Battery device

Abstract

To provide a battery device with excellent fire extinguishing performance for fire generated from a battery cell.SOLUTION: A battery device according to the present disclosure comprises: a module that includes one or more battery cells and an outer casing enclosing the battery cells; a housing that houses the module; and a fire-extinguishing material that is arranged in at least one of the module and the housing. A ratio calculated by the following formula (1) is more than 0 and 100 or less: Ratio=(the inner volume of the housing - the volume of the module) / the volume of the module...(1).SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a battery device. [Background technology]

[0002] Lithium-ion batteries, a typical type of secondary battery, are known to short-circuit and cause fires when overcharged or subjected to strong external shocks. When a lithium-ion battery shorts or experiences thermal runaway, it releases a large amount of flammable gas, which can cause a serious fire. In recent years, therefore, there have been cases where functional materials have been installed in modules equipped with secondary batteries for the purpose of suppressing fires.

[0003] For example, Patent Document 1 discloses an electricity storage module including a flame-retardant heat-insulating sheet, and Patent Document 2 discloses a battery module characterized by having a fire-extinguishing sheet disposed at a specific position. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-147357 A [Patent Document 2] JP 2022-145344 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, although the electricity storage module of Patent Document 1 can prevent the spread of fire, it cannot extinguish flames that break out from the battery cells, nor can it prevent the generation of high-temperature gas.

[0006] In addition, in the battery module of Patent Document 2, if a single cell catches fire, a large amount of high-temperature flammable gas is released from inside. Therefore, the released fire extinguishing agent is pushed out of the battery module in an extremely short time. As a result, there is a possibility that the fire will not be sufficiently extinguished.

[0007] The present disclosure has been made in consideration of the above circumstances, and provides a battery device that has excellent fire extinguishing performance in the event of a fire breaking out in a battery cell. [Means for solving the problem]

[0008] In order to solve the above problems, the present disclosure provides the following battery device. [1] A module having one or more battery cells and an exterior housing that contains the battery cells; A housing for accommodating the module; a fire extinguishing material disposed within at least one of the module and the housing; Equipped with A battery device, wherein a ratio calculated by the following formula (1) is greater than 0 and less than 100: Ratio = (Enclosure volume - Module volume) / Module volume (1) [2] A battery device as described in [1], in which a fire extinguishing material is arranged on at least one of the inner wall and the outer wall of the exterior. [3] The battery device according to [1] or [2], wherein the exterior has an opening that connects the inside and outside of the exterior. [4] The fire extinguishing material has a laminated structure including a base material and a fire extinguishing agent layer; The battery device according to any one of [1] to [3], wherein the fire-extinguishing agent layer contains a fire-extinguishing agent and a binder resin. [5] A battery device described in [4], wherein the extinguishing agent contains potassium citrate and potassium chlorate. [6] The fire extinguishing material further comprises an adhesive layer on the base material side, The battery device according to [4] or [5], wherein a fire extinguishing material is attached to at least one of the exterior and the housing by an adhesive layer. [7] The battery device according to any one of [1] to [6], wherein the fire extinguishing material is enclosed in a packaging material. Effect of the Invention

[0009] According to the present disclosure, a battery device is provided that has excellent fire extinguishing performance in the event of a fire breaking out in a battery cell. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a horizontal cross-sectional view that shows a schematic diagram of a battery device according to one embodiment. [Diagram 2] FIG. 2 is a horizontal cross-sectional view that shows a schematic diagram of a battery device according to one embodiment. [Diagram 3] FIG. 3 is a horizontal cross-sectional view that illustrates a battery device according to one embodiment. [Figure 4] FIG. 4 is a cross-sectional view that illustrates an example of the fire-extinguishing material. [Diagram 5] FIG. 5 is a cross-sectional view that illustrates an example of the fire-extinguishing material. [Figure 6] FIG. 6 is a plan view illustrating an example of the fire extinguishing material. [Figure 7] FIG. 7 is a schematic cross-sectional view of the fire-extinguishing material shown in FIG. 6 taken along line II-II. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, preferred embodiments of the present disclosure will be described in detail. However, the present disclosure is not limited to the following embodiments. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and duplicated explanations will be omitted.

[0012] [Battery device] Fig. 1 is a horizontal cross-sectional view showing a battery device according to the present embodiment. The battery device 100 shown in Fig. 1 includes a module 10 having a battery cell 11 and an exterior 12 enclosing the battery cell 11, a fire extinguishing material 20 disposed within the module 10, and a housing 30 housing the module 10. The battery device 100 has a ratio calculated by the following formula (1) that is greater than 0 and equal to or less than 100. Ratio = (Enclosure volume - Module volume) / Module volume (1)

[0013] The battery device 100 has excellent fire extinguishing performance against a fire that occurs in a battery cell. The inventors of the present invention speculate that the reason for this effect is as follows. That is, when a fire occurs in a battery cell, high-temperature gas is generated. The battery device 100 includes a housing 30 in addition to the exterior 12 of the module 10, and the ratio calculated by the above formula (1) is within the above numerical range. This prevents the fire extinguishing material 20 from being released into the gap between the module 10 and the housing 30, and prevents the fire extinguishing material 20 from being pushed out of the housing 30 by the generated gas. The fire extinguishing material 20 remains inside the housing 30, and the battery device 100 has excellent fire extinguishing performance against a fire that occurs in a battery cell.

[0014] The ratio calculated by the above formula (1) is more than 0, and is preferably 0.3 or more, and more preferably 3 or more. The ratio calculated by the above formula (1) is 100 or less, and is preferably 50 or less, and more preferably 10 or less. When the ratio calculated by the above formula (1) is 0.3 or more, the released extinguishing agent tends to remain more easily inside the housing. When the ratio calculated by the above formula (1) is 50 or less, the concentration of the extinguishing agent remaining inside the housing during extinguishing tends to be more sufficient.

[0015] In formula (1), the volume of the module is the volume of the exterior 12. In the case where the exterior 12 has an opening described below, the volume of the module is the volume calculated as if the exterior 12 did not have the opening.

[0016] In this embodiment, the fire extinguishing material 20 is disposed on the side surface of the inner wall of the exterior packaging 12. The position at which the fire extinguishing material is disposed is not limited to the embodiment shown in Fig. 1 and can be appropriately adjusted according to the arrangement of the battery cells 11. The fire extinguishing material 20 may be disposed on the bottom surface or top surface of the inner wall of the exterior packaging 12, for example.

[0017] The fire extinguishing material 20 may be disposed on a side surface of the outer wall of the exterior 12 as shown in Fig. 2, or may be disposed on a bottom surface or a top surface of the outer wall of the exterior 12. The fire extinguishing material 20 may be disposed on a side surface of the inner wall of the housing 30 as shown in Fig. 3, or may be disposed on a bottom surface or a top surface of the outer wall of the exterior 12. The fire extinguishing material 20 may be disposed in one location, or in two or more locations.

[0018] The extinguishing material 20 is preferably disposed on at least one of the inner wall and the outer wall of the exterior 12. This makes it possible to suppress the flame from spreading inside the housing and to effectively release the extinguishing agent to the flame. As a result, the battery device 100 tends to have even better fire extinguishing performance. The extinguishing material 20 is more preferably disposed on the outer wall of the exterior 12. This makes it easier to fill the gap between the module 10 and the housing 30 with the extinguishing material. As a result, the battery device 100 tends to have even better fire extinguishing performance.

[0019] The fire extinguishing material 20 may be disposed on a wall surface of the exterior 12 facing the positive electrode of the battery cell 11. When the exterior 12 has an opening, which will be described later, the fire extinguishing material 20 is preferably disposed so as to cover the opening. High-temperature gas and flames are ejected from the opening into the housing. By covering the opening with the fire extinguishing material 20, it is possible to reliably expose the fire to the fire extinguishing material 20 and cause it to react. This tends to result in the battery device having even better fire extinguishing performance.

[0020] <module> A module is a combination of a single battery cell or multiple battery cells to adjust to any voltage, etc.

[0021] (Battery cell) 1 to 3 show three battery cells, but the number of battery cells is not limited to this. There are no particular limitations on the connection between the battery cells 11, and the battery cells 11 may be connected in series or in parallel.

[0022] The shape of the battery cell 11 is not particularly limited, and examples of the shape include a cylindrical shape, a rectangular shape, and a pouch shape. When there are multiple battery cells 11, the shapes of the battery cells may be the same or different.

[0023] Examples of the battery cells include primary batteries and secondary batteries. Since the battery device 100 has excellent fire extinguishing performance, the battery cells can be preferably used even in the case of secondary batteries, which generally cause a large fire when ignited. Examples of the secondary battery include lead-acid batteries, lithium-ion batteries, nickel-metal hydride batteries, and nickel-cadmium batteries. Since the secondary battery has a large capacity, it is preferable that it is a lithium-ion battery. The orientation of the battery cells can be any direction, top-bottom, left-right, or right-side of the module.

[0024] (Exterior) The material constituting the exterior 12 may be a resin or a metal. Examples of metals include SUS (stainless steel), aluminum, iron, and high tensile materials. Examples of resins include PE (polyethylene), PP (polypropylene), PVC (vinyl chloride resin), PS (polystyrene), ABS resin, AS resin, PET (polyethylene terephthalate), PMMA (acrylic resin), PC (polycarbonate), PA (polyamide), POM (acetal resin), PBT (polybutylene terephthalate), phenol resin, and epoxy resin. In addition, from the viewpoint of heat resistance, it is preferable that one or more flame retardants are added to these resins. Examples of flame retardants include halogen-based flame retardants, phosphorus-based flame retardants, inorganic flame retardants, nitrogen-based flame retardants, and silicon-based flame retardants.

[0025] The shape of the exterior 12 is not particularly limited, but examples thereof include a cube, a rectangular parallelepiped, and a cylinder.

[0026] The exterior 12 preferably has an opening that connects its interior with the exterior. Flames and gases generated inside the module 10 are released from the opening. The battery device 100 includes a housing 30, and the ratio calculated by the above formula (1) is greater than 0 and equal to or less than 100. Therefore, by having the opening in the exterior 12, it tends to be possible to suppress an increase in the internal pressure of the module 10 while retaining the fire extinguishing material in the gap between the housing 30 and the module 10.

[0027] The shape of the opening is not particularly limited, and may be, for example, a rectangle with a width of 0.5 to 200 mm and a height of 0.5 to 200 mm, or a circle with a diameter of 1 to 30 mm. A safety valve may be provided at the opening so that when the internal pressure of the module 10 increases, gas can be released through the safety valve to reduce the pressure.

[0028] Inside the module 10, a flame retardant material or the like may be appropriately arranged to prevent the spread of fire.

[0029] <Fire extinguishing material> Fig. 4 is a schematic cross-sectional view showing an example of a fire extinguishing material. As shown in Fig. 4, the fire extinguishing material 20 has a laminated structure including a substrate 21 and a fire extinguishing agent layer 22. Each layer of the fire extinguishing material 20 will be described in detail below.

[0030] (base material) Considering that the temperature of a flame is generally about 700°C to 900°C, a resin can be selected as the material of the base material 21. Examples of the resin include polyolefin (LLDPE, PP, COP, CPP, etc.), polyester (PET, etc.), fluororesin (PTFE, ETFE, EFEP, PFA, FEP, PCTFE, etc.), PVC, PVA, acrylic resin, epoxy resin, polyamide, and polyimide. These resins can be perforated by heat. Furthermore, by selecting a transparent material, it becomes easier to visually inspect the fire extinguishing material and to check when it needs to be replaced. The base material may contain a fire extinguishing agent, which will be described later.

[0031] The thickness and breaking strength of the substrate can be appropriately selected according to the amount of heat, impact, allowable space, etc., at the time of fire outbreak. For example, a thick substrate can provide strength and rigidity, and can provide a highly flat form, making handling easy. A thin substrate can be used to place the fire extinguishing material in a narrow space, and can shorten the time to start extinguishing the fire because a hole is formed in a short time. The thickness of the substrate can be, for example, 4.5 to 100 μm, and may be 12 to 50 μm. The substrate may be a laminate of a plurality of substrates.

[0032] (Fire extinguishing agent layer) The extinguishing agent layer preferably contains an extinguishing agent and a binder resin that fixes the extinguishing agent.

[0033] As the extinguishing agent, those having the four elements of extinguishing (removal action, cooling action, smothering action, negative catalytic action) can be appropriately used according to the target of extinguishing. As the extinguishing agent, potassium salt, sodium salt, ammonium salt, etc. can be mentioned, and in particular, from the viewpoint of extinguishing performance, potassium citrate, which is a potassium salt, is preferably used. In addition, the extinguishing agent preferably contains an oxidizing agent to promote the reaction of the agent, and in particular, potassium chlorate is preferably used in terms of oxidation performance.

[0034] The content of the extinguishing agent may be 60% by mass or more, 90% by mass or more, or even 100% by mass, based on the total amount of the extinguishing agent layer. This makes it easier for the battery device 100 to exhibit excellent fire extinguishing performance.

[0035] The ratio (%) of the amount of fire extinguishing agent to the void inside the housing, calculated by the following formula (2), may be 0.015% or more, 0.55% or more, 1.5% or more, or 10% or less.

[0036] Ratio (%) = {Volume of extinguishing agent contained in extinguishing agent layer / (Volume of housing - Volume of module)} × 100 (2)

[0037] Thermoplastic resins and thermosetting resins can be used as the binder resin. Examples of the thermoplastic resin 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).

[0038] 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), multi-vulcanized rubber (T), silicone rubber (Q), fluororubber (FKM, FZ), urethane rubber (U), polyurethane resin, phenolic resin, epoxy resin, and polyvinyl ether (PMVE)-maleic anhydride resin.

[0039] The content of the binder resin may be 30% by mass or less, 15% by mass or less, or 13% by mass or less, based on the total amount of the fire-extinguishing agent layer.

[0040] The binder resin may contain a curing agent component. From the viewpoint of property stability, the binder resin may further contain any additives such as a surfactant, a silane coupling agent, and an antiblocking agent.

[0041] The extinguishing agent layer 22 may contain other components in addition to the extinguishing agent and the binder resin. Examples of the other components include a curing agent. In addition, examples of the other components include a surfactant, a silane coupling agent, and an antiblocking agent from the viewpoint of property stability.

[0042] The extinguishing agent layer 22 may be formed by molding a composition containing an extinguishing agent and a binder resin. The composition may further contain a liquid medium in addition to the extinguishing agent and the binder resin.

[0043] The liquid medium may be an organic solvent. The organic solvent may be a water-soluble solvent, for example, alcohols such as methanol, ethanol, isopropyl alcohol, n-propyl alcohol, etc.; ketones such as acetone, methyl ethyl ketone, etc.; glycols such as ethylene glycol, diethylene glycol, etc.; glycol ethers such as N-methylpyrrolidone (NMP), tetrahydrofuran, butyl cellosolve, etc. From the viewpoint that the organic salt and the inorganic salt have deliquescent properties, the liquid medium may be an alcohol-based solvent, specifically, ethanol.

[0044] The fire-extinguishing agent layer 22 is formed, for example, by applying the above-mentioned composition to the substrate 21 to form a coating film, and then drying the coating film. The coating can be performed by a wet coating method. Examples of the wet coating method include gravure coating, comma coating, dip coating, curtain coating, spin coating, sponge roll coating, and die coating.

[0045] Although an example of the fire extinguishing material has been described above, the fire extinguishing material is not limited to the above example. For example, as shown in FIG. 5, the fire extinguishing material may further include an adhesive layer 23 on the surface of the substrate 21 opposite to the fire extinguishing agent layer 22.

[0046] (Adhesive layer) The adhesive layer may be made of any known adhesive material, such as an acrylic adhesive, a urethane adhesive, a silicone adhesive, or a rubber adhesive. The thickness of the adhesive layer is preferably 1 μm to 100 μm.

[0047] (packaging material) The substrate 21 and the extinguishing agent layer 22 may be enclosed in a packaging material 24. FIG. 6 is a plan view showing an example of the extinguishing material. FIG. 7 is a schematic cross-sectional view of the extinguishing material shown in FIG. 6 taken along line II-II. The extinguishing material 20 has a peripheral portion 20a. As shown in FIG. 7, the packaging material 24 has a resin film 24a, a water vapor barrier layer 24b, and an adhesive layer 24c. The peripheral portion 20a is formed by a sealing portion formed by the adhesive layers 24c of a pair of packaging materials 24. Each layer of the packaging material 24 will be described in detail below.

[0048] Examples of materials for the resin film 24a include polyolefin resin, polyester resin, fluororesin, vinyl resin, acrylic resin, epoxy resin, polyamide, polyimide, urethane resin, styrene resin, polycarbonate, ketone resin, sulfone resin, and cellulose resin.

[0049] Examples of the water vapor barrier layer 24b include inorganic metal oxide deposition layers such as an alumina deposition layer and a silica deposition layer, and metal foils such as aluminum foil. When the water vapor barrier layer is a metal oxide deposition layer, the metal oxide deposition layer may be disposed on the main surface of the resin film on the fire extinguishing agent layer side.

[0050] The water vapor permeability of the packaging material 24 is 2×10 2 / m 2 / day, can be 1×10 2 g / m 2 The water vapor transmission rate is measured in accordance with JIS K 7129 under conditions of 40° C. and 90% RH.

[0051] Examples of the material for the adhesive layer 24c include a heat seal material, an adhesive, and a pressure sensitive adhesive.

[0052] The peripheral portion 20a is constituted by a sealed portion. The sealed portion prevents the fire extinguishing agent layer 22 from coming into contact with air, and can suppress deterioration of the stability of the properties. When the adhesive layer 24c has a heat sealability, the sealed portion may be formed by heat fusion.

[0053] The adhesive strength between the packaging materials 24 at the sealed portion may be 5 N / 15 mm or more, and from the viewpoint of stably enclosing the fire extinguishing agent layer, may be 7 N / 15 mm or more, or 10 N / 15 mm or more. The adhesive strength can be varied by adjusting the thickness of the resin layer, the adhesive, the heat sealing conditions (heat sealing temperature, pressure and time), etc.

[0054] The adhesion strength between the packaging materials 24 is measured as follows. That is, a sample is prepared in which a pair of packaging materials 24 are bonded together. The sealed portion of this sample is cut to a width of 15 mm, and T-peeled at a peeling speed of 300 mm / min using a tensile tester placed in an environment of room temperature of 23° C. in accordance with JIS K6854-3. The average strength from the start of peeling until the sealed portions of the packaging materials 24 are separated is taken as the adhesion strength between the packaging materials 24.

[0055] Although the packaging material shown in Fig. 7 has a water vapor barrier layer, the packaging material may not have a water vapor barrier layer. Although the fire extinguishing material shown in Fig. 7 has a substrate, the fire extinguishing material may not have a substrate.

[0056] Although the embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the above-described embodiments. EXAMPLES

[0057] The present disclosure will be described in more detail with reference to the following examples, but the present disclosure is not limited to these examples.

[0058] [Example 1] <Fire extinguishing agent layer> A fire extinguishing agent was prepared by crushing potassium chlorate (KClO3) and tripotassium citrate as an oxidizing agent in an agate mortar so that the average particle size D50 was 12 μm or less. This fire extinguishing agent was mixed with various materials in the following compounding ratios to obtain a composition for forming a fire extinguishing agent layer.

[0059] Fire extinguishing agent (potassium chlorate, tripotassium citrate) 87 parts by weight Ether-based urethane resin solution (a solution obtained by dissolving 100 parts by weight of ether-based polyurethane resin in 210 parts by weight of isopropyl alcohol) 40 parts by weight Ethanol 87 parts by weight

[0060] The composition for forming a fire extinguishing agent layer was applied to the entire surface of one main surface of a polyethylene terephthalate (PET) substrate (product name: E7002, manufactured by Toyobo Co., Ltd., thickness 50 μm) using a comma coater to form a coating film. The coating film was dried to obtain a laminate in which a fire extinguishing agent layer (thickness: 150 μm) was formed on the PET substrate. The laminate was processed into sheets (size: 80 mm × 80 mm, or 80 mm × 40 mm) using a slitter and a cutter.

[0061] <Packaging material> Epoxy-urethane synthetic adhesives AD-393 and CAT-EP5 manufactured by Toyo Ink Mfg. Co., Ltd., and isopropyl alcohol as a dilution solvent were prepared. These were mixed in a compounding ratio (AD-393:CAT-EP5:isopropyl alcohol) of 15:1:25.7 to obtain a mixture. The mixture was stirred for 1 minute to produce a dry lamination adhesive (solid content: 20% by mass).

[0062] The above adhesive for dry lamination was applied to the deposition layer side of GL-RD (alumina deposition polyester film manufactured by Toppan Printing Co., Ltd.) using a dry laminator to form a coating film. The coating film was dried in a drying oven set at 80°C to form an adhesive layer (coating amount at dry time: 2 g / m 2Next, the corona-treated surface of a non-oriented polypropylene film MC-S (Mitsui Chemicals Tohcello, thickness 30 μm) was attached to the above GL-RD from the second feed of the dry laminator to prepare a packaging material (size: 100 mm × 100 mm or 100 mm × 60 mm).

[0063] <Fire extinguishing agent layer inclusion> The base material (size: 80mm x 80mm) on which the extinguishing agent layer was formed was sandwiched between a pair of packaging materials (size: 100mm x 100mm) and the four sides were sealed at 140°C for 2 seconds to a seal width of 10mm. This resulted in a sheet-shaped extinguishing material in which the extinguishing agent layer was enclosed inside the packaging material. Similarly, a sheet-shaped extinguishing material was obtained using the base material (size: 80mm x 40mm) on which the extinguishing agent layer was formed and the packaging material (size: 100mm x 60mm).

[0064] <Preparing the module> A rectangular box (width 80 mm, depth 80 mm, height 40 mm) made of SUS material was prepared. An opening (width 80 mm, height 5 mm) for flammable gas to escape was provided on one side of the box to obtain a first module exterior. One cylindrical lithium-ion battery and SUS rods were arranged as dummy batteries to sandwich the lithium-ion battery, and were housed inside the module exterior. The cylindrical lithium-ion batteries were arranged so that all three batteries' positive electrodes faced the side of the module exterior with the opening, and the cylindrical surfaces were in contact with each other. This resulted in a module.

[0065] <Preparation of battery device> The extinguishing material prepared above was attached in a stack of three sheets each to the side of the positive electrode side of the lithium ion battery and the top surface of the inner wall of the module exterior. A fire extinguishing material measuring 80 mm x 80 mm was attached to the top surface, and a fire extinguishing material measuring 80 mm x 40 mm was attached to the side surface. The opening of the module exterior was covered with the fire extinguishing agent. A first housing (width 140 mm, depth 170 mm, height 70 mm) was made of an acrylic plate (thickness 3 mm). The above module was fixed to the center of the bottom surface of the housing. In this way, a battery device was obtained. The ratio calculated by the above formula (1) is shown in Table 1. The ratio (%) calculated by the above formula (2) was 0.27%.

[0066] [Example 2] A second housing (width 30 cm, depth 40 cm, height 20 mm) was made from an acrylic plate (thickness 3 mm). A battery device was obtained in the same manner as in Example 1, except that the second housing was used instead of the first housing. The ratio calculated by the above formula (1) is shown in Table 1. The ratio (%) calculated by the above formula (2) was 0.016%.

[0067] [Example 3] A fire extinguishing material was obtained in the same manner as in Example 1, except that the size of the fire extinguishing agent layer was 170 mm x 90 mm and the size of the packaging material was 190 mm x 110 mm. A fire extinguishing material was obtained in the same manner as in Example 1, except that the size of the fire extinguishing agent layer was 170 mm x 75 mm and the size of the packaging material was 190 mm x 95 mm. A rectangular box (width 170 mm, depth 90 mm, height 75 mm) made of SUS material was prepared as a module exterior. A second module exterior was obtained by providing an opening (width 80 mm, height 5 mm) for releasing flammable gas on one side of the box. A module was obtained in the same manner as in Example 1, except that the second module exterior was used instead of the first module exterior.

[0068] The extinguishing material prepared above was attached in a stack of three sheets each to the side of the positive electrode side of the lithium ion battery and the top surface of the inner wall of the module exterior. A fire extinguishing material measuring 170 mm x 90 mm was attached to the top surface, and a fire extinguishing material measuring 170 mm x 75 mm was attached to the side surface. The opening of the module exterior was covered with the extinguishing agent. A third housing (width 184 cm, depth 93 cm, height 104 mm) was made of an acrylic plate (thickness 3 mm). The above module was fixed to the center of the bottom surface of the third housing. In this way, a battery device was obtained. The ratio calculated by the above formula (1) is shown in Table 1. The ratio (%) calculated by the above formula (2) was 1.74%.

[0069] [Example 4] A battery device was obtained in the same manner as in Example 3, except that instead of attaching the fire extinguishing material to the inner wall of the module exterior, three sheets of the fire extinguishing material prepared above were attached to the side surface and top surface of the positive electrode side of the lithium ion battery of the outer wall of the module exterior in a stacked state. The opening of the module exterior was covered with the fire extinguishing agent. The ratio calculated by the above formula (1) is shown in Table 1. The ratio (%) calculated by the above formula (2) was 1.74%.

[0070] [Example 5] A battery device was obtained in the same manner as in Example 3, except that instead of attaching the fire extinguishing material to the inner wall of the module exterior, three sheets of the fire extinguishing material prepared above were attached to each of the side surface of the positive electrode side of the lithium ion battery and the top surface of the inner wall of the housing. The ratio calculated by the above formula (1) is shown in Table 1. The ratio (%) calculated by the above formula (2) was 1.74%.

[0071] [Example 6] A battery device was obtained in the same manner as in Example 4, except that one sheet of fire extinguishing material was attached to each of the side surface of the positive electrode side of the outer wall of the module exterior and the top surface. The ratio calculated by the above formula (1) is shown in Table 1. The ratio (%) calculated by the above formula (2) was 1.74%.

[0072] [Comparative Example 1] A first module was obtained in the same manner as in Example 1. The first module was used as a battery device as it was without installing a case.

[0073] <Fire extinguishing test> The nail penetration test was carried out indoors at a temperature of 25±5°C and humidity of 30-80%. That is, a nail was inserted from the outside of the housing, facing the lithium-ion battery inside the housing. The nail used had a sufficiently sharp tip (N65 nail made of stainless steel, 65 mm long, and a diameter of the body: about 3.05 mm). The nail penetration speed was 40 mm / sec. The nail penetration depth into the lithium-ion battery was set to 18 mm or more. That is, the nail penetrated the housing and the fire-extinguishing material attached to the top side, the exterior of the module, and the lithium-ion battery, and the tip of the nail was inserted into the bottom plate. This caused thermal runaway of the lithium-ion battery, and the lithium-ion battery ignited. After that, it was confirmed whether the fire-extinguishing agent of the fire-extinguishing material reacted to extinguish the fire, and it was evaluated according to the following criteria. The results are shown in Table 1.

[0074] (standard) A: The fire was extinguished. B: The fire could not be extinguished.

[0075] <Amount of extinguishing agent released> After the fire extinguishing test, the reacted area of ​​the fire extinguishing material placed on the positive electrode side was calculated by visual inspection. The area was evaluated according to the following criteria. The results are shown in Table 1. When the fire extinguishing test is evaluated in the same way, the higher the reacted area ratio on the main surface of the fire extinguishing material, the more fire extinguishing agent can be released. Therefore, the fire extinguishing performance is high.

[0076] (standard) A: The area ratio where the reaction occurred is 70% or more. B: The area ratio where the reaction occurred is between 30% and 70%. C: The area ratio where the reaction occurred is less than 30%.

[0077] [Table 1]

[0078] In the battery devices of Examples 1 to 6, the extinguishing agent discharged upon ignition filled the housing, and the fire was extinguished. On the other hand, in the battery device of Comparative Example 1, the extinguishing agent discharged upon ignition was instantly discharged outside the module, and the fire could not be extinguished. [Explanation of symbols]

[0079] Reference Signs List 10: module, 11: battery cell, 12: exterior, 20: fire extinguishing material, 21: substrate, 22: fire extinguishing agent layer, 23: adhesive layer, 24: packaging material, 30: housing, 100: battery device.

Claims

1. A module having one or more battery cells and an exterior housing that contains the battery cells; A housing that houses the module; a fire extinguishing material disposed within at least one of the module and the housing; Equipped with A battery device, wherein a ratio calculated by the following formula (1) is greater than 0 and less than 100: Ratio=(Volume of the housing−Volume of the module) / Volume of the module (1)

2. The battery device according to claim 1 , wherein the fire-extinguishing material is disposed on at least one of an inner wall and an outer wall of the exterior packaging.

3. The battery device according to claim 1 , wherein the exterior has an opening that communicates between the inside and the outside of the exterior.

4. The extinguishing material has a laminated structure including a substrate and an extinguishing agent layer, The battery device according to claim 1 or 2, wherein the fire-extinguishing agent layer contains a fire-extinguishing agent and a binder resin.

5. The battery device according to claim 4 , wherein the extinguishing agent contains potassium citrate and potassium chlorate.

6. The fire extinguishing material further includes an adhesive layer on the base material side, The battery device according to claim 4 , wherein the fire extinguishing material is attached to at least one of the exterior and the housing by the adhesive layer.

7. The battery device according to claim 1 or 2, wherein the fire extinguishing material is enclosed in a packaging material.

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