Composite fire-resistant heat insulation pad for battery pack and preparation method of composite fire-resistant heat insulation pad

Abstract

The invention discloses a composite fireproof heat insulation pad for a battery pack and a preparation method thereof, and belongs to the technical field of battery safety. The heat insulation pad is of a double-layer composite structure, the inner layer is a high-silicon-dioxide glass fiber needled felt heat insulation core layer, and the outer layer is a ceramic silica gel glass fiber cloth fireproof coating layer. The two layers are sewn into a whole through high-temperature-resistant sewing threads, and a back adhesive layer is arranged on one side of the two layers. The product provided by the invention has excellent fire resistance (can tolerate flame at 1000 DEG C for 30 minutes), excellent heat insulation, excellent flexibility and thermal shock resistance, and is convenient to install. The preparation process is simple, can be completed through cutting, wrapping and sewing and gum application, and is suitable for large-scale production. The product can effectively delay or prevent heat spreading in the battery pack, and the battery safety level of the new energy automobile is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of new energy vehicle battery safety protection technology, specifically to a composite fire-resistant heat insulation pad for battery packs (modules) and its preparation method. Background Technology

[0002] With the rapid development of new energy vehicles, the thermal safety of battery packs has become increasingly prominent. Battery thermal runaway is a major cause of vehicle fires and explosions. When a battery cell experiences thermal runaway, the extremely high heat it releases (reaching over 1000°C) can rapidly transfer to adjacent cells and the battery pack casing, triggering a chain reaction (thermal propagation).

[0003] Currently, commonly used thermal insulation materials in battery packs include aerogel felt, ceramic fiberboard, and mica board. However, these materials have the following limitations: Aerogel felt: high cost, low mechanical strength, prone to pulverization under long-term vibration, and generally cannot withstand prolonged exposure to open flame. Ceramic fiberboard / rigid insulation board: hard and brittle, difficult to fit the complex curved structure inside the battery pack, and prone to cracking under severe temperature shocks. Ordinary silicone fiberglass cloth: good flexibility, but its silicone component will completely ablate at ultra-high temperatures, losing structural integrity and failing to form an effective fire barrier. Therefore, there is an urgent need for a dedicated thermal insulation product for battery packs that can withstand extreme high temperatures and open flame impacts, while also possessing excellent flexibility, thermal insulation, and ease of installation. Summary of the Invention

[0004] This invention aims to overcome the shortcomings of existing technologies and provide a composite fire-resistant heat insulation pad for battery packs and its preparation method. This heat insulation pad possesses an extremely high fire resistance rating, excellent heat insulation performance, outstanding flexibility and thermal shock stability, and can be easily installed using an adhesive backing method, providing reliable protection against thermal spread for battery packs.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A composite fire-resistant heat insulation pad for battery packs, characterized in that it adopts a double-layer composite structure, consisting of a heat insulation core layer and a fire-resistant covering layer from the inside out; The heat insulation core layer is a high silica content glass fiber needle-punched felt with a silica content ≥96% and a long-term service temperature ≥1000℃. It has low thermal conductivity and high thermal stability. The fire-resistant coating is a ceramicized silicone composite glass fiber cloth, which can withstand a horizontal impact of 1000℃ open flame (such as a flame gun) for 30 minutes without being burned through, and the surface silicone layer transforms into a hard ceramic shell at high temperature. The heat insulation core layer is completely wrapped in the fire-resistant coating layer and is sewn and fixed along the edge with high-temperature resistant sewing thread to form an integrated flexible pad. A high-temperature pressure-sensitive adhesive layer is coated on one outer surface of the pad (i.e., the outer side of the fire-resistant coating layer), and a release paper is covered thereon.

[0006] Furthermore, the long-term temperature resistance of the high-temperature resistant sewing thread is not lower than 600℃ to ensure that the sewing structure does not fail in high-temperature environments.

[0007] A method for preparing a composite fire-resistant and heat-insulating pad for the above-mentioned battery pack, characterized by comprising the following steps: (1) Material preparation: cut high silica glass fiber needle-punched felt of predetermined size as core material, and ceramicized silicone glass fiber cloth of larger size as covering cloth; (2) Covering and sewing: Place the needle-punched felt core material in the center of the ceramicized silicone cloth, fold the edge of the silicone cloth inward to completely cover the core material; use high-performance sewing thread with a temperature resistance of ≥600℃ to sew along the edge of the covering, so that the two layers of materials are tightly bonded to form a sealed pad. (3) Backing treatment: On a complete outer surface of the pad made in step two, a high-temperature resistant acrylic silicone pressure-sensitive adhesive is uniformly coated to form an adhesive layer; (4) Covering with release paper: Covering the adhesive layer with release paper to protect the adhesive surface; finally, a composite pad is obtained.

[0008] The beneficial effects of this invention are that, compared with the prior art, the composite fire-resistant heat insulation pad for battery packs and its preparation method provided by this invention have the following significant advantages: Exceptional fire resistance and thermal insulation performance: Through a composite design of "high-silica needle-punched felt (thermal insulation body) + ceramicized silicone cloth (fire-resistant outer shell)," the product effectively blocks heat transfer by utilizing the low thermal conductivity of the needle-punched felt, while relying on the ceramicized cloth's ability to form a hard ceramic shell under extreme flame conditions to provide long-lasting protection for the internal insulation layer, achieving a protective effect of "1+1>2." The product can withstand the impact of a 1000℃ flame for 30 minutes and can withstand short-term high temperatures of 1300℃.

[0009] Excellent structural integrity and thermal shock resistance: The use of high-temperature resistant sewing thread ensures the structural integrity of the product under high temperatures and mechanical vibration. The double-layer flexible material composite allows it to withstand drastic temperature changes without cracking or pulverizing, adapting to extreme conditions during battery thermal runaway.

[0010] Excellent flexibility and ease of installation: The product is flexible and can be bent and folded to perfectly fit the complex spaces such as the inner wall of the battery pack casing and the gaps between cells. The pre-installed high-temperature resistant adhesive on one side makes the installation process extremely simple, fast, and reliable, requiring no other fasteners and significantly improving production and assembly efficiency.

[0011] Excellent overall performance: In addition to fire resistance and heat insulation, this composite material also has good electrical insulation, chemical corrosion resistance (except for a few strong acids such as hydrofluoric acid) and a certain tensile strength, providing a multi-functional safety protection layer for the battery pack.

[0012] Simple process and controllable cost: The preparation method mainly adopts cutting, sewing and adhesive backing processes. The process is simple and easy to achieve large-scale production. While ensuring high performance, it has a good cost advantage. Attached Figure Description

[0013] Figure 1 This is a schematic cross-sectional view of the composite fire-resistant and heat-insulating pad of the present invention.

[0014] (The diagram shows: 1-fire-resistant coating (ceramicized silicone fiberglass cloth), 2-heat insulation core layer (high-silica fiberglass needle-punched felt), 3-high-temperature resistant sewing thread, 4-high-temperature resistant pressure-sensitive adhesive layer, 5-release paper.) Detailed Implementation The present invention will now be described in detail with reference to specific embodiments. like Figure 1 As shown, the composite fire-resistant heat-insulating pad for battery packs provided by this invention has a core double-layer structure. The inner heat-insulating core layer (2) is composed of high silica glass fiber needle-punched felt with a thickness of 3-10mm (which can be adjusted according to requirements). The outer fire-resistant covering layer (1) is composed of ceramicized silicone glass fiber cloth with a thickness of about 0.2-0.5mm. The covering layer (1) completely wraps the core layer (2) and is stitched with high-temperature resistant sewing thread (3) made of aramid to ensure that the core material is not exposed. On one side of the pad, a high-temperature resistant acrylic silicone pressure-sensitive adhesive layer (4) with a thickness of about 0.1-0.2mm is coated and covered with release paper (5) for protection and transportation.

[0015] During manufacturing, the core material and covering fabric are first designed and cut according to the internal shape and size of the battery pack. The area of ​​the covering fabric needs to be larger than that of the core material to ensure sufficient allowance for folding and wrapping. During sewing, even and tight stitches must be ensured. An adhesive with a long-term temperature resistance of ≥200℃ is selected for the backing to ensure that the adhesive strength does not decrease at the battery pack's operating temperature. The final product can be made into various shapes to meet the design requirements of different battery packs.

Claims

1. A composite fire resistant and thermal insulation mat for battery packs, characterized by, include: High silica content glass fiber needle-punched felt as the heat insulation core layer; ceramicized silicone composite glass fiber cloth as the fire-resistant coating layer and completely wrapping the heat insulation core layer; high temperature resistant sewing thread for sewing the edges of the fire-resistant coating layer to fix the heat insulation core layer; and a high temperature resistant pressure-sensitive adhesive layer coated on one outer side of the pad.

2. The composite fire-resistant and thermal insulation mat for battery pack according to claim 1, characterized in that, The high silica content glass fiber needle-punched felt has a silica content of not less than 96%.

3. The composite fire-resistant and thermal insulation mat for battery pack according to claim 1, characterized in that, The ceramicized silicone composite glass fiber cloth can withstand a horizontal impact of 1000℃ open flame for 30 minutes without being burned through.

4. The composite fire-resistant and thermal insulation mat for battery pack according to claim 1, characterized in that, The long-term temperature resistance rating of the high-temperature resistant sewing thread is not lower than 600℃.

5. The composite fire-resistant and thermal insulation mat for battery pack according to claim 1, characterized in that, The high-temperature resistant pressure-sensitive adhesive layer is covered with release paper.

6. A method of making a composite fire-resistant and heat-insulating mat for a battery pack according to any one of claims 1-5, characterized in that, Includes the following steps: S1. Cut fiberglass needle-punched felt to a predetermined size and ceramicized silicone fiberglass cloth to a larger size; S2. Wrap the glass fiber needle-punched felt with the ceramicized silicone fiberglass cloth and sew it along the edges with high-temperature resistant sewing thread to form an integrated pad; S3. Coat one outer surface of the pad with a high-temperature pressure-sensitive adhesive to form an adhesive layer; S4. Cover the adhesive layer with release paper.

7. The method of claim 6, wherein, In step S2, the stitching is a lock seam or a wrap seam to ensure that the heat insulation core layer is completely sealed and wrapped.

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