flow channel plate is set between 8% and 10%.

[0012] According to another aspect of the present invention, a power battery is provided, which includes a plurality of first battery mold cores and the liquid cooling plate provided above, wherein the plurality of first battery mold cores are distributed on a cover plate of the liquid cooling plate along a width direction of the liquid cooling plate, and a plurality of first mounting portions are arranged on the cover plate along a length direction, the first mounting portions are fixed to the cover plate by brazing, and the first battery mold cores are threadedly connected to the first mounting portions.

[0013] According to another aspect of the present invention, there is provided an energy storage battery, which includes a plurality of second battery mold cores and the liquid cooling plate provided above, wherein the plurality of second battery mold cores are distributed on a cover plate of the liquid cooling plate along a width direction of the liquid cooling plate, and a plurality of second mounting portions are arranged on the cover plate along a length direction, the second mounting portions are fixed to the cover plate by brazing, and the second battery mold cores are threadedly connected to the second mounting portions.

[0014] According to another aspect of the present invention, a method for preparing a liquid cooling plate is provided. The liquid cooling plate is the liquid cooling plate provided above, and the method for preparing the liquid cooling plate comprises: step 1, performing solid solution treatment on a cover plate and a flow channel plate of the liquid cooling plate; step 2, stamping the flow channel plate to process a flow channel of the flow channel plate; step 3, stacking the flow channel plate and the cover plate, with the first lower protective layer abutting against the first welding layer; step 4, sending the flow channel plate and the cover plate into a brazing furnace for welding; step 5, artificially aging the welded flow channel plate and the cover plate.

[0015] Furthermore, step 1 also includes: solution treatment of the support plate and multiple reinforcement plates of the liquid cooling plate; step 2 also includes: stamping the support plate to process the support protrusion of the support plate; step 3 also includes: stacking the support plate and the reinforcement plate, placing the flow channel plate on the support plate, the third welding layer abutting the third lower protective layer, and the second welding layer abutting the second lower protective layer; step 4 also includes: sending multiple reinforcement plates, support plates, flow channel plates and cover plates into a brazing furnace for welding; step 5 also includes artificial aging of the welded multiple reinforcement plates, support plates, flow channel plates and cover plates.

[0016] Further, the liquid cooling plate passes through 6 brazing zones in sequence, which are brazing zone 1, brazing zone 2, brazing zone 3, brazing zone 4, brazing zone 5 and brazing zone 6 in sequence, the temperature of brazing zone 1 is set between 585°C and 595°C, the temperature of brazing zone 2 is set between 600°C and 615°C, the temperature of brazing zone 3 is set between 610°C and 625°C, the temperature of brazing zone 4 is set between 615°C and 625°C, the temperature of brazing zone 5 is set between 625°C and 635°C, and the temperature of brazing zone 6 is set between 625°C and 635°C. Step 4 specifically includes: the liquid cooling plate passes through brazing zone 1, brazing zone 2, brazing zone 3, brazing zone 4, brazing zone 5 and brazing zone 6 in sequence at a speed of 750mm / min to 1050mm / min.

[0017] Furthermore, step 5 specifically includes: the liquid cooling plate is kept at a heat preservation temperature of 200° C. to 240° C. for 10 min to 30 min.

[0018] The technical solution of the present invention is applied, the cover plate has a first core material layer, the flow channel plate has a second core material layer, the first core material layer and the second core material layer are both 6XXX series aluminum alloys, the cover plate is placed on the flow channel plate, and a circulation channel is provided on the side of the flow channel plate facing the cover plate, and the circulation channel is used to circulate fluid. In this way, the heat dissipation of the liquid cooling plate is achieved by passing a refrigerant into the circulation channel. At the same time, controlling the content of Mg and Si elements in the 6XXX series aluminum alloy within the above range, and controlling the content of Si element to be lower than the content of Mg element, helps to promote the formation of strengthening phases of Mg and Si elements, thereby helping to improve the yield strength, tensile strength and elongation of the cover plate and the flow channel plate. Controlling the content of Cu and Zn elements in the 6XXX series aluminum alloy within the above range helps to promote the formation of strengthening phases between Cu and Zn elements and aluminum elements, thereby helping to further improve the yield strength, tensile strength and elongation of the cover plate and the flow channel plate. The presence of Mn, Zr and Cr elements helps to refine the grains. Controlling the content of Mn, Zr and Cr elements within the above range helps to cooperate with other elements in the 6XXX series aluminum alloy, thereby helping to further refine the grains, and then helping to improve the yield strength, tensile strength and elongation of the cover plate and the runner plate. In addition, the present application can have a higher iron content, which helps to reduce the production cost of the cover plate and the runner plate. Therefore, the cover plate and runner plate of the present application not only have higher yield strength, tensile strength and elongation, but also can improve the structural strength of the liquid cooling plate, so that the liquid cooling plate can support the battery module, reduce the weight of the battery system, meet the lightweight goal, and also can reduce the production cost of the liquid cooling plate. And there is no need to process the bracket, so that the processing steps of the battery system can be reduced to avoid negative pollution to the air environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0020] Figure 1 It shows a front view of a cover plate provided according to the first embodiment of the present invention;

[0021] Figure 2 It shows a front view of a flow channel plate provided according to the first embodiment of the present invention;

[0022] Figure 3 It shows a schematic structural diagram of a flow channel plate provided according to the first embodiment of the present invention;

[0023] Figure 4 It shows a schematic structural diagram of a liquid cooling plate provided according to the first embodiment of the present invention;

[0024] Figure 5 It shows a front view of a liquid cooling plate provided according to the first embodiment of the present invention;

[0025] Figure 6 An exploded view of a liquid cooling plate provided according to a second embodiment of the present invention is shown;

[0026] Figure 7 It shows a schematic structural diagram of a liquid cooling plate provided according to the second embodiment of the present invention;

[0027] Figure 8 A schematic diagram of the structure of the cover plate and the flow channel plate according to the first embodiment of the present invention is shown;

[0028] Fig. 9 shows the grain structure diagram of the composite plate A in Example 7 of the present application;

[0029] Fig.10 The burnt structure diagram of the composite board A in Comparative Example 2 of the present application is shown;

[0030] Fig.11 The grain structure diagram of the composite plate A in Comparative Example 4 of the present application is shown;

[0031] Fig.12 The metallographic structure diagram of the composite plate B in Example 27 of the present application is shown.

[0032] The above drawings include the following reference numerals:

[0033] 10. Cover plate;

[0034] 11. first upper protective layer; 12. first core material layer; 13. first lower protective layer;

[0035] 20. Runner plate;

[0036] 21. second upper protective layer; 22. second core material layer; 23. second lower protective layer; 24. first welding layer; 25. circulation channel;

[0037] 30. Support plate;

[0038] 31. Support bulge;

[0039] 40. Reinforcement plate. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] like Figures 1 to 5 and Figure 8 As shown, the first embodiment of the present application provides a liquid cooling plate, which includes a cover plate 10 and a flow channel plate 20. The cover plate 10 has a first upper protective layer 11, a first core material layer 12 and a first lower protective layer 13, and the first upper protective layer 11 and the first lower protective layer 13 are respectively located on both sides of the first core material layer 12. The flow channel plate 20 has a second upper protective layer 21, a second core material layer 22, a second lower protective layer 23 and a first welding layer 24, and the second upper protective layer 21 and the second lower protective layer 23 are respectively located on both sides of the second core material layer 22, and the first welding layer 24 is located on the side of the second upper protective layer 21 away from the second core material layer 22. The cover plate 10 is arranged on the flow channel plate 20, and the first welding layer 24 is used to fix the first lower protective layer 13 and the flow channel plate 20. The flow channel plate 20 is provided with a circulation channel 25 on the side facing the cover plate 10, and the circulation channel 25 is used to circulate fluid. The first core material layer 12 and the second core material layer 22 are both 6XXX series aluminum alloys. In terms of mass percentage, the 6XXX series aluminum alloys include the following elements: Si element content of 0.3~0.7%, Mg element content of 0.6~0.9%, Cu element content of 0.1~0.3%, Zn element content of 0.05~0.3%, Mn element content of 0.01~0.15%, Zr element content of 0.01~0.08%, Cr element content of 0.001~0.1%, Ti element content of 0.001~0.04%, Fe element content of 0.05~0.6%, and the Si element content is lower than the Mg element content, the total content of inevitable impurities is ≤0.15wt%, the content of a single impurity is lower than 0.05wt%, and the balance is Al element.

[0042] Applying the technical solution of the present application, the cover plate 10 has a first core material layer 12, the flow channel plate 20 has a second core material layer 22, the first core material layer 12 and the second core material layer 22 are both 6XXX aluminum alloys, the cover plate 10 is placed on the flow channel plate 20, and the flow channel plate 20 is provided with a circulation channel 25 on the side facing the cover plate 10, and the circulation channel 25 is used to circulate fluid. In this way, the heat dissipation of the liquid cooling plate is achieved by passing a refrigerant into the circulation channel 25. At the same time, controlling the content of Mg and Si elements in the 6XXX aluminum alloy within the above range, and controlling the content of Si element to be lower than the content of Mg element, helps to promote the formation of strengthening phases between Mg and Si elements, thereby helping to improve the yield strength, tensile strength and elongation of the cover plate 10 and the flow channel plate 20. Controlling the content of Cu and Zn elements in the 6XXX aluminum alloy within the above range helps to promote the formation of strengthening phases between Cu and Zn elements and aluminum elements, thereby helping to further improve the yield strength, tensile strength and elongation of the cover plate 10 and the flow channel plate 20. The presence of Mn, Zr and Cr elements helps to refine the grains. Controlling the content of Mn, Zr and Cr elements within the above range helps to cooperate with other elements in the 6XXX series aluminum alloy, thereby helping to further refine the grains, and then helping to improve the yield strength, tensile strength and elongation of the cover plate 10 and the flow channel plate 20. In addition, the present application can have a higher iron content, which helps to reduce the production cost of the cover plate 10 and the flow channel plate 20. Therefore, the cover plate 10 and the flow channel plate 20 of the present application not only have higher yield strength, tensile strength and elongation, but also can improve the structural strength of the liquid cooling plate, so that the liquid cooling plate can support the battery module, reduce the weight of the battery system, meet the lightweight goal, and also can reduce the production cost of the liquid cooling plate. And there is no need to process the bracket, so that the processing steps of the battery system can be reduced, avoiding negative pollution to the air environment.

[0043] Among them, the 6XXX series aluminum alloy involved in the present application optimizes the alloy ratio of Mg and Si elements, and adjusts the quenching sensitivity of the material by adding trace alloy elements, which not only avoids the low-melting-point second phase dissolution and overburning of the alloy during the subsequent high-temperature brazing of the cover plate 10 and the flow channel plate 20, but also reduces the precipitation rate of the Mg2Si precipitation phase in the material when the cover plate 10 and the flow channel plate 20 are naturally cooled in the brazing furnace, thereby ensuring that the material can have higher strength performance after artificial aging treatment.

[0044] In the present application, the cover plate 10 is made of composite plate A, and the flow channel plate 20 is made of composite plate B.

[0045] In order to further improve the yield strength, tensile strength and elongation of the composite plate A, in one embodiment of the present application, the 6XXX series aluminum alloy preferably includes the following elements, by mass percentage: the content of Si element is 0.3-0.6%, the content of Mg element is 0.7-0.9%, the content of Cu element is 0.2-0.3%, the content of Zn element is 0.2-0.3%, the content of Mn element is 0.01-0.15%, the content of Zr element is 0.01-0.05%, the content of Cr element is 0.001-0.05%, the content of Ti element is 0.02-0.04%, the content of Fe element is 0.25-0.6%, and the content of Si element is lower than that of Mg element, the total content of inevitable impurities is ≤0.15wt%, the content of single impurity is less than 0.05wt%, and the balance is Al element.

[0046] In order to further improve the yield strength, tensile strength and elongation of the composite plate B, in one embodiment of the present application, the 6XXX series aluminum alloy preferably includes the following elements, by mass percentage: the Si element content is 0.45-0.7%, the Mg element content is 0.8-0.9%, the Cu element content is 0.15-0.25%, the Zn element content is 0.15-0.25%, the Mn element content is 0.02-0.15%, the Zr element content is 0.04-0.08%, the Cr element content is 0.01-0.1%, the Ti element content is 0.03-0.04%, the Fe element content is 0.25-0.6%, and the Si element content is lower than the Mg element content, the total content of inevitable impurities is ≤0.15wt%, the content of a single impurity is less than 0.05wt%, and the balance is Al element.

[0047] Preferably, in the present application, the mass ratio of Si element to Mg element of 6XXX series aluminum alloy is 0.50~0.67:1. The mass ratio of Cu element to Zn element is 1~2:1. The mass ratio of Mn element, Zr element and Cr element is 1:0.27~4:0.5~0.7. Among them, the 6XXX series aluminum alloys of composite plate A and composite plate B are all within this range. In this way, controlling the mass ratio of Si element to Mg element within the above range helps to further improve the interaction between Si element and Mg element, thereby helping to further promote the formation of strengthening phase between Mg element and Si element, and then helping to improve the yield strength, tensile strength and elongation of composite plate B. Controlling the mass ratio of Cu element to Zn element within the above range helps to further improve the interaction between Cu element and Zn element, thereby helping to further promote the formation of strengthening phase between Cu element and Zn element and aluminum element, and then helping to further improve the yield strength, tensile strength and elongation of composite plate B. Controlling the mass ratio of Mn, Zr and Cr elements within the above range helps to improve the interaction between Mn, Zr and Cr elements, thereby helping to further refine the grains, and further helping to further improve the yield strength, tensile strength and elongation of the composite plate B.

[0048] However, in this application, after actual production:

[0049] In composite plate A, the mass ratio of Si element to Mg element is 0.33~0.67:1, specifically 0.33:1, 0.40:1, 0.45:1, 0.50:1, 0.55:1, 0.60:1, 0.67:1 and the range value between any two ratios; and / or the mass ratio of Cu element to Zn element is 1~2:1, specifically 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2:1 and the range value between any two ratios; and / or the mass ratio of Mn element, Zr element and Cr element is 1:0.07~4:0.007~4.

[0050] Furthermore, the mass ratio of the Ti element to the Fe element is 11-14:1, specifically 11:1, 11.5:1, 12:1, 12.5:1, 13:1, 13.5:1, 14:1 and a range value between any two ratios.

[0051] The presence of Ti element helps to stabilize the precipitated phase in the material, reduces the aggregation of the precipitated phase during the aging treatment, and helps to improve its uniform distribution. The presence of Fe element helps to promote the stability of these precipitated phases, further improving the strength and hardness of the material. Controlling the mass ratio of Ti element to Fe element within the above range helps to optimize the distribution of precipitation strengthening phases, thereby helping to further improve the yield strength, tensile strength and elongation of the composite plate A.

[0052] In composite plate B, the mass ratio of Si element to Mg element is 0.50~0.76:1, specifically 0.50:1, 0.55:1, 0.60:1, 0.65:1, 0.70:1, 0.76:1 and a range value between any two ratios; and / or the mass ratio of Cu element to Zn element is 1~2:1, specifically 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2:1 and a range value between any two ratios; and / or the mass ratio of Mn element, Zr element and Cr element is 1:0.27~4:0.5~0.7.

[0053] Furthermore, the mass ratio of the Ti element to the Fe element is 0.10-0.15:1, specifically 0.10:1, 0.11:1, 0.12:1, 0.13:1, 0.14:1, 0.15:1 and a range value between any two ratios.

[0054] In this way, the presence of the Ti element helps to stabilize the precipitated phase in the material, reduces the aggregation of the precipitated phase during the aging treatment, and helps to improve its uniform distribution. The presence of the Fe element helps to promote the stability of these precipitated phases, further improving the strength and hardness of the material. Controlling the mass ratio of the Ti element to the Fe element within the above range helps to optimize the distribution of the precipitation strengthening phase, thereby helping to further improve the yield strength, tensile strength and elongation of the composite plate B.

[0055] like Figure 1 and Figure 2 As shown, the first upper protective layer 11, the first lower protective layer 13, the second upper protective layer 21 and the second lower protective layer 23 are 3XXX series aluminum alloys, which are selected from any one or more of 3003 alloy, 3004 alloy and 3105 alloy. The first welding layer 24 is 4XXX series aluminum alloy, which is selected from any one or more of 4004 alloy, 4045 alloy, 4047 alloy, 4104 alloy, 4147 alloy and 4343 alloy.

[0056] In this way, the present application arranges the 6XXX series aluminum alloy between the 3XXX series aluminum alloy, which helps to prevent the high-temperature volatilization of the Mg element in the 6XXX series aluminum alloy, thereby helping to improve the high temperature resistance of the cover plate 10 and the flow channel plate 20. In addition, the 3XXX series aluminum alloy has a high corrosion resistance. The 6XXX series aluminum alloy is arranged between the 3XXX series aluminum alloy, which helps to improve the corrosion resistance of the cover plate 10 and the flow channel plate 20. The effect of the 4XXX series aluminum alloy enables the composite plate B to be brazed with other aluminum alloy plates. In addition, in the present application, the first upper protective layer 11, the first lower protective layer 13, the second upper protective layer 21, the second lower protective layer 23 and the first welding layer 24 are selected from conventional alloy materials, which can reduce the cost of the cover plate 10 and the flow channel plate 20.

[0057] The thickness of the cover plate 10 and / or the flow channel plate 20 is set between 0.5 mm and 3.0 mm.

[0058] Specifically, in the present application, the thickness of the composite plate A is 0.5~3.0mm. Optionally, the thickness of the composite plate A may be 0.5mm, 1.5mm or 3.0mm. In the present application, the thickness of the composite plate A is 1.5mm. The average grain size of the composite plate A is 70~100μm. The yield strength of the composite plate A is ≥165MPa. The tensile strength of the composite plate A is ≥215MPa. The elongation of the composite plate A is ≥13.0%. Preferably, the yield strength of the composite plate A is 175~185MPa. The tensile strength of the composite plate A is 224~241MPa. The elongation of the composite plate A is 14.0~16.5%.

[0059] Controlling the average grain size of the composite plate A within the above range is helpful to further improve the yield strength, tensile strength and elongation of the composite plate A. The composite plate A having the above yield strength, tensile strength and elongation is more suitable for a liquid cooling plate.

[0060] Among them, in the present application, the thickness of the composite plate B is preferably 0.5~2.0mm. Optionally, the thickness of the composite plate B can be 0.5mm, 1.0mm or 2.0mm. In the present application, the thickness of the composite plate B is 1.0mm. The average grain size of the composite plate B is 80~90μm. The yield strength of the composite plate B is ≥156MPa. The tensile strength of the composite plate B is ≥205MPa. The elongation of the composite plate B is ≥14.3%. Preferably, the yield strength of the composite plate B is 167~175MPa; the tensile strength of the composite plate B is 215~219MPa; and the elongation of the composite plate B is 15.2~15.5%.

[0061] Controlling the thickness of the composite plate B within the above range helps to improve the stamping performance of the composite plate B, and controlling the average grain size of the composite plate B within the above range helps to further improve the yield strength, tensile strength and elongation of the composite plate B. The composite plate B having the above yield strength, tensile strength and elongation is more suitable for a liquid cooling plate.

[0062] Furthermore, the ratio of the thickness of the first upper protective layer 11 and the first lower protective layer 13 to the overall thickness of the cover plate 10 is set between 10% and 15%. The ratio of the thickness of the second upper protective layer 21 and the second lower protective layer 23 to the overall thickness of the flow channel plate 20 is set between 10% and 15%. The ratio of the first welding layer 24 to the overall thickness of the flow channel plate 20 is set between 8% and 10%. In this way, the proportion of the first core material layer 12 and the second core material layer 22 can be guaranteed, thereby ensuring the structural strength of the cover plate 10 and the flow channel plate 20 and improving the service life of the liquid cooling plate.

[0063] Among them, in this application, the first upper protective layer 11 is made of 3003 alloy, and its thickness accounts for 15% of the thickness of the entire composite plate A; the first lower protective layer 13 is made of 3003 alloy, and its thickness accounts for 8% of the thickness of the entire composite plate A. In this way, the first upper protective layer 11 and the first lower protective layer 13 prevent the Mg element from diffusing to the surface and affecting the brazing effect; the smaller the proportion of the first upper protective layer 11 and the first lower protective layer 13, the greater the proportion of the first core material layer 12, and accordingly, the higher the aging strengthening performance of the composite plate. After the brazing process, the first core material layer 12 can be artificially aged heat treated, and the yield strength of the liquid cooling plate structure performance is greater than the target of 160MPa.

[0064] Specifically, in the present application, the first welding layer 24 is made of the commonly used AL-Si 4045 alloy, and its thickness accounts for 8% of the thickness of the entire composite plate B, and the thickness of the second core material layer 22 accounts for 68% of the overall thickness of the composite plate B. After the brazing process, the second core material layer 22 can be subjected to artificial aging heat treatment to achieve the requirement of a yield strength greater than 160 MPa in the structural performance of the liquid cooling plate.

[0065] In one embodiment of the present application, a method for preparing a composite plate A is provided, the method comprising:

[0066] Step S1, sequentially slitting and performing a first hot rolling process on a 3XXX series aluminum alloy ingot to obtain a first layer of hot rolled plate and a third layer of hot rolled plate, and performing surface milling on a 6XXX series aluminum alloy ingot to obtain a second layer of cast plate;

[0067] Step S2, stacking the first layer of hot-rolled plate, the second layer of cast plate and the third layer of hot-rolled plate in sequence, and then welding and fixing them, performing a second hot rolling treatment and a cold rolling treatment in sequence to obtain a composite plate A.

[0068] In step S1, the 3XXX series aluminum alloy ingots and the 6XXX series aluminum alloy ingots are pre-treated to obtain a first layer hot-rolled plate, a second layer cast plate and a third layer hot-rolled plate of appropriate specifications.

[0069] In step S2, the first layer of hot-rolled plate, the second layer of cast plate and the third layer of hot-rolled plate are stacked and welded in sequence, which helps to closely combine the first layer of hot-rolled plate, the second layer of cast plate and the third layer of hot-rolled plate to form a strong interlayer interface. The second hot rolling treatment helps to promote the uniform distribution of alloy elements in the aluminum matrix, while the grains are refined, which is conducive to the formation of a microstructure that improves the strength and ductility of the material. The cold rolling treatment helps to accurately control the thickness of the composite plate A and improve the surface finish of the composite plate A.

[0070] In one embodiment of the present application, the thickness ratio of the first layer of hot-rolled plate, the second layer of cast plate and the third layer of hot-rolled plate is 101-106:400-410:62-67.

[0071] The presence of the first layer of hot-rolled plate and the third layer of hot-rolled plate helps to improve the corrosion resistance and high temperature stability of the composite plate A, the presence of the second layer of cast plate helps to improve the yield strength, tensile strength and elongation of the composite plate A, and controlling the thickness ratio of the first layer of hot-rolled plate, the second layer of cast plate and the third layer of hot-rolled plate within the above range helps to improve the mutual synergy between the three, thereby helping to improve the comprehensive performance of the composite plate A, making it more suitable for liquid cooling plates.

[0072] In one embodiment of the present application, the temperature of the second hot rolling treatment is 480-490° C.; and / or the thickness of the plate after the second hot rolling treatment is 3.0-6.0 mm.

[0073] Controlling the temperature of the second hot rolling treatment within the above range helps to promote the refinement and homogenization of the internal grains, thereby helping to improve the yield strength, tensile strength and elongation of the composite plate A. Controlling the thickness of the plate after the second hot rolling treatment within the above range helps to control the thickness of the composite plate A finally formed.

[0074] In one embodiment of the present application, the above step S2 further includes sequentially performing annealing treatment, brazing treatment and aging treatment on the plate obtained after the cold rolling treatment to obtain a composite plate A.

[0075] The purpose of annealing is to eliminate the work hardening produced during the cold rolling process and restore the plasticity of the material. Brazing treatment helps to form a strong metallurgical bond between the layers of the composite plate, enhances the overall structural strength of the composite plate, and enables it to withstand the weight of the battery module without the need for additional steel support reinforcement. The role of aging treatment is to further improve the yield strength and tensile strength of the composite plate through the precipitation strengthening mechanism while maintaining sufficient elongation. Preferably, the above-mentioned brazing treatment is carried out in a brazing chain furnace. The above-mentioned annealing treatment is carried out in a box furnace or an air cushion furnace.

[0076] In one embodiment of the present application, the temperature of the annealing treatment is 320~420°C; and / or, the holding time of the annealing treatment is 2~8h; and / or, the holding time of the brazing treatment is 20~60min; and / or, the temperature of the aging treatment is 200~240°C; and / or, the holding time of the aging treatment is 20~40min.

[0077] Among them, in the present application, the composite plate A needs to pass through 6 brazing zones during the brazing process, and the 6 brazing zones are brazing zone 1, brazing zone 2, brazing zone 3, brazing zone 4, brazing zone 5 and brazing zone 6. The temperature of brazing zone 1 is set between 580°C and 590°C, the temperature of brazing zone 2 is set between 600°C and 610°C, the temperature of brazing zone 3 is set between 610°C and 615°C, the temperature of brazing zone 4 is set between 615°C and 620°C, the temperature of brazing zone 5 is set between 620°C and 625°C, and the temperature of brazing zone 6 is set between 620°C and 625°C.

[0078] Furthermore, when the composite plate A passes through the six brazing zones, the speed of the composite plate A is between 800 mm / min and 1000 mm / min. Optionally, the speed of the composite plate A may be 800 mm / min, 900 mm / min or 1000 mm / min. In the present application, the speed of the composite plate A is 900 mm / min.

[0079] Controlling the temperature and time of annealing treatment within the above ranges helps to eliminate the work hardening of the composite plate after cold rolling, while reducing the overheating decomposition of alloy elements and maintaining the original composition of the material. Controlling the temperature and time of brazing treatment within the above ranges helps to improve the interaction between the layers and reduce the risk of overburning of composite plate A. Controlling the temperature and time of aging treatment within the above ranges helps to optimize the microstructure of the composite plate, thereby helping to improve the yield strength, tensile strength and elongation of composite plate A.

[0080] The beneficial effects of the present application will be further illustrated below in conjunction with embodiments.

[0081] Example 7: Measured by mass percentage, the element ratio of 6XXX series alloy ingot is: 0.4% Si element, 0.7% Mg element, 0.2% Cu element, 0.2% Zn element, 0.1% Mn element, 0.05% Zr element, 0.05% Cr element, 0.02% Ti element, 0.25% Fe element, and the balance is aluminum element.

[0082] The 3003 alloy ingot was cut and hot-rolled in sequence to obtain a first layer of hot-rolled plate of 101 mm and a third layer of hot-rolled plate of 62 mm. The 6XXX alloy ingot was milled to obtain a second layer of cast plate of 410 mm, and then the surface was cleaned. The first layer of hot-rolled plate, the second layer of cast plate and the third layer of hot-rolled plate were stacked in sequence, the edges were fixed by argon arc welding, and then hot-rolled at 490°C for a second time, hot-rolled to 6.0 mm, and then cold-rolled to finally obtain a cold-rolled plate with a thickness of 1.5 mm. The cold-rolled plate was annealed at a temperature of 380°C for 3 hours, and the annealed plate was brazed at 620°C for 40 minutes. The cooled plate was aged at 240°C for 40 minutes to obtain a composite plate A. Figure 1 As shown, it includes a first lower protective layer 13, a first core material layer 12 and a first upper protective layer 11 stacked in sequence.

[0083] Example 8: The difference from Example 7 is that the content of Si element is 0.3%, and the content of Mg element is 0.6%, and finally a composite plate A is obtained.

[0084] Example 9: The difference from Example 7 is that the content of Si element is 0.3%, and the content of Mg element is 0.9%, and finally a composite plate A is obtained.

[0085] Example 10: The difference from Example 7 is that the content of Si element is 0.6%, and the content of Mg element is 0.9%, and finally a composite plate A is obtained.

[0086] Example 11: The difference from Example 7 is that the content of Si element is 0.5%, and the content of Mg element is 0.9%, and finally a composite plate A is obtained.

[0087] Example 12: The difference from Example 7 is that the content of Si element is 0.5%, and the content of Mg element is 0.8%, and finally a composite plate A is obtained.

[0088] Example 13: The difference from Example 7 is that the content of Cu element is 0.1%, the content of Zn element is 0.05%, and finally a composite plate A is obtained.

[0089] Example 14: The difference from Example 7 is that the content of Cu element is 0.1%, the content of Zn element is 0.1%, and finally a composite plate A is obtained.

[0090] Example 15: The difference from Example 7 is that the content of Cu element is 0.3%, the content of Zn element is 0.3%, and finally a composite plate A is obtained.

[0091] Example 16: The difference from Example 7 is that the content of Mn element is 0.1%, the content of Zr element is 0.01%, and the content of Cr element is 0.08%, and finally a composite plate A is obtained.

[0092] Example 17: The difference from Example 7 is that the content of Mn element is 0.01%, the content of Zr element is 0.04%, and the content of Cr element is 0.04%, and finally a composite plate A is obtained.

[0093] Example 18: The difference from Example 7 is that the content of Mn element is 0.15%, the content of Zr element is 0.01%, and the content of Cr element is 0.001%, and finally a composite plate A is obtained.

[0094] Example 19: The difference from Example 7 is that the annealing treatment, brazing treatment and aging treatment are cancelled, and the plate after cold rolling is used as composite plate A.

[0095] Example 20: The difference from Example 7 is that the content of Si element is 0.6%, and the content of Mg element is 0.8%, and finally a composite plate A is obtained.

[0096] Example 21: The difference from Example 7 is that the content of Cu element is 0.2%, and the content of Zn element is 0.3%, and finally a composite plate A is obtained.

[0097] Example 22: The difference from Example 7 is that the content of Mn element is 0.01%, the content of Zr element is 0.05%, and the content of Cr element is 0.05%, and finally a composite plate A is obtained.

[0098] Example 23: The difference from Example 7 is that the temperature of the brazing treatment is 600°C, the holding time is 60 min, the temperature of the aging treatment is 200°C, and the holding time of the aging treatment is 20 min, and finally a composite plate A is obtained.

[0099] Example 24: The difference from Example 7 is that the temperature of the brazing treatment is 550°C, the holding time is 90 minutes, the temperature of the aging treatment is 150°C, and the holding time of the aging treatment is 50 minutes, and finally a composite plate A is obtained.

[0100] Example 25: The difference from Example 7 is that the thickness of the first layer of hot-rolled plate is 106 mm, the thickness of the second layer of cast plate is 400 mm, and the thickness of the third layer of hot-rolled plate is 67 mm, and finally a composite plate A is obtained.

[0101] Example 26: The difference from Example 7 is that the thickness of the first layer of hot-rolled plate is 110 mm, the thickness of the second layer of cast plate is 393 mm, and the thickness of the third layer of hot-rolled plate is 70 mm, and finally a composite plate A is obtained.

[0102] Comparative Example 1: The difference from Example 7 is that the content of Si element is 0.2%, and the content of Mg element is 0.4%, and finally a composite plate A is obtained.

[0103] Comparative Example 2: The difference from Example 7 is that the content of Si element is 0.8%, and the content of Mg element is 0.5%, and finally a composite plate A is obtained.

[0104] Comparative Example 3: The difference from Example 7 is that the addition of Cu and Zn elements in the 6XXX series alloy ingot is eliminated, and finally a composite plate A is obtained.

[0105] Comparative Example 4: The difference from Example 7 is that the addition of Mn element, Zr element and Cr element in the 6XXX series alloy ingot is eliminated, and finally a composite plate A is obtained.

[0106] The composite plate A prepared in the embodiment and the comparative example was tested for average grain size, yield strength, tensile strength and elongation, and whether the composite plate A was overburned was observed. The test results are shown in Table 1.

[0107] Table 1

[0108]

[0109] Fig. 9 The grain structure diagram of the composite plate A in Example 7 of the present application is shown in FIG. Fig. 9 The average grain size can be measured to be 80 μm.

[0110] Fig.10 The burnt structure diagram of the composite board A in Comparative Example 2 of the present application is shown. Fig.10 It can be seen that the tissue is overburned.

[0111] Fig.11 The grain structure diagram of the composite plate A in Comparative Example 4 of the present application is shown. Fig.11 The average grain size can be measured to be 197 μm.

[0112] In one embodiment of the present application, a method for preparing a composite board B is provided, the method comprising:

[0113] Step S1, sequentially performing slitting and a first hot rolling treatment on a 3XXX series aluminum alloy ingot to obtain a first layer of hot rolled plate and a third layer of hot rolled plate, performing surface milling on a 6XXX series aluminum alloy ingot to obtain a second layer of cast plate, and performing a third hot rolling treatment on a 4XXX series aluminum alloy ingot to obtain a fourth layer of hot rolled plate;

[0114] Step S2, stacking the first layer of hot-rolled plate, the second layer of cast plate, the third layer of hot-rolled plate and the fourth layer of hot-rolled plate in sequence, and then welding and fixing, performing a second hot rolling treatment, a cold rolling treatment and an annealing treatment in sequence to obtain a composite plate B.

[0115] In step S1, 3XXX series aluminum alloy ingots, 6XXX series aluminum alloy ingots and 4XXX series aluminum alloy ingots are pre-treated to obtain a first layer hot-rolled plate, a second layer cast plate, a third layer hot-rolled plate and a fourth layer hot-rolled plate of suitable specifications.

[0116] In step S2, the first layer of hot rolled plate, the second layer of cast plate, the third layer of hot rolled plate and the fourth layer of hot rolled plate are stacked and welded in sequence, which helps to tightly combine the first layer of hot rolled plate, the second layer of cast plate, the third layer of hot rolled plate and the fourth layer of hot rolled plate to form a strong interlayer interface. The second hot rolling treatment helps to promote the uniform distribution of alloy elements in the aluminum matrix, while the grains are refined, which is conducive to the formation of a microstructure that improves the strength and ductility of the material. The cold rolling treatment helps to accurately control the thickness of the composite plate B and improve the surface finish of the composite plate B. The annealing treatment helps to eliminate the work hardening caused by the cold rolling process and restore the plasticity of the material, thereby helping to reduce the cracking of the composite plate B during the stamping process.

[0117] In one embodiment of the present application, the thickness ratio of the first layer of hot-rolled plate, the second layer of cast plate, the third layer of hot-rolled plate and the fourth layer of hot-rolled plate is 90~100:400~410:66~76:39~49.

[0118] The 6XXX series aluminum alloy of the second layer of cast plate provides corresponding strength for the composite plate. The 3XXX series aluminum alloy in the first layer of hot-rolled plate and the third layer of hot-rolled plate acts as a protective layer, which helps to reduce the high-temperature volatilization of the Mg element in the second layer of cast plate, and helps to improve the performance stability of the composite plate. The 4XXX series aluminum alloy of the fourth layer of hot-rolled plate acts as a solder layer, which helps to improve the bonding force between the composite plate and other aluminum alloy plates. Controlling the thickness ratio of the first layer of hot-rolled plate, the second layer of cast plate, the third layer of hot-rolled plate and the fourth layer of hot-rolled plate within the above range helps to give full play to the interaction between the components, thereby helping to improve the yield strength, tensile strength and elongation of composite plate B while improving the stamping performance of composite plate B.

[0119] In one embodiment of the present application, the temperature of the second hot rolling treatment is 480~490°C; and / or the thickness of the plate after the second hot rolling treatment is 3.0~6.0mm; and / or the temperature of the annealing treatment is 380~440°C; and / or the holding time of the annealing treatment is 4~6h.

[0120] Controlling the temperature of the second hot rolling treatment within the above range helps to promote the uniform distribution of alloy elements and reduce abnormal grain growth while ensuring the plasticity of the material, thereby helping to optimize the microstructure of the composite plate and enhance the interlayer bonding strength. Controlling the thickness of the plate after the second hot rolling treatment within the above range helps to provide a good foundation for the subsequent cold rolling treatment, improve the deformation uniformity of the material during the cold rolling process, and reduce the risk of cracking or delamination. Controlling the temperature and holding time of the annealing treatment within the above range helps to eliminate work hardening during the cold rolling process and reduce the risk of alloy element decomposition and performance degradation caused by high temperature.

[0121] In one embodiment of the present application, the above step S2 further includes sequentially performing brazing treatment and aging treatment on the plate obtained after annealing treatment to obtain a composite plate B. Figure 2 As shown, it includes a second lower protective layer 23, a second core material layer 22, a second upper protective layer 21 and a first welding layer 24 stacked in sequence.

[0122] Brazing treatment helps to enhance the bonding strength between the layers of composite plate B and improve the stability and bearing capacity of the overall structure. Aging treatment helps to improve the uniformity of the distribution of precipitated phases in the alloy, thereby helping to improve the yield strength, tensile strength and elongation of the material.

[0123] In one embodiment of the present application, the holding time of the brazing treatment is 20 to 60 minutes; and / or, the temperature of the aging treatment is 200 to 240° C.; and / or, the holding time of the aging treatment is 20 to 40 minutes.

[0124] Among them, in the present application, the composite plate B needs to pass through 6 brazing zones during the brazing process, and the 6 brazing zones are brazing zone 1, brazing zone 2, brazing zone 3, brazing zone 4, brazing zone 5 and brazing zone 6. The temperature of brazing zone 1 is set between 580°C and 590°C, the temperature of brazing zone 2 is set between 600°C and 610°C, the temperature of brazing zone 3 is set between 610°C and 615°C, the temperature of brazing zone 4 is set between 615°C and 620°C, the temperature of brazing zone 5 is set between 620°C and 625°C, and the temperature of brazing zone 6 is set between 620°C and 625°C.

[0125] Furthermore, when the composite plate B passes through the six brazing zones, the speed of the composite plate B is between 800 mm / min and 1000 mm / min. Optionally, the speed of the composite plate B may be 800 mm / min, 900 mm / min or 1000 mm / min. In the present application, the speed of the composite plate B is 900 mm / min.

[0126] Controlling the brazing temperature and holding time within the above ranges helps reduce the risk of overburning of the 6XXX aluminum alloy during the brazing process and helps prevent damage to the mechanical properties of the 6XXX aluminum alloy. Controlling the aging temperature and holding time within the above ranges helps promote the uniform distribution of precipitated phases in the 6XXX aluminum alloy, which can significantly enhance the hardness and strength of the material without excessively sacrificing its ductility.

[0127] The beneficial effects of the present application will be further illustrated below in conjunction with embodiments.

[0128] Example 27: Measured in mass percentage, the element ratio of 6XXX series alloy ingot is: 0.45% Si element, 0.82% Mg element, 0.25% Cu element, 0.25% Zn element, 0.15% Mn element, 0.04% Zr element, 0.1% Cr element, 0.03% Ti element, 0.25% Fe element, and the balance is aluminum element.

[0129] The 3003 alloy ingot was cut and hot-rolled in sequence to obtain a first layer of hot-rolled plate with a thickness of 90 mm and a third layer of hot-rolled plate with a thickness of 66 mm. The 6XXX series alloy ingot was milled to obtain a second layer of cast plate with a thickness of 410 mm. The 4045 alloy ingot was hot-rolled for the third time to obtain a fourth layer of hot-rolled plate with a thickness of 49 mm. The surface was then cleaned. The first layer of hot-rolled plate, the second layer of cast plate, the third layer of hot-rolled plate and the fourth layer of hot-rolled plate were stacked in sequence, and the edges were fixed by argon arc welding. Then, they were composite hot-rolled at 480°C to 6.0 mm, and then cold-rolled to a cold-rolled plate with a thickness of 1.2 mm. The cold-rolled plate was annealed at 380°C for 6 hours, and then brazed at 620°C for 20 minutes. After cooling, it was aged at 220°C for 40 minutes to obtain a composite plate B. Figure 2 As shown, it includes a first welding layer 24, a second upper protective layer 21, a second core material layer 22 and a second lower protective layer 23 stacked in sequence.

[0130] Example 28: The difference from Example 27 is that the content of Si element is 0.68%, the content of Mg element is 0.89%, and finally a composite plate B is obtained.

[0131] Example 29: The difference from Example 27 is that the content of Si element is 0.31%, the content of Mg element is 0.62%, and finally a composite plate B is obtained.

[0132] Example 30: The difference from Example 27 is that the content of Cu element is 0.15%, the content of Zn element is 0.15%, and finally a composite plate B is obtained.

[0133] Example 31: The difference from Example 27 is that the content of Mn element is 0.02%, the content of Zr element is 0.08%, and the content of Cr element is 0.01%, and finally a composite plate B is obtained.

[0134] Example 32: The difference from Example 27 is that the content of Si element is 0.7%, the content of Mg element is 0.9%, and finally a composite plate B is obtained.

[0135] Example 33: The difference from Example 27 is that the content of Cu element is 0.15%, the content of Zn element is 0.25%, and finally a composite plate B is obtained.

[0136] Example 34: The difference from Example 27 is that the content of Mn element is 0.02%, the content of Zr element is 0.08%, and the content of Cr element is 0.1%, and finally a composite plate B is obtained.

[0137] Example 35: The difference from Example 27 is that the content of Ti element is 0.03%, the content of Fe element is 0.6%, and finally a composite plate B is obtained.

[0138] Example 36: The difference from Example 27 is that the thickness of the first layer of hot-rolled plate is 100 mm, the thickness of the second layer of cast plate is 400 mm, the thickness of the third layer of hot-rolled plate is 76 mm, and the thickness of the fourth layer of hot-rolled plate is 39 mm, and finally a composite plate B is obtained.

[0139] Example 37: The difference from Example 27 is that the thickness of the first layer of hot-rolled plate is 110 mm, the thickness of the second layer of cast plate is 390 mm, the thickness of the third layer of hot-rolled plate is 86 mm, and the thickness of the fourth layer of hot-rolled plate is 29 mm, and finally a composite plate B is obtained.

[0140] Example 38: The difference from Example 27 is that the annealing temperature is 440°C, the annealing holding time is 4 hours, and finally a composite plate B is obtained.

[0141] Example 39: The difference from Example 27 is that the annealing temperature is 450°C, the annealing holding time is 3 hours, and finally a composite plate B is obtained.

[0142] Example 40: The difference from Example 27 is that the temperature of the brazing treatment is 600°C, the holding time is 60 min, the temperature of the aging treatment is 240°C, and the holding time of the aging treatment is 20 min, and finally a composite plate B is obtained.

[0143] Example 41: The difference from Example 27 is that the temperature of the brazing treatment is 550°C, the holding time is 90 minutes, the temperature of the aging treatment is 150°C, and the holding time of the aging treatment is 50 minutes, and finally a composite plate B is obtained.

[0144] Comparative Example 5: The difference from Example 27 is that the annealing treatment, brazing treatment and aging treatment are cancelled, and the plate after cold rolling is directly used as composite plate B.

[0145] Comparative Example 6: The difference from Example 27 is that the content of Si element is 0.85%, the content of Mg element is 0.65%, and finally a composite plate B is obtained.

[0146] Comparative Example 7: The difference from Example 27 is that the addition of Mn element, Zr element and Cr element in the 6XXX series alloy ingot is cancelled, and finally a composite plate B is obtained.

[0147] Comparative Example 8: The difference from Example 27 is that the addition of Cu and Zn elements in the 6XXX series alloy ingot is eliminated, and finally a composite plate B is obtained.

[0148] The composite plate B prepared in the embodiment and the comparative example was tested for average grain size, yield strength, tensile strength and elongation, and the stamping condition and overburning of the composite plate B were observed. The test results are shown in Table 2.

[0149] Table 2

[0150]

[0151] Fig.12 This is the metallographic structure diagram of the composite plate B in Example 27 of the present application, from Fig.12 It can be seen that the metallographic structure is distributed more evenly.

[0152] The aluminum alloy of the first core material layer 12 and the second core material layer 22 mainly uses Mg and Si as alloy elements. Such alloy elements have the characteristics of low melting points. In a high temperature environment of 600°C or above, alloy compounds are easily dissolved and overburned, which is an undesirable phenomenon that must not occur for the quality of liquid cooling plate products. This application has been professionally designed and optimized for the composition, and combined with industrial test analysis and demonstration, the alloy element range of the core material applied for can ensure that overburning will not occur in a temperature environment below 620°C.

[0153] like Figure 6and Figure 7 As shown, the second embodiment of the present application provides a liquid cooling plate, which is different from the first embodiment in that the liquid cooling plate also includes a support plate 30 and a plurality of reinforcing plates 40. The support plate 30 has a third core material layer, the flow channel plate 20 is arranged on the support plate 30, the support plate 30 is used to support the flow channel plate 20, and the third core material layer is a 6XXX series aluminum alloy. Multiple reinforcing plates 40 are arranged at intervals along the length direction of the support plate 30, and the length direction of the reinforcing plates 40 extends along the width direction of the support plate 30. Multiple reinforcing plates 40 all have a fourth core material layer, the support plate 30 is arranged on multiple reinforcing plates 40, and the fourth core material layer is a 6XXX series aluminum alloy. In this way, the support plate 30 and the reinforcing plate 40 can further improve the structural strength of the liquid cooling plate, further improve the supporting effect of the liquid cooling plate, thereby improving the reliability and scope of application of the liquid cooling plate. In addition, the multiple reinforcing plates 40 are distributed at intervals, which can reduce the weight of the liquid cooling plate while ensuring the structural strength of the liquid cooling plate.

[0154] Further, in this embodiment, the thickness of the composite board A used in the cover board 10 is set between 0.8 mm and 1.5 mm. Optionally, the thickness of the composite board A can be 0.8 mm, 1.0 mm or 1.5 mm. In this application, the thickness of the composite board A is 1.0 mm.

[0155] The thickness of the composite plate B used in the flow channel plate 20 is set between 0.8 mm and 1.2 mm. Optionally, the thickness of the composite plate B can be 0.8 mm, 1.0 mm or 1.2 mm. In the present application, the thickness of the composite plate B is 1.2 mm.

[0156] Specifically, the support plate 30 also has a third upper protective layer, a third lower protective layer and a second welding layer. The third upper protective layer and the third lower protective layer are respectively located on both sides of the third core material layer. The second welding layer is located on the side of the third upper protective layer away from the third core material layer. The second welding layer is used to fix the second lower protective layer 23 and the support plate 30.

[0157] The reinforcing plate 40 further comprises a fourth upper protective layer, a fourth lower protective layer and a third welding layer, wherein the fourth upper protective layer and the fourth lower protective layer are respectively located on both sides of the fourth core material layer, the third welding layer is located on a side of the fourth upper protective layer away from the fourth core material layer, and the third welding layer is used to fix the third lower protective layer and the reinforcing plate 40. The first upper protective layer 11, the first lower protective layer 13, the second upper protective layer 21, the second lower protective layer 23, the third upper protective layer, the third lower protective layer, the fourth upper protective layer and the fourth lower protective layer are 3XXX series aluminum alloys, and the first welding layer 24, the second welding layer and the third welding layer are 4XXX series aluminum alloys.

[0158] Among them, in the present application, the support plate 30 and the reinforcing plate 40 are also processed by the composite plate B, so that the brazing of the liquid cooling plate is facilitated while ensuring the structural strength of the support plate 30 and the reinforcing plate 40.

[0159] The structural properties of the liquid cooling plates in both Embodiment 1 and Embodiment 2 satisfy the following requirements: yield strength>160MPa, tensile strength>220MPa, and elongation>12%.

[0160] like Figure 7 As shown, a support protrusion 31 is provided on the support plate 30, and the support protrusion 31 is symmetrically arranged with the structure of the circulation channel 25, and the top of the support protrusion 31 abuts against the bottom of the circulation channel 25. Such an arrangement can ensure the support effect of the support plate 30 on the flow channel plate 20, thereby ensuring the structural strength of the liquid cooling plate.

[0161] Specifically, the support plate 30 and the flow channel plate 20 in the present application are the same part, and the components are reused, which reduces the manufacturing process and reduces the development cost.

[0162] Specifically, in the present application, the support plate 30 and the flow channel plate 20 are formed by stamping with the same mold, but during the stamping process, the third upper protective layer of the support plate 30 and the second upper protective layer 21 of the flow channel plate 20 are in opposite directions, that is, the composite plate B is forwardly stamped to form the flow channel plate 20, and the composite plate B is reversely stamped after turning 180° to form the support plate 30. During the assembly process, the support plate 30 and the flow channel plate 20 are placed in reverse, that is, the top of the support protrusion 31 abuts against the bottom of the circulation channel 25, so that the first welding layer 24 contacts the first lower protective layer 13, the second welding layer contacts the second lower protective layer 23, and the third welding layer contacts the third lower protective layer.

[0163] Furthermore, the width of the reinforcing plate 40 is set between 200 mm and 400 mm, and the length of the reinforcing plate 40 is set between 500 mm and 800 mm. In this way, while ensuring the reinforcing effect of the reinforcing plate 40, the volume of the reinforcing plate 40 can be reduced, thereby further reducing the weight of the liquid cooling plate.

[0164] Optionally, the width of the reinforcing plate 40 can be set to 200mm, 300mm or 400mm. In the present application, the width of the reinforcing plate 40 is 300mm. The length of the reinforcing plate 40 can be set to 500mm, 650mm or 800mm. In the present application, the length of the reinforcing plate 40 is 650mm.

[0165] According to the embodiments involved in this application, the battery liquid cooling plate has passed various relevant test verifications. When testing the liquid cooling plate, its yield strength exceeded 160MPa. From the perspective of performance comparison, compared with the liquid cooling plates currently developed and applied in the market, its strength performance has been improved by more than 2 times, which can effectively cope with the load brought by the battery module and ensure the stability of the liquid cooling plate structure and the heat dissipation effect. This has positive significance for achieving the overall lightweighting of the battery pack and reducing development costs, which is in line with the pursuit of the development of the new energy industry.

[0166] Among them, the third embodiment of the present application provides a power battery, which includes a plurality of first battery mold cores and the liquid cooling plate provided above, wherein the plurality of first battery mold cores are distributed on the cover plate 10 of the liquid cooling plate along the width direction of the liquid cooling plate, and a plurality of first mounting parts are arranged on the cover plate 10 along the length direction, and the first mounting parts are fixed by brazing to the cover plate 10, and the first battery mold core is threadedly connected to the first mounting part. Such arrangement facilitates the installation and fixation of the first battery mold core, and at the same time can ensure the stability of the fixation of the first battery mold core, and prevent the first battery mold core from falling off.

[0167] Specifically, in the present application, during welding of the first mounting portion, a groove needs to be provided at the bottom of the first mounting portion, and the welding wire is placed in the groove. After the liquid cooling plate is placed in the brazing furnace, the first mounting portion is fixed to the cover plate 10 by brazing.

[0168] Furthermore, power batteries are mainly used in new energy vehicles, and the above-mentioned liquid cooling plate only relies on its own rigidity and strength to realize the bearing of the entire battery module, without the need for support from other components. The developed high-strength liquid cooling plate not only meets the battery module loading function, but also achieves weight reduction and lightweighting, with a weight reduction ratio of 17%; and it can also use the strength of the high-strength liquid cooling plate itself to remove the steel bottom guard plate parts of the battery pack, further reducing the weight and preparation cost, with the cost reduced by 10% year-on-year. According to comprehensive test data, the liquid cooling plate structure preparation process of this application has low cost, strong reliability and good stability, which can better serve the promotion and application of new energy battery thermal management systems.

[0169] The liquid cooling plate of this application has successfully achieved the dual goals of high strength, light weight and cost reduction on the basis of fully meeting the battery module loading function. In the absence of supporting structural parts, the weight reduction ratio of the liquid cooling plate is more than 45% compared with the original structure. At the same time, relying on the strength performance of the liquid cooling plate itself, the use of supporting structural parts is reduced, and the cost is reduced by 10% compared with the original structure.

[0170] Among them, the fourth embodiment of the present application provides an energy storage battery, which includes a plurality of second battery mold cores and the liquid cooling plate provided above, wherein the plurality of second battery mold cores are distributed on the cover plate 10 of the liquid cooling plate along the width direction of the liquid cooling plate, and a plurality of second mounting parts are arranged on the cover plate 10 along the length direction, the second mounting parts are fixed to the cover plate 10 by brazing, and the second battery mold core is threadedly connected to the second mounting part. Such arrangement facilitates the installation and fixation of the second battery mold core, and at the same time can ensure the stability of the fixation of the second battery mold core, and prevent the second battery mold core from falling off.

[0171] Specifically, in the present application, during welding of the second mounting portion, a groove needs to be provided at the bottom of the second mounting portion, and the welding wire is placed in the groove. After the liquid cooling plate is placed in the brazing furnace, the second mounting portion is fixed to the cover plate 10 by brazing.

[0172] Furthermore, in this embodiment, the liquid cooling plate only relies on its own rigidity and strength to achieve the bearing of the entire battery module, without the need for support from other components. The developed high-strength liquid cooling plate not only achieves weight reduction and lightweighting while meeting the battery module loading function, with a weight reduction ratio of more than 45%; it can also use the strength performance of the liquid cooling plate itself in the energy storage system to remove the supporting structural parts to reduce weight and preparation costs, with costs reduced by 10% year-on-year. Based on comprehensive test data, the liquid cooling plate structure preparation process of this application has low cost, strong reliability and good stability, which can better serve the promotion and application of new energy battery thermal management systems.

[0173] Among them, the fifth embodiment of the present application provides a method for preparing a liquid cooling plate, the liquid cooling plate is the liquid cooling plate provided in the first embodiment, and the method for preparing the liquid cooling plate includes:

[0174] Step 1, performing a solution treatment on the cover plate 10 and the flow channel plate 20 of the liquid cooling plate;

[0175] Step 2, stamping the flow channel plate 20 to form the flow channel 25 of the flow channel plate 20;

[0176] Step 3, stacking the flow channel plate 20 and the cover plate 10, and the first lower protective layer 13 abuts against the first welding layer 24;

[0177] Step 4, sending the flow channel plate 20 and the cover plate 10 into a brazing furnace for welding;

[0178] Step 5, artificial aging is performed on the welded flow channel plate 20 and cover plate 10.

[0179] Furthermore, when the composite plates A and B are subjected to solution treatment, they need to be kept at 550°C for 30 seconds, then taken out of the furnace and allowed to cool naturally, and the O state of the composite plates A and B is obtained through this operation.

[0180] Specifically, the composite panel B of the present application is stamped according to a predetermined structural design. Tests have shown that no undesirable phenomena such as cracking and wrinkling occur during the stamping process, and the composite panel B can meet the technical requirements of customers.

[0181] Furthermore, before brazing the composite plates A and B, the surfaces of the composite plates A and B are wiped, and a uniform layer of brazing flux is coated on the surface of the first lower protective layer 13 .

[0182] Wherein, in the present application, the brazing furnace is a chain brazing furnace.

[0183] Furthermore, the mechanical properties of the composite panels A and B were tested, and the specific test results are shown in Table 3.

[0184] The mechanical properties of the liquid cooling plates of Example 1 and Example 2 were tested, and the specific test results are shown in Table 4.

[0185] Table 3

[0186]

[0187] Table 4

[0188]

[0189] Specifically, the liquid cooling plate passes through 6 brazing zones in sequence, which are brazing zone 1, brazing zone 2, brazing zone 3, brazing zone 4, brazing zone 5 and brazing zone 6. The temperature of brazing zone 1 is set between 585°C and 595°C, the temperature of brazing zone 2 is set between 600°C and 615°C, the temperature of brazing zone 3 is set between 610°C and 625°C, the temperature of brazing zone 4 is set between 615°C and 625°C, the temperature of brazing zone 5 is set between 625°C and 635°C, and the temperature of brazing zone 6 is set between 625°C and 635°C.

[0190] Step 4 specifically includes: the liquid cooling plate passes through brazing zone 1, brazing zone 2, brazing zone 3, brazing zone 4, brazing zone 5 and brazing zone 6 in sequence at a speed of 750 mm / min to 1050 mm / min.

[0191] With this arrangement, the segmented temperature control can gradually increase the temperature when the material passes through different brazing zones, promoting the uniform distribution and phase change of alloying elements. This temperature gradient design, especially the temperature increase from brazing zone 1 to brazing zone 6, helps the material achieve a better microstructure during the brazing process, avoids local overheating and non-uniform precipitation of alloying elements, thereby ensuring the strength, toughness and welding quality of the material. The lower temperature in brazing zone 1 is the material preheating stage, which helps to reduce the temperature gradient inside the material and avoid thermal stress. Starting from brazing zone 2, the temperature gradually increases. This process is a critical stage for the melting and diffusion welding of the material. Accurate temperature control can not only promote good fluidity of the liquid brazing material and ensure the integrity and strength of the weld, but also effectively avoid overburning and performance degradation of the material due to excessive temperature, ensuring the high performance and long life of the final liquid cold plate.

[0192] The high-speed brazing process significantly shortens the time it takes for a single liquid cooling plate to pass through the brazing equipment, thereby greatly improving production efficiency. Within the speed range of 750mm / min to 1050mm / min, the equipment can handle more liquid cooling plates, speeding up the production cycle and meeting the actual situation of the new energy industry's large demand for key components such as liquid cooling plates and tight delivery deadlines.

[0193] Optionally, the speed of the liquid cooling plate may be 750 mm / min, 900 mm / min or 1050 mm / min. In the present application, the speed of the liquid cooling plate is 900 mm / min.

[0194] Among them, step 5 specifically includes: the liquid cooling plate is kept at a heat preservation temperature of 200°C to 240°C for 10 minutes to 30 minutes. Specifically, after the battery liquid cooling plate is brazed to form the liquid cooling plate product structure, artificial aging is carried out within 24 hours. In this way, insulation in the temperature range of 200°C to 240°C can promote the full precipitation of alloy elements inside the material to form fine and evenly distributed precipitation phases, such as Mg2Si, etc., thereby significantly improving the yield strength and tensile strength of the material while maintaining good elongation. This is crucial to improving the load-bearing capacity and structural stability of the liquid cooling plate, ensuring that it can maintain excellent heat dissipation performance and durability in complex application environments.

[0195] Optionally, the insulation temperature of the liquid cooling plate can be 200°C, 220°C or 240°C. In the present application, the insulation temperature of the liquid cooling plate is 220°C. The insulation time of the liquid cooling plate can be 10min, 20min or 30min. In the present application, the insulation time of the liquid cooling plate is 20min.

[0196] Preferably, in this embodiment, the temperature of brazing zone 1 is set between 585°C and 595°C, the temperature of brazing zone 2 is set between 600°C and 615°C, the temperature of brazing zone 3 is set between 610°C and 620°C, the temperature of brazing zone 4 is set between 615°C and 620°C, the temperature of brazing zone 5 is set between 625°C and 635°C, and the temperature of brazing zone 6 is set between 625°C and 630°C.

[0197] Embodiment 6 of the present application provides a method for preparing a liquid cooling plate, which is different from Embodiment 5 in that the liquid cooling plate is the liquid cooling plate provided in Embodiment 2.

[0198] Step 1 also includes: performing a solution treatment on the support plate 30 and the plurality of reinforcing plates 40 of the liquid cooling plate;

[0199] Step 2 also includes: stamping the support plate 30 to form a support protrusion 31 of the support plate 30;

[0200] Step 3 also includes: stacking the support plate 30 and the reinforcing plate 40, placing the flow channel plate 20 on the support plate 30, abutting the third welding layer against the third lower protective layer, and abutting the second welding layer against the second lower protective layer 23;

[0201] Step 4 also includes: sending the plurality of reinforcing plates 40, the support plates 30, the flow channel plates 20 and the cover plates 10 into a brazing furnace for welding;

[0202] Step 5 also includes artificial aging of the welded reinforcing plates 40 , the support plates 30 , the flow channel plates 20 and the cover plates 10 .

[0203] With such configuration, the difference between the sixth embodiment and the fifth embodiment is that the support plate 30 and the reinforcing plate 40 are processed simultaneously to complete the preparation of the liquid cooling plate provided by the second embodiment.

[0204] Preferably, in this embodiment, the temperature of brazing zone 1 is set between 585°C and 595°C, the temperature of brazing zone 2 is set between 600°C and 610°C, the temperature of brazing zone 3 is set between 615°C and 625°C, the temperature of brazing zone 4 is set between 615°C and 625°C, the temperature of brazing zone 5 is set between 625°C and 635°C, and the temperature of brazing zone 6 is set between 625°C and 635°C.

[0205] Among them, when the liquid cooling plate uses more plates, the temperature of the brazing zone can be adaptively increased according to the actual situation, and the speed of the liquid cooling plate can be adaptively reduced according to the actual situation.

[0206] The composite plates A and B of the present application are used in the industrial mass production of battery liquid cooling plates. They have the advantages of easy control and adjustment of the brazing temperature and a short time required for controlling the brazing. At the same time, they have good process stability and high reliability, and can adapt to various types of continuous atmosphere shielded welding with different production requirements, which is conducive to promotion and application.

[0207] According to the embodiments involved in this application, composite plate A and composite plate B are used for battery liquid cooling plates and have passed various relevant test verifications. When testing composite plates A and B used in the liquid cooling plate, their yield strength exceeded 160MPa. From the perspective of performance comparison, compared with the composite materials currently developed and applied on the market, the yield strength of this material is more than 30% higher. Compared with the traditional 3003 / 4045 / 3003 aluminum alloy composite material liquid cooling plate, its strength performance has been improved by more than 2 times, which can effectively deal with various complex external forces of new energy batteries during service, and ensure the stability of the liquid cooling plate structure and the heat dissipation effect.

[0208] The preparation method of the liquid cooling plate involved in the fifth and sixth embodiments of the present invention has outstanding performance in terms of lightweighting compared to the same type of liquid cooling plates currently developed and applied on the market, and its weight reduction can reach more than 40%. If the preparation method is applied to the field of energy storage batteries and power batteries, the development cost can be reduced by more than 10%. This has positive significance for achieving overall lightweighting of the battery pack and reducing development costs, which is in line with the pursuit of the development of the new energy industry.

[0209] When the battery liquid cooling plate of the present application is industrially mass-produced, it has the advantage of easy control of the brazing temperature, good process stability and high reliability. It can be adapted to various types of continuous atmosphere-protected brazing furnaces with different production requirements, and is conducive to the promotion and application of such brazing furnaces.

[0210] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0211] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present invention. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0212] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0213] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0214] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0215] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A liquid cooling plate, characterized in that: The liquid cooling plate comprises: A cover plate (10), the cover plate (10) comprising a first upper protective layer (11), a first core material layer (12) and a first lower protective layer (13), the first upper protective layer (11) and the first lower protective layer (13) being respectively located on both sides of the first core material layer (12); A flow channel plate (20), the flow channel plate (20) comprising a first welding layer (24), a second upper protective layer (21), a second core material layer (22) and a second lower protective layer (23) which are arranged in sequence, the cover plate (10) being arranged on the flow channel plate (20), the first welding layer (24) being used for fixing the first lower protective layer (13) and the flow channel plate (20), and a circulation channel (25) being provided on a side of the flow channel plate (20) facing the cover plate (10), the circulation channel (25) being used for circulating a fluid; The first core material layer (12) and the second core material layer (22) are both 6XXX series aluminum alloys. The 6XXX series aluminum alloys include the following elements in percentage by mass: 0.3-0.7% Si, 0.6-0.9% Mg, 0.1-0.3% Cu, 0.05-0.3% Zn, 0.01-0.15% Mn, 0.01-0.08% Zr, 0.001-0.1% Cr, 0.001-0.1%, 0.001-0.04% Ti, 0.05-0.6% Fe, and the Si content is lower than the Mg content. The total content of unavoidable impurities is ≤0.15wt%, the content of a single impurity is lower than 0.05wt%, and the balance is Al.

2. The liquid cooling plate according to claim 1, characterized in that: The liquid cooling plate also includes: A support plate (30), the support plate (30) having a third core material layer, the flow channel plate (20) being arranged on the support plate (30), the support plate (30) being used to support the flow channel plate (20), and the third core material layer being the 6XXX series aluminum alloy; A plurality of reinforcing plates (40), wherein the plurality of reinforcing plates (40) are arranged at intervals along the length direction of the support plate (30), the length direction of the reinforcing plates (40) extending along the width direction of the support plate (30), the plurality of reinforcing plates (40) all having a fourth core material layer, the support plate (30) being arranged on the plurality of reinforcing plates (40), and the fourth core material layer being the 6XXX series aluminum alloy.

3. The liquid cooling plate according to claim 2, characterized in that: The support plate (30) further comprises a third upper protective layer, a third lower protective layer and a second welding layer, the third upper protective layer and the third lower protective layer are respectively located on both sides of the third core material layer, the second welding layer is located on a side of the third upper protective layer away from the third core material layer, and the second welding layer is used to fix the second lower protective layer (23) and the support plate (30); The reinforcing plate (40) further comprises a fourth upper protective layer, a fourth lower protective layer and a third welding layer, the fourth upper protective layer and the fourth lower protective layer are respectively located on both sides of the fourth core material layer, the third welding layer is located on a side of the fourth upper protective layer away from the fourth core material layer, and the third welding layer is used to fix the third lower protective layer and the reinforcing plate (40); The third upper protective layer, the third lower protective layer, the fourth upper protective layer and the fourth lower protective layer are 3XXX series aluminum alloy, and the second welding layer and the third welding layer are 4XXX series aluminum alloy.

4. The liquid cooling plate according to claim 2, characterized in that: The support plate (30) is provided with a support protrusion (31), the support protrusion (31) and the circulation channel (25) are symmetrically arranged in structure, and the top of the support protrusion (31) abuts against the bottom of the circulation channel (25).

5. The liquid cooling plate according to claim 2, characterized in that: The width of the reinforcing plate (40) is set between 200 mm and 400 mm, and the length of the reinforcing plate (40) is set between 500 mm and 800 mm.

6. The liquid cooling plate according to claim 1, characterized in that: The mass ratio of the Si element to the Mg element is (0.50-0.67):1; and / or the mass ratio of the Cu element to the Zn element is (1-2):1; and / or the mass ratio of the Mn element, the Zr element and the Cr element is 1:(0.27-4):(0.5-0.7); and / or, the first upper protective layer (11), the first lower protective layer (13), the second upper protective layer (21) and the second lower protective layer (23) are 3XXX series aluminum alloys, and the 3XXX series aluminum alloys are selected from any one or more of 3003 alloy, 3004 alloy and 3105 alloy; And / or, the first welding layer (24) is a 4XXX series aluminum alloy, and the 4XXX series aluminum alloy is selected from any one or more of 4004 alloy, 4045 alloy, 4047 alloy, 4104 alloy, 4147 alloy and 4343 alloy.

7. The liquid cooling plate according to claim 1, characterized in that: The thickness of the cover plate (10) and / or the flow channel plate (20) is set between 0.5 mm and 3.0 mm.

8. The liquid cooling plate according to claim 1, characterized in that: The ratio of the thickness of the first upper protective layer (11) and the first lower protective layer (13) to the overall thickness of the cover plate (10) is set between 10% and 15%, and / or the ratio of the thickness of the second upper protective layer (21) and the second lower protective layer (23) to the overall thickness of the flow channel plate (20) is set between 10% and 15%, and / or the ratio of the first welding layer (24) to the overall thickness of the flow channel plate (20) is set between 8% and 10%.

9. A power battery, characterized in that: The power battery comprises a plurality of first battery mold cores and a liquid cooling plate according to claim 1 and any one of claims 6 to 8, wherein the plurality of first battery mold cores are distributed on a cover plate (10) of the liquid cooling plate along a width direction of the liquid cooling plate, and a plurality of first mounting portions are provided on the cover plate (10) along a length direction, wherein the first mounting portions are fixed to the cover plate (10) by brazing, and the first battery mold cores are threadedly connected to the first mounting portions.

10. An energy storage battery, characterized in that: The energy storage battery comprises a plurality of second battery mold cores and a liquid cooling plate according to any one of claims 2 to 8, wherein the plurality of second battery mold cores are distributed on a cover plate (10) of the liquid cooling plate along a width direction of the liquid cooling plate, and a plurality of second mounting portions are provided on the cover plate (10) along a length direction, the second mounting portions are fixed to the cover plate (10) by brazing, and the second battery mold cores are threadedly connected to the second mounting portions.

11. A method for preparing a liquid cooling plate, characterized in that: The liquid cooling plate is the liquid cooling plate according to any one of claims 1 to 8, and the preparation method of the liquid cooling plate comprises: Step 1, performing a solution treatment on the cover plate (10) and the flow channel plate (20) of the liquid cooling plate; Step 2, stamping the flow channel plate (20) to form a flow channel (25) of the flow channel plate (20); Step 3, stacking the flow channel plate (20) and the cover plate (10), with the first lower protective layer (13) abutting against the first welding layer (24); Step 4, sending the flow channel plate (20) and the cover plate (10) into a brazing furnace for welding; Step 5, artificially aging the welded flow channel plate (20) and the cover plate (10).

12. The method for preparing a liquid cooling plate according to claim 11, characterized in that: The liquid cooling plate is the liquid cooling plate according to claim 2, The step 1 further comprises: performing a solution treatment on the support plate (30) and the plurality of reinforcing plates (40) of the liquid cooling plate; The step 2 further comprises: punching the support plate (30) to form a support protrusion (31) of the support plate (30); The step 3 further comprises: the support plate (30) and the reinforcing plate (40) are stacked, the flow channel plate (20) is placed on the support plate (30), the third welding layer is abutted against the third lower protective layer, and the second welding layer is abutted against the second lower protective layer (23); The step 4 further comprises: sending the plurality of reinforcing plates (40), the support plates (30), the flow channel plates (20) and the cover plates (10) into a brazing furnace for welding; The step 5 further comprises artificially aging the welded plurality of reinforcing plates (40), the support plate (30), the flow channel plate (20) and the cover plate (10).

13. The method for preparing a liquid cooling plate according to claim 11, characterized in that: The liquid cooling plate passes through 6 brazing zones in sequence, and the 6 brazing zones are brazing zone 1, brazing zone 2, brazing zone 3, brazing zone 4, brazing zone 5 and brazing zone 6 in sequence. The temperature of brazing zone 1 is set between 585°C and 595°C, the temperature of brazing zone 2 is set between 600°C and 615°C, the temperature of brazing zone 3 is set between 610°C and 625°C, the temperature of brazing zone 4 is set between 615°C and 625°C, the temperature of brazing zone 5 is set between 625°C and 635°C, and the temperature of brazing zone 6 is set between 625°C and 635°C. The step 4 specifically includes: The liquid cooling plate passes through the brazing zone 1, the brazing zone 2, the brazing zone 3, the brazing zone 4, the brazing zone 5 and the brazing zone 6 in sequence at a speed of 750 mm / min to 1050 mm / min.

14. The method for preparing a liquid cooling plate according to claim 11, characterized in that: The step 5 specifically includes: The liquid cooling plate is kept at a temperature of 200° C. to 240° C. for 10 to 30 minutes.

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