Fire extinguishing devices and battery packs

Abstract

To provide a fire extinguishing device that can be easily replaced even after it has been loaded into the battery pack. [Solution] A fire extinguishing body comprising a base material and a fire extinguishing agent-containing layer on the base material, wherein the Young's modulus of the base material is 2 MPa or more.

Description

Technical Field

[0001] The present invention relates to a fire extinguishing body and a battery pack.

Background Art

[0002] There is known a technique of incorporating a film having a fire extinguishing function inside a battery (see, for example, Patent Document 1). According to this technique, a material having a fire extinguishing function is wrapped with a film and installed inside a battery can. When a fire or high-temperature gas occurs during a battery abnormality, the film is broken and the fire extinguishing function is exhibited, ensuring safety in an emergency.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a battery can, particularly in a lithium-ion battery pack for vehicle use or a storage battery in a power plant, the housing itself has a durability of 10 years or more. However, a general fire extinguishing agent needs to be replaced in 1 to 5 years, and a resin film covering the fire extinguishing agent also becomes brittle and easily broken in 1 to 5 years. When the fire extinguishing agent is incorporated by attaching it inside the battery can or the storage battery, problems such as damage to the fire extinguishing agent that is not assumed to be replaced occur during replacement, and thus the fire extinguishing agent cannot be easily replaced.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a fire extinguishing body that can be easily replaced even after being loaded into a battery pack. Another object of the present invention is to provide a battery pack including such a fire extinguishing body.

Means for Solving the Problems

[0006] A fire extinguishing body according to one aspect of the present invention comprises a base material and a fire extinguishing agent-containing layer on the base material, wherein the Young's modulus of the base material is 2 MPa or more.

[0007] In one embodiment, the substrate may include a resin layer.

[0008] In one embodiment, the Young's modulus of the resin layer may be 2 MPa to 5 GPa.

[0009] In one embodiment, the substrate may include at least one of a wood layer, a metal layer, and a glass layer.

[0010] In one embodiment, the Young's modulus of the wood layer, metal layer, and glass layer may be 10 to 700 GPa.

[0011] A battery pack according to one aspect of the present invention comprises a housing, the fire extinguishing element and the battery housed within the housing.

[0012] In one aspect, the battery may be a lithium-ion battery. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a fire extinguishing element that can be easily replaced even after it has been loaded into a battery pack. Furthermore, according to the present invention, it is possible to provide a battery pack equipped with such a fire extinguishing element. [Brief explanation of the drawing]

[0014] [Figure 1] Figure 1 is a schematic cross-sectional view of a fire extinguishing device according to one embodiment. [Figure 2] Figure 2 is a schematic cross-sectional view of a battery pack according to one embodiment. [Figure 3] Figure 3 is a schematic cross-sectional view of a battery pack according to another embodiment. [Modes for carrying out the invention]

[0015] Embodiments of the present invention will be described in detail below. However, the present invention is not limited to the following embodiments.

[0016] <Fire extinguishing device> Figure 1 is a schematic cross-sectional view of a fire extinguishing body according to one embodiment. The fire extinguishing body 10 comprises a base material 1 and a fire extinguishing agent-containing layer 2 in that order. The fire extinguishing body can be a laminate comprising a flat (film-like) base material and a fire extinguishing agent-containing layer formed on the base material.

[0017] The thickness of the fire extinguishing element is not necessarily limited as it varies depending on its layer structure, but from the viewpoint of making it thinner so as not to be limited in installation space while maintaining ease of handling, it can be, for example, 2 to 20 mm. In addition, the area of ​​the main surface of the fire extinguishing element (the surface when the fire extinguishing element is viewed from the top in the vertical direction) can be, for example, 9 to 620 cm² from the viewpoint of fire extinguishing performance and ease of handling. 2 It can be done this way.

[0018] (base material) The base material can be made of a material with a Young's modulus of 2 MPa or higher. A Young's modulus of 2 MPa or higher ensures sufficient strength for the fire extinguishing body and facilitates loading the fire extinguishing body into and discharging it from the battery pack. From this perspective, the Young's modulus of the base material may be 2.5 MPa or higher, or even 4 MPa or higher. While there is no particular upper limit to the Young's modulus of the base material, it can be set to 700 GPa in cases where the base material includes a rigid substrate.

[0019] The base material can include a resin layer. Examples of the material of the resin layer include polyolefins (such as LLDPE, PP, COP, CPP, etc.), polyesters (such as PET, etc.), fluororesins (such as PTFE, ETFE, EFEP, PFA, FEP, PCTFE, etc.), PVC, PVA, acrylic resins, epoxy resins, polyamides, polyimides, etc. The base material may include one resin layer formed from these materials, or may include multiple layers. By selecting a transparent material, it becomes easier to inspect the appearance of the fire extinguisher and to confirm the replacement time. From the perspective of adjusting the water vapor permeability, the base material may be provided with a vapor deposition layer (such as an alumina vapor deposition layer or a silica vapor deposition layer) having a water vapor barrier property.

[0020] The Young's modulus of the resin layer can be 2 MPa to 5 GPa, and may be 2.5 MPa to 4 GPa. Thereby, the strength of the fire extinguisher can be sufficiently ensured. The Young's modulus of the resin layer can be measured according to ASTM-D-882.

[0021] The thickness of the resin layer can be appropriately selected according to the required strength, the allowable space, etc., and for example, it can be 0.0045 to 1 mm, and may be 0.012 to 0.1 mm.

[0022] The base material can include a rigid substrate, specifically, it can include a rigid substrate including at least one of a wood layer, a metal layer, and a glass layer (inorganic composition layer). Examples of the material of the wood layer include cedar, cypress, teak wood, etc. Examples of the material of the metal layer include iron, stainless steel, tungsten superalloys, etc.

[0023] The Young's modulus of the rigid substrate can be 10 to 700 GPa, may be 10 to 640 GPa, and may be 13 to 630 GPa. Thereby, the strength of the fire extinguisher can be more sufficiently ensured. The Young's modulus of the rigid substrate can be measured according to JIS-Z-2280.

[0024] The thickness of the rigid substrate can be appropriately selected depending on the required strength, allowable space, etc., but for example it can be 0.012 to 10 mm, or 0.1 to 5 mm.

[0025] When the base material includes a resin layer and a rigid substrate, the order in which they are laminated in the fire extinguishing body is not particularly limited. However, from the viewpoint of handling during the manufacturing process, the fire extinguishing body may be provided with the fire extinguishing agent-containing layer, resin layer, and rigid substrate in this order.

[0026] (Fire extinguishing agent-containing layer) The fire extinguishing agent-containing layer is, for example, a layer containing a fire extinguishing agent and a binder resin. The fire extinguishing agent is not particularly limited, and any agent having the so-called four elements of fire extinguishing (removal action, cooling action, suffocation action, and negative catalytic action) can be used as appropriate depending on the nature of the object. Examples of fire extinguishing agents include general fire extinguishing agents (powder-based fire extinguishing agents, water-based fire extinguishing agents, or foam-based fire extinguishing agents), as well as sand (standard sand), dry ice, water, etc. ABC fire extinguishing agents are used as all-purpose fire extinguishing agents, while BC fire extinguishing agents are used for oil and electrical fires. If the object is a lithium-ion battery, BC fire extinguishing agents, water-based fire extinguishing agents, or other fire extinguishing agents for lithium-ion batteries are used.

[0027] Thermoplastic resins and thermosetting resins can be used as binder resins. Examples of thermoplastic resins include polyolefin resins such as polypropylene resins, polyethylene resins, poly(1-)butene resins, and polypentene resins, polystyrene resins, acrylonitrile-butadiene-styrene resins, methyl methacrylate-butadiene-styrene resins, ethylene-vinyl acetate resins, ethylene-propylene resins, polycarbonate resins, polyphenylene ether resins, acrylic resins, polyamide resins, polyvinyl chloride resins, polyvinyl alcohol (PVA), and polyvinyl butyral (PVB). Examples of thermosetting resins include natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), 1,2-polybutadiene rubber (1,2-BR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), nitrile rubber (NBR), butyl rubber (IIR), ethylene-propylene rubber (EPR, EPDM), chlorosulfonated polyethylene (CSM), acrylic rubber (ACM, ANM), epichlorohydrin rubber (CO, ECO), polyvulcanized rubber (T), silicone rubber (Q), fluororubber (FKM, FZ), urethane rubber (U), and other rubbers, as well as polyurethane resins, polyisocyanate resins, polyisocyanurate resins, phenolic resins, epoxy resins, etc. The binder resin may contain a curing agent component.

[0028] The fire extinguishing agent-containing layer may also contain other components such as colorants, antioxidants, flame retardants, and inorganic fillers. These components can be appropriately selected depending on the composition of the fire extinguishing agent-containing layer and the type of binder resin.

[0029] The fire extinguishing agent-containing layer can be formed by applying a slurry containing the fire extinguishing agent and binder to a substrate, or by kneading the fire extinguishing agent into a resin. In other words, the fire extinguishing agent-containing layer may consist of a layer of the composition containing the fire extinguishing agent and binder as described above, or a resin layer containing the fire extinguishing agent. Examples of resins into which the fire extinguishing agent is kneaded include polyolefin resins (polypropylene, polyethylene, etc.), polystyrene resins, acrylic resins, ethylene-vinyl acetate resins, polycarbonate resins, polyamide resins, polyvinyl chloride resins, and fluororesins.

[0030] The amount of fire extinguishing agent in the fire extinguishing agent-containing layer (based on the mass of the fire extinguishing agent-containing layer) can be 70 to 97% by mass, may be 80 to 95% by mass, or may be 85 to 92% by mass. A fire extinguishing agent content of 70% by mass or more makes it easier to achieve excellent fire extinguishing performance, while a content of 97% by mass or less makes it easier to achieve excellent moldability. If the fire extinguishing agent-containing layer contains other components, the amount of these other components in the fire extinguishing agent-containing layer (based on the mass of the fire extinguishing agent-containing layer) can be 10% by mass or less.

[0031] The thickness of the fire extinguishing agent-containing layer can be appropriately set according to the location where the fire extinguishing device is installed and the amount of fire extinguishing agent to be mixed. For example, the thickness of the fire extinguishing agent-containing layer can be 1 mm or less, may be 30 to 1000 μm, may be 100 to 500 μm, or may be 150 to 500 μm.

[0032] (Adhesive layer) The fire extinguishing body may further include an adhesive layer. This improves the handling of the fire extinguishing body and makes it easier to stably hold the fire extinguishing agent-containing layer on the substrate. The adhesive layer may be provided, for example, between the substrate and the fire extinguishing agent-containing layer, or between the resin layer in the substrate and the rigid substrate.

[0033] The adhesive layer can be appropriately selected depending on the type of substrate, fire extinguishing agent, etc. The adhesive layer can be formed from materials such as adhesives or tacks. The thickness of the adhesive layer may be, for example, 1 to 100 μm (1 to 30 μm or 30 to 100 μm depending on the material used).

[0034] <Manufacturing method for fire extinguishing devices> The method for manufacturing the fire extinguishing body is not particularly limited, and it can be manufactured by appropriately laminating each of the above layers. The method for providing the fire extinguishing agent-containing layer can be adjusted according to the configuration. For example, the fire extinguishing agent-containing layer can be formed by applying a slurry containing the fire extinguishing agent and binder onto a substrate. Alternatively, the fire extinguishing agent-containing layer can be formed by co-extruding a resin mixed with the fire extinguishing agent with the substrate. The fire extinguishing agent-containing layer and the substrate may be prepared separately and bonded together by lamination. Alternatively, the fire extinguishing body may be obtained by processing the fire extinguishing agent-containing layer on a resin layer that is easy to handle, and then bonding the rigid substrate and the resin layer.

[0035] <Battery Pack> The battery pack comprises a housing, the fire extinguishing element and battery housed within the housing. Examples of batteries include lithium-ion batteries, nickel-cadmium batteries, lithium-ion polymer secondary batteries, and nickel-metal hydride batteries. The fire extinguishing element can be used particularly well with the lithium-ion battery.

[0036] Figure 2 is a schematic cross-sectional view of a battery pack according to one embodiment. In the figure, the battery pack 100 comprises a housing 30, the fire extinguishing body 10 housed within the housing 30, and a plurality of laminate-type batteries 20. In the figure, the fire extinguishing body 10 is positioned in a location that is easily accessible from the outside, allowing for easy replacement of the fire extinguishing body.

[0037] Figure 3 is a schematic cross-sectional view of a battery pack according to another embodiment. In this figure, the battery pack 200 comprises a housing 30, the fire extinguishing body 10 housed within the housing 30, and a plurality of cylindrical batteries 20. The fire extinguishing body 10 is positioned as a fire extinguishing body 10a at the bottom of the housing 30, and is also rolled into a cylindrical shape and positioned as a fire extinguishing body 10b in the gaps between the cylindrical batteries. In this figure, these fire extinguishing bodies 10 are positioned in locations that are easily accessible from the outside, allowing for easy replacement of the fire extinguishing bodies.

[0038] The fire extinguishing element in a battery pack does not necessarily need to be located in a position that is easily accessible from the outside; it is sufficient if it is located in a position that allows for loading and unloading of the fire extinguishing element. For example, in the case of battery pack 100, fire extinguishing elements 10 may be placed between multiple laminated batteries 20.

[0039] The above describes the case where the fire extinguishing body is a laminate comprising a flat (film-like) base material and a fire extinguishing agent-containing layer formed on the base material. However, the fire extinguishing body may have a core-sheath structure comprising a columnar (cylindrical or prismatic) base material and a fire extinguishing agent-containing layer formed on the base material. [Examples]

[0040] The present invention will be described in more detail by the following examples, but the present invention is not limited to these examples.

[0041] <Preparing the materials> • Film substrate: LLDPE (manufactured by Mitsui Chemicals Tohcello Co., Ltd., 30 μm thick, brand: MCS, used in Example 1) • Film substrate: LLDPE (manufactured by Mitsui Chemicals Tohcello Co., Ltd., thickness 12 μm, brand: MCS, used in Comparative Example 2) • Film substrate: PET (Toray Industries, 50μm thickness, brand name: Lumirror S10) • Film substrate: ETFE (manufactured by AGC, 50 μm thick, brand name: Aflex) • Rigid base plate: Wood (teak, 5mm thick) • Rigid substrate: Iron (5mm thick) • Rigid substrate: SUS430 (thickness 5mm) • Rigid substrate: Carbide alloy (manufactured by Nippon Tungsten Co., Ltd., brand name: UM-10, thickness 5mm) • Fire extinguishing agent: ABC fire extinguishing agent (manufactured by Morita Miyata Industries Co., Ltd.) • Binder resin: epoxy resin and epoxy resin hardener

[0042] <Preparation of fire extinguishing devices> (Example 1) A coating solution was prepared by adding a binder resin to the fire extinguishing agent, and this solution was applied to a film substrate (resin layer) and dried at 90°C for 2 minutes. This resulted in a fire extinguishing body with a fire extinguishing agent-containing layer formed on the film substrate. The thickness of the fire extinguishing agent-containing layer was 200 μm. The method for forming the fire extinguishing agent-containing layer was the same regardless of its size.

[0043] The Young's modulus of the substrate was measured as follows. When the layer structure consisted only of a fire extinguishing agent-containing layer (Comparative Example 1), the Young's modulus of the fire extinguishing agent-containing layer was measured in accordance with the measurement method for the resin layer. The Young's modulus of the fire extinguishing agent-containing layer itself was 1 MPa. Resin layer: Measured according to ASTM-D-882 Rigid substrate (wood, metal): Measured in accordance with JIS-Z-2280.

[0044] (Examples 2-3) The fire extinguishing body was manufactured in the same manner as in Example 1, except that the layer structure was changed as shown in Table 1.

[0045] (Example 4) A fire extinguishing agent-containing layer with a thickness of 200 μm was formed on a film substrate in the same manner as in Example 1. Then, the rigid substrate and the film substrate were bonded together using adhesive tape (thickness 50 μm) to obtain a fire extinguishing body.

[0046] (Examples 5-7) The fire extinguishing body was manufactured in the same manner as in Example 4, except that the layer configuration was changed as shown in Table 1.

[0047] (Example 8) A cylindrical fire extinguishing body was obtained by rolling the fire extinguishing body of Example 3 into a cylindrical shape.

[0048] (Example 9) A fire extinguishing agent-containing layer with a thickness of 200 μm was formed on a film substrate in the same manner as in Example 7. This was rolled into a cylindrical shape and wrapped around a rigid substrate that had been processed into a cylindrical shape to obtain a fire extinguishing body.

[0049] (Comparative Example 1) A coating solution was prepared by adding a binder resin to the fire extinguishing agent, and this solution was applied to a silicone release agent coated PET film (manufactured by Toyobo Co., Ltd.) and dried at 90°C for 2 minutes. This formed a fire extinguishing agent-containing layer on the film. A single layer of fire extinguishing agent-containing material was obtained by peeling only the fire extinguishing agent-containing layer from the film. The thickness of the fire extinguishing agent-containing layer was 200 μm.

[0050] (Comparative Example 2) The fire extinguishing body was manufactured in the same manner as in Example 1, except that the layer structure was changed as shown in Table 1.

[0051] <Evaluation of fire extinguishing device loading and discharge> (Regarding small cylindrical battery packs) A small cylindrical battery pack (housing size: cube with dimensions of 70mm x 70mm x 70mm) was prepared. When the fire extinguishing bodies prepared as in each example were loaded into the battery pack, and when they were subsequently removed, the presence or absence of damage to the fire extinguishing bodies was checked. The results are shown in Table 1. The plate-shaped fire extinguishing bodies were placed at the bottom of the battery pack, as shown in fire extinguishing body 10a in Figure 3. The cylindrical fire extinguishing bodies were placed in the gaps between the batteries, as shown in fire extinguishing body 10b in Figure 3.

[0052] (Regarding large laminated battery packs) A large laminate battery pack (a rectangular prism with dimensions of 210mm (length) x 180mm (width) x 115mm (height)) was prepared. The fire extinguishing bodies, prepared according to each example, were loaded into the battery pack, and the presence or absence of damage to the extinguishing bodies during subsequent removal was checked. The results are shown in Table 1. The fire extinguishing bodies were placed at the bottom of the battery pack, as shown in fire extinguishing body 10 in Figure 2.

[0053] [Table 1] [Industrial applicability]

[0054] The fire extinguishing element of this invention can be easily replaced even after it has been loaded into the battery pack. Therefore, by replacing the fire extinguishing element at regular intervals to ensure fire extinguishing capabilities, a safer battery pack can be created. [Explanation of symbols]

[0055] 1...Base material, 2...Fire extinguishing agent-containing layer, 10...Fire extinguishing body, 20...Battery, 30...Housing, 100, 200...Battery pack.

Claims

1. The invention comprises a base material and a fire extinguishing agent-containing layer on the base material, A fire extinguishing body wherein the Young's modulus of the base material is 2 MPa or more.

2. The fire extinguishing body according to claim 1, wherein the base material includes a resin layer.

3. The fire extinguishing body according to claim 2, wherein the Young's modulus of the resin layer is 2 MPa to 5 GPa.

4. The fire extinguishing body according to any one of claims 1 to 3, wherein the base material includes at least one of a wood layer, a metal layer, and a glass layer.

5. The fire extinguishing body according to claim 4, wherein the Young's modulus of the wood layer, the metal layer, and the glass layer is 10 to 700 GPa.

6. A battery pack comprising a housing, and a fire extinguishing body and battery according to any one of claims 1 to 5 housed within the housing.

7. The battery pack according to claim 6, wherein the battery is a lithium-ion battery.

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