Fire prevention unit and battery equipped with same

Abstract

[Problem] To provide: a fire spreading prevention unit that prevents fire spreading by reducing thermal conduction between heat sources during a rise in temperature of the heat sources, that is not easily damaged during expansion of the heat sources, and that can actively dissipate heat from the heat sources; and a battery provided with the same.　[Solution] The present invention relates to a fire spreading prevention unit 1, comprising: fire spreading prevention sheets 20 each disposed so as to be sandwiched between a plurality of heat sources; and a thermally conductive member 10 disposed between the heat sources and a member to which heat from the heat sources is transmitted. The fire spreading prevention sheets 20 are multilayer sheets each obtained by laminating one or more rubber sheets 23, one or more heat resistant sheets 21, and one or more thermally conductive sheets 22. The thermally conductive sheets 22 each have a protrusion 25 that protrudes beyond the rubber sheet 23 and the heat resistant sheet 21 and has both surfaces in the thickness direction of the thermally conductive sheet 22 exposed. The fire spreading prevention sheets 20 are erected on the thermally conductive member 10 in a state in which the respective protrusions 25 are brought into contact with the thermally conductive member 10. The present invention also relates to a battery provided with the fire spreading prevention unit.

Description

Cross References

[0001] The entire disclosures of the patents, patent applications and publications cited in this application are hereby incorporated by reference. [Technical field]

[0002] The present invention relates to a fire prevention unit and a battery equipped with the same. [Background technology]

[0003] 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.

[0004] 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]

[0005] [Patent Document 1] JP 2018-206604 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, the temperature of the battery cells rises during charging and discharging. In addition, some of the battery cells may overheat abnormally. In such a case, it is necessary to reduce the thermal conduction between the battery cells. In addition, as the temperature of the battery cells rises, the battery cells, especially the side surfaces, may expand. For this reason, it is required that the fire prevention member between the battery cells does not break when the battery cells expand. Furthermore, it is preferable not only to simply reduce the thermal conduction between the battery cells, but also to actively release the heat to the outside to cool the battery cells. The above demand applies not only to the battery cells, but also to other heat sources such as circuit boards, electronic components, or electronic device bodies. In addition, meeting such demands will contribute to the achievement of the applicant's sustainable development goal of "ensuring access to affordable, reliable, sustainable and modern energy for all."

[0007] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a fire spread prevention unit and a battery equipped with the same that prevent fire spread by reducing thermal conduction between heat sources when the temperature of the heat sources rises, is less likely to be damaged when the heat sources expand, and actively allows heat to be dissipated from the heat sources. [Means for solving the problem]

[0008] (1) In order to achieve the above object, a fire spread prevention unit according to one embodiment includes a fire spread prevention sheet sandwiched between a plurality of heat sources; a heat conducting member disposed between the heat source and a member to which heat is transferred from the heat source; The fire prevention sheet is One or more rubber sheets; One or more heat-resistant sheets having better heat resistance than the rubber sheet; one or more thermally conductive sheets having superior thermal conductivity to the rubber sheet and the heat-resistant sheet; A multilayer sheet comprising: the thermally conductive sheet has a protruding portion protruding beyond the rubber sheet and the heat-resistant sheet to expose both surfaces of the thermally conductive sheet in a thickness direction; The fire spread prevention sheet is provided upright on the heat conductive member with the protruding portion of the heat conductive sheet in contact with the heat conductive member. (2) In the fire spread prevention unit according to another embodiment, preferably, the heat conductive member includes a heat conductive filler in a rubber-like elastomer, the heat conductive filler having a higher thermal conductivity than the rubber-like elastomer, The protrusion may be inserted from a surface of the heat conducting member to an interior thereof. (3) In the fire spread prevention unit according to another embodiment, preferably, the heat conductive member includes a molded body mainly made of rubber or resin, and a heat conductive film having superior thermal conductivity to the molded body, The thermally conductive film is exposed on an outer surface of the molded body, The protrusion may be connected to the thermally conductive film. (4) In the fire spread prevention unit according to another embodiment, the rubber sheet may preferably be a porous sponge sheet. (5) In the fire spread prevention unit according to another embodiment, the heat resistant sheet may preferably be a sheet containing talc and / or silica. (6) In the fire spread prevention unit according to another embodiment, the heat conductive sheet may preferably be a sheet containing graphite and / or an aluminum compound. (7) In the fire spread prevention unit according to another embodiment, preferably, the multilayer sheet forms a bag having both surfaces in its thickness direction and at least one end surface connecting the both surfaces, The thermally conductive sheet is disposed inside the bag, The thermally conductive sheet may have the protrusion penetrating the bag and protruding outward. (8) A battery according to one embodiment for achieving the above object comprises: A battery including a plurality of battery cells as a heat source in a housing, The battery includes a fire spread prevention unit according to any one of claims 1 to 7 in the housing, the fire prevention sheet is sandwiched between the battery cells, The thermally conductive member is sandwiched between the battery cell and a cooling portion of the housing. Effect of the Invention

[0009] According to the present invention, it is possible to provide a fire spread prevention unit and a battery equipped with the same that prevent the spread of fire by reducing thermal conduction between heat sources when the temperature of the heat sources rises, are less likely to be damaged when the heat sources expand, and actively allow heat to be dissipated from the heat sources. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 shows a perspective view of a manufacturing situation of the fire spread prevention unit according to the first embodiment and an enlarged view of a part B of the heat conduction member. [Diagram 2] FIG. 2 shows a perspective view of the fire prevention unit of FIG. 1 after manufacture. [Diagram 3] FIG. 3 shows a cross-sectional view of the fire spread prevention unit taken along line CC in FIG. 2 and an enlarged view of a part D. [Figure 4] FIG. 4 shows a cross-sectional view taken along line CC of the first embodiment, a cross-sectional view taken along line CC of the first embodiment, and an enlarged view of a part E of the fire spread prevention unit according to the second embodiment. [Diagram 5] FIG. 5 shows a cross-sectional view taken along line CC of the first embodiment, a cross-sectional view taken along line CC of the first embodiment, and an enlarged view of a part F in a fire spread prevention unit according to a third embodiment. [Figure 6] FIG. 6 shows a cross-sectional view taken along line CC of the first embodiment, a cross-sectional view taken along line CC of the first embodiment, and an enlarged view of a part G in a fire spread prevention unit according to a fourth embodiment. [Figure 7] Figure 7 shows a cross-sectional view taken along the CC cross-sectional view of the first embodiment of the fire spread prevention unit and the fire spread prevention sheet constituting the same in the fifth embodiment, as well as a plan view and a right side view of the heat conduction member constituting the fire spread prevention unit. [Figure 8]FIG. 8 shows a cross-sectional view taken along line CC of the first embodiment in a fire spread prevention unit according to the sixth embodiment. [Figure 9] FIG. 9 shows a cross-sectional view taken along line CC of the first embodiment in a fire spread prevention unit according to the seventh embodiment, as well as a plan view and a right side view of a heat conductive member. [Figure 10] FIG. 10 shows a cross-sectional view of a fire spread prevention sheet according to a modified example. [Figure 11] FIG. 11 shows a plan view of a heat conductive member of a fire spread prevention unit according to the eighth embodiment. [Figure 12] FIG. 12 shows a manufacturing situation of the fire spread prevention unit according to the eighth embodiment in a cross-sectional view taken along the line CC of the first embodiment. [Figure 13] FIG. 13 shows a vertical cross-sectional view of the battery according to the first embodiment. [Figure 14] FIG. 14 shows a vertical cross-sectional view of the battery according to the second embodiment. [Explanation of symbols]

[0011] 1, 1a, 1b, 1c, 1d, 1e, 1f, 1g···Fire spread prevention unit, 10, 30, 40, 50···Heat conductive member, 11···Heat conductive filler, 20, 20a, 20b, 20c, 20d, 20e, 20f···Fire spread prevention sheet (multilayer sheet), 21···Heat resistant sheet, 22···Heat conductive sheet, 23···Rubber sheet (one example is a sponge sheet), 25, 25d···Protrusion, 27···Bag, 31, 41···Molded body, 32, 42, 60···Heat conductive film, 61···Rubber tube (molded body), 70, 70a···Battery, 71···Housing, 72···Bottom (member to which heat is transferred, cooling part), 80···Battery cell (one example of a heat source). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] 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.

[0013] 1. Fire prevention unit (First embodiment) Fig. 1 shows a perspective view of a state in which the fire spread prevention unit according to the first embodiment is manufactured and an enlarged view of a part B of a heat conductive member. Fig. 2 shows a perspective view of a state after the fire spread prevention unit of Fig. 1 is manufactured. Fig. 3 shows a cross-sectional view of the fire spread prevention unit of Fig. 2 taken along line CC and an enlarged view of a part D.

[0014] The fire spread prevention unit 1 according to this embodiment includes a fire spread prevention sheet 20 sandwiched between a plurality of heat sources, and a heat conductive member 10 arranged between a member to which heat from the heat sources is transferred and the heat sources. The fire spread prevention sheets 20 are erected on the heat conductive member 10 at a predetermined interval. A heat source can be arranged at the predetermined interval. The fire spread prevention unit 1 can be manufactured by making a cut in the heat conductive member 10 and inserting the fire spread prevention sheet 20 into the cut. The fire spread prevention unit 1 may also be manufactured by inserting the fire spread prevention sheet 20 into a member before hardening of the heat conductive member 10, and hardening the member before hardening to obtain the heat conductive member 10. The number of fire spread prevention sheets 20 is nine in this embodiment and the following embodiments. The number of fire spread prevention sheets 20 can be increased or decreased according to the number of heat sources as long as it is one or two or more. The number of heat conductive members 10 is one in this embodiment, but there is no particular restriction and it may be one or two or more.

[0015] The fire spread prevention sheet 20 is a multi-layer sheet obtained by laminating one or more rubber sheets 23, one or more heat-resistant sheets 21, and one or more heat-conductive sheets 22. The fire spread prevention sheet 20 according to this embodiment is a multi-layer sheet obtained by laminating one heat-resistant sheet 21, one heat-conductive sheet 22, and one rubber sheet 23 in this order. The number of each of the heat-resistant sheets 21, heat-conductive sheets 22, and rubber sheets 23 constituting the fire spread prevention sheet 20 may be one or more. There are no particular restrictions on the method of laminating adjacent sheets, and in addition to a method of laminating the sheets with a connecting means of adhesive, pressure-sensitive adhesive, or double-sided tape interposed therebetween, a method without the interposition of the connecting means (for example, pressure bonding) may also be used.

[0016] The heat-resistant sheet 21 is a sheet having better heat resistance than the rubber sheet 23. The thermally conductive sheet 22 is a sheet having better thermal conductivity than the rubber sheet 23 and the heat-resistant sheet 21.

[0017] (1) Rubber sheet The rubber sheet 23 is a sheet made of a rubber-like elastic material. The term "elastic material" or "cushion member" may be used instead of the term "rubber-like elastic material". The rubber sheet 23 has a function as a protective member that provides cushioning between multiple heat sources to prevent the heat-resistant sheet 21 from being damaged by a load applied to the heat-resistant sheet 21, and a function of deforming with the expansion of the heat source. In this embodiment, the rubber sheet 23 also has a function of facilitating integration of the fire spread prevention sheet 20 and the heat source in contact therewith.

[0018] The rubber sheet 23 may be a sponge-like member having air bubbles therein or a rubber-like elastic body not having air bubbles, but is more preferably a sponge-like member. The rubber sheet 23 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.

[0019] The rubber sheet 23 preferably has a heat resistance to such an extent that it does not easily melt or decompose due to heat transmitted from a heat source and can maintain its shape. In this embodiment, the rubber sheet 23 is preferably a porous sponge sheet. This is because the pores in the sheet contain air, which has excellent heat insulation effect. The rubber sheet 23 is preferably a sheet mainly containing silicone rubber. This is because silicone rubber can withstand heat up to about 200°C. In the present application, "mainly" or "main material" means that it occupies a ratio of more than 50 mass% of the whole. The rubber sheet 23 is more preferably a sponge sheet of silicone rubber. The hardness of the rubber sheet 23 is preferably 20 degrees to 80 degrees, more preferably 30 degrees to 70 degrees, in Shore A hardness. The rubber sheet 23 may be configured by dispersing a flame retardant material such as carbon or boric acid in the rubber in order to increase flame retardancy. The thickness of the rubber sheet 23 is not limited, but is preferably 2 to 20 mm, more preferably 3 to 8 mm. The rubber sheet 23 is preferably the thickest of the layers constituting the fire spread prevention sheet 20. This can reduce damage to the heat resistant sheet 21 or the heat conductive sheet 22 constituting the fire spread prevention sheet 20. However, it is preferable to determine the thickness of the rubber sheet 23 by comprehensively considering the strength, flexibility, and heat resistance of the sheet. When the rubber sheet 23 is a solid rubber sheet, it is preferable to provide a recess or groove on one or both sides of the rubber sheet 23, or to provide a hole penetrating in the thickness direction. This is because the air in the recess, groove, or hole can exert a heat insulating effect. Also, one or both sides of the rubber sheet 23 may be mirror-finished.

[0020] (2) Thermally conductive sheet The heat conductive sheet 22 has a protruding portion 25 that protrudes beyond the rubber sheet 23 and the heat resistant sheet 21 and exposes both sides of the heat conductive sheet 22 in the thickness direction. The fire spread prevention sheet 20 is inserted into the heat conductive member 10 with the protruding portion 25 facing the heat conductive member 10 (see arrow A in FIG. 1). The fire spread prevention sheet 20 is erected on the heat conductive member 10 with the protruding portion 25 of the heat conductive sheet 22 in contact with the heat conductive member 10. The protruding portion 25 is a portion that is not covered by the rubber sheet 23 and the heat resistant sheet 21 and exposes the heat conductive sheet 22. Therefore, the heat transmitted from the heat source to the heat conductive sheet 22 can be rapidly transmitted to the heat conductive member 10. That is, the heat conductive sheet 22 functions as a heat transport path in the fire spread prevention sheet 20.

[0021] The thermally conductive sheet 22 is made of carbon (for example, graphite), Al 2 O 3 , AlN, cBN or hBN sheets, as well as carbon, Al 2 O 3 The heat conductive sheet 22 may be a resin sheet containing AlN, cBN or hBN as a filler, or a paper sheet containing the same filler. An example of the resin is aramid fiber. More preferably, the heat conductive sheet 22 is a sheet containing graphite and / or an aluminum compound. In this embodiment, the heat conductive sheet 22 is preferably a graphite sheet or a sheet in which graphite is dispersed as a filler in a resin. There is no restriction on the thickness of the heat conductive sheet 22, but it is preferably 0.05 to 3 mm, and more preferably 0.08 to 0.6 mm. However, it is preferable to determine the thickness of the heat conductive sheet 22 by comprehensively considering the strength, flexibility and heat resistance of the sheet.

[0022] (3) Heat-resistant sheet The heat-resistant sheet 21 preferably has a function of effectively preventing the spread of fire between heat sources. The heat-resistant sheet 21 may be made of any material, but is preferably a sheet mainly containing talc. The heat-resistant sheet 21 may be, for example, a sheet containing talc and resin (which may be paper). An example of the resin is aramid fiber. The content of talc in the heat-resistant sheet 21 is preferably 55 to 99 mass%, more preferably 75 to 90 mass%. Talc is generally a ceramic mainly composed of hydrated magnesium silicate, 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 21 is not particularly limited in these respects. 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 21 may contain only one type of talc as described above, or may contain two or more types that differ in particle size, type, surface treatment agent, and the like.

[0023] The heat-resistant sheet 21 is preferably a sheet having excellent heat resistance and flame retardancy. The heat-resistant sheet 21 is not limited to a sheet mainly containing talc, and may be made of a material having at least higher heat resistance and higher flame retardancy than the rubber sheet 23. Examples of such materials include materials having relatively low thermal conductivity such as silica, mullite, cordierite, steatite, forsterite, titania, and zirconia. The heat-resistant sheet 21 is more preferably a sheet containing the above-mentioned talc and / or the above-mentioned silica. The heat-resistant sheet 21 may or may not have excellent electrical conductivity. The heat-resistant sheet 21 is preferably a sheet having excellent curvature (or bending property), and although there is no restriction on its thickness, it is preferably 0.05 to 2.0 mm, and more preferably 0.1 to 1.0 mm. The thickness of the heat-resistant sheet 21 is preferably smaller than that of the rubber sheet 23. However, it is preferable to determine the thickness of the heat-resistant sheet 21 by comprehensively considering the strength, flexibility, and heat resistance of the sheet.

[0024] (4) Thermally conductive materials The heat conducting member 10 is a member that is disposed between the heat source and a member (e.g., a cooling section) at the destination of heat dissipation from the heat source. In this embodiment, the heat conducting member 10 contains a rubber-like elastomer and a heat conducting filler 11 having better thermal conductivity than the rubber-like elastomer (see the enlarged view of part B in FIG. 1). The rubber-like elastomer is preferably selected from the same options as the rubber that constitutes the rubber sheet 23. The rubber-like elastomer that constitutes the heat conducting member 10 is preferably silicone rubber, which has relatively good heat resistance. The heat conducting filler 11 may be carbon (e.g., graphite), Al, or the like. 2 O 3 In addition to AlN, cBN, or hBN, metals such as Al and Cu can be used. Ferromagnetic fillers such as iron, cobalt, and nickel can also be used in place of the metal.

[0025] The protruding portion 25 of the heat conductive sheet 22 is inserted from the surface into the heat conductive member 10. The protruding portion 25 may be inserted over the entire length of the heat conductive member 10 in the thickness direction, other than being inserted halfway in the thickness direction of the heat conductive member 10. In addition to the protruding portion 25, a part of the heat resistant sheet 21 and / or the rubber sheet 23 may also be inserted into the heat conductive member 10.

[0026] Second embodiment Next, a fire spread prevention unit according to a second embodiment will be described. Explanations of parts common to the previous embodiment will be omitted.

[0027] FIG. 4 shows a cross-sectional view taken along line CC of the first embodiment, a cross-sectional view taken along line CC of the first embodiment, and an enlarged view of a part E of the fire spread prevention unit according to the second embodiment.

[0028] The fire spread prevention unit 1a according to the second embodiment includes a fire spread prevention sheet 20a sandwiched between a plurality of heat sources, and a heat conductive member 10 arranged between the heat source and a member to which heat from the heat source is transferred. The fire spread prevention sheet 20a is erected on the heat conductive member 10 at a predetermined interval. The fire spread prevention sheet 20a according to this embodiment has two heat resistant sheets 21, one heat conductive sheet 22, and one rubber sheet 23. More specifically, the fire spread prevention sheet 20a is a multi-layer sheet in which one heat resistant sheet 21, one heat conductive sheet 22, one rubber sheet 23, and one heat resistant sheet 21 are laminated in this order. The heat resistant sheets 21 constitute the two outermost layers of the fire spread prevention sheet 20a. Therefore, the fire spread prevention sheet 20a is a sheet with excellent fire spread prevention effect. The protruding portion 25 of the heat conductive sheet 22 protrudes outward beyond the two heat resistant sheets 21 and the one rubber sheet 23. Fire spread prevention sheet 20a is provided upright on heat conductive member 10 with protruding portion 25 inserted into heat conductive member 10. Points other than those described above are common to the first embodiment, so duplicated explanations will be omitted.

[0029] Third embodiment Next, a fire spread prevention unit according to a third embodiment will be described. Explanations of parts common to the previous embodiment will be omitted.

[0030] FIG. 5 shows a cross-sectional view taken along line CC of the first embodiment, a cross-sectional view taken along line CC of the first embodiment, and an enlarged view of a part F in a fire spread prevention unit according to a third embodiment.

[0031] The fire spread prevention unit 1b according to the third embodiment includes a fire spread prevention sheet 20b sandwiched between a plurality of heat sources, and a heat conductive member 10 arranged between the heat source and a member to which heat from the heat source is transferred. The fire spread prevention sheet 20b is erected on the heat conductive member 10 at a predetermined interval. The fire spread prevention sheet 20b according to this embodiment has two heat resistant sheets 21, one heat conductive sheet 22, and one rubber sheet 23. More specifically, the fire spread prevention sheet 20b is a multi-layer sheet in which one heat conductive sheet 22, one heat resistant sheet 21, one rubber sheet 23, and one heat resistant sheet 21 are laminated in this order. The heat conductive sheet 22 constitutes one outermost layer of the fire spread prevention sheet 20b. Therefore, the fire spread prevention sheet 20b can quickly transfer heat from one heat source to the heat conductive member 10. The protruding portion 25 of the heat conductive sheet 22 protrudes outward beyond the two heat resistant sheets 21 and the one rubber sheet 23. The fire spread prevention sheet 20b is provided upright on the heat conductive member 10 with the protruding portion 25 inserted into the heat conductive member 10. Points other than those described above are common to the above-mentioned embodiments, and therefore repeated explanations will be omitted.

[0032] (Fourth embodiment) Next, a fire spread prevention unit according to a fourth embodiment will be described. Explanations of parts common to the previous embodiments will be omitted.

[0033] FIG. 6 shows a cross-sectional view taken along line CC of the first embodiment, a cross-sectional view taken along line CC of the first embodiment, and an enlarged view of a part G in a fire spread prevention unit according to a fourth embodiment.

[0034] The fire spread prevention unit 1c according to the fourth embodiment includes a fire spread prevention sheet 20c sandwiched between a plurality of heat sources, and a heat conductive member 10 arranged between the heat source and a member to which heat from the heat source is transferred. The fire spread prevention sheet 20c is erected on the heat conductive member 10 at a predetermined interval. The fire spread prevention sheet 20c according to this embodiment has two heat resistant sheets 21, two heat conductive sheets 22, and one rubber sheet 23. More specifically, the fire spread prevention sheet 20c is a multi-layer sheet in which one heat conductive sheet 22, one heat resistant sheet 21, one rubber sheet 23, one heat resistant sheet 21, and one heat conductive sheet 22 are laminated in this order. The heat conductive sheets 22 constitute the two outermost layers of the fire spread prevention sheet 20c. Therefore, the fire spread prevention sheet 20c can more quickly transfer heat from the heat source sandwiched between the sheet 20c and the heat conductive member 10. The protruding portion 25 of the heat conductive sheet 22 protrudes outward beyond the two heat resistant sheets 21 and the one rubber sheet 23. The fire spread prevention sheet 20c is provided upright on the heat conductive member 10 by inserting the two protruding portions 25 into the heat conductive member 10. Points other than those described above are common to the above-mentioned embodiments, and therefore repeated explanations will be omitted.

[0035] Fifth embodiment Next, a fire spread prevention unit according to a fifth embodiment will be described. Explanations of parts common to the previous embodiments will be omitted.

[0036] Figure 7 shows a cross-sectional view taken along the CC cross-sectional view of the first embodiment of the fire spread prevention unit and the fire spread prevention sheet constituting the same in the fifth embodiment, as well as a plan view and a right side view of the heat conduction member constituting the fire spread prevention unit.

[0037] The fire spread prevention unit 1d according to the fifth embodiment includes a fire spread prevention sheet 20d sandwiched between a plurality of heat sources, and a heat conductive member 30 arranged between the heat source and a component to which heat from the heat source is transferred. The fire spread prevention sheet 20d is erected on the heat conductive member 30 at a predetermined interval. The fire spread prevention sheet 20d according to this embodiment has the same layer structure as the fire spread prevention sheet 20 according to the first embodiment, but differs from the fire spread prevention sheet 20 in that the protruding portion 25d of the heat conductive sheet 22 is bent into an L-shape in cross section.

[0038] The heat conductive member 30 is not one heat conductive member 10 constituting the fire spread prevention unit 1 according to the first embodiment, but ten plate-shaped members. FIG. 7 shows a plan view and a right side view of one plate-shaped heat conductive member 30. The heat conductive member 30 includes a molded body 31 mainly made of rubber or resin, and a heat conductive film 32 having better thermal conductivity than the molded body 31. The molded body 31 is preferably made of the same material as the rubber of the rubber sheet 23. The heat conductive film 32 is preferably a carbon film mainly made of carbon (including graphite), or a film in which a heat conductive filler (filler such as carbon, metal, ceramics, etc.) is dispersed in a resin.

[0039] The heat conductive film 32 is exposed on the outer surface of the molded body 31. More specifically, the molded body 31 has a thin rectangular parallelepiped shape. The band-shaped heat conductive film 32 is fixed in a bellows-like shape while being alternately exposed on the front and back surfaces in the thickness direction of the molded body 31 toward the length direction (the direction of the longest side) of the molded body 31. The protruding portion 25d is fixed to the heat conductive member 30 so as to contact the side and bottom surfaces of the heat conductive member 30 and to contact the heat conductive film 32. There are no particular restrictions on the method of fixing the protruding portion 25d to the heat conductive member 30, and it may be a method using an adhesive, a pressure sensitive adhesive, or a double-sided tape, or a method without any intermediate material such as pressure bonding.

[0040] Sixth embodiment Next, a fire spread prevention unit according to a sixth embodiment will be described. Explanations of parts common to the previous embodiments will be omitted.

[0041] FIG. 8 shows a cross-sectional view taken along line CC of the first embodiment in a fire spread prevention unit according to the sixth embodiment.

[0042] The fire spread prevention unit 1e according to the sixth embodiment has a similar configuration to the fire spread prevention unit 1d according to the fifth embodiment, except that the fire spread prevention sheet 20d according to the fifth embodiment is fixed to the heat conductive film 32 on the front surface of the heat conductive member 30. In this manner, the protrusion 25d may be fixed to the front surface of the heat conductive member 30. The heat conductive member 30 may be a single member having the same structure as that described above.

[0043] Seventh embodiment Next, a fire spread prevention unit according to a seventh embodiment will be described. Explanations of parts common to the previous embodiments will be omitted.

[0044] FIG. 9 shows a cross-sectional view taken along line CC of the first embodiment in a fire spread prevention unit according to the seventh embodiment, as well as a plan view and a right side view of a heat conductive member.

[0045] The fire spread prevention unit 1f according to the seventh embodiment has the same configuration as the fire spread prevention unit 1e according to the sixth embodiment, except that the heat conduction member 30 of the sixth embodiment is changed to a heat conduction member 40. The number of heat conduction members 40 is 15 in total, including three in the direction in which the fire spread prevention sheets 20d are arranged and five in the depth direction of the paper. However, there is no restriction on the number of heat conduction members 40.

[0046] 9 shows a plan view and a right side view of one plate-shaped heat conductive member 40. Heat conductive member 40 includes a molded body 41 made mainly of rubber or resin, and a heat conductive film 42 having superior heat conductivity to that of molded body 41. Molded body 41 is preferably made of the same material as the rubber of rubber sheet 23. Heat conductive film 42 is preferably a carbon film made mainly of carbon (including graphite), or a film in which heat conductive filler (filler such as carbon, metal, ceramic, etc.) is dispersed in resin.

[0047] The heat conductive film 42 is exposed on the outer surface of the molded body 41. More specifically, the molded body 41 has a thin rectangular parallelepiped shape. The band-shaped heat conductive film 42 is advanced in an accordion-like manner toward the width direction (direction of the second longest side) of the molded body 41 while being alternately exposed on the front surface and the back surface in the thickness direction of the molded body 41. The heat conductive film 42 is fixed in two rows in the length direction (direction of the longest side) of the molded body 41. The protruding portion 25d is fixed to the front surface of the heat conductive member 40 so as to contact the heat conductive film 42 of the heat conductive member 40. There are no particular restrictions on the method of fixing the protruding portion 25d and the heat conductive member 40, and in addition to a method using an adhesive, a pressure sensitive adhesive, or a double-sided tape, a method without any intermediate material such as pressure bonding may be used. The protruding portion 25d may be fixed to the back surface of the heat conductive member 40. The heat conductive member 40 may be a single member having the same structure as the above-mentioned structure.

[0048] (Modification) Next, modified examples of the fire spread prevention sheet that constitutes the fire spread prevention unit will be described.

[0049] FIG. 10 shows a cross-sectional view of a fire spread prevention sheet according to a modified example.

[0050] The fire spread prevention sheet 20e according to the first modification is a four-layered multi-layered sheet of a heat-resistant sheet 21, a thermally conductive sheet 22, a rubber sheet 23, and a heat-resistant sheet 21. The multi-layered sheet forms a bag 27 having both sides in the thickness direction and one end face 21a connecting the both sides. That is, the bag 27 is formed by the heat-resistant sheet 21. The thermally conductive sheet 21 and the rubber sheet 23 are disposed inside the bag 27. The thermally conductive sheet 21 has a protrusion 25 protruding outward from an opening 21b formed in a part of the end face 21a through the bag 27.

[0051] The fire spread prevention sheet 20f according to the second modification is a multi-layer sheet having five layers, namely, a heat resistant sheet 21, a rubber sheet 23, a heat conductive sheet 22, a rubber sheet 23, and a heat resistant sheet 21. The other configurations of the fire spread prevention sheet 20f are the same as those of the fire spread prevention sheet 20e according to the first modification. The bag 27 may be formed of the rubber sheet 23 instead of the heat resistant sheet 21. The bag 27 has a form in which only the surface facing the end surface 21a (the upper end surface in FIG. 10) is open. However, the upper end surface may be closed. The bag 27 may have a form in which the periphery is completely closed.

[0052] Eighth embodiment Next, a fire spread prevention unit according to an eighth embodiment will be described. Explanations of parts common to the previous embodiments will be omitted.

[0053] Fig. 11 shows a plan view of a heat conductive member of the fire spread prevention unit according to the eighth embodiment. Fig. 12 shows a manufacturing situation of the fire spread prevention unit according to the eighth embodiment in a cross-sectional view taken along the line CC of the first embodiment.

[0054] The heat conductive member 50 constituting the fire spread prevention unit 1g according to the eighth embodiment includes a rubber tube 61, which is an example of a molded body mainly made of rubber or resin, and a heat conductive film 60 having superior thermal conductivity to the rubber tube 61. The heat conductive film 60 is exposed on the outer surface of the rubber tube 61. A more specific configuration of the heat conductive member 50 will be described below.

[0055] The heat conducting member 50 has a form in which a plurality of long cylindrical bodies 55 are arranged and connected. In this embodiment, the heat conducting member 50 has 20 cylindrical bodies 55. However, the number of the cylindrical bodies 55 is not limited to 20, and may be two or more. In this embodiment, the means for connecting the cylindrical bodies 55 to each other is thread 56. However, a connecting means other than the thread 56 may be used. The heat conducting member 50 has a gap 65 between the cylindrical bodies 55. The gap 65 is a space necessary for the cylindrical bodies 55 to collapse when the heat conducting member 50 is compressed in the thickness direction. The gap 65 can also be a space into which the protrusion 25 of the fire spread prevention sheet 20 can be inserted.

[0056] The tube 55 has a shape in which a band-shaped heat conductive film 60 is wound in a spiral shape on the outer surface of a cylindrical rubber tube 61 having a through passage 62 in the longitudinal direction. The shape of the rubber tube 61 is not limited to a cylindrical shape, and may be other shapes such as an elliptical tube or a square tube. The heat conductive film 60 and the rubber tube 61 may be fixed by any means such as adhesion, welding, or adhesion. The rubber tube 61 may be preferably made of the same selective rubber material as the rubber sheet 23. The heat conductive film 60 may be made of the same selective material as the heat conductive film 42 in the seventh embodiment.

[0057] The fire spread prevention sheets 20 are preferably fixed to the heat conductive film 60 of the cylindrical body 55 by inserting the protruding parts 25 into the gaps 65 of the heat conductive member 50. The method of fixing the protruding parts 25 to the heat conductive film 60 is not particularly limited, and examples include adhesion, adhesion, and fitting. The protruding parts 25 may be bent into an L shape and fixed to the front surface of the cylindrical body 55 as shown by the dotted arrow S. The protruding parts 25 may also be bent into an L shape and fixed to the side and back surfaces of the cylindrical body 55 as shown by the dotted arrow T, penetrating the thickness direction of the heat conductive member 50 from the gaps 65, and bent into an L shape.

[0058] 2. Battery Next, a preferred embodiment of the battery according to the present invention will be described.

[0059] (First embodiment) First, the battery according to the first embodiment will be described.

[0060] FIG. 13 shows a vertical cross-sectional view of the battery according to the first embodiment.

[0061] Here, the term "longitudinal cross-sectional view" refers to a view of the battery 70 cut in the length direction of the battery cells 80 inside the housing 71 of the battery 70. In addition, in Fig. 13, the battery 70 includes ten battery cells 80, but the number of the battery cells 80 is not particularly limited.

[0062] In this embodiment, the battery 70 is, for example, a battery for an electric vehicle. The battery 70 includes a housing 71 with a bottom that opens on one side. The housing 71 is preferably made of aluminum or an aluminum-based alloy. The battery 70 includes a plurality of battery cells 80 as heat sources in the housing 71. The battery 70 includes a fire spread prevention unit 1 according to the first embodiment in the housing 71. The fire spread prevention sheet 20 is sandwiched between the battery cells 80. The heat conductive member 10 is sandwiched between the battery cells 80 and a bottom 72 (an example of a cooling unit) of the housing 71. The type of the battery 70 is not limited, and is preferably a lithium-ion battery. An electrode is provided protruding above the battery cell 80. The plurality of battery cells 80 are preferably in close contact with each other in the housing 71 by applying a force in a compressive direction from both sides thereof using a screw or the like (not shown). The bottom 72 of the housing 71 is provided with one or more water-cooling pipes 73 for flowing cooling water, which is an example of a coolant 75. Coolant 75 may be referred to as a cooling medium or a coolant.

[0063] In this way, the battery 70 has the fire spread prevention sheet 20 interposed between the battery cells 80, the heat conductive member 10 interposed between the battery cells 80 and the bottom 72 of the housing 71 (the member to which heat is transferred), and the protruding portion 25 of the heat conductive sheet 22 of the fire spread prevention sheet 20 is in contact with the heat conductive member 10. Therefore, when the battery cell 80 overheats, heat is transferred from the battery cell 80 to the bottom 72 via the heat conductive member 10, and the heat transfer from the overheated battery cell 80 to the adjacent battery cell 80 is reduced, and the transferred heat can be transferred from the heat conductive sheet 22 to the heat conductive member 10 via the protruding portion 25. The protruding portion 25 can be used not only on its end surface but also on both sides in the thickness direction as a heat transfer site. Therefore, the heat transfer from the fire spread prevention sheet 20 to the heat conductive member 10 can be promoted.

[0064] The battery 70 may include the fire spread prevention units 1, 1a, 1b, and 1c. The fire spread prevention sheets 20, 20a, 20b, and 20c may be replaced with fire spread prevention sheets 20e and 20f according to modified examples.

[0065] Second embodiment Next, a battery according to a second embodiment will be described. Regarding the parts of the second embodiment common to the first embodiment, duplicated descriptions will be omitted.

[0066] FIG. 14 shows a vertical cross-sectional view of the battery according to the second embodiment.

[0067] In this embodiment, the battery 70a includes a housing 71 with a bottom that is open on one side. The battery 70a includes a plurality of battery cells 80 as heat sources within the housing 71. The battery 70a includes a fire spread prevention unit 1d according to the fifth embodiment within the housing 71. A fire spread prevention sheet 20d is sandwiched between the battery cells 80. A heat conductive member 30 is sandwiched between the battery cells 80 and a bottom 72 (an example of a cooling section) of the housing 71. The type of the battery 70a is not limited, and is preferably a lithium ion battery.

[0068] In this way, the battery 70a has the fire spread prevention sheet 20d interposed between the battery cells 80, the heat conduction member 30 interposed between the battery cells 80 and the bottom 72 of the housing 71 (the member to which heat is transferred), and the protruding portion 25d of the heat conduction sheet 22 of the fire spread prevention sheet 20d in contact with the heat conduction member 30. Therefore, when the battery cell 80 overheats, heat is transferred from the battery cell 80 to the bottom 72 via the heat conduction member 30, and the heat conduction from the overheated battery cell 80 to the adjacent battery cell 80 is reduced, and the conducted heat can be transferred from the heat conduction sheet 22 to the heat conduction member 30 via the protruding portion 25d. The protruding portion 25d can use not only its end face but also at least one side in the thickness direction as a heat conduction site. Therefore, the heat transfer from the fire spread prevention sheet 20d to the heat conduction member 30 can be promoted.

[0069] The battery 70a may include fire prevention units 1e, 1f, and 1g. The fire prevention sheet 20d may be replaced with the fire prevention sheets 20, 20a, 20b, 20c, 20e, and 20f.

[0070] 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.

[0071] In the fire spread prevention units 1, 1a, 1b, 1c, 1d, 1e, 1f, and 1g according to each embodiment, the rubber sheet 23 may have a number of recesses recessed inward from one surface thereof. The heat conductive members 30 and 40 may have the flat protrusions 25 in contact with the heat conductive films 32 and 42, rather than the L-shaped protrusions 25d in contact with the heat conductive films 32 and 42.

[0072] The heat source includes not only the battery cell 80 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. The fire spread prevention units 1, 1a, 1b, 1c, 1d, 1e, 1f, and 1g may be disposed in structures other than the batteries 70 and 70a, such as electronic devices, home appliances, and power generation devices.

[0073] In addition, the components of each of the above-mentioned embodiments can be freely combined, except when they cannot be combined with each other. For example, the protruding portion 20 of the fire spread prevention sheet 20e, 20f may be bent and transformed into the protruding portion 25 and used in the fire spread prevention unit 1d, 1e, 1f, 1g. [Industrial Applicability]

[0074] 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.

Claims

1. A fire prevention sheet disposed between a plurality of heat sources; a heat conducting member disposed between the heat source and a member to which heat is transferred from the heat source; The fire prevention sheet is One or more rubber sheets; One or more heat-resistant sheets having higher heat resistance than the rubber sheet; one or more thermally conductive sheets having superior thermal conductivity to the rubber sheet and the heat-resistant sheet; A multilayer sheet comprising: the thermally conductive sheet has a protruding portion protruding beyond the rubber sheet and the heat-resistant sheet to expose both surfaces of the thermally conductive sheet in a thickness direction; A fire spread prevention unit characterized in that the fire spread prevention sheet is erected on the heat conduction member with the protrusion of the heat conduction sheet in contact with the heat conduction member.

2. the thermally conductive member includes a thermally conductive filler in a rubber-like elastomer, the thermally conductive filler having a higher thermal conductivity than the rubber-like elastomer; The fire spread prevention unit according to claim 1 , wherein the protrusion is inserted from a surface of the heat conductive member to an inside thereof.

3. the heat conductive member includes a molded body mainly made of rubber or resin, and a heat conductive film having a higher thermal conductivity than the molded body; the thermally conductive film is exposed on an outer surface of the molded body, The fire spread prevention unit according to claim 1 , wherein the protrusion is connected to the thermally conductive film.

4. 4. The fire spread prevention unit according to claim 1, wherein the rubber sheet is a porous sponge sheet.

5. 5. The fire spread prevention unit according to claim 1, wherein the heat resistant sheet is a sheet containing talc and / or silica.

6. 6. The fire spread prevention unit according to claim 1, wherein the heat conductive sheet is a sheet containing graphite and / or an aluminum compound.

7. the multilayer sheet forms a bag having both surfaces in a thickness direction and at least one end surface connecting the both surfaces, The thermally conductive sheet is disposed inside the bag, The fire spread prevention unit according to any one of claims 1 to 6, wherein the heat conductive sheet has the protrusion penetrating the bag and protruding outward.

8. A battery including a plurality of battery cells as a heat source in a housing, The battery includes a fire spread prevention unit according to any one of claims 1 to 7 in the housing, the fire prevention sheet is sandwiched between the battery cells, A battery characterized in that the thermally conductive member is sandwiched between the battery cell and a cooling portion of the housing.

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