JP7656740B2 - Fire prevention member and battery equipped with same - Google Patents

Description

The present invention relates to a fire prevention member and a battery equipped with the same.

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 popular in Europe, particularly in France, the Netherlands, Germany, and other European countries, 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 numerous charging stations.

Various batteries, such as the above-mentioned automobile batteries, may experience thermal runaway due to an internal short circuit or the like, which may result in fire or smoke. In recent years, automobile batteries in which multiple battery cells are arranged and mounted inside a housing have become known. In such batteries in which multiple battery cells are arranged and mounted, if one battery cell ignites or emits smoke, the heat may be transferred to the surrounding battery cells, which may cause further malfunctions such as fire, smoke, or explosion. In order to minimize damage caused by such malfunctions, methods have been considered that make it difficult for heat from abnormally hot battery cells to be transferred to the surrounding battery cells. For example, a method is known in which a fire-prevention member such as a fire-resistant material or a heat insulating layer is provided between multiple battery cells (see Patent Document 1).

JP 2018-206604 A

However, the temperature of battery cells 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, the entire battery cell unit must be integrated. The above demand applies 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."

The present invention was made in consideration of the above 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 contribute to the integration of multiple heat sources, and a battery equipped with the same.

(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 comprises: a rubber sheet made of a rubber-like elastic material; and a heat-resistant sheet that is laminated to or connected to both sides of the rubber sheet and has higher heat resistance than the rubber sheet, wherein the rubber sheet has at least one recess or through-hole that is recessed from one side to the other side on which the heat-resistant sheet is laminated, inside the peripheral edges of both sides of the rubber sheet, making the inner region softer than the peripheral edges.
(2) In a fire spread prevention member according to another embodiment, the rubber sheet may preferably include a plurality of the recesses or the through holes arranged at intervals.
(3) In a 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 that face 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 according to one embodiment is a battery having a plurality of battery cells as heat sources within a housing, and at least one of the fire spread prevention members described above is arranged between the plurality of battery cells.

The present invention provides a fire prevention member that is difficult to burn or spread fire, follows the expansion and contraction of a heat source, and can contribute to the integration of multiple heat sources, as well as a battery equipped with the fire prevention member.

FIG. 1 shows an exploded perspective view of a fire spread prevention member according to a 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. 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. 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. 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. 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. FIG. 8 shows a vertical cross-sectional view of a battery equipped with a fire spread prevention member.

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 not all of the elements and combinations thereof described in each embodiment are necessarily essential to the solution of the present invention.

1. Fire spread prevention member (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.

(1) Schematic configuration of the fire spread prevention member 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, i.e., 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 be provided with 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.

Next, we will explain each component of the fire spread prevention member 1.

(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 that extends outward beyond the edge of the rubber sheet 12. In the fire spread prevention member 1, the joints 5 that face 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 that extend outward from 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 that face 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 A-A line cross section (see FIG. 2) is the same as FIG. 3, so it is omitted from the illustration. The same applies to the following embodiments. 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 open.

The heat-resistant sheet 11 is disposed between heat sources and has the 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 this application, "mainly" or "mainly" means a proportion exceeding 50% by mass of the total mass. The same applies to similar terms hereinafter. 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. In addition, 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, etc.

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 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 flexibility), and although there are no restrictions on its thickness, 0.02 to 3 mm is preferable, and 0.1 to 0.5 mm is more preferable. 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 that the rubber sheet 12 has. However, it is preferable to determine the thickness of the heat-resistant sheet 11 by taking into consideration the strength, flexibility, and heat resistance of the sheet as a whole.

(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 facilitating integration of 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.

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 Al ₂ O ₃ , 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.

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 sides 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 peripheral portion 13 is not limited in width, but is preferably 8 to 15 mm, and more preferably 10 to 12 mm. The through holes 15 or recesses 15a are not limited in size, but are preferably 1 to 20 mm in diameter, and more preferably 5 to 10 mm. There is also no restriction on the number of through holes 15 or recesses 15a, as long as there is at least one. Furthermore, there are no restrictions on the cross-sectional and planar shapes of the through holes 15 or recesses 15a, and they may be, for example, polygonal, elliptical, semicircular, or substantially polygonal 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. There are no restrictions on the thickness of the rubber sheet 12, but it is preferably 4 to 20 mm, and more preferably 5 to 10 mm.

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-holes 15 or recesses 15a are formed, so that the through-holes 15 or recesses 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 due to 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 together, 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, if the rubber sheet 12 has the peripheral portion 13 and the through-holes 15 or recesses 15a in the inner area 14, it becomes easier to integrate the fire spread prevention member 1 as a heat source unit when sandwiching it between heat sources. This is because the peripheral portion 13 has a higher hardness than the region where the through holes 15 are present (i.e., the region 14 inside the peripheral portion 13). On the other hand, when the heat source expands, the inner region 14 where the through holes 15 or recesses 15a are present has a lower hardness than the peripheral portion 13, so it is easy to deform in response to the heat source. In addition, by providing the through holes 15 or recesses 15a in the rubber sheet 12, the fire spread prevention member 1 can be made lighter.

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.

Figure 4 shows a cross-sectional view of the fire spread prevention member according to the second embodiment, taken from the same perspective as Figure 3.

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

The heat-resistant sheet 11a differs 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 joined. 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 a detailed description will be omitted. In addition, there is no particular restriction on the size of the heat-resistant sheet 11a, but it is preferable that the heat-resistant sheet 11a is the same size as the rubber sheet 12.

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.

Figure 5 shows a cross-sectional view of a fire spread prevention member according to the third embodiment, taken from the same perspective as Figure 3.

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

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. In addition, 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, etc.

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.

Figure 6 shows a cross-sectional view of a fire spread prevention member according to the fourth embodiment, taken from the same perspective as Figure 3.

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

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. Note that the cross-sectional view of the fire spread prevention member 1c taken along the line A-A (see FIG. 2) 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.

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 descriptions will be omitted.

Figure 7 shows a cross-sectional view of a fire spread prevention member according to the fifth embodiment, taken from the same perspective as Figure 3.

The fire spread prevention member 1d of the fifth 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 a heat-resistant sheet 11d is laminated on one side of the rubber sheet 12 instead of the heat-resistant sheet 11.

In the fire spread prevention member 1d, the heat-resistant sheet 11 of the first embodiment is laminated on one side of the rubber sheet 12, and the heat-resistant sheet 11d is 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, 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, among the joints 5, 5c that face each other across the rubber sheet 12. 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 that face 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 and 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 and 11d may have three joints 5 and 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 may be folded back and joined. In this case, the heat-resistant sheets 11 and 11d have a bag shape with the sides that do not have the joints 5 and 5c open. The fire spread prevention member 1d configured in this manner also has the same effect as the above-mentioned embodiments. In addition, the fire spread prevention member 1d has the joints 5 and 5c folded back and joined to the joint 5 side facing each other across the rubber sheet 12, so that the joints 5 and 5c are more firmly joined, further reducing the risk of fire spreading from the heat source to the rubber sheet 12, and thus preventing the rubber sheet 12 from burning.

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

Figure 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 of the battery cut in the longitudinal direction of the battery cells inside the battery housing. In addition, in Figure 8, the battery 40 has six battery cells 50, but the number of battery cells 50 is not particularly limited.

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 the housing 41 at the inside 44. An electrode (not shown) is provided protruding from the upper part of the battery cell 50. The battery cells 50 are preferably pressed against each other in the housing 41 by applying a compressive force 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 in the housing 41 with a fire spread prevention member 1 sandwiched between adjacent battery cells 50.

In the battery 40 having such a structure, the heat of the battery cell 50 is transferred from the bottom of the battery cell 50 to the bottom 42 of the housing 41, and the heat is effectively removed by water cooling. In addition, since the fire spread prevention member 1 is arranged 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 sheet 11. Fire spread means the spread of combustion. In addition, the air layer (space S) formed by the heat-resistant sheet 11 and the through-hole 15 of the rubber sheet 12 can reduce the 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 fire spread prevention member 1 between the battery cells 50 while providing the through-hole 15. The coolant 45 is not limited to cooling water, but may also include liquid nitrogen, ethanol, and other organic solvents. The coolant 45 is not limited to being 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 aforementioned fire prevention members 1a, 1b, 1c, and 1d instead of the fire prevention member 1.

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.

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 to 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 of one surface, or may have the recess 15a on each of the inside of the peripheral portion 13 of 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) becomes, so that the thermal insulation can be improved. In addition, there is no restriction on the number of recesses 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.

In addition, 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 a joint 5a that forms an uneven surface as in the third embodiment, and a joint 5c that is folded back and joined as in the fifth embodiment.

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 are no restrictions 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 side.

In addition, there are no restrictions on the shape of the heat-resistant sheets 11, 11b, 11c, and 11d as long as they have a bag shape that encases 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.

The heat source includes not only the battery cell 50 but also all objects that generate heat, such as a circuit board or the main body of an electronic device. 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. Furthermore, 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.

Furthermore, the multiple components of each of the above-mentioned embodiments can be freely combined, except in cases where they cannot be combined with each other. For example, the fire spread prevention member 1a may be provided in the battery 40.

The present invention can be used in fields where it is desirable to prevent fire from spreading between heat sources or from a heat source to other locations.

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

Claims (8)

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. The fire spread prevention member according to claim 1, characterized in that the rubber sheet is a rubber-like elastic body having air bubbles inside. The fire spread prevention member according to claim 1 or 2, characterized in that the rubber sheet has a plurality of the recesses or the through holes arranged at intervals. The fire spread prevention member according to any one of claims 1 to 3, characterized in that the heat-resistant sheet has a bag shape that encases the rubber sheet. 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. The fire spread prevention member according to claim 1, wherein the rubber sheet is a sheet mainly containing silicone rubber. 7. The fire spread prevention member according to claim 1, wherein the rubber sheet is a silicone rubber sponge sheet. 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.