Fire prevention member and battery equipped with same

Abstract

To provide a fire spread prevention member that is difficult to fire or fire spread, follows expansion and shrinkage of a heat source, and can contribute to integrate heat sources and a battery therewith.SOLUTION: The present invention relates to a fire spread prevention member 1 that is arranged at least between a plurality of heat sources, and includes a rubber sheet 12 made of a rubber-like elastic body, and a heat-resistant sheet 11 laminated on both sides of the rubber sheet 12 in a continuous manner or separately, and prevents fire spread between heat sources, the rubber sheet 12 has at least one of a recess that hollows from one surface on which the heat-resistant sheet 11 is laminated toward the other surface or a throughhole 15 penetrating through, inside than a periphery section 13 of both surfaces, a fire spread prevention member 1 that makes an area 14 inside thereof compared with the periphery section 13 soft and a battery provided therewith.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a fire spread prevention member and a battery equipped with the same. [Background technology]

[0002] Currently, there is a growing movement around the world to gradually replace conventional gasoline or diesel vehicles with electric vehicles in order to reduce the burden on the global environment. Electric vehicles are becoming more and more popular, particularly in European countries such as France, the Netherlands, and Germany, as well as in China. The widespread use of electric vehicles faces challenges such as the development of high-performance batteries and the installation of a large number of charging stations.

[0003] In various batteries such as the above-mentioned automobile batteries, there is a risk that the battery will go into thermal runaway due to an internal short circuit or the like, resulting in fire, smoke, or the like. In recent years, automobile batteries in which a plurality of battery cells are arranged and mounted in a housing are known. In such a battery in which a plurality of battery cells are arranged and mounted, if fire or smoke occurs in one battery cell, the heat may be transferred to the surrounding battery cells, resulting in further malfunctions such as fire, smoke, and explosion. In order to minimize damage caused by such malfunctions, methods have been considered that make it difficult for the heat of an abnormally hot battery cell to be transferred to the surrounding battery cells. For example, a method of providing a fire-spread prevention member such as a fire-resistant material or a heat insulating layer between a plurality of battery cells is known (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-206604 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the temperature of a battery cell rises during charging and discharging. Therefore, if the battery cell container itself is made of a flexible material, the battery cell may swell, especially on its side. For this reason, the fire prevention member between the battery cells must be resistant to combustion or fire spread, and must be able to follow the expansion and contraction of the battery cells. On the other hand, when the fire prevention member is sandwiched between the battery cells and mounted, the entire battery cell unit must be integrated. The above demand is applicable not only to battery cells, but also to other heat sources such as circuit boards, electronic components, or electronic device bodies. Meeting such demands will also contribute to the achievement of the applicant's sustainable development goal of "ensuring access to affordable, reliable, sustainable and modern energy for all."

[0006] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a fire prevention member that is difficult to burn or spread fire, follows the expansion and contraction of a heat source, and can also contribute to the integration of multiple heat sources, and a battery equipped with the same. [Means for solving the problem]

[0007] (1) A fire spread prevention member according to one embodiment for achieving the above-mentioned object is a fire spread prevention member that is at least arranged between a plurality of heat sources, and includes a rubber sheet made of a rubber-like elastomer, and a heat-resistant sheet that is laminated to both sides of the rubber sheet, either adjacent to or separately from the rubber sheet, and has higher heat resistance than the rubber sheet, and the rubber sheet has at least one recess that is recessed from one side to the other side on which the heat-resistant sheet is laminated, or at least one through hole that penetrates the rubber sheet, inside the peripheral edges of both sides of the rubber sheet, making the inner region softer than the peripheral edges. (2) In the fire spread prevention member according to another embodiment, preferably, the rubber sheet may include a plurality of the recesses or the through holes arranged at intervals. (3) In the fire spread prevention member according to another embodiment, the heat resistant sheet may preferably have a bag shape that encases the rubber sheet. (4) In another embodiment of the fire spread prevention member, the heat-resistant sheet preferably has a joint extending outward beyond the edge of the rubber sheet, and the joints facing each other across the rubber sheet may be joined together. (5) In the fire spread prevention member according to another embodiment, the heat resistant sheet may preferably be a sheet containing talc as a main component. (6) In the fire spread prevention member according to another embodiment, the rubber sheet may preferably be a sheet mainly containing silicone rubber. (7) A battery in one embodiment is a battery having a plurality of battery cells as heat sources within a housing, and at least one of the above-mentioned fire spread prevention members is arranged between the plurality of battery cells. Effect of the Invention

[0008] According to the present invention, it is possible to provide a fire spread prevention member that is difficult to burn or spread fire, that follows the expansion and contraction of a heat source, and that can also contribute to the integration of multiple heat sources, and a battery equipped with the same. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 shows an exploded perspective view of a fire spread prevention member according to a first embodiment. [Diagram 2] FIG. 2 shows a perspective view of the fire spread prevention member according to the first embodiment. [Diagram 3] FIG. 3 shows a cross-sectional view taken along line AA in FIG. [Figure 4] FIG. 4 shows a cross-sectional view of a fire spread prevention member according to a second embodiment, taken in the same direction as FIG. [Diagram 5] FIG. 5 shows a cross-sectional view of a fire spread prevention member according to a third embodiment taken in the same direction as FIG. [Figure 6] FIG. 6 shows a cross-sectional view of a fire spread prevention member according to a fourth embodiment, taken in the same direction as FIG. [Figure 7] FIG. 7 shows a cross-sectional view of a fire spread prevention member according to a fifth embodiment, taken in the same direction as FIG. [Figure 8]FIG. 8 shows a vertical cross-sectional view of a battery equipped with a fire spread prevention member. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Next, each embodiment of the present invention will be described with reference to the drawings. Note that each embodiment described below does not limit the invention according to the claims, and all of the elements and combinations thereof described in each embodiment are not necessarily essential to the solution of the present invention.

[0011] 1. Fire prevention materials (First embodiment) Fig. 1 shows an exploded perspective view of the fire spread prevention member according to the first embodiment. Fig. 2 shows a perspective view of the fire spread prevention member according to the first embodiment. Fig. 3 shows a cross-sectional view taken along line AA in Fig. 2.

[0012] (1) Overview of fire prevention components The fire spread prevention member 1 according to this embodiment is a member at least disposed between a plurality of (here, two) heat sources. The fire spread prevention member 1 includes a rubber sheet 12 made of a rubber-like elastic body, and a heat-resistant sheet 11 that is laminated on both sides of the rubber sheet 12 and has higher heat resistance than the rubber sheet 12. The heat-resistant sheet 11 wraps the rubber sheet 12. The rubber sheet 12 has at least one through hole 15 penetrating from one side on which the heat-resistant sheet 11 is laminated to the other side, inside the peripheral portion 13 (the frame-shaped area outside the dotted line in FIG. 1) on both sides of the rubber sheet 12, that is, in the inner area 14 surrounded by the dotted line in FIG. 1. As will be described later, instead of the through hole 15 or together with the through hole 15, the rubber sheet 12 may have at least one recess 15a that does not penetrate both sides of the rubber sheet 12 and is recessed in the thickness direction of the rubber sheet 12.

[0013] Next, each component of the fire spread prevention member 1 will be described.

[0014] (2) Heat-resistant sheet As shown in FIG. 1, the heat-resistant sheet 11 is a sheet laminated on the outside of the rubber sheet 12. The heat-resistant sheet 11 preferably has a bag shape that encases the rubber sheet 12. More preferably, the heat-resistant sheet 11 has a joint 5 extending outward from the edge of the rubber sheet 12. In the fire spread prevention member 1, the joints 5 facing each other across the rubber sheet 12 are preferably joined together. The joints 5 may be joined by thermocompression bonding, or may be joined using a fixing means such as a heat-resistant adhesive or double-sided tape. In this embodiment, the heat-resistant sheet 11 has four joints 5 extending outward from each of the four sides that form the outer periphery of the rubber sheet 12. That is, the heat-resistant sheet 11 has a sealed shape in which the four joints 5 are joined to the joints 5 facing each other across the rubber sheet 12 (see FIG. 2). In the fire spread prevention member 1, a cross-sectional view in a direction perpendicular to the AA cross section (see FIG. 2) is the same as FIG. 3, and is therefore omitted from the illustration. This is the same in the following embodiments. Furthermore, the heat-resistant sheet 11 is not limited in shape as long as it has a bag shape that encases the rubber sheet 12, and may have, for example, three joints 5 extending outward from three of the four sides that form the outer periphery of the rubber sheet 12, and the three joints 5 are joined together. In this case, the heat-resistant sheet 11 has a bag shape with the side that does not have the joints 5 being open.

[0015] The heat-resistant sheet 11 is disposed between heat sources and has a function of effectively preventing the spread of fire between the heat sources. The heat-resistant sheet 11 may be made of any material, but is preferably a sheet containing talc as a main component. In the present application, "mainly" or "mainly" means a ratio of more than 50% by mass with respect to the total mass. The same applies to the following similar terms. Talc is generally a ceramic containing magnesium silicate hydrate as a main component and contains a small amount of impurities such as iron oxide. The type and amount of impurities vary depending on the origin of the talc ore, but the talc contained in the heat-resistant sheet 11 is not particularly limited in these respects. The average particle size of the talc measured by the laser light diffraction method is preferably 0.1 μm to 50 μm, more preferably 1 μm to 30 μm. The talc may be surface-treated with a known surface treatment agent such as an organic silane compound, an organic borane compound, an epoxy compound, an organic titanate compound, or an isocyanate compound. The heat-resistant sheet 11 may contain only one type of talc as described above, or may contain two or more types that differ in average particle size, type, surface treatment agent, and the like.

[0016] The heat-resistant sheet 11 is preferably a sheet having excellent heat resistance and flame retardancy. The heat-resistant sheet 11 is not limited to a sheet containing talc as a main component, and may be made of a material having at least higher heat resistance and higher flame retardancy than the rubber sheet 12. Examples of such materials include materials having a relatively low thermal conductivity compared to aluminum nitride, alumina, or graphite, such as mullite, cordierite, steatite, forsterite, titania, and zirconia. The heat-resistant sheet 11 may or may not have excellent electrical conductivity. The heat-resistant sheet 11 is preferably a sheet having excellent curvature (or bending property), and although there is no restriction on its thickness, it is preferably 0.02 to 3 mm, and more preferably 0.1 to 0.5 mm. The thickness of the heat-resistant sheet 11 is preferably smaller than that of the rubber sheet 12. This is because it is easy to realize a fire spread prevention member 1 that exhibits the ease of deformation of the rubber sheet 12. However, it is preferable to determine the thickness of the heat-resistant sheet 11 by comprehensively taking into consideration the strength, flexibility, and heat resistance of the sheet.

[0017] (3) Rubber sheet The rubber sheet 12 is a sheet sandwiched between the heat-resistant sheets 11 as shown in FIG. 1. The rubber sheet 12 is a sheet made of a rubber-like elastic body. The term "elastic body" or "cushion member" may be used instead of the term "rubber-like elastic body". The rubber sheet 12 has a function as a protective member that exhibits cushioning properties between multiple heat sources to prevent the heat-resistant sheet 11 from being damaged by a load applied to the heat-resistant sheet 11, and a function of deforming with the expansion of the heat source. In addition, as described later, the rubber sheet 12 also has a function of easily integrating the fire spread prevention member 1 and at least two heat sources sandwiching it by making the peripheral portion 13 harder than the inner region 14. The rubber sheet 12 is more flammable than the heat-resistant sheet 11. However, by sandwiching the rubber sheet 12 between the heat-resistant sheets 11 from both sides, and more preferably by completely wrapping the rubber sheet 12 with the heat-resistant sheets 11, it becomes difficult to burn.

[0018] The rubber sheet 12 may be either a sponge-like member having bubbles therein or a rubber-like elastic body not containing bubbles, but is more preferably a sponge-like member. The rubber sheet 12 is preferably configured to include a thermosetting elastomer such as silicone rubber, urethane rubber, isoprene rubber, ethylene propylene rubber, natural rubber, ethylene propylene diene rubber, nitrile rubber (NBR) or styrene butadiene rubber (SBR); a thermoplastic elastomer such as a urethane-based, ester-based, styrene-based, olefin-based, butadiene-based or fluorine-based elastomer, or a composite thereof. The rubber sheet 12 has a heat resistance to such an extent that it can maintain its shape without melting or decomposing due to the heat transmitted through the heat-resistant sheet 11. In this embodiment, the rubber sheet 12 is preferably a sheet mainly containing silicone rubber, and more preferably a silicone sponge sheet which is a silicone rubber foam sheet. However, the peripheral portion 13 of the rubber sheet 12 has a smaller total volume of holes than the inner region 14, or has no holes. The hardness of the rubber sheet 12 is preferably 20 to 80 degrees, and more preferably 30 to 70 degrees, in Shore A hardness. The rubber sheet 12 may be configured by dispersing fillers, such as Al2O3, AlN, cBN, hBN, diamond particles, etc., in the rubber in order to increase the thermal conductivity of the rubber sheet 12 as much as possible.

[0019] The rubber sheet 12 is preferably a sheet in which a plurality of through holes 15 or recesses 15a are arranged at intervals, penetrating from one surface on which the heat-resistant sheet 11 is laminated to the other surface (see FIG. 1). The through holes 15 or recesses 15a are not provided in the peripheral portion 13 on both surfaces of the rubber sheet 12. The peripheral portion 13 is a region provided in a frame shape or a U-shape (also called a U-shape) on the outer edge of the widest surface of the rubber sheet 12. The width of the peripheral portion 13 is not limited, but is preferably 8 to 15 mm, and more preferably 10 to 12 mm. The size of the through holes 15 or recesses 15a is not limited, but is preferably 1 to 20 mm in diameter, and more preferably 5 to 10 mm. The number of the through holes 15 or recesses 15a is not limited, and it is sufficient that at least one or more are provided. The through-hole 15 or the recess 15a is not limited in its cross-sectional shape or planar shape, and may be, for example, a polygon, an ellipse, a semicircle, or a substantially polygonal shape with rounded apexes. The heat-resistant sheet 11 and the rubber sheet 12 may be fixed using a fixing means such as a heat-resistant adhesive or double-sided tape, or may be fixed without using any fixing means. The rubber sheet 12 is not limited in its thickness, but is preferably 4 to 20 mm, and more preferably 5 to 10 mm.

[0020] In the fire spread prevention member 1, the heat-resistant sheet 11 is laminated on both sides of the rubber sheet 12 in which the through-hole 15 or the recess 15a is formed, so that the through-hole 15 or the recess 15a and the heat-resistant sheet 11 form a space S. In the fire spread prevention member 1, the space S forms an air layer, so that the thermal conductivity is lower than that of the area other than the space S of the rubber sheet 12. Therefore, in the fire spread prevention member 1, the rubber sheet 12 can improve the insulation property by the space S, so that the thermal conduction from one heat source to another heat source can be reduced. In addition, in the fire spread prevention member 1, the joints 5 of the heat-resistant sheet 11 are joined to each other, so that the thermal conduction between the heat source and the rubber sheet 12 can be further reduced, and the rubber sheet 12 can be prevented from burning. In this way, when the rubber sheet 12 is provided with the peripheral portion 13 and the through-hole 15 or the recess 15a in the area 14 inside the peripheral portion 13, it becomes easy to integrate the fire spread prevention member 1 as a heat source unit when sandwiching and mounting the fire spread prevention member 1 between the heat sources. This is because peripheral portion 13 has a higher hardness than the region where through holes 15 exist (i.e., region 14 inside peripheral portion 13). On the other hand, when the heat source expands, inner region 14 where through holes 15 or recesses 15a exist has a lower hardness than peripheral portion 13, and therefore is likely to deform in response to the heat source. Furthermore, by providing rubber sheet 12 with through holes 15 or recesses 15a, the weight of fire spread prevention member 1 can also be reduced.

[0021] Second embodiment Next, a fire spread prevention member according to a second embodiment will be described. Parts common to the previous embodiment will be given the same reference numerals and duplicated explanations will be omitted. Hereinafter, unless otherwise specified, an example having only the through hole 15 will be described.

[0022] FIG. 4 shows a cross-sectional view of a fire spread prevention member according to a second embodiment, taken in the same direction as FIG.

[0023] The fire spread prevention member 1a of the second embodiment has a similar structure to the fire spread prevention member 1 of the first embodiment, but differs from the fire spread prevention member 1 of the first embodiment in that it is equipped with a heat-resistant sheet 11a instead of the heat-resistant sheet 11.

[0024] The heat-resistant sheet 11a is different from the heat-resistant sheet 11 of the first embodiment in that it does not have a joint 5. That is, the fire spread prevention member 1a includes a rubber sheet 12 made of a rubber-like elastic body, and a heat-resistant sheet 11a that is laminated separately on both sides of the rubber sheet 12 and has higher heat resistance than the rubber sheet 12. In this embodiment, the heat-resistant sheets 11a laminated on both sides of the rubber sheet 12 are arranged to face each other with the rubber sheet 12 sandwiched between them without being bonded. The fire spread prevention member 1a configured in this manner also achieves the same effects as the above-mentioned embodiment. Note that the configuration of the heat-resistant sheet 11a other than the joint 5 is the same as that of the heat-resistant sheet 11 of the first embodiment, so detailed description will be omitted. In addition, the size of the heat-resistant sheet 11a is not particularly limited, but it is preferable that the heat-resistant sheet 11a is the same as that of the rubber sheet 12.

[0025] Third embodiment Next, a fire spread prevention member according to a third embodiment will be described. The same reference numerals will be used to designate parts common to the previous embodiment, and duplicated descriptions will be omitted.

[0026] FIG. 5 shows a cross-sectional view of a fire spread prevention member according to a third embodiment taken in the same direction as FIG.

[0027] The fire spread prevention member 1b of the third embodiment has a similar structure to the fire spread prevention member 1 of the first embodiment, but differs from the fire spread prevention member 1 of the first embodiment in that it is equipped with a heat-resistant sheet 11b instead of the heat-resistant sheet 11.

[0028] The heat-resistant sheet 11b has the same configuration as the heat-resistant sheet 11 of the first embodiment except for the joining method of the joints 5, so detailed description will be omitted. The heat-resistant sheet 11b has four joints 5a extending outward from each of the four sides forming the outer periphery of the rubber sheet 12, like the heat-resistant sheet 11 of the first embodiment. The fire-spread prevention member 1b forms unevenness when the joints 5a facing each other across the rubber sheet 12 are joined together. That is, the heat-resistant sheet 11b forms unevenness when the four joints 5a are joined to the joints 5a facing each other across the rubber sheet 12. The joints 5a may be joined by thermocompression bonding, or may be joined using a fixing means such as a heat-resistant adhesive or double-sided tape. The fire-spread prevention member 1b configured in this manner also has the same effects as the above-mentioned embodiments. In addition, the fire spread prevention member 1b forms unevenness when the joints 5a are joined together, which strengthens the bond between the joints 5a and further reduces the risk of fire spreading from the heat source to the rubber sheet 12, thereby preventing the rubber sheet 12 from burning. The number of unevenness is not limited to the joints 5a of the heat-resistant sheet 11b as long as at least one unevenness is formed. The shape of the unevenness of the joints 5a is not limited to a rectangular shape, and may be, for example, a semicircular shape, a triangular shape, a polygonal shape, or the like.

[0029] (Fourth embodiment) Next, a fire spread prevention member according to a fourth embodiment will be described. The same reference numerals will be used to designate parts common to the previous embodiment, and duplicated descriptions will be omitted.

[0030] FIG. 6 shows a cross-sectional view of a fire spread prevention member according to a fourth embodiment, taken in the same direction as FIG.

[0031] The fire spread prevention member 1c of the fourth embodiment has a structure similar to that of the fire spread prevention member 1 of the first embodiment, but differs from the fire spread prevention member 1 of the first embodiment in that it is equipped with a heat-resistant sheet 11c instead of the heat-resistant sheet 11.

[0032] The heat-resistant sheet 11c has three joints 5b extending outward from three of the four sides (in this embodiment, the three sides other than the lower side) that form the outer periphery of the rubber sheet 12. The heat-resistant sheet 11c has three joints 5b that are joined to the joints 5b that face each other across the rubber sheet 12, forming an uneven surface. That is, the heat-resistant sheet 11c has a bag shape with an open side (in this embodiment, the lower side) that does not have the joints 5b. Therefore, the fire spread prevention member 1c is configured so that the bag-shaped heat-resistant sheet 11c wraps the rubber sheet 12. The fire spread prevention member 1c configured in this way also has the same effect as the above-mentioned embodiments when the lower side is in contact with the side of the cooling part. In the fire spread prevention member 1c, a cross-sectional view of the fire spread prevention member 1c taken along the line AA (see FIG. 2) perpendicular to the cross-sectional view is the same as the cross-sectional view of the fire spread prevention member 1 according to the first embodiment (see FIG. 3), and is therefore omitted from the illustration.

[0033] Fifth embodiment Next, a fire spread prevention member according to a fifth embodiment will be described. The same reference numerals will be used to designate parts common to the previous embodiment, and duplicated explanations will be omitted.

[0034] FIG. 7 shows a cross-sectional view of a fire spread prevention member according to a fifth embodiment, taken in the same direction as FIG.

[0035] The fire spread prevention member 1d of the fifth embodiment has a structure similar to the fire spread prevention member 1 of the first embodiment, but differs from the fire spread prevention member 1 of the first embodiment in that a heat-resistant sheet 11d is laminated on one side of the rubber sheet 12 instead of the heat-resistant sheet 11.

[0036] The fire spread prevention member 1d has the heat-resistant sheet 11 of the first embodiment laminated on one side of the rubber sheet 12, and the heat-resistant sheet 11d laminated on the other side. The heat-resistant sheet 11d has four joints 5c extending outward from each of the four sides forming the outer periphery of the rubber sheet 12. The joints 5c extend outward beyond the joints 5 of the heat-resistant sheet 11. In the fire spread prevention member 1d, among the joints 5, 5c facing each other across the rubber sheet 12, the joints 5c of the heat-resistant sheet 11d are folded back and joined to the joints 5 side of the heat-resistant sheet 11. That is, in the fire spread prevention member 1d, the four joints 5c of the heat-resistant sheet 11d are folded back and joined to the joints 5 side of the heat-resistant sheet 11 facing each other across the rubber sheet 12. The joints 5, 5c may be joined by thermocompression bonding, or may be joined using a fixing means such as a heat-resistant adhesive or double-sided tape. In addition, the heat-resistant sheets 11, 11d are not limited in shape as long as they have a bag shape that encases the rubber sheet 12. For example, the heat-resistant sheets 11, 11d may have three joints 5, 5c extending outward from three of the four sides that form the outer periphery of the rubber sheet 12, and the joints 5 and 5c are folded back and joined. In this case, the heat-resistant sheets 11, 11d have a bag shape with the sides that do not have the joints 5, 5c open. The fire spread prevention member 1d configured in this manner also achieves the same effects as the above-mentioned embodiments. In addition, in the fire spread prevention member 1d, the joints 5, 5c are folded back and joined to the joint 5 side facing each other across the rubber sheet 12, so that the joints 5, 5c are more firmly joined, which further reduces the risk of fire spreading from the heat source to the rubber sheet 12, and thus prevents the rubber sheet 12 from burning.

[0037] 2. Battery Next, a preferred embodiment of the battery according to the present invention will be described.

[0038] Fig. 8 shows a longitudinal cross-sectional view of a battery equipped with a fire spread prevention member. Here, "longitudinal cross-sectional view" means a view cutting the battery in the longitudinal direction of the battery cells inside the battery housing. In Fig. 8, the battery 40 includes six battery cells 50, but the number of battery cells 50 is not particularly limited.

[0039] In this embodiment, the battery 40 is, for example, a battery for an electric vehicle, and includes a number of battery cells 50. The battery 40 includes a bottomed housing 41 that opens on one side. The housing 41 is preferably made of aluminum or an aluminum-based alloy. The battery cells 50 are disposed inside 44 of the housing 41. An electrode (not shown) is provided protruding from the upper side of the battery cell 50. The battery cells 50 are preferably in close contact with each other inside the housing 41 by applying a force in a compressive direction from both sides of the battery cells 50 using a screw or the like (not shown). The bottom 42 (an example of a cooling portion) of the housing 41 is provided with one or more water-cooled pipes 43 for flowing cooling water, which is an example of a coolant 45. The coolant 45 may be referred to as a cooling medium or a coolant. The battery cells 50 are disposed inside the housing 41 such that a fire spread prevention member 1 is sandwiched between adjacent battery cells 50.

[0040] In the battery 40 having such a structure, heat of the battery cells 50 is transferred from the bottom of the battery cells 50 to the bottom 42 of the housing 41, and is effectively removed by water cooling. In addition, since the fire spread prevention member 1 is disposed between the battery cells 50, even if one battery cell 50 abnormally heats up or catches fire, the fire spread can be prevented because the rubber sheet 12 is sandwiched between the heat-resistant sheets 11. Fire spread refers to the spread of combustion. In addition, the air layer (space S) formed by the heat-resistant sheet 11 and the through-holes 15 of the rubber sheet 12 can reduce heat conduction between the adjacent battery cells 50. In addition, even if the battery cell 50 expands during charging and discharging (heat generation), the fire spread prevention member 1 can follow the shape of the battery cell 50 due to the rubber sheet 12. In addition, by providing the peripheral portion 13 on the rubber sheet 12, it is easy to integrate the battery cells 50 in a state where the fire spread prevention member 1 is sandwiched between them, even if the through-holes 15 are provided. The coolant 45 is not limited to cooling water, but may be liquid nitrogen, ethanol, or other organic solvents. The coolant 45 is not limited to liquid under the conditions in which it is used for cooling, and may be gas or solid. The battery 40 may be equipped with the above-mentioned fire spread prevention members 1a, 1b, 1c, and 1d instead of the fire spread prevention member 1.

[0041] 3. Other embodiments As described above, the preferred embodiments of the present invention have been described, but the present invention is not limited to these and can be practiced in various modifications.

[0042] In the fire spread prevention members 1, 1a, 1b, 1c, and 1d according to the above-described embodiments, the rubber sheet 12 may have a recess 15a recessed from one surface on which the heat-resistant sheets 11, 11a, 11b, 11c, and 11d are laminated toward the other surface, instead of the through hole 15. In this case, the rubber sheet 12 may have the recess 15a only on the inside of the peripheral portion 13 on one surface, or may have the recess 15a on each of the inside of the peripheral portion 13 on both surfaces. The rubber sheet 12 is not limited in the size of the recess 15a in the thickness direction, but the larger the recess in the thickness direction, the larger the space S (air layer) is, so that the heat insulation can be improved. In addition, there is no restriction on the number of the recess 15a, and it is sufficient that at least one or more recesses are provided. In addition, there is no restriction on the cross-sectional shape of the recess 15a, and it may be, for example, a polygon, an ellipse, a semicircle, or a substantially polygonal shape with rounded vertices.

[0043] In the fire spread prevention members 1, 1b, 1c, and 1d according to the above-mentioned embodiments, the joining method of the three or four joints 5, 5a, 5b, and 5c provided on the heat-resistant sheets 11, 11b, 11c, and 11d does not have to be the same. For example, the fire spread prevention members 1, 1b, 1c, and 1d may have the joints 5a that form unevenness as in the third embodiment and the joints 5c that are folded back and joined as in the fifth embodiment.

[0044] In the fire spread prevention member 1d according to the fifth embodiment, the joint 5c of the heat-resistant sheet 11d is folded back and joined to the joint 5 side of the heat-resistant sheet 11 facing the rubber sheet 12, but there is no restriction on the joining method as long as one of the two opposing joints is folded back and joined to the other joint side. For example, in the fire spread prevention member 1d, the heat-resistant sheets 11 and 11d may have both joints 5 and 5c folded back to the joint 5 side or the joint 5c side. In the fire spread prevention member 1 according to the first embodiment, the heat-resistant sheet 11 may have both joined joints 5 folded back to either one of the joints 5 sides.

[0045] Furthermore, there are no limitations on the form of the heat-resistant sheets 11, 11b, 11c, and 11d as long as they have a bag shape that wraps the rubber sheet 12. For example, the rubber sheet 12 may be wrapped in the heat-resistant sheets 11, 11b, 11c, and 11d in a wrapping cloth-like manner.

[0046] The heat source includes not only the battery cell 50 but also all objects that generate heat, such as a circuit board and an electronic device body. For example, the heat source may be an electronic component such as a capacitor or an IC chip. Similarly, the coolant 45 may be not only water for cooling but also an organic solvent, liquid nitrogen, or a gas for cooling. The fire spread prevention members 1, 1a, 1b, 1c, and 1d may be disposed in structures other than the battery 40, such as electronic devices, home appliances, and power generation devices.

[0047] In addition, the components of each of the above-described embodiments can be freely combined, except for cases where they cannot be combined with each other. For example, the fire spread prevention member 1a may be provided in the battery 40. [Industrial Applicability]

[0048] The present invention can be used in any field where it is desired to prevent the spread of fire between heat sources or from a heat source to other locations. [Explanation of symbols]

[0049] 1, 1a, 1b, 1c, 1d...fire spread prevention member, 11, 11a, 11b, 11c, 11d...heat resistant sheet, 12...rubber sheet, 13...periphery, 14...inner area, 15...through hole, 15a...recess, 40...battery, 41...casing, 50...battery cell (an example of a heat source).

Claims

1. A fire spread prevention member disposed at least between a plurality of heat sources, A rubber sheet made of a rubber-like elastic material; and a heat-resistant sheet laminated on both sides of the rubber sheet, either adjacent to or separately from the rubber sheet, for preventing the spread of fire between heat sources. The rubber sheet has at least one recess or one through hole extending from one side on which the heat-resistant sheet is laminated to the other side, inside the peripheral edges of both sides of the rubber sheet, making the inner area softer than the peripheral edges.

2. 2. The fire spread prevention member according to claim 1, wherein the rubber sheet is a rubber-like elastic body having air bubbles therein.

3. 3. The fire spread prevention member according to claim 1, wherein the rubber sheet has a plurality of the recesses or the through holes arranged at intervals.

4. 4. The fire spread prevention member according to claim 1, wherein the heat resistant sheet has a bag shape that encases the rubber sheet.

5. The heat-resistant sheet is A joint portion extending outward beyond an edge of the rubber sheet is provided, The fire spread prevention member according to claim 4, wherein the joints that face each other across the rubber sheet are joined together.

6. 6. The fire spread prevention member according to claim 1, wherein the rubber sheet is a sheet mainly containing silicone rubber.

7. 7. The fire spread prevention member according to claim 1, wherein the rubber sheet is a silicone rubber sponge sheet.

8. A battery including a plurality of battery cells as a heat source in a housing, A battery comprising the fire spread prevention member according to any one of claims 1 to 7, which is disposed at least between a plurality of the battery cells.

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