High-temperature-resistant insulating cover film for liquid cooling plate of new energy battery

Abstract

The utility model discloses a high-temperature-resistant insulating cover film for a liquid cooling plate of a new energy battery. The high-temperature-resistant insulating cover film comprises a protective film layer, an adhesive layer, an insulating base material layer and a coating which are sequentially overlapped. When the high-temperature-resistant insulating cover film is used, the protective film is torn off, and the adhesive layer of the insulating cover film is attached to the surface of a liquid cooling plate in a hot roller attaching mode, so that excellent insulating performance is provided for the liquid cooling plate of a new energy battery; meanwhile, a layer of high-adhesion weather-resistant coating is introduced to the surface of the insulating base material layer in contact with the battery heat-conducting structural adhesive, so that better adhesive force can be provided for subsequent adhesion of the battery heat-conducting structural adhesive.

Description

Technical Field

[0001] The utility model relates to the technical field of battery liquid cooling plate protective films, in particular to a high temperature resistant insulating covering film for a new energy battery liquid cooling plate. Background Art

[0002] At present, the batteries of new energy vehicles mostly use liquid cooling systems for constant temperature control. Specifically, the excess heat generated by the battery when it is working is transferred through the contact between the battery or module and the surface of the plate-shaped aluminum device, and finally carried away by the coolant passing through the internal flow channel of the device, and the coolant is used to physically cool the battery. With the widespread application of liquid cooling systems, the insulation protection performance of the liquid cooling plate of the battery pack has increased, and many battery manufacturers choose to use coating technology for the liquid cooling plate. However, the coating process itself has inherent disadvantages such as large equipment investment and high environmental protection requirements, and it is very easy to cause environmental problems. At the same time, the performance of insulating coatings often changes due to the influence of production processes and environmental factors. For example, the thickness, flatness, tensile strength, adhesion and other properties of the paint film are related to the preparation process and the use environment; the construction of insulating coatings is difficult, and certain professional skills and operating techniques need to be mastered, otherwise bubbles, sagging, and missing coatings are prone to occur, affecting the quality of the coating. Utility Model Content

[0003] In order to solve the above problems, the utility model provides a high temperature resistant insulating covering film for a new energy battery liquid cooling plate, which can not only provide excellent insulation performance and weather resistance for the new energy battery liquid cooling plate, but also provide better adhesion for the subsequent bonding of the thermal conductive structural adhesive of the battery cell.

[0004] The utility model includes the following technical solutions:

[0005] The utility model provides a high-temperature resistant insulating covering film for a new energy battery liquid cooling plate, wherein the high-temperature resistant insulating covering film comprises a protective film layer, an adhesive layer, an insulating substrate layer and a coating layer which are sequentially stacked; the adhesive layer is arranged on one side of the insulating substrate layer, the coating layer is arranged on the other side of the insulating substrate layer away from the adhesive layer, and the protective film layer is arranged on the side of the adhesive layer away from the insulating substrate layer.

[0006] Furthermore, the adhesive layer is a hot melt adhesive or a thermosetting adhesive; the hot melt adhesive is preferably a polyolefin hot melt adhesive or a polyurethane hot melt adhesive, and the thermosetting adhesive is preferably a polyester resin, polyurethane, alkyd resin, epoxy resin, acrylic resin or silicone. Hot melt adhesives or thermosetting adhesives have good bonding strength for metal plates (such as copper plates, tinned copper plates, aluminum plates) and insulating substrate layers, and have a certain bonding strength even at low temperatures of -40°C and high temperatures of 85°C.

[0007] Furthermore, the thickness of the adhesive layer is 0.025 mm-0.05 mm, more preferably 0.03 mm-0.04 mm.

[0008] Furthermore, the adhesive layer contains a halogen-free flame retardant filler; the halogen-free flame retardant filler is one or a combination of phosphorus flame retardants, nitrogen flame retardants, silicon flame retardants, metal hydroxide flame retardants, metal oxide flame retardants or metal boride flame retardants, such as diethyl aluminum hypophosphite, aluminum hydroxide, polyphosphate melamine, etc. By introducing an appropriate amount of halogen-free flame retardant filler into the adhesive layer, such as a halogen-free flame retardant filler with a mass percentage of 10% to 30%, the flame retardant performance of the high temperature resistant insulating cover film can be improved.

[0009] Furthermore, the insulating substrate layer is preferably a polyimide film layer with excellent heat resistance, and its material can be a double-stranded or single-stranded polyimide film.

[0010] Furthermore, the thickness of the insulating substrate layer is preferably 0.05 mm to 0.125 mm, more preferably 0.075 mm to 0.1 mm. The thickness of the insulating substrate layer can be adjusted accordingly according to the insulation requirements of the battery liquid cooling plate.

[0011] Furthermore, the coating is preferably a fluorocarbon coating, an epoxy coating, a polyurethane coating or an acrylate coating. By coating a high-adhesion weather-resistant coating on the side of the insulating substrate layer away from the adhesive layer, excellent adhesion is provided for the thermally conductive structural adhesive for bonding the new energy battery cell, so that the new energy battery cell and the liquid cooling plate can be better bonded.

[0012] Furthermore, the thickness of the coating is preferably 2 μm-8 μm, more preferably 3 μm-5 μm.

[0013] Furthermore, the coating completely or partially covers the side of the insulating substrate layer away from the adhesive layer. For example, the coating partially covers the insulating substrate layer in the form of spaced stripes or grids.

[0014] Furthermore, the protective film layer is a PET release film layer with a thickness of 15-30 μm. By arranging the protective film layer on the adhesive layer, the adhesive layer of the high temperature resistant insulating cover film is prevented from being contaminated, thereby affecting the bonding performance of the adhesive.

[0015] Compared with the prior art, the beneficial effects of the utility model are:

[0016] The utility model provides a high temperature resistant insulating covering film for a new energy battery liquid cooling plate, the covering film having a protective film layer, an adhesive layer, an insulating substrate layer and a coating layer stacked in sequence. When in use, the protective film is torn off, and the adhesive layer of the insulating covering film is attached to and completely infiltrated with the surface of the liquid cooling plate by hot roller pasting and baking, thereby completing the bonding and curing of the insulating covering film on the surface of the liquid cooling plate. Compared with directly coating the insulating coating on the surface of the liquid cooling plate, the operation of pasting the insulating covering film on the surface of the liquid cooling plate is more convenient and the quality is controllable. The setting of the insulating substrate layer provides excellent heat resistance and insulation performance for the new energy battery liquid cooling plate; at the same time, the high-bonding and weather-resistant coating introduced on the surface of the high temperature resistant insulating covering film provides excellent adhesion for the battery thermal conductive structural adhesive, so that the battery cell of the new energy battery and the liquid cooling plate can be better bonded. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the high temperature resistant insulating covering film;

[0018] Among them, 1 is a protective film layer, 2 is an adhesive layer, 3 is an insulating substrate layer, and 4 is a coating layer. DETAILED DESCRIPTION

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the technical field of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0020] The present invention is further described below through the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0021] Example 1

[0022] This embodiment discloses a high temperature resistant insulating covering film for a new energy battery liquid cooling plate, such as Figure 1 As shown, it includes a protective film layer 1, an adhesive layer 2, an insulating substrate layer 3 and a coating layer 4 which are arranged in sequence.

[0023] In this embodiment, the protective film layer is a PET release film with a thickness of 25 μm.

[0024] In this embodiment, the adhesive layer is composed of polyester resin and diethyl aluminum hypophosphite, wherein the mass proportion of diethyl aluminum hypophosphite in the adhesive layer is 20%, and the thickness of the adhesive layer is 30 μm.

[0025] In this embodiment, the insulating base material layer is a polyimide film with a thickness of 75 μm.

[0026] In this embodiment, the coating is a polyurethane coating with a thickness of 3 μm.

[0027] Example 2

[0028] This embodiment discloses a high temperature resistant insulating covering film for a new energy battery liquid cooling plate, comprising a protective film layer, an adhesive layer, an insulating substrate layer and a coating layer which are arranged in sequence.

[0029] In this embodiment, the protective film layer is a PET release film with a thickness of 25 μm.

[0030] In this embodiment, the adhesive layer is composed of polyester resin and diethyl aluminum hypophosphite, wherein the mass proportion of the halogen-free flame retardant filler in the adhesive layer is 20%, and the thickness of the adhesive layer is 30 μm.

[0031] In this embodiment, the insulating base material layer is a polyimide film with a thickness of 75 μm.

[0032] In this embodiment, the coating is a polyurethane coating with a thickness of 5 μm.

[0033] Example 3

[0034] This embodiment discloses a high temperature resistant insulating covering film for a new energy battery liquid cooling plate, comprising a protective film layer, an adhesive layer, an insulating substrate layer and a coating layer which are arranged in sequence.

[0035] In this embodiment, the protective film layer is a PET release film with a thickness of 25 μm.

[0036] In this embodiment, the adhesive layer is composed of polyester resin and diethyl aluminum hypophosphite, wherein the mass proportion of the halogen-free flame retardant filler in the adhesive layer is 20%, and the thickness of the adhesive layer is 40 μm.

[0037] In this embodiment, the insulating base material layer is a polyimide film with a thickness of 75 μm.

[0038] In this embodiment, the coating is a polyurethane coating with a thickness of 5 μm.

[0039] Example 4

[0040] This embodiment discloses a high temperature resistant insulating covering film for a new energy battery liquid cooling plate, comprising a protective film layer, an adhesive layer, an insulating substrate layer and a coating layer which are arranged in sequence.

[0041] In this embodiment, the protective film layer is a PET release film with a thickness of 25 μm.

[0042] In this embodiment, the adhesive layer is composed of polyester resin and diethyl aluminum hypophosphite, wherein the mass proportion of the halogen-free flame retardant filler in the adhesive layer is 20%, and the thickness of the adhesive layer is 30 μm.

[0043] In this embodiment, the insulating base material layer is a polyimide film with a thickness of 100 μm.

[0044] In this embodiment, the coating is a polyurethane coating with a thickness of 4 μm.

[0045] Example 5

[0046] This embodiment discloses a high temperature resistant insulating covering film for a new energy battery liquid cooling plate, comprising a protective film layer, an adhesive layer, an insulating substrate layer and a coating layer which are arranged in sequence.

[0047] In this embodiment, the protective film layer is a PET release film with a thickness of 25 μm.

[0048] In this embodiment, the adhesive layer is composed of polyester resin and diethyl aluminum hypophosphite, wherein the mass proportion of the halogen-free flame retardant filler in the adhesive layer is 30%, and the thickness of the adhesive layer is 30 μm.

[0049] In this embodiment, the insulating base material layer is a polyimide film with a thickness of 100 μm.

[0050] In this embodiment, the coating may be a polyurethane coating with a thickness of 5 μm.

[0051] Comparative Example 1

[0052] This comparative example discloses a high temperature resistant insulating covering film, comprising a protective film layer, an adhesive layer and an insulating substrate layer arranged in sequence, and is different from Example 4 in that it does not include a coating layer.

[0053] Comparative Example 2

[0054] This comparative example discloses a high temperature resistant insulating covering film, comprising a protective film layer, an adhesive layer, an insulating substrate layer and a coating layer arranged in sequence, and the only difference from Example 4 is that no halogen-free flame retardant filler is added to the adhesive layer.

[0055] Comparative Example 3

[0056] This comparative example discloses a high temperature resistant insulating covering film, comprising a protective film layer, an adhesive layer, an insulating substrate layer and a coating arranged in sequence. The only difference from Example 4 is: the thickness of the insulating substrate layer and the coating. In this comparative example, the thickness of the insulating substrate layer is 25 μm, and the thickness of the coating is 8 μm.

[0057] Performance Testing

[0058] The performance of the high temperature resistant insulating covering films in the above embodiments and comparative examples was tested, and the test standards were as follows:

[0059] Peel strength test: Cut the film into 300mm×150mm size, and hot roll the cut film onto 3003 aluminum plate, roll temperature: 160-180℃, roll speed: 0.5-1m / min, pressure 0.5-0.7Mpa, bake at 150℃ for 1h, cool to room temperature and test 180° peeling, speed 300mm / min;

[0060] Shear strength test: Cut the cured aluminum plate-bonded product into 25mm×100mm samples, use a blank aluminum plate of the same size to apply high-strength thermal conductive structural adhesive with an overlap area of ​​25mm×12.5mm, bake at 80℃ for 8h to cure and cross-link the structural adhesive, cool to room temperature after complete curing and place for 24h before testing; stretching direction 180°, stretching rate 4mm / min, shear strength = maximum test force ÷ actual bonding area.

[0061] Glue layer flame retardant performance test: Tested in accordance with UL94 VTM flame retardant test standard.

[0062] Breakdown voltage test in air: Cut 3 A4-sized films as samples, set the voltage rise rate of the breakdown voltage tester to ensure the breakdown time is within 10-20s, select 1Kv / s, surrounding medium: air, electrode size: 75mm / 25mm; calculate the average breakdown voltage of the 3 samples.

[0063] High temperature and high humidity aging test (85°C×85%RH / 1000h): Place the sample (preparation method is consistent with the above peel strength and shear strength tests) in a high temperature and high humidity environment box for 1000h, take it out and cool it to room temperature, and test the peel strength, 180° peeling, and a speed of 300mm / min.

[0064] Thermal shock aging test (-40℃~105℃ / 1000 cycles): Place the sample (the sample preparation method is consistent with the sample preparation method in the above peel strength and shear strength tests) in a thermal shock environment box for 1000h, -40℃ / 0.5h, 105℃ / 0.5h, and the hot and cold switching time is within 2mins. After 1000 cycles, take out and cool to room temperature, and test the peel strength and shear strength.

[0065] High temperature aging test (aging at 130°C for 1000h): Place the sample (the sample preparation method is consistent with the sample preparation method in the above peel strength and shear strength tests) in a high temperature oven for 1000h. After aging for 1000h, take it out and cool it to room temperature, and test the peel strength and shear strength.

[0066] Comprehensive performance: ◎ indicates the best comprehensive performance; ○ indicates OK performance, which can meet the use requirements; △ indicates poor performance; × indicates extremely poor performance.

[0067] The test results are shown in Table 1 below:

[0068] Table 1 Performance data of high temperature resistant insulating covering films in different embodiments and comparative examples

[0069]

[0070]

[0071] As can be seen from the above table, the samples made by laminating the high temperature resistant insulating covering film to the aluminum plate in Examples 1 to 5 have high initial peel strength, shear strength and breakdown voltage, and the adhesive layer has excellent flame retardancy. After high temperature and humidity, hot and cold shock cycles and high temperature aging tests, the samples can still maintain high peel strength and shear strength, which also shows that the high temperature resistant insulating covering film has good weather resistance.

[0072] Compared with Example 4, Comparative Example 1 does not include a coating, and the sample prepared by bonding the high-temperature resistant insulating covering film to an aluminum plate has a low shear strength. After being placed in a high-temperature and high-humidity environment for 1000 hours, the shear strength drops to 0; the adhesive layer of the high-temperature resistant insulating covering film in Comparative Example 2 does not include a halogen-free flame retardant filler, and the flame retardant performance of the corresponding prepared sample is poor; the thickness of the insulating substrate layer of the high-temperature resistant insulating covering film in Comparative Example 3 is thin, and the thickness of the coating is thick. The sample prepared by bonding it to an aluminum plate has a low shear strength and poor insulation.

[0073] The above-described embodiments are only preferred embodiments for fully illustrating the present utility model, and the protection scope of the present utility model is not limited thereto. Equivalent substitutions or changes made by technicians in the technical field on the basis of the present utility model are all within the protection scope of the present utility model. The protection scope of the present utility model shall be subject to the claims.

Claims

1. A high temperature resistant insulating covering film for a new energy battery liquid cooling plate, characterized in that: The high temperature resistant insulating covering film comprises a protective film layer, an adhesive layer, an insulating base material layer and a coating layer which are stacked in sequence; The protective film layer is a PET release film layer with a thickness of 15-30 μm; The adhesive layer is a hot melt adhesive or a thermosetting adhesive with a thickness of 0.025 mm-0.05 mm; The insulating substrate layer is a polyimide film layer with a thickness of 0.05 mm-0.125 mm; The coating is a fluorocarbon coating, an epoxy coating, a polyurethane coating or an acrylic coating, and has a thickness of 2 μm-8 μm.

2. The high temperature resistant insulating covering film according to claim 1, characterized in that: The hot melt adhesive is a polyolefin hot melt adhesive or a polyurethane hot melt adhesive; The thermosetting adhesive is polyester resin, polyurethane, alkyd resin, epoxy resin, acrylic resin or silica gel.

3. The high temperature resistant insulating covering film according to claim 1, characterized in that: The coating layer completely or partially covers the side of the insulating substrate layer away from the adhesive layer.

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