Special film for anti-burning test of energy storage container cabinet

Abstract

The invention discloses a special film for an anti-burning test of an energy storage container cabinet, and relates to the technical field of anti-burning test films. The film comprises a film body, the film body is composed of a base film layer, a flame-retardant penetration control layer and a carbonized heat insulation layer, and the base film layer is formed by laminating composite ceramic silicon oxide fibers and a polyimide heat-resistant film and used for providing high-temperature strength and overall support; the flame-retardant penetration control layer is coated on the outer surface of the base film layer, adopts a composite coating structure containing microporous fluorosilicone gel and flame-retardant particles, and is used for realizing controllable gas trace penetration while preventing fire; and the carbonization heat insulation layer is arranged on the inner side of the base film layer and contains expanded graphite, alumina micro powder and a borate antioxidant. Through the multi-layer composite structure design of the base film layer, the flame-retardant permeability control layer, the carbonization heat insulation layer and the self-repairing heat conduction layer, organic unification of high-temperature strength, controllable ventilation, efficient heat insulation and a self-repairing function is achieved, and the composite film is suitable for an extreme high-temperature testing environment.

Description

Technical Field

[0001] This invention relates to the field of anti-burn test film technology, specifically to a special film for anti-burn test of energy storage container cabinets. Background Technology

[0002] In recent years, with the popularization of photovoltaic energy storage and new power systems, energy storage battery containers (including lithium battery modules) have been widely used in industrial and commercial energy storage power stations. In order to verify the safety and thermal runaway protection performance of energy storage systems, thermal propagation, fire prevention, explosion prevention and burn-proof tests are usually required.

[0003] In existing burn resistance tests, traditional protective films are made of ordinary polyester or polyimide films, which are prone to carbonization or cracking under high-temperature burning conditions, making it impossible to maintain integrity. This leads to smoke leakage or heat conduction and diffusion, distorting the test environment. It is difficult to balance the air permeability and flame retardant properties of the film material. Complete sealing will cause abnormal air pressure in the test chamber, while high air permeability films are difficult to resist flame burning. Moreover, existing film materials mostly require external metal frames for fixation, which is complicated to install and affects the uniformity of the temperature field.

[0004] To address this, a special membrane for fire-resistant testing of energy storage container cabinets is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a special membrane for fire prevention testing of energy storage containers in order to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention specifically adopts the following technical solution: A special membrane for fire-resistant testing of energy storage containers includes a membrane body, which is composed of a base membrane layer, a flame-retardant and breathable layer, and a carbonized heat-insulating layer. The base film layer is formed by laminating composite ceramic silica fiber and polyimide heat-resistant film to provide high-temperature strength and overall support; A flame-retardant and gas-permeable layer is coated on the outer surface of the base film layer. It adopts a composite coating structure containing microporous fluorosilicone gel and flame-retardant particles to achieve controlled gas permeation while providing fire protection. A carbonized heat insulation layer is disposed on the inner side of the base film layer and contains expanded graphite, alumina micro powder and borate antioxidant, forming a dense carbonized layer at high temperature to prevent heat conduction. An edge fixing structure is installed at the edge of the membrane body for detachable installation of the membrane body onto the test window of the energy storage container.

[0007] Furthermore, the edge fixing structure includes a wire braided frame disposed at the edge of the membrane body, and the inside of the wire braided frame is provided with a wire skeleton and a flexible strong magnet. The magnetic force of the flexible strong magnet is used to detachably install the membrane body onto the test window of the energy storage container cabinet.

[0008] Furthermore, the thickness of the base film layer is 0.3 to 0.6 mm, wherein the thickness of the ceramic silica fiber cloth layer accounts for 60% to 70% of the total thickness of the base film layer, and the thickness of the polyimide film accounts for 30% to 40%.

[0009] Furthermore, the average pore size of the flame-retardant and breathable layer is 20–50 μm, and its overall air permeability rate is controlled at 2–5 L / min to maintain pressure balance within the test chamber.

[0010] Furthermore, the flame-retardant and breathable layer contains 5-15 parts of antimony trioxide powder and 1-3 parts of foaming agent to form a microporous flame-retardant structure, thereby improving its penetration resistance and burn resistance.

[0011] Furthermore, the thickness of the carbonized heat insulation layer is 0.1 to 0.3 mm, the mass ratio of expanded graphite to alumina micro powder is 2 to 3:1, and the carbonization under high temperature forms a heat reflective layer.

[0012] Furthermore, a self-healing thermal conductive layer, made of high-temperature resistant silicone rubber, is provided between the base film layer and the carbonized heat insulation layer to automatically fill the cracks after ablation.

[0013] Furthermore, the thermal conductivity of the membrane is less than 0.3 W / (m·K), the tensile strength is not less than 45 MPa, and after being continuously burned by a flame at 800-1000℃ for 5-10 minutes, the membrane is not penetrated, the flame-retardant and breathable layer still maintains an airtight structure, and the thickness of the carbonized heat insulation layer expands to 2-4 times the original thickness.

[0014] A method for testing the fire resistance of an energy storage container, using the aforementioned special film to cover the test window, includes the following steps: Step 1: Attach the membrane to the test window of the energy storage container using the edge fixing structure to ensure the membrane edges are sealed; Step 2: Perform thermal runaway or flame burning tests in the test chamber, using the flame-retardant and permeability-controlled layer of the membrane to maintain the pressure balance in the test chamber, and using the carbonized heat insulation layer to prevent heat from being conducted outward; Step 3: After the test is completed, disassemble the membrane and check its integrity and reusability.

[0015] The beneficial effects of this invention are as follows: Through a multi-layered composite structure design consisting of a base film layer, a flame-retardant and breathable layer, a carbonized heat insulation layer, and a self-healing thermal conductive layer, a unified high-temperature strength, controllable breathability, efficient heat insulation, and self-healing function is achieved, making it suitable for extreme high-temperature testing environments. The base film layer employs a composite laminate structure of ceramic silica fiber and polyimide, ensuring excellent high-temperature strength and thermal stability. It remains intact and unpenetrated after being burned in a flame at 800–1000℃ for 5–10 minutes. The flame-retardant and breathable layer utilizes a microporous fluorosilicone gel structure in synergy with antimony trioxide and a foaming agent. While maintaining controllable air permeability of 2-5 L / min, it effectively blocks flame penetration, ensuring pressure balance and test authenticity within the test chamber; the carbonized heat insulation layer expands to 2-4 times its original thickness at high temperatures, forming a dense heat reflective layer with a thermal conductivity coefficient of less than 0.3 W / (m·K); the self-healing thermal conductive layer can automatically fill cracks after ablation, improving the membrane's durability and sealing; the edge fixing structure uses a combination of a steel wire braided frame and a flexible strong magnet, enabling rapid attachment and removal without the need for an external frame, making installation simple and not affecting temperature field uniformity. Attached Figure Description

[0016] Figure 1 This is a three-dimensional structural schematic diagram of the present invention; Figure 2 This is a cross-sectional view of the present invention; Figure 3 This is the present invention. Figure 2 Enlarged view of part A; Reference numerals: 1. Base film layer; 2. Flame retardant and light-retaining layer; 3. Carbonized heat insulation layer; 4. Edge fixing structure; 401. Steel wire braided frame; 402. Steel wire skeleton; 403. Flexible strong magnet. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0018] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0019] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0020] In the description of the embodiments of the present invention, it should be noted that the terms "inner", "outer", "upper", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0021] like Figures 1 to 3 As shown, a special membrane for fire prevention testing of energy storage container cabinets includes a membrane body, which is composed of a base membrane layer 1, a flame-retardant and breathable layer 2, and a carbonized heat insulation layer 3. The base film layer 1 is formed by laminating composite ceramic silica fiber and polyimide heat-resistant film, and is used to provide high-temperature strength and overall support. The thickness of the base film layer 1 is 0.3 to 0.6 mm, of which the thickness of the ceramic silica fiber cloth layer accounts for 60% to 70% of the total thickness of the base film layer, and the thickness of the polyimide film accounts for 30% to 40%.

[0022] The flame-retardant and gas-controlling layer 2 is coated on the outer surface of the base film layer 1. It adopts a composite coating structure containing microporous fluorosilicone gel and flame-retardant particles to achieve controlled micro-permeability of gas while providing fire protection. The average pore size of the flame-retardant and gas-controlling layer 2 is 20-50 μm, and its overall gas permeability rate is controlled at 2-5 L / min to maintain the pressure balance in the test chamber. The flame-retardant and gas-controlling layer 2 contains 5-15 parts of antimony trioxide powder and 1-3 parts of foaming agent to form a microporous flame-retardant structure, which improves the penetration resistance and burn resistance.

[0023] The carbonized heat insulation layer 3 is disposed on the inner side of the base film layer and contains expanded graphite, alumina micro powder and borate antioxidant. It forms a dense carbonized layer at high temperature to prevent heat conduction. The thickness of the carbonized heat insulation layer 3 is 0.1 to 0.3 mm, and the mass ratio of expanded graphite to alumina micro powder is 2 to 3:1. It forms a heat reflective layer under high temperature.

[0024] An edge fixing structure 4 is set at the edge of the membrane body for detachable installation of the membrane body onto the test window of the energy storage container. The edge fixing structure 4 includes a wire braided frame 401 set at the edge of the membrane body, and the inside of the wire braided frame 401 is provided with a wire skeleton 402 and a flexible strong magnet 403. The magnetic force of the flexible strong magnet 403 is used to detachably install the membrane body onto the test window of the energy storage container.

[0025] A self-healing thermal conductive layer between the base film layer 1 and the carbonized heat insulation layer 3, which is made of high-temperature resistant silicone rubber, is used to automatically fill the cracks after ablation.

[0026] More specifically, its high-temperature resistant silicone rubber has flexibility and local flowability, which allows it to automatically fill cracks after ablation.

[0027] The thermal conductivity of the membrane is less than 0.3 W / (m·K), the tensile strength is not less than 45 MPa, and after being continuously burned by a flame at 800-1000℃ for 5-10 minutes, the membrane is not penetrated, the flame-retardant and breathable layer 2 still maintains an airtight structure, and the thickness of the carbonized heat insulation layer 3 expands to 2-4 times its original thickness.

[0028] In practical applications, a fire-resistant testing method for energy storage containers, using a special film to cover the test window, includes the following steps: Step 1: Attach the membrane to the test window of the energy storage container using the edge fixing structure 4, ensuring that the edges of the membrane are sealed. Step 2: Perform thermal runaway or flame burning tests in the test chamber, using the flame-retardant and permeability-controlled layer 2 of the membrane to maintain the pressure balance in the test chamber, and using the carbonized heat insulation layer 3 to prevent heat from being conducted outward; Step 3: After the test is completed, disassemble the membrane and check its integrity and reusability.

[0029] Example 1 A special membrane for fire-resistant testing of energy storage containers was prepared, with the following specific parameters: The thickness of the base film layer is 1:0.45mm (the ceramic silica fiber layer accounts for 65%, and the polyimide film accounts for 35%). Flame-retardant and breathable layer 2: average pore size 30μm, air permeability rate 3.5L / min, containing 10 parts antimony trioxide and 2 parts foaming agent; The thickness of the carbonized insulation layer is 3:0.2mm, and the mass ratio of expanded graphite to alumina micro powder is 2.5:1. Self-healing thermal conductive layer: 0.05mm thick, made of high-temperature resistant silicone rubber.

[0030] Performance test results The special membrane prepared in this embodiment was installed in the test window of a standard energy storage container, and the following tests were conducted: Burn at 900℃ for 8 minutes; The membrane was not penetrated, and the flame-retardant and breathable layer maintained an airtight structure. The carbonized insulation layer 3 expands to 0.6 mm, with a thermal conductivity of 0.25 W / (m·K). The membrane has a tensile strength of 48 MPa. After testing, it was disassembled and inspected, and the structure was found to be intact and reusable.

[0031] Example 2 Based on Example 1, the mass ratio of expanded graphite to alumina micro powder in the carbonized heat insulation layer 3 was adjusted to 3:1, while other parameters remained unchanged. After being burned in a flame at 1000°C for 10 minutes, the carbonized heat insulation layer 3 expanded to 3.5 times its original thickness, further improving its heat reflection performance, while the film remained intact.

[0032] In summary, the multi-layered composite structure design, consisting of a base film layer 1, a flame-retardant and breathable layer 2, a carbonized heat insulation layer 3, and a self-healing thermal conductive layer, achieves a harmonious balance between high-temperature strength, controllable permeability, efficient heat insulation, and self-healing function, making it suitable for extreme high-temperature testing environments. The base film layer 1 utilizes a composite laminate structure of ceramic silica fiber and polyimide, ensuring excellent high-temperature strength and thermal stability. It remains intact and unbroken after being burned in a flame at 800–1000℃ for 5–10 minutes. The flame-retardant and breathable layer 2, through its microporous fluorosilicone gel structure and the synergistic effect of antimony trioxide and a foaming agent… Its functions include maintaining controllable air permeability of 2-5 L / min while effectively blocking flame penetration, ensuring pressure balance and test authenticity within the test chamber; the carbonized heat insulation layer 3 expands to 2-4 times its original thickness at high temperatures, forming a dense heat reflective layer with a thermal conductivity coefficient of less than 0.3 W / (m·K); the self-healing heat-conducting layer can automatically fill cracks after ablation, improving the membrane's durability and sealing; the edge fixing structure 4 uses a combination of a steel wire braided frame 401 and a flexible strong magnet 403 to achieve rapid attachment and disassembly without the need for an external frame, making installation simple and not affecting temperature field uniformity.

[0033] The foregoing has shown and described 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 embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A special membrane for fire-resistant testing of energy storage container cabinets, characterized in that, The membrane consists of a base membrane layer (1), a flame-retardant and breathable layer (2), and a carbonized heat-insulating layer (3). The base film layer (1) is formed by laminating composite ceramic silica fiber and polyimide heat-resistant film to provide high-temperature strength and overall support; A flame-retardant and permeability-controlled layer (2) is coated on the outer surface of the base film layer (1). It adopts a composite coating structure containing microporous fluorosilicone gel and flame-retardant particles to achieve controllable gas permeation while providing fire protection. A carbonized heat insulation layer (3) is disposed on the inner side of the base film layer and contains expanded graphite, alumina micro powder and borate antioxidant, forming a dense carbonized layer at high temperature to prevent heat conduction; Edge fixing structure (4) is set at the edge of the membrane body for the membrane body to be detachably installed on the test window of the energy storage container cabinet.

2. The special membrane for fireproof testing of energy storage container cabinets according to claim 1, characterized in that, The edge fixing structure (4) includes a wire braided frame (401) set at the edge of the membrane body, and the wire braided frame (401) is provided with a wire skeleton (402) and a flexible strong magnet (403) inside. The magnetic force of the flexible strong magnet (403) is used to detachably install the membrane body on the test window of the energy storage container cabinet.

3. The special membrane for fireproof testing of energy storage container cabinets according to claim 1, characterized in that, The thickness of the base film layer (1) is 0.3 to 0.6 mm, wherein the thickness of the ceramic silica fiber cloth layer accounts for 60% to 70% of the total thickness of the base film layer, and the thickness of the polyimide film accounts for 30% to 40%.

4. The special membrane for fire prevention testing of energy storage container cabinets according to claim 1, characterized in that, The flame-retardant and breathable layer (2) has an average pore size of 20-50 μm and its overall air permeability is controlled at 2-5 L / min to maintain the pressure balance in the test chamber.

5. The special membrane for fireproof testing of energy storage container cabinets according to claim 1, characterized in that, The flame-retardant and permeable layer (2) contains 5 to 15 parts of antimony trioxide powder and 1 to 3 parts of foaming agent to form a microporous flame-retardant structure, thereby improving its resistance to penetration and its heat resistance.

6. The special membrane for fireproof testing of energy storage container cabinets according to claim 1, characterized in that, The thickness of the carbonized heat insulation layer (3) is 0.1 to 0.3 mm, and the mass ratio of expanded graphite to alumina micro powder is 2 to 3:

1. Under high temperature, carbonization forms a heat reflective layer.

7. The special membrane for fireproof testing of energy storage container cabinets according to claim 1, characterized in that, The self-healing thermal conductive layer between the base film layer (1) and the carbonized heat insulation layer (3) is made of high-temperature resistant silicone rubber and is used to automatically fill the cracks after ablation.

8. A special membrane for fire-resistant testing of energy storage container cabinets according to any one of claims 1 to 7, characterized in that, The thermal conductivity of the membrane is less than 0.3 W / (m·K), the tensile strength is not less than 45 MPa, and after being continuously burned by a flame at 800-1000℃ for 5-10 minutes, the membrane is not penetrated, the flame-retardant and breathable layer (2) still maintains an airtight structure, and the thickness of the carbonized heat insulation layer (3) expands to 2-4 times the original thickness.

9. A method for testing the fire resistance of an energy storage container, characterized in that, Covering the test window with the special film as described in any one of claims 1 to 8 includes the following steps: Step 1: Attach the membrane to the test window of the energy storage container cabinet using the edge fixing structure (4) to ensure that the edge of the membrane is sealed; Step 2: Perform thermal runaway or flame burning tests in the test chamber, use the flame-retardant and breathable layer (2) of the membrane to maintain the pressure balance in the test chamber, and use the carbonized heat insulation layer (3) to prevent heat from being conducted outward; Step 3: After the test is completed, disassemble the membrane and check its integrity and reusability.

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