A battery core thermal insulation sheet and preparation method thereof

Abstract

The present invention discloses a battery core thermal insulation sheet and a preparation method thereof. The sheet comprises, from top to bottom, a first electronic glass fiber cloth layer, a first adhesive layer, a polyurethane foam layer containing a substrate, a second adhesive layer, and a second electronic glass fiber cloth layer. The first adhesive layer and the second adhesive layer are independently made of the following raw materials: silicon boron carbon nitrogen polymer, 2-(1-propylene-2-yl)benzo[d]oxazole, tetrabromobisphenol A bisallyl ether, a coupling agent, a filler, an amino-containing hyperbranched liquid crystal polymer, bis(oxiranylmethyl)-5-(2-propylene)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, a defoamer, an initiator, and a solvent. The battery core thermal insulation sheet has excellent thermal insulation performance, long service life, excellent flame retardancy and fire resistance, and good compression resilience.

Description

Technical Field

[0001] The present invention relates to the technical field of battery components, and in particular to a battery core thermal insulation sheet and a preparation method thereof. Background Art

[0002] Thermal runaway protection between battery cells in new energy vehicle battery modules is a key factor influencing vehicle safety. To achieve this, thermal insulation sheets are typically used between the battery cells in new energy vehicle power batteries and energy storage batteries to effectively insulate and ensure battery safety. The performance of these insulation sheets directly impacts the safety and cycle life of power batteries. Therefore, the development of thermal insulation sheets with excellent overall performance and stability is imperative.

[0003] Existing battery cell thermal insulation sheets are mostly made of aerogel felt. This material has low thermal conductivity, low density, high temperature resistance, and excellent flame retardancy. However, it is expensive, suffers from poor impact and flex resistance, is difficult to control powder shedding, does not adhere tightly to complex shapes, and has limited compression and resilience. Other types of battery cell thermal insulation sheets on the market also have various technical drawbacks, such as poor insulation effectiveness, low structural strength, limited compression resilience, and a short service life.

[0004] For example, Chinese invention patent document ZL202210970182.X discloses an aerogel battery cell thermal insulation sheet, which is made from PET, an aerogel thermal insulation composition, and an additive in a weight ratio of 2:1:0.1. The aerogel thermal insulation composition is made from the following components in parts by weight: 30-78 parts aerogel, 10-25 parts sunscreen, and 10-20 parts high-silica glass fiber. The invention also provides a method for preparing the aerogel battery cell thermal insulation sheet. The aerogel battery cell thermal insulation sheet provided by this invention has good thermal insulation and compressive resistance. However, its compression resilience still needs to be further improved.

[0005] Therefore, the development of a battery cell thermal insulation sheet with good thermal insulation performance, long service life, excellent flame retardancy and fire resistance, and good compression resilience and its preparation method meets market demand, has broad market value and application prospects, and is of great significance to promoting the development of the battery cell thermal insulation sheet field. Summary of the Invention

[0006] The main purpose of the present invention is to provide a battery core thermal insulation sheet with good thermal insulation performance, long service life, excellent flame retardancy and fire resistance, and good compression resilience, and a preparation method thereof.

[0007] To achieve the above objectives, the present invention provides a battery core thermal insulation sheet, which comprises, from top to bottom, a first electronic glass fiber cloth layer, a first adhesive layer, a polyurethane foam layer containing a substrate, a second adhesive layer, and a second electronic glass fiber cloth layer; the first adhesive layer and the second adhesive layer are independently made of the following raw materials in parts by weight: 30-40 parts of silicon boron carbon nitrogen polymer, 2-5 parts of 2-(1-propylene-2-yl)benzo[d]oxazole, 3-4 parts of tetrabromobisphenol A bisallyl ether, and 1-6 parts of tetrabromobisphenol A bisallyl ether. 5 parts, 1-2 parts of coupling agent, 5-8 parts of filler, 10-15 parts of amino-containing hyperbranched liquid crystal polymer, 3-5 parts of bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1-3 parts of 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 0.8-1.2 parts of defoaming agent, 1-2 parts of initiator, and 50-80 parts of solvent.

[0008] Preferably, the thickness of the first electronic glass fiber cloth layer is 0.02-0.2 mm; the thickness of the first adhesive layer is 0.03-0.15 mm; the thickness of the second electronic glass fiber cloth layer is 0.02-0.2 mm; and the thickness of the second adhesive layer is 0.03-0.15 mm.

[0009] Preferably, the thickness of the polyurethane foam layer containing the substrate is 1.2-5.5 mm.

[0010] Preferably, the base material in the polyurethane foam layer containing a base material is made of PET, and the thickness of the base material is 0.01-0.25 mm.

[0011] Preferably, the polyurethane foam layer containing the substrate is made according to the method of Example 1 in Chinese invention patent document CN113292764B.

[0012] Preferably, there is no special requirement for the source of the silicon boron carbon nitrogen polymer. In one embodiment of the present invention, the silicon boron carbon nitrogen polymer is prepared according to the method of Example 1 in Chinese invention patent document CN102604108B.

[0013] Preferably, the coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570.

[0014] Preferably, the filler is a mixture of mica powder, glass fiber, and silica aerogel in a mass ratio of (3-5):1:(0.3-0.8).

[0015] Preferably, the particle size of the mica powder is 1000-1500 mesh; the glass fiber is alkali-free chopped glass fiber, with a single fiber diameter of 3-9 μm and a length of 3-4.5 mm; and the silica aerogel is CABOT silica aerogel.

[0016] Preferably, there is no special requirement for the source of the amino-containing hyperbranched liquid crystal polymer. In one embodiment of the present invention, the amino-containing hyperbranched liquid crystal polymer is prepared according to the method of Example 4 in Chinese invention patent CN114437493B.

[0017] The initiator is benzoyl peroxide; the solvent is at least one of N,N-dimethylformamide and N-methylpyrrolidone; the defoaming agent is one or more of tributyl phosphate, defoaming agent Deqian 3100, and defoaming agent BYK088.

[0018] Another object of the present invention is to provide a method for preparing the battery core thermal insulation sheet, comprising the following steps:

[0019] Step S1: After uniformly mixing the raw materials of the first adhesive layer, the mixture is coated on the surface of the polyurethane foam substrate containing the substrate to form the first adhesive layer, and then the first electronic glass fiber cloth is attached to the surface of the first adhesive layer, heated and cured, and pressed into shape in one step;

[0020] Step S2: After the raw materials of the second adhesive layer are evenly mixed, they are coated on the foam surface of the polyurethane foam containing the substrate to form the second adhesive layer. Then, the second electronic glass fiber cloth is attached to the surface of the second adhesive layer, heated and cured, pressed into shape in one go, and then die-cut into customized sizes.

[0021] Preferably, the heating curing temperature is 100-120° C., and the curing time is 1-3 hours.

[0022] Preferably, the first electronic glass fiber cloth layer and the second electronic glass fiber cloth layer are independently made of 2116 electronic grade glass fiber cloth.

[0023] Preferably, the pressure of the pressing molding is 2-6 MPa, and the time is 10-20 s.

[0024] Due to the application of the above technical solution, the present invention has the following beneficial effects:

[0025] The preparation method of the battery core thermal insulation sheet disclosed in the present invention has simple process, convenient operation, high preparation efficiency and finished product qualification rate, low dependence on equipment, low energy consumption and capital investment, is suitable for continuous large-scale production, and has high promotion and application value.

[0026] The battery cell thermal insulation sheet disclosed in this invention comprises, from top to bottom, a first electronic fiberglass cloth layer, a first adhesive layer, a polyurethane foam layer containing a substrate, a second adhesive layer, and a second electronic fiberglass cloth layer. This structural design results in excellent thermal insulation, a long service life, and superior flame retardancy. The rational selection of materials for each layer reduces delamination, improves safety and reliability, extends service life, and reduces the risk of thermal runaway, thereby ensuring the safety of life and property. The introduction of a polyurethane foam structure improves the product's compression resilience.

[0027] The battery core thermal insulation sheet disclosed by the present invention comprises the following raw materials, each of which is independently made of the following raw materials in parts by weight: 30-40 parts of silicon boron carbon nitrogen polymer, 2-5 parts of 2-(1-propylene-2-yl)benzo[d]oxazole, 3-5 parts of tetrabromobisphenol A bisallyl ether, 1-2 parts of a coupling agent, 5-8 parts of a filler, 10-15 parts of an amino-containing hyperbranched liquid crystal polymer, 3-5 parts of bis(oxiranylmethyl)-5-(2-propylene)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1-3 parts of 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 0.8-1.2 parts of a defoaming agent, 1-2 parts of an initiator, and 50-80 parts of a solvent. The interaction between the various raw materials results in a thermal insulation sheet with excellent thermal insulation performance, a long service life, and superior flame retardancy. This avoids the poor film-forming properties and poor compatibility with other raw materials that can affect product stability when silicon boron carbon nitrogen polymer is used alone. By combining these materials with other raw materials, tetrabromobisphenol A, silicon boron carbon nitrogen polymer, benzo[d]oxazole, hyperbranched liquid crystal polymer, triazone, and phenoxyphenylhexafluoropropane structures are simultaneously introduced into the adhesive's molecular structure. These structures, through multiple interactions such as electronic, steric, and conjugated effects, work together to achieve even better thermal insulation, a longer service life, and superior flame retardancy.

[0028] In the battery core thermal insulation sheet disclosed in the present invention, fillers are added to the raw materials for preparing the first adhesive layer and the second adhesive layer. The fillers are a mixture of mica powder, glass fiber, and silica aerogel in a mass ratio of (3-5):1:(0.3-0.8). Through the reasonable selection of the filler formula, the adhesive layer has excellent thermal insulation performance and can also improve its compatibility with the electronic glass fiber cloth layer, thereby improving the structural stability of the manufactured battery core thermal insulation sheet. DETAILED DESCRIPTION

[0029] The following description is intended to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are merely examples, and those skilled in the art may conceive of other obvious variations. Example 1

[0030] A battery core thermal insulation sheet comprises, from top to bottom, a first electronic glass fiber cloth layer, a first adhesive layer, a polyurethane foam layer containing a substrate, a second adhesive layer, and a second electronic glass fiber cloth layer; the first adhesive layer and the second adhesive layer are independently made of the following raw materials, measured in parts by weight: 30 parts of silicon boron carbon nitrogen polymer, 2 parts of 2-(1-propylene-2-yl)benzo[d]oxazole, 3 parts of tetrabromobisphenol A bisallyl ether, 1 part of a coupling agent, 5 parts of a filler, 10 parts of an amino-containing hyperbranched liquid crystal polymer, 3 parts of bis(oxiranylmethyl)-5-(2-propylene)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1 part of 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 0.8 parts of a defoamer, 1 part of an initiator, and 50 parts of a solvent.

[0031] The first electronic glass fiber cloth layer and the second electronic glass fiber cloth layer are independently made of 2116 electronic grade glass fiber cloth; the thickness of the first adhesive layer is 0.05 mm; the thickness of the second adhesive layer is 0.05 mm; the polyurethane foam layer containing the substrate is made according to the method of Example 1 in Chinese invention patent document CN113292764B; the silicon boron carbon nitrogen polymer is made according to the method of Example 1 in Chinese invention patent document CN102604108B. The coupling agent is silane coupling agent KH550; the filler is a mixture of mica powder, glass fiber, and silica aerogel in a mass ratio of 3:1:0.3; the particle size of the mica powder is 1000 mesh; the glass fiber is alkali-free chopped glass fiber, with a single fiber diameter of 3 μm and a length of 3 mm; the silica aerogel is CABOT silica aerogel; the amino-containing hyperbranched liquid crystal polymer is prepared according to the method of Example 4 in Chinese invention patent CN114437493B; the initiator is benzoyl peroxide; the solvent is N,N-dimethylformamide; and the defoaming agent is tributyl phosphate.

[0032] A method for preparing the battery core thermal insulation sheet comprises the following steps:

[0033] Step S1: After uniformly mixing the raw materials of the first adhesive layer, the mixture is coated on the surface of the polyurethane foam substrate containing the substrate to form the first adhesive layer, and then the first electronic glass fiber cloth is attached to the surface of the first adhesive layer, heated and cured, and pressed into shape in one step;

[0034] Step S2: After the raw materials of the second adhesive layer are evenly mixed, they are coated on the foam surface of the polyurethane foam containing the substrate to form the second adhesive layer. Then, the second electronic glass fiber cloth is attached to the surface of the second adhesive layer, heated and cured, pressed into shape in one go, and then die-cut into customized sizes.

[0035] The heating curing temperature is 100° C. and the time is 1 hour; the pressing pressure is 2 MPa and the time is 10 seconds. Example 2

[0036] A battery core thermal insulation sheet, comprising, from top to bottom, a first electronic glass fiber cloth layer, a first adhesive layer, a polyurethane foam layer containing a substrate, a second adhesive layer, and a second electronic glass fiber cloth layer; the first adhesive layer and the second adhesive layer are independently made of the following raw materials in parts by weight: 33 parts of silicon boron carbon nitrogen polymer, 3 parts of 2-(1-propylene-2-yl)benzo[d]oxazole, 3.5 parts of tetrabromobisphenol A bisallyl ether, 1.2 parts of coupling agent, 6 parts of filler, 11 parts of amino-containing hyperbranched liquid crystal polymer, 3.5 parts of bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1.5 parts of 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 0.9 parts of defoaming agent, 1.2 parts of initiator, and 60 parts of solvent.

[0037] The thickness of the first adhesive layer is 0.05 mm; the thickness of the second adhesive layer is 0.05 mm; the first electronic glass fiber cloth layer and the second electronic glass fiber cloth layer are independently made of 2116 electronic grade glass fiber cloth; the polyurethane foam layer containing the substrate is made according to the method of Example 1 in the Chinese invention patent document CN113292764B; the silicon boron carbon nitrogen polymer is made according to the method of Example 1 in the Chinese invention patent document CN102604108B; the coupling agent is the silane coupling agent KH560; the filler is a mixture of mica powder, glass fiber, and silica aerogel in a mass ratio of 3.5:1:0.4; the particle size of the mica powder is 1100 mesh; the glass fiber is alkali-free chopped glass fiber, the single filament diameter is 5 μm, and the length is 3.5 mm; the silica aerogel is CABOT silica aerogel.

[0038] The amino-containing hyperbranched liquid crystal polymer is prepared according to the method of Example 4 in Chinese invention patent CN114437493B; the initiator is benzoyl peroxide; the solvent is N-methylpyrrolidone; and the defoamer is Deqian 3100.

[0039] A method for preparing the battery core thermal insulation sheet comprises the following steps:

[0040] Step S1: After uniformly mixing the raw materials of the first adhesive layer, the mixture is coated on the surface of the polyurethane foam substrate containing the substrate to form the first adhesive layer, and then the first electronic glass fiber cloth is attached to the surface of the first adhesive layer, heated and cured, and pressed into shape in one step;

[0041] Step S2: After the raw materials of the second adhesive layer are evenly mixed, they are coated on the foam surface of the polyurethane foam containing the substrate to form the second adhesive layer. Then, the second electronic glass fiber cloth is attached to the surface of the second adhesive layer, heated and cured, pressed into shape in one go, and then die-cut into customized sizes.

[0042] The heating curing temperature is 105° C. and the time is 1.5 hours; the pressing pressure is 3 MPa and the time is 13 seconds. Example 3

[0043] A battery core thermal insulation sheet, comprising, from top to bottom, a first electronic glass fiber cloth layer, a first adhesive layer, a polyurethane foam layer containing a substrate, a second adhesive layer, and a second electronic glass fiber cloth layer; the first adhesive layer and the second adhesive layer are independently made of the following raw materials in parts by weight: 35 parts of silicon boron carbon nitrogen polymer, 3.5 parts of 2-(1-propylene-2-yl)benzo[d]oxazole, 4 parts of tetrabromobisphenol A bisallyl ether, and 10 parts of tetrabromobisphenol A bisallyl ether. parts, 1.5 parts of coupling agent, 6.5 parts of filler, 13 parts of amino-containing hyperbranched liquid crystal polymer, 4 parts of bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 2 parts of 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 1 part of defoaming agent, 1.5 parts of initiator, and 65 parts of solvent.

[0044] The first electronic glass fiber cloth layer and the second electronic glass fiber cloth layer are independently made of 2116 electronic grade glass fiber cloth; the thickness of the first adhesive layer is 0.05 mm; the thickness of the second adhesive layer is 0.05 mm; the polyurethane foam layer containing the substrate is made according to the method of Example 1 in Chinese invention patent document CN113292764B; the silicon boron carbon nitrogen polymer is made according to the method of Example 1 in Chinese invention patent document CN102604108B; the coupling agent is silane coupling agent KH570; the filler is a mixture of mica powder, glass fiber, and silica aerogel in a mass ratio of 4:1:0.55.

[0045] The mica powder has a particle size of 1300 mesh; the glass fiber is an alkali-free chopped glass fiber with a single filament diameter of 6 μm and a length of 4 mm; the silica aerogel is CABOT silica aerogel; the amino-containing hyperbranched liquid crystal polymer is prepared according to the method of Example 4 in Chinese invention patent CN114437493B; the initiator is benzoyl peroxide; the solvent is N,N-dimethylformamide; and the defoamer is defoamer BYK088.

[0046] A method for preparing the battery core thermal insulation sheet comprises the following steps:

[0047] Step S1: After uniformly mixing the raw materials of the first adhesive layer, the mixture is coated on the surface of the polyurethane foam substrate containing the substrate to form the first adhesive layer, and then the first electronic glass fiber cloth is attached to the surface of the first adhesive layer, heated and cured, and pressed into shape in one step;

[0048] Step S2: After the raw materials of the second adhesive layer are evenly mixed, they are coated on the foam surface of the polyurethane foam containing the substrate to form the second adhesive layer. Then, the second electronic glass fiber cloth is attached to the surface of the second adhesive layer, heated and cured, pressed into shape in one go, and then die-cut into customized sizes.

[0049] The heating curing temperature is 110° C. and the time is 2 hours; the pressing pressure is 4 MPa and the time is 15 seconds. Example 4

[0050] A battery core thermal insulation sheet, comprising, from top to bottom, a first electronic glass fiber cloth layer, a first adhesive layer, a polyurethane foam layer containing a substrate, a second adhesive layer, and a second electronic glass fiber cloth layer; the first adhesive layer and the second adhesive layer are independently made of the following raw materials in parts by weight: 38 parts of silicon boron carbon nitrogen polymer, 4.5 parts of 2-(1-propylene-2-yl)benzo[d]oxazole, 4.5 parts of tetrabromobisphenol A bisallyl ether, 1.8 parts of coupling agent, 7.5 parts of filler, 14 parts of amino-containing hyperbranched liquid crystal polymer, 4.5 parts of bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 2.5 parts of 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 1.1 parts of defoaming agent, 1.8 parts of initiator, and 75 parts of solvent.

[0051] The thickness of the first adhesive layer is 0.05 mm; the thickness of the second adhesive layer is 0.05 mm; the first electronic glass fiber cloth layer and the second electronic glass fiber cloth layer are independently made of 2116 electronic grade glass fiber cloth; the polyurethane foam layer containing the substrate is made according to the method of Example 1 in the Chinese invention patent document CN113292764B; the silicon boron carbon nitrogen polymer is made according to the method of Example 1 in the Chinese invention patent document CN102604108B.

[0052] Preferably, the coupling agent is a mixture of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570 in a mass ratio of 1:2:3; the filler is a mixture of mica powder, glass fiber, and silica aerogel in a mass ratio of 4.5:1:0.7; the particle size of the mica powder is 1400 mesh; the glass fiber is alkali-free chopped glass fiber, the monofilament diameter is 8 μm, and the length is 4.3 mm; the silica aerogel The invention relates to a CABOT silica aerogel; the amino-containing hyperbranched liquid crystal polymer is prepared according to the method of Example 4 in Chinese invention patent CN114437493B; the initiator is benzoyl peroxide; the solvent is a mixture of N,N-dimethylformamide and N-methylpyrrolidone in a mass ratio of 3:5; and the defoamer is a mixture of tributyl phosphate, defoamer Deqian 3100, and defoamer BYK088 in a mass ratio of 1:2:3.

[0053] A method for preparing the battery core thermal insulation sheet comprises the following steps:

[0054] Step S1: After uniformly mixing the raw materials of the first adhesive layer, the mixture is coated on the surface of the polyurethane foam substrate containing the substrate to form the first adhesive layer, and then the first electronic glass fiber cloth is attached to the surface of the first adhesive layer, heated and cured, and pressed into shape in one step;

[0055] Step S2: After the raw materials of the second adhesive layer are evenly mixed, they are coated on the foam surface of the polyurethane foam containing the substrate to form the second adhesive layer. Then, the second electronic glass fiber cloth is attached to the surface of the second adhesive layer, heated and cured, pressed into shape in one go, and then die-cut into customized sizes.

[0056] The heating curing temperature is 115° C. and the time is 2.5 hours; the pressing pressure is 5 MPa and the time is 18 seconds. Example 5

[0057] A battery core thermal insulation sheet comprises, from top to bottom, a first electronic glass fiber cloth layer, a first adhesive layer, a polyurethane foam layer containing a substrate, a second adhesive layer, and a second electronic glass fiber cloth layer; the first adhesive layer and the second adhesive layer are independently made of the following raw materials, measured in parts by weight: 40 parts of silicon boron carbon nitrogen polymer, 5 parts of 2-(1-propylene-2-yl)benzo[d]oxazole, 5 parts of tetrabromobisphenol A bisallyl ether, 2 parts of a coupling agent, 8 parts of a filler, 15 parts of an amino-containing hyperbranched liquid crystal polymer, 5 parts of bis(oxiranylmethyl)-5-(2-propylene)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 3 parts of 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 1.2 parts of a defoamer, 2 parts of an initiator, and 80 parts of a solvent.

[0058] The thickness of the first adhesive layer is 0.05 mm; the thickness of the second adhesive layer is 0.05 mm; the first electronic glass fiber cloth layer and the second electronic glass fiber cloth layer are independently made of 2116 electronic grade glass fiber cloth; the polyurethane foam layer containing the substrate is made according to the method of Example 1 in the Chinese invention patent document CN113292764B; the silicon boron carbon nitrogen polymer is made according to the method of Example 1 in the Chinese invention patent document CN102604108B; the coupling agent is the silane coupling agent KH550; the filler is a mixture of mica powder, glass fiber, and silica aerogel in a mass ratio of 5:1:0.8; the particle size of the mica powder is 1500 mesh; the glass fiber is alkali-free chopped glass fiber, the single fiber diameter is 9 μm, and the length is 4.5 mm; the silica aerogel is CABOT silica aerogel.

[0059] The amino-containing hyperbranched liquid crystal polymer is prepared according to the method of Example 4 in Chinese invention patent CN114437493B; the initiator is benzoyl peroxide; the solvent is N-methylpyrrolidone; and the defoamer is Deqian 3100.

[0060] A method for preparing the battery core thermal insulation sheet comprises the following steps:

[0061] Step S1: After uniformly mixing the raw materials of the first adhesive layer, the mixture is coated on the surface of the polyurethane foam substrate containing the substrate to form the first adhesive layer, and then the first electronic glass fiber cloth is attached to the surface of the first adhesive layer, heated and cured, and pressed into shape in one step;

[0062] Step S2: After the raw materials of the second adhesive layer are evenly mixed, they are coated on the foam surface of the polyurethane foam containing the substrate to form the second adhesive layer. Then, the second electronic glass fiber cloth is attached to the surface of the second adhesive layer, heated and cured, pressed into shape in one go, and then die-cut into customized sizes.

[0063] The heating curing temperature is 120° C. and the time is 3 hours; the pressing pressure is 6 MPa and the time is 20 seconds.

[0064] Comparative Example 1

[0065] The present invention provides a battery core thermal insulation sheet, which is similar to Example 1, except that no amino-containing hyperbranched liquid crystal polymer and 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane are added.

[0066] Comparative Example 2

[0067] The present invention provides a battery core thermal insulation sheet, which is similar to Example 1, except that 2-(1-propylene-2-yl)benzo[d]oxazole and tetrabromobisphenol A bisallyl ether are not added.

[0068] The battery core thermal insulation sheet samples prepared in Examples 1-5 and Comparative Examples 1-2 were subjected to relevant performance tests. The test results are shown in Table 1. The test method is as follows:

[0069] Flame retardancy: tested in accordance with UL-94.

[0070] Thermal conductivity: tested according to GB / T10295-2008.

[0071] Cold surface temperature: The test is conducted using a back surface temperature tester with a heating platform temperature of 700°C. Each product is placed on the heating platform with a temperature sensor wire attached to the other side. The test lasts for 15 minutes with a pressure of 27N, and the cold surface temperature is recorded.

[0072] Compression set rate: Refer to the test method in GB / T7759.1-2015 to test the compression set rate. The test temperature is 25℃, the test time is 168h, the applied compression is 25% of the initial height of the specimen, and the test is performed using a type A specimen.

[0073]

[0074] As can be seen from Table 1, the battery cell thermal insulation sheet disclosed in the embodiment of the present invention has better flame retardancy and thermal insulation properties, and better compression resilience than the comparative example product; the addition of amino-containing hyperbranched liquid crystal polymer, 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 2-(1-propylene-2-yl)benzo[d]oxazole and tetrabromobisphenol A bisallyl ether is beneficial to improving the above properties.

[0075] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions merely illustrate the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A battery core thermal insulation sheet, characterized in that: From top to bottom, it includes a first electronic glass fiber cloth layer, a first adhesive layer, a polyurethane foam layer containing a substrate, a second adhesive layer, and a second electronic glass fiber cloth layer; the first adhesive layer and the second adhesive layer are independently made of the following raw materials in parts by weight: 30-40 parts of silicon boron carbon nitrogen polymer, 2-5 parts of 2-(1-propylene-2-yl)benzo[d]oxazole, 3-5 parts of tetrabromobisphenol A bisallyl ether, 1-2 parts of coupling agent, 5-8 parts of filler, 10-15 parts of amino-containing hyperbranched liquid crystal polymer, 3-5 parts of bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1-3 parts of 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 0.8-1.2 parts of defoaming agent, 1-2 parts of initiator, and 50-80 parts of solvent.

2. The battery core thermal insulation sheet according to claim 1, characterized in that: The thickness of the first electronic glass fiber cloth layer is 0.02-0.2 mm; the thickness of the first adhesive layer is 0.03-0.15 mm; the thickness of the second electronic glass fiber cloth layer is 0.02-0.2 mm; the thickness of the second adhesive layer is 0.03-0.15 mm.

3. The battery core thermal insulation sheet according to claim 1, characterized in that: The thickness of the polyurethane foam layer containing a substrate is 1.2-5.5 mm; the substrate in the polyurethane foam layer containing a substrate is made of PET, and the thickness of the substrate is 0.01-0.25 mm.

4. The battery core thermal insulation sheet according to claim 1, characterized in that: The coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570; the filler is a mixture of mica powder, glass fiber, and silica aerogel in a mass ratio of (3-5):1:(0.3-0.8).

5. The battery core thermal insulation sheet according to claim 4, characterized in that: The particle size of the mica powder is 1000-1500 mesh; the glass fiber is alkali-free chopped glass fiber, the single fiber diameter is 3-9 μm, and the length is 3-4.5 mm; the silica aerogel is CABOT silica aerogel.

6. The battery core thermal insulation sheet according to claim 1, characterized in that: The initiator is benzoyl peroxide; the solvent is at least one of N,N-dimethylformamide and N-methylpyrrolidone; the defoaming agent is one or more of tributyl phosphate, defoaming agent Deqian 3100, and defoaming agent BYK088.

7. A method for preparing the battery core thermal insulation sheet according to any one of claims 1 to 6, characterized in that: The steps include: Step S1: After uniformly mixing the raw materials of the first adhesive layer, the mixture is coated on the surface of the polyurethane foam substrate containing the substrate to form the first adhesive layer, and then the first electronic glass fiber cloth is attached to the surface of the first adhesive layer, heated and cured, and pressed into shape in one step; Step S2: After the raw materials of the second adhesive layer are evenly mixed, they are coated on the foam surface of the polyurethane foam containing the substrate to form the second adhesive layer. Then, the second electronic glass fiber cloth is attached to the surface of the second adhesive layer, heated and cured, pressed into shape in one go, and then die-cut into customized sizes.

8. The method for preparing the battery core thermal insulation sheet according to claim 7, characterized in that: The heating curing temperature is 100-120° C., and the curing time is 1-3 hours.

9. The method for preparing the battery core thermal insulation sheet according to claim 7, characterized in that: The first electronic glass fiber cloth layer and the second electronic glass fiber cloth layer are independently made of 2116 electronic grade glass fiber cloth.

10. The method for preparing the battery core thermal insulation sheet according to claim 7, characterized in that: The pressure of the pressing molding is 2-6 MPa, and the time is 10-20 seconds.

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