Liquid cooling part and preparation method thereof, liquid cooling assembly, liquid cooling system, battery and power utilization device

Abstract

The invention belongs to the technical field of batteries, and provides a liquid cooling part and a preparation method thereof, a liquid cooling assembly, a liquid cooling system, a battery and an electric device. The liquid cooling piece comprises a heat conduction piece with a cooling channel and an insulating layer wrapping the surface of the heat conduction piece, and the insulating layer comprises a modified PET material. The insulating layer in the liquid cooling piece has relatively high flame retardance and toughness, and can play an effective role in protecting the liquid cooling piece.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and specifically provides a liquid cooling component and a preparation method thereof, a liquid cooling assembly, a liquid cooling system, a battery and an electrical device. Background Art

[0002] With the rapid development of new energy vehicles and other electrical devices, the capacity requirements for power batteries are getting higher and higher, and the number of battery cells in the battery pack is also increasing. However, the increase in the number of battery cells causes the power battery to generate a lot of heat during fast charging, causing the battery to heat up significantly, and the heat dissipation inside the battery is difficult, affecting the battery performance and reducing the battery life. For this reason, a liquid cooling system can usually be arranged inside the battery to assist in battery heat dissipation.

[0003] Liquid cooling parts are widely used in new energy vehicles and other industries due to their easy heat dissipation. The surface of liquid cooling parts usually has an insulating layer, which plays a protective role, preventing the charge in the battery cells from overflowing, and avoiding leakage or short circuit. However, during the use of traditional liquid cooling parts, the insulating layer is prone to damage and shedding, and the process of forming the insulating layer is cumbersome, resulting in a long production cycle of liquid cooling parts and high manufacturing costs. Summary of the invention

[0004] In view of the above-mentioned problems, the purpose of the present application is to provide a liquid cooling component and a preparation method thereof, a liquid cooling component, a liquid cooling system, a battery and an electrical device. The insulating layer in the liquid cooling component has both high flame retardancy and toughness, and can effectively protect the liquid cooling component.

[0005] In the first aspect, the present application provides a liquid cooling part, comprising a heat conductive part and an insulating layer coated on the surface of the heat conductive part, wherein the heat conductive part has a cooling channel, and the insulating layer comprises a modified PET material, and the modified PET material is made of a PET raw material composition comprising a PET resin, a toughening agent and a flame retardant. In the liquid cooling part of the present application, the surface of the heat conductive part having a cooling channel is coated with an insulating layer comprising the modified PET material, and the insulating layer not only has flame retardancy and insulation, but also has high toughness, thereby reducing the possibility of cracking and damage of the insulating layer due to deformation of the heat conductive part under vibration and other working conditions.

[0006] In some embodiments of the present application, the thermally conductive member comprises a harmonica tube plate.

[0007] In some embodiments of the present application, the material of the heat conducting member includes aluminum alloy or magnesium alloy, thereby improving the adhesion between the heat conducting member and the insulating layer.

[0008] In some embodiments of the present application, based on the total weight of the PET raw material composition, the content of the PET resin is 70% to 90% by weight, the content of the toughening agent is 3% to 15% by weight, and the content of the flame retardant is 5% to 20% by weight. Thus, the prepared modified PET material has good processability, can not only directly form an insulating layer on the surface of the heat conductor by extrusion molding, but also can improve the stability of the extrusion process.

[0009] Optionally, based on the total weight of the PET raw material composition, the content of the PET resin is 75% to 85% by weight, the content of the toughening agent is 5% to 10% by weight, and the content of the flame retardant is 5% to 10% by weight, thereby further improving the comprehensive mechanical properties of the insulating layer.

[0010] In some embodiments of the present application, the toughening agent includes an ethylene terpolymer containing epoxy functional groups. By introducing the toughening agent containing epoxy functional groups, the compatibility between other components and the PET resin can be promoted, so that the modified PET material can be more evenly coated on the thermal conductive member, thereby improving the apparent quality of the insulating layer.

[0011] Optionally, the epoxy functional group-containing ethylene terpolymer includes ethylene-n-butyl acrylate-glycidyl methacrylate terpolymer and / or ethylene-methyl acrylate-glycidyl methacrylate terpolymer. Thus, the bonding force between the toughening agent and the PET resin can be further improved, so that the insulating layer has both high elongation at break and impact strength.

[0012] In some embodiments of the present application, the flame retardant includes at least one of brominated epoxy resin, brominated epoxy resin, brominated polystyrene or dodecabromodiphenylethane, thereby making the insulating layer have higher flame retardancy.

[0013] Optionally, the flame retardant includes the brominated epoxy resin. The flame retardant can improve the comprehensive mechanical properties of the insulating layer and make the insulating layer have a higher apparent quality.

[0014] In some embodiments of the present application, the PET raw material composition further includes an antioxidant. Thus, the aging resistance of the insulating layer can be improved. Optionally, based on the total weight of the PET raw material composition, the content of the antioxidant is 0.1 wt%-5 wt%, and more preferably 0.2 wt%-2 wt%.

[0015] In some embodiments of the present application, the antioxidant includes hindered phenol antioxidants and phosphite antioxidants.

[0016] Optionally, the mass ratio of the hindered phenol antioxidant to the phosphite antioxidant is 1:(0.5-2). Thus, the insulating layer has higher comprehensive mechanical properties.

[0017] In some embodiments of the present application, the PET raw material composition further comprises a lubricant. Optionally, based on the total weight of the PET raw material composition, the content of the lubricant is 0.1 wt%-5 wt%, and more preferably 0.2 wt%-2 wt%.

[0018] In some embodiments of the present application, the lubricant includes at least one of calcium stearate, polyethylene wax, pentaerythritol stearate, silicone or fluorine-containing resin.

[0019] Optionally, the lubricant includes pentaerythritol stearate, which can further improve the comprehensive mechanical properties of the insulating layer.

[0020] In some embodiments of the present application, the PET modified material is formed by heating and melting the PET raw material composition. Optionally, the heating and melting temperature is 230°C-280°C.

[0021] In some embodiments of the present application, the thickness of the insulating layer is 0.5 mm to 1 mm, thereby making the liquid cooling element have a higher heat exchange effect while exerting the protective effect of the insulating layer.

[0022] In a second aspect, the present application provides a method for preparing the liquid cooling component, comprising: extruding pellets of the modified PET material to coat the surface of the heat conductive component with the modified PET material to form an insulating layer.

[0023] In the preparation method of the present application, the modified PET material has good processability and can be directly coated on the surface of the heat-conducting part (for example, the harmonica tube plate) through an extrusion molding process to achieve continuous production of the product. In this way, the formation process of the insulating layer is simplified, thereby improving the production efficiency of the liquid cooling part and reducing the production cost.

[0024] In some embodiments of the present application, the extrusion molding includes the following process: melting the pellets of the modified PET material through a screw extruder and conveying them to a die head equipped with the heat conductive member, allowing the melt to flow onto the surface of the heat conductive member, and cooling to form the insulating layer. In the case of a screw extruder, continuous coating of the insulating material of heat conductive members of different specifications can be achieved only by adjusting the die head.

[0025] Optionally, in the screw extruder, the temperature of the screw feeding zone is 100°C-120°C, the temperature of the compression section is 250°C-270°C, the temperature of the extrusion section is 260°C-280°C, and the screw speed is 300rpm-350rpm. Thus, the stability of the extrusion molding process can be improved.

[0026] In some embodiments of the present application, the method further includes: premixing the components in the PET raw material composition to obtain a premix; heating and melting the premix and extruding and granulating the premix to prepare pellets of the modified PET material.

[0027] In a third aspect, the present application provides a liquid cooling component, comprising a current collecting part and a liquid cooling part, wherein the liquid cooling part is the liquid cooling part described in the first aspect of the present application or a liquid cooling part prepared by the method described in the second aspect of the present application; the current collecting part is connected to the liquid cooling part, the current collecting part has a current collecting space, and the current collecting space is connected to the cooling channel.

[0028] In a fourth aspect, the present application provides a liquid cooling system, comprising the liquid cooling assembly described in the third aspect of the present application; and a liquid supply assembly, wherein the liquid supply assembly is connected to the collecting member to supply cooling medium into the cooling channel.

[0029] In a fifth aspect, the present application provides a battery, comprising: a plurality of battery cells, and a liquid cooling component, wherein the liquid cooling component is the liquid cooling component described in the first aspect of the present application or a liquid cooling component prepared by the method described in the second aspect of the present application; and at least some of the plurality of battery cells are attached to the liquid cooling component.

[0030] In a sixth aspect, the present application provides an electrical device, comprising the battery described in the fifth aspect of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only used to illustrate the preferred embodiments and are not to be considered as limiting the present application. In the accompanying drawings:

[0032] Figure 1 is a disassembly diagram of a liquid cooling component according to some embodiments of the present application;

[0033] Figure 2 This is a schematic diagram of the structure of a liquid cooling assembly in some embodiments of the present application;

[0034] Figure 3 The liquid cooling components of some embodiments of the present application are Figure 2 Schematic diagram of the cross-sectional structure in the middle BB direction;

[0035] Figure 4A schematic diagram of the use status of the liquid cooling system of some embodiments of the present application;

[0036] Figure 5 A schematic diagram of the structure of a battery in some embodiments of the present application;

[0037] Figure 6 Schematic diagram of an electrical device according to some embodiments of the present application.

[0038] Description of reference numerals:

[0039] 400: liquid cooling component; 41: insulating layer; 42: harmonica tube plate; 500: current collecting component; 51: current collecting space; 600: liquid supply component; 61: body pump; 62: liquid supply pipeline; 63: heat exchanger; 11: battery cell; 100: battery. DETAILED DESCRIPTION

[0040] The present application is further described below in conjunction with specific implementations. It should be understood that these specific implementations are only used to illustrate the present application and are not used to limit the scope of the present application.

[0041] In this application, the reference to "embodiment" means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0042] "Scope" disclosed in the present application is defined in the form of lower limit and / or upper limit, and a given range is defined by selecting a lower limit and / or an upper limit, and the selected lower limit and / or the rear upper limit define the boundary of a special range. The scope defined in this way can be including or excluding end values, and can be combined arbitrarily, that is, any lower limit can be combined with any upper limit to form a scope that is not clearly recorded, and any lower limit can be combined with other lower limits to form a scope that is not clearly recorded, and any upper limit can be combined with any other upper limit to form a scope that is not clearly recorded. In addition, each separately disclosed point or single numerical value itself can be used as a lower limit or upper limit and any other point or single numerical value combination or with other lower limits or upper limits to form a scope that is not clearly recorded.

[0043] If not otherwise specified, all embodiments and optional embodiments of the present application may be combined with each other to form new technical solutions, and such technical solutions should be deemed to be included in the disclosure of the present application.

[0044] Unless otherwise specified, all technical features and optional technical features of the present application may be combined with each other to form new technical solutions, and such technical solutions should be deemed to be included in the disclosure of the present application.

[0045] Unless otherwise specified, the terms "include", "comprising", "including", "containing", "having" mentioned in this application are open-ended. For example, the terms "include", "comprising", "containing", "containing", and "having" may indicate that other components not listed may also be included or contained. In addition, in this application, the terms "plurality", "multiple", and "at least one" refer to more than two. "Above" and "below" include the number itself. For example, "more than two" includes two itself, such as two, three, four or more.

[0046] If not specifically stated, in this application, the term "or" is inclusive. More specifically, any of the following conditions satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0047] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as those commonly understood by technicians in the technical field of this application; the terms used in this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and any variations thereof are intended to cover non-exclusive inclusions. Unless otherwise specified, the terms used in this application have the well-known meanings commonly understood by those skilled in the art. Unless otherwise specified, the numerical values ​​of the parameters mentioned in this application can be measured using various measurement methods commonly used in the art (for example, they can be tested according to the methods given in the embodiments of this application).

[0048] The traditional method usually uses epoxy resin, a reactive raw material, to form an insulating layer on the heat conductor by spraying to prepare a liquid cooling part. The main process of forming an insulating layer on the surface of the heat conductor by this method includes: surface treatment of the heat conductor, epoxy resin coating and heating and curing. However, the process is too complicated: on the one hand, in order to make the epoxy resin after spraying effectively adhere to the surface of the heat conductor, in addition to rust removal and oil removal, pretreatments such as neutralization, surface adjustment and phosphating are required; on the other hand, the epoxy resin after spraying needs to be baked and cured and then cooled to form an insulating layer; this also makes it impossible to continuously produce liquid cooling parts. In addition, although the epoxy resin plays an insulating and protective role on the heat conductor after curing, the epoxy hot resin is a thermosetting resin, which has the problem of poor toughness and ductility. This causes the battery to crack and fall off with the deformation of the heat conductor when facing working conditions such as extrusion, vibration, and collision during use, resulting in the failure of the insulation layer.

[0049] To this end, the first aspect of the present application provides a liquid cooling part, including a heat-conducting part and an insulating layer coated on the surface of the heat-conducting part, wherein the heat-conducting part has a cooling channel, and the modified PET material is made of a PET raw material composition including a PET resin, a toughening agent and a flame retardant. In the PET raw material composition, by introducing a flame retardant, the flame retardant modification of the PET resin can be achieved, and the flame retardant properties of the PET material can be improved. The addition of a toughening agent can adjust the toughness of the resin and its viscosity and fluidity in a molten state, and improve the compatibility between the PET resin and the flame retardant, so that the prepared modified PET material has good processability and can be continuously and stably coated on the surface of the heat-conducting part by extrusion molding. It can be understood that the PET raw material composition can be a mixed material obtained by physically mixing the components (no reaction occurs between the components), such as a premix used in the preparation of the modified PET material.

[0050] In some embodiments, based on the total weight of the PET raw material composition, the content of the PET resin is 70% by weight to 90% by weight, such as 70%, 71%, 72%, 73%, 74%, 75%, 80%, 85%, 88%, 90% by weight, etc.; the content of the toughening agent is 3% by weight to 15% by weight, such as 3%, 5%, 7.5%, 8%, 8.5%, 10%, 15% by weight; the content of the flame retardant is 5% by weight to 20% by weight, such as 5%, 7%, 7.5%, 8%, 9%, 10%, 11%, 12%, 15%, 18%, 20% by weight, etc. The modified PET material formed by this raw material composition has good processability, and an insulating layer can be directly formed on the tube body by extrusion molding, simplifying the preparation process of the insulating layer.

[0051] Optionally, based on the total weight of the PET raw material composition, the content of the PET resin is 75% to 85% by weight, the content of the toughening agent is 5% to 10% by weight, and the content of the flame retardant is 8% to 15% by weight. Thus, while the modified PET material has higher processability, the comprehensive mechanical properties of the insulating layer can be further improved.

[0052] In the present application, PET (polyethylene terephthalate) resin is a thermoplastic polyester with good processability. As an example, the number average molecular weight of the PET resin is 20000-30000, the melting point is 220°C-270°C, and the melt index at 250°C and 2.16kg load is 0.5g / 10min-5g / 10min. The number average molecular weight (Mn) of the PET resin can be measured according to gel permeation chromatography (GPC), for example, using Shimadzu's gel permeation chromatograph with THF as the mobile phase, narrow distribution polystyrene as the standard sample, and the molecular weight is measured at a flow rate of 1.0mL / min at a temperature of 25°C, and the test temperature is 25°C. The melt index can be measured according to the method specified in GB / T 3682-2000. As another example, the PET resin can be obtained commercially, such as a product purchased from Sinopec Yizheng Chemical Fiber Company with a brand name of FG720.

[0053] In some embodiments, the toughening agent includes an ethylene terpolymer containing epoxy functional groups. In the process of preparing the modified PET material, the epoxy group reacts with the end group (e.g., carboxyl group, hydroxyl group) of the PET resin to increase the viscosity of the system, thereby making the insulating layer have both higher strength and toughness.

[0054] Optionally, the epoxy-functional ethylene terpolymer includes ethylene-n-butyl acrylate-glycidyl methacrylate terpolymer (eg, PTW) and / or ethylene-methyl acrylate-glycidyl methacrylate terpolymer (eg, EMA).

[0055] In the present application, the flame retardant may include a brominated flame retardant. In some embodiments, the flame retardant includes at least one of brominated epoxy resin, brominated polystyrene or dodecabromodiphenylethane. Thus, the insulating layer has higher flame retardancy.

[0056] Optionally, the flame retardant includes the brominated epoxy resin. The flame retardant can enhance the toughness of the PET resin, improve the comprehensive mechanical properties of the insulating layer, and has higher compatibility with the PET material, can reduce the generation of flow lines during the extrusion molding process, and improve the surface quality of the insulating layer.

[0057] In some embodiments, the PET material composition further comprises an antioxidant, thereby improving the aging resistance of the insulating layer.

[0058] Optionally, based on the total weight of the PET raw material composition, the content of the antioxidant is 0.1 wt%-5 wt%, such as 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.8 wt%, 1 wt%, 1.5 wt%, 2 wt%, 3 wt%, 4 wt%, etc. Further, based on the total weight of the PET raw material composition, the content of the antioxidant is 0.2 wt%-2 wt%.

[0059] The present application does not particularly limit the antioxidant, and it can be selected from various antioxidants in the field of thermoplastic resin processing. Generally, the antioxidant may include a hindered phenol antioxidant and / or a phosphite antioxidant. In some embodiments, the antioxidant may include a hindered phenol antioxidant and a phosphite antioxidant. Optionally, the mass ratio of the hindered phenol antioxidant to the phosphite antioxidant is 1:(0.5-2), for example, 1:0.5, 1:0.8, 1:1, 1:1.2, 1:1.5, 1:2, etc. As a result, the insulating layer has higher comprehensive mechanical properties.

[0060] As an example, the hindered phenol antioxidant may include at least one of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine (antioxidant 1098), β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2,6-di-tert-butyl-4-methylphenol, tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester (antioxidant 1010), diethylenethiobis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate or 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene.

[0061] As an example, the phosphite antioxidant may include at least one of tris[2,4-di-tert-butylphenyl]phosphite (Antioxidant 168), tetrakis(2,4-di-tert-butylphenol)-4,4'-biphenyl diphosphite or bis(2,4-di-tert-butylphenol)pentaerythritol diphosphite.

[0062] In some specific embodiments, the antioxidant includes antioxidant 1098 and antioxidant 168.

[0063] In some embodiments, the PET material composition further includes a lubricant. Optionally, based on the total weight of the PET raw material composition, the content of the lubricant is 0.1 wt%-5 wt%, such as 0.1 wt%, 0.2 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 1 wt%, 1.5 wt%, 2 wt%, 3 wt%, 4 wt%, etc. Further, based on the total weight of the PET raw material composition, the content of the lubricant is 0.2 wt%-2 wt%.

[0064] In some embodiments, the lubricant may include at least one of calcium stearate, polyethylene wax, pentaerythritol stearate, silicone, or a fluorine-containing resin.

[0065] Optionally, the lubricant includes pentaerythritol stearate, which can further improve the comprehensive mechanical properties of the insulating layer.

[0066] As an example, the PET modified material is formed by heating and melting the PET raw material composition. Optionally, the heating and melting temperature is 230° C.-280° C., such as 230° C., 240° C., etc. The heating and melting can be performed, for example, by a twin-screw extruder.

[0067] In the present application, the heat conductor may generally include a metal tube sheet having one or more fluid channels. When the metal tube sheet has multiple fluid channels, the multiple fluid channels may be arranged in parallel in the same direction of the tube sheet, for example, all arranged in the length direction of the tube sheet.

[0068] In some embodiments, the thermally conductive member comprises a harmonica tube sheet.

[0069] In the present application, the specifications of the harmonica tube plate can be selected according to its specific application in the battery. From the perspective of improving the continuous stability of the preparation process, in some embodiments, the aspect ratio of the harmonica tube plate is (10-20):1, such as 10:1, 12:1, 15:1, 16:1, 17:1, 18:1, 20:1, etc.

[0070] In some embodiments, the material of the heat conducting member includes at least one of an aluminum alloy or a magnesium alloy, thereby improving the adhesion between the heat conducting member and the insulating layer.

[0071] In some embodiments, the thickness of the insulating layer is 0.5 mm-1 mm, such as 0.5 mm, 0.6 mm, 0.5 mm, 0.5 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, etc. Thus, the insulating layer can provide protection while enabling the liquid cooling element to have a higher heat exchange effect.

[0072] In some specific embodiments, the liquid cooling element includes a harmonica tube plate and an insulating layer covering the surface of the harmonica tube plate. Figure 1 The disassembly diagram of the liquid cooling component is used as an example, wherein the liquid cooling component 400 includes a harmonica tube plate 42 with a cooling channel and an insulating layer 41.

[0073] The second aspect of the present application provides a method for preparing the liquid cooling part, comprising: extruding the pellets of the modified PET material so that the modified PET material is coated on the surface of the heat-conducting part to form an insulating layer. It can be understood that extrusion molding is also called extrusion molding, which mainly refers to a continuous molding method in which the heat-melted modified PET material is pushed by pressure through a die head mold by means of an extrusion molding device (for example, a screw extruder). Compared with forming an insulating layer with epoxy resin, the method of the present application omits the pretreatment steps such as neutralization, surface adjustment, and phosphating before spraying, and does not require high-temperature curing operations after spraying; thus, the process of forming the insulating layer is simplified, the production efficiency of the liquid cooling part is improved, and the production cost is reduced.

[0074] In some embodiments, the extrusion molding includes the following process: the pellets of the modified PET material are melted by a screw extruder and conveyed to a die head equipped with the heat conductive member, so that the melt flows onto the surface of the heat conductive member, and after cooling, the insulating layer is formed. In the case of a screw extruder, continuous coating of insulating materials of heat conductive members of different specifications can be achieved only by adjusting the die head. Generally, the screw extruder may include a single screw extruder.

[0075] In the present application, the temperature of each zone of the screw can be set according to the modified PET resin. It can be understood that the screw can include a feed section, a compression section and an extrusion section in sequence according to the material flow direction, wherein the main functions of the compression section include propulsion (transportation) and heating and melting. Generally, compared with the compression section, the temperature of the feed section is lower, which can play a role in drying the material to reduce the possibility of bubbles in the insulation layer; the temperature of the extrusion section is higher, so that the melt maintains a higher fluidity in the die head mold and improves the coating uniformity.

[0076] In some embodiments, in the screw extruder, the temperature of the screw feed zone is 100°C-120°C, the temperature of the compression section is 250°C-270°C, the temperature of the extrusion section is 260°C-280°C, and the screw speed is 300rpm-350rpm. Thus, the stability of the extrusion molding process can be improved.

[0077] As an example, the screw extruder adopts a nine-zone single screw, and the following temperature parameters may be included in the extrusion molding process. Zone 1 temperature setting: 100℃-120℃, such as 105℃, 110℃, 120℃, etc.; Zone 2 temperature setting: 250℃-260℃, such as 250℃, 255℃, 260℃, etc.; Zone 3 temperature setting: 260℃-280℃, such as 260℃, 265℃, 270℃, 275℃, 280℃, etc.; Zone 4 temperature setting 260℃-280℃, such as 260℃, 265℃, 270℃, 275℃, 280℃, etc.; Zone 5 temperature setting: 250℃-270℃, such as 250℃, 255℃, 260℃, 265℃, 270℃, etc.; Zone 6 temperature setting: 250℃-270℃ , for example, 260℃, 265℃, 270℃, 275℃, 280℃, etc.; seven-zone temperature setting: 260℃-280℃, for example, 265℃, 270℃, 280℃, etc.; eight-zone temperature setting: 260℃-280℃, for example, 260℃, 265℃, 270℃, 275℃, 280℃, etc.; nine-zone temperature setting: 260℃-280℃, for example, 265℃, 270℃, 280℃, etc.; die head temperature setting: 270℃-290℃, for example, 275℃, 280℃, 285℃, 290℃, etc.; cooling water temperature is 40℃-60℃, for example, 40℃, 45℃, 50℃, 55℃, 60℃, etc.

[0078] As an example, the pellets of the modified PET material are coated on the surface of the harmonica tube plate with a fluid channel by extrusion molding to form an insulating layer. In this example, the head of the single-screw extruder can be modified so that the harmonica tube plate passes through the mold cavity and is heated, and the melt of the modified PET material is continuously extruded from the die head and coated on the surface of the harmonica tube plate, thereby forming an insulating layer.

[0079] As an example, in order to meet different usage requirements of the battery, the method may further include: cutting the product after the modified PET material is coated on the surface of the thermal conductor.

[0080] In some embodiments, the method further comprises preparing pellets of the modified PET material, specifically comprising:

[0081] Premixing the components in the PET raw material composition (including PET resin, toughening agent and flame retardant, and optional lubricant and optional antioxidant) to obtain a premix;

[0082] The premix is ​​heated, melted and extruded into granules to prepare granules of the modified PET material.

[0083] As an example, the premixing can be carried out in a high-speed mixer at 15° C.-40° C. (such as room temperature), and the mixing time can be 2 min-10 min, such as 2 min, 5 min.

[0084] Optionally, the heating and melting temperature is 230°C-250°C, such as 230°C, 240°C, 250°C, etc.

[0085] As an example, when the heat conductive component is made of metal, before extrusion molding, it can be selected whether to perform rust removal and / or degreasing according to the specific conditions of the heat conductive component used.

[0086] In the method provided in the present application, when forming the insulating layer, extrusion molding is used instead of the traditional epoxy resin spraying and heating curing process, thereby simplifying the process, and the insulating layer has higher ductility, reducing the risk of insulation failure.

[0087] A third aspect of the present application provides a liquid cooling assembly, comprising a current collecting member and the liquid cooling member of the present application; wherein the current collecting member is connected to the liquid cooling member, the current collecting member has a current collecting space, and the current collecting space is connected to the cooling channel.

[0088] In some embodiments, two current collectors are provided and are respectively arranged at both ends of the liquid cooling component. In this way, the cooling medium in the liquid cooling component can form a smooth circulation loop through the current collector and the external liquid supply component to improve the temperature control effect of the liquid cooling component.

[0089] As an example, see Figure 2 and Figure 3 In the liquid cooling assembly, the current collecting member 500 is connected to the liquid cooling member 400, and the current collecting member 500 has a current collecting space 51. The current collecting space 51 is communicated with the cooling channel.

[0090] Further references Figure 4 The current collecting part 500 may refer to a structural part that collects the cooling medium provided by the external liquid supply component 600 into the cooling channel in the liquid cooling component 400, or collects the cooling medium output through the cooling channel and outputs it to the external liquid supply component 600. In addition, a current collecting part 500 may be connected to multiple liquid cooling components 400, or may be a pipe connecting part that connects a single liquid cooling component 400 and an external liquid supply component 600. The current collecting part 500 may be sealed and connected to the liquid cooling component 400 by means of socketing, plugging, welding, etc. The current collecting space 51 generally has two openings, one of which is connected to the cooling channel, and the other opening is used to communicate with the external liquid supply component 600.

[0091] As an example, see Figures 2 to 4, two current collecting members 500 are provided and are respectively arranged at both ends of the liquid cooling member 400. In this way, the cooling medium in the liquid cooling member 400 can form a smooth circulation loop through the current collecting member 500 and the external liquid supply assembly 600.

[0092] As an example, the current collecting member 500 is welded to the corresponding end of the liquid cooling member 400 and connected to the heat conducting portion 41 by welding. In this way, the sealing performance of the liquid cooling assembly can be improved and the risk of cooling medium leakage can be reduced.

[0093] A fourth aspect of the present application provides a liquid cooling system, referring to Figure 4 As shown, the liquid cooling system includes a liquid supply assembly 600 and the above-mentioned liquid cooling assembly. The liquid supply assembly 600 is communicated with the manifold 500 to supply cooling medium into the cooling channel.

[0094] The liquid supply assembly 600 may only include a liquid supply line 62 connecting the cooling channel and the external water circuit to supply the cooling medium to the channel in the liquid cooling assembly, or guide the cooling medium discharged from the liquid cooling component out of the liquid cooling assembly or the battery 100 through the liquid supply line 62. In addition, the liquid supply assembly 600 may also include a liquid pump 61, a heat exchanger 63, etc., to control the flow rate and on-off of the cooling medium. When in use, the liquid cooling assembly can be installed in the battery 100, and most of the liquid supply assembly 600, except for part of the liquid supply line 62, can be installed outside the battery.

[0095] In a fifth aspect, the present application provides a battery, comprising a plurality of battery cells, and a liquid cooling member of the present application; wherein at least some of the battery cells of the plurality of battery cells are in contact with the liquid cooling member for cooling the battery cells. It is understandable that the in contact may be in direct or indirect contact with the battery cells, as long as the battery cells can be cooled. The battery is, for example, a secondary battery, and the battery cells may include battery cells.

[0096] In some embodiments, the battery further comprises a box, wherein the box is used to provide a storage space for each battery cell, and the liquid cooling element is located in the box and contacts at least part of the battery cells.

[0097] In some embodiments, the battery may include one or more liquid cooling elements. When there are multiple liquid cooling elements, the multiple liquid cooling elements may be arranged in parallel on the same side of at least some of the battery cells (such as battery cells); or, the multiple liquid cooling elements may be divided into several groups, each group being located on different sides of at least some of the battery cells, and the number of liquid cooling elements in each group may be one or more than two, the latter being arranged in parallel.

[0098] In some embodiments, the battery cells may be assembled into a battery module. As an example, the liquid cooling plate may be arranged on at least one side of the battery module. In addition, the number of battery cells contained in the battery module may be adjusted according to the application and capacity of the battery module.

[0099] In some embodiments, the liquid cooling plates are arranged in parallel and sandwiched between adjacent battery cells. Figure 5 As shown, the multiple battery cells 11 in the battery are divided into multiple groups. The battery cells 11 in each group are arranged in the same direction and the groups are arranged in parallel. A liquid cooling plate 400 is sandwiched between adjacent groups.

[0100] The sixth aspect of the present application provides an electric device, the electric device comprising the battery of the present application. The battery can be used as a power source for the electric device. The electric device may include, but is not limited to, mobile devices, electric vehicles, electric trains, ships and satellites, energy storage systems, etc.

[0101] Figure 6 The power consumption device is used as an example. The power consumption device may be a pure electric vehicle, a hybrid electric vehicle or a plug-in hybrid electric vehicle.

[0102] Hereinafter, the embodiments of the present application will be described. The embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If no specific techniques or conditions are indicated in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. If the manufacturer is not indicated in the reagents or instruments used, they are all conventional products that can be obtained commercially.

[0103] In the following examples and comparative examples,

[0104] Brominated epoxy resin was purchased from Kaimei Chemical with the brand name KBE-2025K;

[0105] Polybrominated styrene was purchased from Chemtura, USA, with the brand name PBS-64HW;

[0106] EMA is Arkema's AX8900;

[0107] PTW is Elvaloy PTW of DuPont, USA;

[0108] PET resin was purchased from Sinopec Yizheng Chemical Fiber Company with the brand name FG720;

[0109] The specifications of the harmonica tube plate are: 150mm×10mm×1mm, and the material is aluminum alloy AL3003.

[0110] Example 1

[0111] 1) Preparation of modified PET materials

[0112] According to the mass percentage, the raw material formula is as follows:

[0113]

[0114] Each component was added into a high-speed mixer and mixed for 5 minutes to obtain a premix (ie, a raw material composition). The premix was melt-extruded at 240° C. through a twin-screw extruder, cooled, and granulated to obtain a modified PET material.

[0115] 2) Insulation layer

[0116] PET modified PET material pellets are added to a single screw extruder, heated, melted, conveyed and extruded, extruded from a die, the harmonica tube sheet passes through the die, the extruded insulation layer is coated on the surface of the tube sheet, and after cooling, a liquid cooling part with an insulation layer thickness of 0.8 mm is obtained. Among them, the temperature setting of the first zone of the single screw extruder is: 110°C, the temperature setting of the second zone is: 250°C, the temperature setting of the third zone is: 260°C, the temperature setting of the fourth zone is: 270°C, the temperature setting of the fifth zone is: 260°C, the temperature setting of the sixth zone is: 265°C, the temperature setting of the seventh zone is: 270°C, the temperature setting of the eighth zone is: 275°C, the temperature setting of the ninth zone is: 280°C, the temperature setting of the die head is: 285°C, the screw speed is 350rpm, and the cooling water temperature is 50°C.

[0117] Example 2

[0118] 1) Preparation of modified PET materials

[0119] According to the mass percentage, the raw material formula is as follows:

[0120]

[0121] The components were added into a high-speed mixer and mixed for 5 minutes to obtain a premix. The premix was extruded through a twin-screw extruder, melt-extruded at 230° C., cooled, and granulated to obtain a modified PET material.

[0122] 2) Insulation layer

[0123] PET modified PET material pellets are added to a single screw extruder, heated, melted, conveyed and extruded, extruded from a die, the harmonica tube sheet passes through the die, the extruded insulation layer is coated on the surface of the tube sheet, and after cooling, a liquid cooling part with an insulation layer thickness of 0.8 mm is obtained. Among them, the temperature setting of the single screw extruder in the first zone is 100°C, the temperature setting of the second zone is 260°C, the temperature setting of the third zone is 270°C, the temperature setting of the fourth zone is 280°C, the temperature setting of the fifth zone is 270°C, the temperature setting of the sixth zone is 265°C, the temperature setting of the seventh zone is 270°C, the temperature setting of the eighth zone is 280°C, the temperature setting of the ninth zone is 280°C, the temperature setting of the die head is 290°C, the screw speed is 300rpm, and the cooling water temperature is 45°C.

[0124] Example 3

[0125] 1) Preparation of modified PET materials

[0126] According to the mass percentage, the raw material formula is as follows:

[0127]

[0128]

[0129] The components were added into a high-speed mixer and mixed for 5 minutes to obtain a premix. The premix was extruded through a twin-screw extruder, melt-extruded at 230° C., cooled, and granulated to obtain a modified PET material.

[0130] 2) Insulation layer

[0131] PET modified PET material pellets are added to a single screw extruder, heated, melted, conveyed and extruded, extruded from a die, the harmonica tube sheet passes through the die, the extruded insulation layer is coated on the surface of the tube sheet, and after cooling, a liquid cooling part with an insulation layer thickness of 0.8 mm is obtained. Among them, the temperature setting of the single screw extruder in the first zone is 120°C, the temperature setting of the second zone is 260°C, the temperature setting of the third zone is 270°C, the temperature setting of the fourth zone is 280°C, the temperature setting of the fifth zone is 275°C, the temperature setting of the sixth zone is 265°C, the temperature setting of the seventh zone is 275°C, the temperature setting of the eighth zone is 280°C, the temperature setting of the ninth zone is 290°C, the temperature setting of the die head is 290°C, the screw speed is 300rpm, and the cooling water temperature is 45°C.

[0132] Embodiment 4-10

[0133] The liquid cooling element was prepared according to the method of Example 1, except that when preparing the modified PET material, the component type and / or content in the PET raw material composition was adjusted, as shown in Table 1.

[0134] Embodiment 11

[0135] The liquid cooling element was prepared according to the method of Example 1, except that no lubricant was added when preparing the modified PET material, and the amount of PET resin was increased to 80.5 parts.

[0136] Example 12

[0137] The liquid cooling element was prepared according to the method of Example 1, except that no antioxidant was added when preparing the modified PET material, and the amount of PET resin was increased to 81 parts.

[0138] Comparative Example 1

[0139] The liquid cooling part was prepared according to the method of Example 1, except that no toughening agent was added when preparing the modified PET material, and the amount of PET resin was increased to 87.5 parts.

[0140] Comparative Example 2

[0141] The liquid cooling element was prepared according to the method of Example 1, except that no flame retardant was added when preparing the modified PET material, and the amount of PET resin was increased to 91 parts.

[0142] Table 1

[0143]

[0144] The parts in Table 1 are all parts by mass.

[0145] Test Case

[0146] The following properties of the modified PET material were tested.

[0147] 1. Flame retardancy test

[0148] According to the UL94 flammability test method, keep the longitudinal axis of the specimen vertical and burn vertically in the thickness direction.

[0149] 2. Insulation test

[0150] The insulation resistance value is tested according to standard IEC 60243-1.

[0151] 3. Mechanical properties test

[0152] The elongation at break was tested according to standard ISO 527 at a tensile rate of 50 mm / min.

[0153] Impact strength is tested according to standard ISO 179.

[0154] Table 2

[0155]

[0156] Combined with the data in Table 2, by comparing Examples 1-12 with Comparative Examples 1 and 2, it can be seen that the modified PET materials of Examples 1-12 have higher elongation at break and impact strength, indicating that they have higher toughness. At the same time, the material also has flame retardancy and insulation properties.

[0157] In addition, compared with Example 9, the surface of the insulating layer formed by Examples 1-8, 10-12 is smoother and has no flow lines, indicating that the brominated epoxy resin and the PET resin have higher compatibility in the presence of the toughening agent, so that the components maintain basically consistent fluidity during the extrusion molding process of the modified PET material. In the process of forming the insulating layer of Comparative Example 1, the melt flow is unstable, wrinkles appear on the surface of the product, and the stability of extrusion molding is poor.

[0158] In summary, in Examples 1-12, the modified PET material can stably form an insulating layer on the harmonica tube plate by an extrusion molding process, and the insulating layer has high toughness and ductility, and the insulating layer formed in this way can effectively protect the harmonica tube plate due to its high toughness and ductility. For example, when the battery is subjected to vibration and collision conditions that cause the metal harmonica tube plate to deform, due to the good ductility and excellent toughness of the thermoplastic extrusion material (modified PET material) of the present application, when subjected to the above conditions, no insulation failure caused by cracking or falling off will occur.

[0159] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A liquid cooling component, characterized in that: It comprises a heat-conducting part and an insulating layer coated on the surface of the heat-conducting part, wherein the heat-conducting part has a cooling channel, and the insulating layer comprises a modified PET material, and the modified PET material is made of a PET raw material composition including a PET resin, a toughening agent and a flame retardant.

2. The liquid cooling element according to claim 1, characterized in that: The heat conducting member includes a harmonica tube plate.

3. The liquid cooling element according to claim 1 or 2, characterized in that: The material of the heat conducting member includes at least one of aluminum alloy and magnesium alloy.

4. The liquid cooling element according to any one of claims 1 to 3, characterized in that: Based on the total weight of the PET raw material composition, the content of the PET resin is 70% by weight to 90% by weight, the content of the toughening agent is 3% by weight to 15% by weight, and the content of the flame retardant is 5% by weight to 20% by weight; Optionally, based on the total weight of the PET raw material composition, the content of the PET resin is 75% to 85% by weight, the content of the toughening agent is 5% to 10% by weight, and the content of the flame retardant is 8% to 15% by weight.

5. The liquid cooling element according to any one of claims 1 to 4, characterized in that: The toughening agent includes an ethylene terpolymer containing epoxy functional groups; Optionally, the epoxy-functional group-containing ethylene terpolymer includes ethylene-n-butyl acrylate-glycidyl methacrylate terpolymer and / or ethylene-methyl acrylate-glycidyl methacrylate terpolymer.

6. The liquid cooling element according to any one of claims 1 to 5, characterized in that: The flame retardant comprises at least one of brominated epoxy resin, brominated polystyrene or dodecabromodiphenylethane; Optionally, the flame retardant includes the brominated epoxy resin.

7. The liquid cooling element according to any one of claims 1 to 6, characterized in that: The PET raw material composition also includes an antioxidant; Optionally, based on the total weight of the PET raw material composition, the content of the antioxidant is 0.1 wt%-5 wt%, and more preferably 0.2 wt%-2 wt%; Optionally, the antioxidant includes a hindered phenol antioxidant and / or a phosphite antioxidant; Optionally, the mass ratio of the hindered phenol antioxidant to the phosphite antioxidant is 1:(0.5-2).

8. The liquid cooling element according to any one of claims 1 to 7, characterized in that: The PET raw material composition also includes a lubricant; Optionally, based on the total weight of the PET raw material composition, the content of the lubricant is 0.1 wt%-5 wt%, and more preferably 0.2 wt%-2 wt%; Optionally, the lubricant includes at least one of pentaerythritol stearate, calcium stearate, polyethylene wax, silicone or fluorine-containing resin; More optionally, the lubricant comprises pentaerythritol stearate.

9. The liquid cooling element according to any one of claims 1 to 8, characterized in that: The modified PET material is formed by heating and melting the PET raw material composition; Optionally, the heating and melting temperature is 230°C-280°C.

10. The liquid cooling element according to any one of claims 1 to 9, characterized in that: The thickness of the insulating layer is 0.5 mm-1 mm.

11. A method for preparing the liquid cooling element according to any one of claims 1 to 10, characterized in that: include: The modified PET material pellets are extruded and molded, so that the modified PET material is coated on the surface of the heat conducting member to form an insulating layer.

12. The method according to claim 11, characterized in that The extrusion molding includes the following processes: The pellets of the modified PET material are melted by a screw extruder and conveyed to a die head equipped with the heat-conducting member, so that the melt flows onto the surface of the heat-conducting member and is cooled to form the insulating layer; Optionally, in the screw extruder, the temperature of the screw feeding section is 100°C-120°C, the temperature of the compression section is 250°C-280°C, the temperature of the extrusion section is 260°C-290°C; and the screw speed is 300rpm-350rpm.

13. The method according to claim 11 or 12, characterized in that: Also includes: Premixing the components in the PET raw material composition to obtain a premix; The premix is ​​heated, melted and extruded into granules to prepare granules of the modified PET material.

14. A liquid cooling assembly, characterized in that: It includes a current collecting part and a liquid cooling part, wherein: The liquid cooling element is a liquid cooling element as described in any one of claims 1 to 10 or a liquid cooling element prepared by the method as described in any one of claims 11 to 13; The current collecting member is connected to the liquid cooling member, and the current collecting member has a current collecting space, and the current collecting space is communicated with the cooling channel.

15. A liquid cooling system, characterized in that: include: The liquid cooling assembly of claim 14; as well as A liquid supply assembly is communicated with the current collecting member to supply cooling medium into the cooling channel.

16. A battery, characterized in that: include: A plurality of battery cells, and a liquid cooling element, wherein the liquid cooling element is the liquid cooling element according to any one of claims 1-10 or the liquid cooling element prepared by the method according to any one of claims 11-13; and at least some of the plurality of battery cells are in contact with the liquid cooling element.

17. An electrical device, characterized in that: Comprising the battery of claim 16.

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